43 results on '"Khalid S. Mohammad"'
Search Results
2. Intersecting Paths: Unraveling the Complex Journey of Cancer to Bone Metastasis
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Nour Arakil, Shahid Akhtar Akhund, Basant Elaasser, and Khalid S. Mohammad
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bone metastases ,bone microenvironment ,bone remodeling ,interleukin ,therapy ,Biology (General) ,QH301-705.5 - Abstract
The phenomenon of bone metastases presents a significant challenge within the context of advanced cancer treatments, particularly pertaining to breast, prostate, and lung cancers. These metastatic occurrences stem from the dissemination of cancerous cells into the bone, thereby interrupting the equilibrium between osteoblasts and osteoclasts. Such disruption results in skeletal complications, adversely affecting patient morbidity and quality of life. This review discusses the intricate interplay between cancer cells and the bone microenvironment, positing the bone not merely as a passive recipient of metastatic cells but as an active contributor to cancer progression through its distinctive biochemical and cellular makeup. A thorough examination of bone structure and the dynamics of bone remodeling is undertaken, elucidating how metastatic cancer cells exploit these processes. This review explores the genetic and molecular pathways that underpin the onset and development of bone metastases. Particular emphasis is placed on the roles of cytokines and growth factors in facilitating osteoclastogenesis and influencing osteoblast activity. Additionally, this paper offers a meticulous critique of current diagnostic methodologies, ranging from conventional radiography to advanced molecular imaging techniques, and discusses the implications of a nuanced understanding of bone metastasis biology for therapeutic intervention. This includes the development of targeted therapies and strategies for managing bone pain and other skeletal-related events. Moreover, this review underscores the imperative of ongoing research efforts aimed at identifying novel therapeutic targets and refining management approaches for bone metastases. It advocates for a multidisciplinary strategy that integrates advancements in medical oncology and radiology with insights derived from molecular biology and genetics, to enhance prognostic outcomes and the quality of life for patients afflicted by this debilitating condition. In summary, bone metastases constitute a complex issue that demands a comprehensive and informed approach to treatment. This article contributes to the ongoing discourse by consolidating existing knowledge and identifying avenues for future investigation, with the overarching objective of ameliorating patient care in the domain of oncology.
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- 2024
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3. Aging‐associated skeletal muscle defects in HER2/Neu transgenic mammary tumour model
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Ruizhong Wang, Brijesh Kumar, Poornima Bhat‐Nakshatri, Mayuri S. Prasad, Max H. Jacobsen, Gabriela Ovalle, Calli Maguire, George Sandusky, Trupti Trivedi, Khalid S. Mohammad, Theresa Guise, Narsimha R. Penthala, Peter A. Crooks, Jianguo Liu, Teresa Zimmers, and Harikrishna Nakshatri
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Breast cancer ,Functional limitations ,Skeletal muscle ,Cytokines/chemokines ,NF‐κB ,Internal medicine ,RC31-1245 - Abstract
Abstract Background Loss of skeletal muscle volume and functional limitations are poor prognostic markers in breast cancer patients. Several molecular defects in skeletal muscle including reduced myoblast determination protein 1 (MyoD) levels and increased protein turn over due to enhanced proteosomal activity have been suggested as causes of skeletal muscle loss in cancer patients. However, it is unknown whether molecular defects in skeletal muscle are dependent on tumour aetiology. Methods We characterized functional and molecular defects of skeletal muscle in mouse mammary tumour virus (MMTV)‐Neu (Neu+) mice (n = 6–12), an animal model that represents HER2 + human breast cancer, and compared the results with well‐characterized luminal B breast cancer model MMTV‐PyMT (PyMT+). Functional studies such as grip strength, rotarod performance, and ex vivo muscle contraction were performed to measure the effects of cancer on skeletal muscle. Expression of muscle‐enriched genes and microRNAs as well as circulating cytokines/chemokines were measured. Because nuclear factor‐kappaB (NF‐κB) pathway plays a significant role in skeletal muscle defects, the ability of NF‐κB inhibitor dimethylaminoparthenolide (DMAPT) to reverse skeletal muscle defects was examined. Results Neu+ mice showed skeletal muscle defects similar to accelerated aging. Compared with age and sex‐matched wild type mice, Neu+ tumour‐bearing mice had lower grip strength (202 ± 6.9 vs. 179 ± 6.8 g grip force, P = 0.0069) and impaired rotarod performance (108 ± 12.1 vs. 30 ± 3.9 s, P
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- 2021
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4. TG-interacting factor 1 (Tgif1)-deficiency attenuates bone remodeling and blunts the anabolic response to parathyroid hormone
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Hiroaki Saito, Andreas Gasser, Simona Bolamperti, Miki Maeda, Levi Matthies, Katharina Jähn, Courtney L. Long, Hartmut Schlüter, Marcel Kwiatkowski, Vaibhav Saini, Paola Divieti Pajevic, Teresita Bellido, Andre J. van Wijnen, Khalid S. Mohammad, Theresa A. Guise, Hanna Taipaleenmäki, and Eric Hesse
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Science - Abstract
Parathyroid hormone (PTH) is used to treat osteoporosis, but its therapeutic mechanism remains unclear. Here, the authors show that Tgif1 is a PTH target gene, and that its deletion impairs the function of osteoblasts and PTH-induced bone formation in mice.
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- 2019
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5. Translational Strategies to Target Metastatic Bone Disease
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Gabriel M. Pagnotti, Trupti Trivedi, and Khalid S. Mohammad
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metastatic bone disease ,osteolytic lesions ,osteoblastic lesions ,bone marrow microenvironment ,radiotherapy ,palliative therapy ,Cytology ,QH573-671 - Abstract
Metastatic bone disease is a common and devastating complication to cancer, confounding treatments and recovery efforts and presenting a significant barrier to de-escalating the adverse outcomes associated with disease progression. Despite significant advances in the field, bone metastases remain presently incurable and contribute heavily to cancer-associated morbidity and mortality. Mechanisms associated with metastatic bone disease perpetuation and paralleled disruption of bone remodeling are highlighted to convey how they provide the foundation for therapeutic targets to stem disease escalation. The focus of this review aims to describe the preclinical modeling and diagnostic evaluation of metastatic bone disease as well as discuss the range of therapeutic modalities used clinically and how they may impact skeletal tissue.
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- 2022
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6. Tip110/SART3 regulates IL-8 expression and predicts the clinical outcomes in melanoma
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Khalid Amine Timani, Balázs Győrffy, Ying Liu, Khalid S. Mohammad, and Johnny J. He
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Tip110/SART3 ,IL-8 ,Melanoma ,Hypoxia ,TP53, NF-κB ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Tip110, an important regulator of several oncogenic proteins, was significantly downregulated in human metastatic melanoma cells exposed to a hypoxic condition. Therefore, in this study, we set to determine whether differential expression of Tip110 could be an important indicator for melanoma tumorigenesis and metastasis. We found that in melanoma, but not in other cancer types, Tip110 knockdown enhanced significant expression and secretion of IL-8 and melanoma cells invasions. This induction was further potentiated under hypoxia and by inflammatory cytokine and found independent of TNF-α autocrine signaling. We further showed that Tip110 knockdown-mediated IL-8 induction involved IL-8 mRNA stability. Furthermore, the transcriptomic profiling data and survival from 455 melanoma patients demonstrated that the correlation between Tip110 expression and the clinical outcomes in melanoma was stage-dependent. These findings uncover important roles of Tip110 in melanoma tumorigenesis and metastasis through regulation of IL-8 and hope to provide new clues for future therapeutic strategies.
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- 2018
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7. The Role of TGF-β in Bone Metastases
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Trupti Trivedi, Gabriel M. Pagnotti, Theresa A. Guise, and Khalid S. Mohammad
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bone metastases ,transforming growth factor-β (TGF-β) ,programmed cell death ligand (PD-L1) ,immune cells ,TGF-β therapeutic targets ,check-point inhibitors ,Microbiology ,QR1-502 - Abstract
Complications associated with advanced cancer are a major clinical challenge and, if associated with bone metastases, worsen the prognosis and compromise the survival of the patients. Breast and prostate cancer cells exhibit a high propensity to metastasize to bone. The bone microenvironment is unique, providing fertile soil for cancer cell propagation, while mineralized bone matrices store potent growth factors and cytokines. Biologically active transforming growth factor β (TGF-β), one of the most abundant growth factors, is released following tumor-induced osteoclastic bone resorption. TGF-β promotes tumor cell secretion of factors that accelerate bone loss and fuel tumor cells to colonize. Thus, TGF-β is critical for driving the feed-forward vicious cycle of tumor growth in bone. Further, TGF-β promotes epithelial-mesenchymal transition (EMT), increasing cell invasiveness, angiogenesis, and metastatic progression. Emerging evidence shows TGF-β suppresses immune responses, enabling opportunistic cancer cells to escape immune checkpoints and promote bone metastases. Blocking TGF-β signaling pathways could disrupt the vicious cycle, revert EMT, and enhance immune response. However, TGF-β’s dual role as both tumor suppressor and enhancer presents a significant challenge in developing therapeutics that target TGF-β signaling. This review presents TGF-β’s role in cancer progression and bone metastases, while highlighting current perspectives on the therapeutic potential of targeting TGF-β pathways.
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- 2021
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8. Osteocyte-Intrinsic TGF-β Signaling Regulates Bone Quality through Perilacunar/Canalicular Remodeling
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Neha S. Dole, Courtney M. Mazur, Claire Acevedo, Justin P. Lopez, David A. Monteiro, Tristan W. Fowler, Bernd Gludovatz, Flynn Walsh, Jenna N. Regan, Sara Messina, Daniel S. Evans, Thomas F. Lang, Bin Zhang, Robert O. Ritchie, Khalid S. Mohammad, and Tamara Alliston
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osteocyte ,TGF-β ,bone quality ,perilacunar/canalicular remodeling ,bone fragility ,Biology (General) ,QH301-705.5 - Abstract
Poor bone quality contributes to bone fragility in diabetes, aging, and osteogenesis imperfecta. However, the mechanisms controlling bone quality are not well understood, contributing to the current lack of strategies to diagnose or treat bone quality deficits. Transforming growth factor beta (TGF-β) signaling is a crucial mechanism known to regulate the material quality of bone, but its cellular target in this regulation is unknown. Studies showing that osteocytes directly remodel their perilacunar/canalicular matrix led us to hypothesize that TGF-β controls bone quality through perilacunar/canalicular remodeling (PLR). Using inhibitors and mice with an osteocyte-intrinsic defect in TGF-β signaling (TβRIIocy−/−), we show that TGF-β regulates PLR in a cell-intrinsic manner to control bone quality. Altogether, this study emphasizes that osteocytes are key in executing the biological control of bone quality through PLR, thereby highlighting the fundamental role of osteocyte-mediated PLR in bone homeostasis and fragility.
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- 2017
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9. Loss of Asxl1 Alters Self-Renewal and Cell Fate of Bone Marrow Stromal Cells, Leading to Bohring-Opitz-like Syndrome in Mice
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Peng Zhang, Caihong Xing, Steven D. Rhodes, Yongzheng He, Kai Deng, Zhaomin Li, Fuhong He, Caiying Zhu, Lihn Nguyen, Yuan Zhou, Shi Chen, Khalid S. Mohammad, Theresa A. Guise, Omar Abdel-Wahab, Mingjiang Xu, Qian-Fei Wang, and Feng-Chun Yang
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Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Summary: De novo ASXL1 mutations are found in patients with Bohring-Opitz syndrome, a disease with severe developmental defects and early childhood mortality. The underlying pathologic mechanisms remain largely unknown. Using Asxl1-targeted murine models, we found that Asxl1 global loss as well as conditional deletion in osteoblasts and their progenitors led to significant bone loss and a markedly decreased number of bone marrow stromal cells (BMSCs) compared with wild-type littermates. Asxl1−/− BMSCs displayed impaired self-renewal and skewed differentiation, away from osteoblasts and favoring adipocytes. RNA-sequencing analysis revealed altered expression of genes involved in cell proliferation, skeletal development, and morphogenesis. Furthermore, gene set enrichment analysis showed decreased expression of stem cell self-renewal gene signature, suggesting a role of Asxl1 in regulating the stemness of BMSCs. Importantly, re-introduction of Asxl1 normalized NANOG and OCT4 expression and restored the self-renewal capacity of Asxl1−/− BMSCs. Our study unveils a pivotal role of ASXL1 in the maintenance of BMSC functions and skeletal development. : In this article, Yang, Wang, and colleagues show that loss of Asxl1 led to multiple skeletal developmental defects, closely reminiscent of Bohring-Opitz syndrome. They identified that the skeletal defects were associated with an impaired self-renewal and skewed lineage commitment of bone marrow stromal cells (BMSCs). These findings indicate a pivotal role of ASXL1 in the maintenance of BMSC functions and skeletal development. Keywords: Bohring-Opitz syndrome, ASXL1 mutation, bone marrow stromal cell, self-renewal and differentiation, skeletal development
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- 2016
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10. Osteolytic Breast Cancer Causes Skeletal Muscle Weakness in an Immunocompetent Syngeneic Mouse Model
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Jenna N. Regan, Carter Mikesell, Steven Reiken, Haifang Xu, Andrew R. Marks, Khalid S. Mohammad, Theresa A. Guise, and David L. Waning
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breast cancer ,osteolytic disease ,muscle weakness ,immune competent ,syngeneic tumor model ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
Muscle weakness and cachexia are significant paraneoplastic syndromes of many advanced cancers. Osteolytic bone metastases are common in advanced breast cancer and are a major contributor to decreased survival, performance, and quality of life for patients. Pathologic fracture caused by osteolytic cancer in bone (OCIB) leads to a significant (32%) increased risk of death compared to patients without fracture. Since muscle weakness is linked to risk of falls which are a major cause of fracture, we have investigated skeletal muscle response to OCIB. Here, we show that a syngeneic mouse model of OCIB (4T1 mammary tumor cells) leads to cachexia and skeletal muscle weakness associated with oxidation of the ryanodine receptor and calcium (Ca2+) release channel (RyR1). Muscle atrophy follows known pathways via both myostatin signaling and expression of muscle-specific ubiquitin ligases, atrogin-1 and MuRF1. We have identified a mechanism for skeletal muscle weakness due to increased oxidative stress on RyR1 via NAPDH oxidases [NADPH oxidase 2 (Nox2) and NADPH oxidase 4 (Nox4)]. In addition, SMAD3 phosphorylation is higher in muscle from tumor-bearing mice, a critical step in the intracellular signaling pathway that transmits TGFβ signaling to the nucleus. This is the first time that skeletal muscle weakness has been described in a syngeneic model of OCIB and represents a unique model system in which to study cachexia and changes in skeletal muscle.
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- 2017
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11. Comparison of electric motors used in electric vehicle propulsion system
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Khalid S. Mohammad and Aqeel S. Jaber
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Control and Optimization ,Electric vehicles ,Computer Networks and Communications ,Hardware and Architecture ,Signal Processing ,Electrical and Electronic Engineering ,Induction motor ,Switched reluctance motor artificial intelligent ,Information Systems ,DC motors ,Permanent magnet brushless motors - Abstract
Now days, it is vital to use electric vehicles (EVs) instead of traditional cars with internal combustion engines (ICEs) in order to reduce the high level of pollution in the environment, and many researchers are investigating the possible improvements on these vehicles. The main component of EVs is the electric motor and the selection of a motor with high efficiency, excellent dynamic response and high starting torque has a strong effect on the performance of EVs. In addition to that a reasonable price for the electric motor is required. This work focuses on the selection of the most suitable electric motor for EVs. Therefore a detailed study to compare between the performance of the major types of electric motors that are used in EVs is addressed in this paper. The results of this comparative study is tabulated and by careful consideration for all these results, the appropriate electric motor for EVs has been chosen. From the other hand, the artificial intelligent (AI) techniques play a crucial role in the EVs technologies, and several kinds of AI techniques used in EVs applications are overviewed in this work.
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- 2022
12. Increased S1P expression in osteoclasts enhances bone formation in an animal model of Paget's disease
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Kazuaki Miyagawa, Theresa A. Guise, Khalid S. Mohammad, Noriyoshi Kurihara, Daniela N. Petrusca, Jolene J. Windle, Yuki Nagata, Yasuhisa Ohata, G. David Roodman, and Gabriel M. Pagnotti
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0301 basic medicine ,Agonist ,Genetically modified mouse ,Male ,medicine.drug_class ,medicine.medical_treatment ,Immunoblotting ,Osteoclasts ,Enzyme-Linked Immunosorbent Assay ,Biochemistry ,S1P ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,SphK‐1 ,Osteogenesis ,Sphingosine ,medicine ,Animals ,Humans ,Bone formation ,Phosphorylation ,Molecular Biology ,S1PR3 ,Sphingosine-1-Phosphate Receptors ,Research Articles ,bone formation ,Paget's bone disease ,Interleukin-6 ,Growth factor ,Antagonist ,Cell Biology ,Osteitis Deformans ,Molecular biology ,Immunohistochemistry ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,Female ,Lysophospholipids ,Research Article - Abstract
Paget's disease (PD) is characterized by increased numbers of abnormal osteoclasts (OCLs) that drive exuberant bone formation, but the mechanisms responsible for the increased bone formation remain unclear. We previously reported that OCLs from 70% of PD patients express measles virus nucleocapsid protein (MVNP), and that transgenic mice with targeted expression of MVNP in OCLs (MVNP mice) develop bone lesions and abnormal OCLs characteristic of PD. In this report, we examined if OCL‐derived sphingosine‐1‐phosphate (S1P) contributed to the abnormal bone formation in PD, since OCL‐derived S1P can act as a coupling factor to increase normal bone formation via binding S1P‐receptor‐3 (S1PR3) on osteoblasts (OBs). We report that OCLs from MVNP mice and PD patients expressed high levels of sphingosine kinase‐1 (SphK‐1) compared with wild‐type (WT) mouse and normal donor OCLs. SphK‐1 production by MVNP‐OCLs was interleukin‐6 (IL‐6)‐dependent since OCLs from MVNP/IL‐6 −/− mice expressed lower levels of SphK‐1. Immunohistochemistry of bone biopsies from a normal donor, a PD patient, WT and MVNP mice confirmed increased expression levels of SphK‐1 in OCLs and S1PR3 in OBs of the PD patient and MVNP mice compared with normal donor and WT mice. Further, MVNP‐OCLs cocultured with OBs from MVNP or WT mice increased OB‐S1PR3 expression and enhanced expression of OB differentiation markers in MVNP‐OBs precursors compared with WT‐OBs, which was mediated by IL‐6 and insulin‐like growth factor 1 secreted by MVNP‐OCLs. Finally, the addition of an S1PR3 antagonist (VPC23019) to WT or MVNP‐OBs treated with WT and MVNP‐OCL‐conditioned media (CM) blocked enhanced OB differentiation of MVNP‐OBs treated with MVNP‐OCL‐CM. In contrast, the addition of the SIPR3 agonist, VPC24191, to the cultures enhanced osterix and Col‐1A expression in MVNP‐OBs treated with MVNP‐OCL‐CM compared with WT‐OBs treated with WT‐OCL‐CM. These results suggest that IL‐6 produced by PD‐OCLs increases S1P in OCLs and S1PR3 on OBs, to increase bone formation in PD., Model for the effects of sphingosine kinase‐1/sphingosine‐1‐phosphate/S1P‐receptor‐3 (SphK‐1/S1P/S1PR3) in abnormal bone remodeling in Paget's disease (PD). Measles virus nucleocapsid protein (MVNP) in PD‐osteoclasts (OCLs) induces interleukin‐6 (IL‐6), which upregulates insulin‐like growth factor 1 (IGF‐1) and Sphk1. SphK‐1 enhances S1P levels in OCLs, and IL‐6 and IGF‐1 increase S1PR3 on osteoblast (OBs). S1P then increases OB differentiation and bone formation via enhanced S1PR3 expression on OBs.
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- 2020
13. Aging-associated skeletal muscle defects in HER2/Neu transgenic mammary tumor model
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Trupti Trivedi, Peter A. Crooks, Teresa Zimmers, Narsimha Reddy Penthala, Jianguo Liu, Khalid S. Mohammad, Mayuri S. Prasad, Ruizhong Wang, Brijesh Kumar, Max Jacobsen, Theresa A. Guise, Harikrishna Nakshatri, George E. Sandusky, Calli Maguire, Poornima Bhat-Nakshatri, and Gabriela Ovalle
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medicine.medical_specialty ,lcsh:Internal medicine ,Skeletal muscle ,MyoD ,HER2/neu ,Article ,Cachexia ,Breast cancer ,Internal medicine ,medicine ,Cytokines/chemokines ,Progenitor cell ,lcsh:RC31-1245 ,Mammary tumor ,biology ,Chemistry ,NF‐κB ,Cancer ,medicine.disease ,Functional limitations ,medicine.anatomical_structure ,Endocrinology ,biology.protein ,medicine.symptom ,Muscle contraction - Abstract
Background Loss of skeletal muscle volume and functional limitations are poor prognostic markers in breast cancer patients. Several molecular defects in skeletal muscle including reduced myoblast determination protein 1 (MyoD) levels and increased protein turn over due to enhanced proteosomal activity have been suggested as causes of skeletal muscle loss in cancer patients. However, it is unknown whether molecular defects in skeletal muscle are dependent on tumour aetiology. Methods We characterized functional and molecular defects of skeletal muscle in mouse mammary tumour virus (MMTV)‐Neu (Neu+) mice (n = 6–12), an animal model that represents HER2 + human breast cancer, and compared the results with well‐characterized luminal B breast cancer model MMTV‐PyMT (PyMT+). Functional studies such as grip strength, rotarod performance, and ex vivo muscle contraction were performed to measure the effects of cancer on skeletal muscle. Expression of muscle‐enriched genes and microRNAs as well as circulating cytokines/chemokines were measured. Because nuclear factor‐kappaB (NF‐κB) pathway plays a significant role in skeletal muscle defects, the ability of NF‐κB inhibitor dimethylaminoparthenolide (DMAPT) to reverse skeletal muscle defects was examined. Results Neu+ mice showed skeletal muscle defects similar to accelerated aging. Compared with age and sex‐matched wild type mice, Neu+ tumour‐bearing mice had lower grip strength (202 ± 6.9 vs. 179 ± 6.8 g grip force, P = 0.0069) and impaired rotarod performance (108 ± 12.1 vs. 30 ± 3.9 s, P
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- 2020
14. Halofuginone inhibits TGF-β/BMP signaling and in combination with zoledronic acid enhances inhibition of breast cancer bone metastasis
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Khalid S. Mohammad, Pierrick G.J. Fournier, John M. Chirgwin, Holly W. Davis, Xiang H. Peng, Alain Mauviel, Ryan C. McKenna, Theresa A. Guise, Patricia Juárez, and Maria Niewolna
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0301 basic medicine ,TGF-β ,Pathology ,medicine.medical_specialty ,Osteolysis ,03 medical and health sciences ,Prostate cancer ,zoledronic acid ,0302 clinical medicine ,Breast cancer ,halofuginone ,bone metastases ,medicine ,BMP ,Halofuginone ,business.industry ,Bone metastasis ,medicine.disease ,3. Good health ,030104 developmental biology ,Zoledronic acid ,Oncology ,030220 oncology & carcinogenesis ,Cancer cell ,Cancer research ,business ,Transforming growth factor ,medicine.drug ,Research Paper - Abstract
// Patricia Juarez 1, 2 , Pierrick G.J. Fournier 1, 2 , Khalid S. Mohammad 1 , Ryan C. McKenna 3 , Holly W. Davis 3 , Xiang H. Peng 1 , Maria Niewolna 1 , Alain Mauviel 4, 5, 6, 7 John M. Chirgwin 1 and Theresa A. Guise 1 1 Division of Endocrinology, Department of Medicine, Indiana University Purdue University at Indianapolis, Indiana, USA 2 Ensenada Center for Scientific Research and Higher Education, Ensenada, Mexico 3 University of Virginia, Charlottesville, Virginia, USA 4 Institute Curie, Orsay, France 5 INSERM U1021, Orsay, France 6 CNRS UMR3347, Orsay, France 7 Universite Paris XI, Orsay, France Correspondence to: Theresa A. Guise, email: tguise@iu.edu Keywords: halofuginone, zoledronic acid, bone metastases, TGF-β, BMP Received: June 21, 2017 Accepted: August 04, 2017 Published: September 23, 2017 ABSTRACT More efficient therapies that target multiple molecular mechanisms are needed for the treatment of incurable bone metastases. Halofuginone is a plant alkaloid-derivative with antiangiogenic and antiproliferative effects. Here we demonstrate that halofuginone is an effective therapy for the treatment of bone metastases, through multiple actions that include inhibition of TGFβ and BMP-signaling. Halofuginone blocked TGF-β-signaling in MDA-MB-231 and PC3 cells showed by inhibition of TGF-β-induced Smad-reporter, phosphorylation of Smad-proteins, and expression of TGF-β-regulated metastatic genes. Halofuginone increased inhibitory Smad7-mRNA and reduced TGF-β-receptor II protein. Proline supplementation but not Smad7-knockdown reversed halofuginone-inhibition of TGF-β-signaling. Halofuginone also decreased BMP-signaling. Treatment of MDA-MB-231 and PC3 cells with halofuginone reduced the BMP-Smad-reporter (BRE) 4 , Smad1/5/8-phosphorylation and mRNA of the BMP-regulated gene Id-1. Halofuginone decreased immunostaining of phospho-Smad2/3 and phospho-Smad1/5/8 in cancer cells in vivo . Furthermore, halofuginone decreased tumor-take and growth of orthotopic-tumors. Mice with breast or prostate bone metastases treated with halofuginone had significantly less osteolysis than control mice. Combined treatment with halofuginone and zoledronic-acid significantly reduced osteolytic area more than either treatment alone. Thus, halofuginone reduces breast and prostate cancer bone metastases in mice and combined with treatment currently approved by the FDA is an effective treatment for this devastating complication of breast and prostate-cancer.
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- 2017
15. Mechanical Suppression of Breast Cancer Cell Invasion and Paracrine Signaling Requires Nucleo-Cytoskeletal Connectivity
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Gabriel M. Pagnotti, Khalid S. Mohammad, Xin Yi, Laura E. Wright, William Roy Thompson, Clinton T. Rubin, Joseph M. Wallace, Katherine M Powell, Theresa A. Guise, Gunes Uzer, and Uma Sankar
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Gene knockdown ,LINC complex ,Cancer ,Biology ,medicine.disease ,Cell biology ,Paracrine signalling ,medicine.anatomical_structure ,Osteoclast ,RANKL ,Cancer cell ,medicine ,biology.protein ,Secretion - Abstract
SummaryExercise benefits the musculoskeletal system and reduces the effects of cancer. The beneficial effects of exercise are multifactorial, where metabolic changes and tissue adaptation influence outcomes. Mechanical signals, a principal component of exercise, are anabolic to the musculoskeletal system and restrict cancer progression. We examined the mechanisms through which cancer cells sense and respond to mechanical signals. Low-magnitude, high-frequency signals were applied to human breast cancer cells in the form of low-intensity vibration (LIV). LIV decreased invasion through matrix and impaired secretion of osteolytic factors PTHLH, IL-11, and RANKL. Furthermore, paracrine signals from mechanically stimulated cancer cells, reduced osteoclast differentiation resorptive capacity. Physically disconnecting the nucleus by knockdown of SUN1 and SUN2 impaired the ability of LIV to suppress invasion and production of osteolytic factors. LIV also increased cell stiffness; an effect dependent on an intact LINC complex. These data show that mechanical signals alter the metastatic potential of human breast cancer cells, where the nucleus serves as a mechanosensory apparatus to alter cell structure and intercellular signaling.
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- 2019
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16. Aromatase inhibitor-induced bone loss increases the progression of estrogen receptor-negative breast cancer in bone and exacerbates muscle weakness in vivo
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Laura E. Wright, Khalid S. Mohammad, Theresa A. Guise, Jenna N. Regan, Maryla Niewolna, Sreemala Murthy, David L. Waning, Yun She, Wende M. Kozlow, Andrew R. Marks, Ahmed Harhash, and Sutha John
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0301 basic medicine ,Pathology ,Osteolysis ,Time Factors ,Bone density ,medicine.medical_treatment ,bone ,Zoledronic Acid ,0302 clinical medicine ,Bone Density ,Tumor Microenvironment ,Mice, Inbred BALB C ,Muscle Weakness ,Bone Density Conservation Agents ,Diphosphonates ,Estradiol ,Aromatase Inhibitors ,Imidazoles ,Tumor Burden ,medicine.anatomical_structure ,Oncology ,Receptors, Estrogen ,030220 oncology & carcinogenesis ,Letrozole ,Disease Progression ,Female ,medicine.symptom ,medicine.drug ,Research Paper ,medicine.medical_specialty ,Antineoplastic Agents, Hormonal ,Ovariectomy ,Mice, Nude ,Bone Neoplasms ,Breast Neoplasms ,Bone resorption ,03 medical and health sciences ,breast cancer ,Internal medicine ,Cell Line, Tumor ,Nitriles ,medicine ,metastasis ,Animals ,Humans ,Muscle Strength ,skeletal muscle ,Muscle, Skeletal ,business.industry ,Muscle weakness ,Skeletal muscle ,Bisphosphonate ,Triazoles ,medicine.disease ,Xenograft Model Antitumor Assays ,030104 developmental biology ,Zoledronic acid ,Endocrinology ,aromatase inhibitor ,business - Abstract
// Laura E. Wright 1 , Ahmed A. Harhash 1 , Wende M. Kozlow 2 , David L. Waning 3 , Jenna N. Regan 1 , Yun She 1 , Sutha K. John 1 , Sreemala Murthy 1 , Maryla Niewolna 1 , Andrew R. Marks 4 , Khalid S. Mohammad 1 , Theresa A. Guise 1 1 Department of Medicine, Division of Endocrinology, Indiana University, Indianapolis, IN, USA 2 Department of Internal Medicine, Division of Endocrinology, University of Virginia, Charlottesville, VA, USA 3 Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA 4 Department of Physiology, Columbia University, New York, NY, USA Correspondence to: Laura E. Wright, email: laewrig@iu.edu Keywords: breast cancer, bone, metastasis, aromatase inhibitor, skeletal muscle Received: October 20, 2016 Accepted: November 23, 2016 Published: December 25, 2016 ABSTRACT Aromatase inhibitors (AIs) cause muscle weakness, bone loss, and joint pain in up to half of cancer patients. Preclinical studies have demonstrated that increased osteoclastic bone resorption can impair muscle contractility and prime the bone microenvironment to accelerate metastatic growth. We hypothesized that AI-induced bone loss could increase breast cancer progression in bone and exacerbate muscle weakness associated with bone metastases. Female athymic nude mice underwent ovariectomy (OVX) or sham surgery and were treated with vehicle or AI (letrozole; Let). An OVX-Let group was then further treated with bisphosphonate (zoledronic acid; Zol). At week three, trabecular bone volume was measured and mice were inoculated with MDA-MB-231 cells into the cardiac ventricle and followed for progression of bone metastases. Five weeks after tumor cell inoculation, tumor-induced osteolytic lesion area was increased in OVX-Let mice and reduced in OVX-Let-Zol mice compared to sham-vehicle. Tumor burden in bone was increased in OVX-Let mice relative to sham-vehicle and OVX-Let-Zol mice. At the termination of the study, muscle-specific force of the extensor digitorum longus muscle was reduced in OVX-Let mice compared to sham-vehicle mice, however, the addition of Zol improved muscle function. In summary, AI treatment induced bone loss and skeletal muscle weakness, recapitulating effects observed in cancer patients. Prevention of AI-induced osteoclastic bone resorption using a bisphosphonate attenuated the development of breast cancer bone metastases and improved muscle function in mice. These findings highlight the bone microenvironment as a modulator of tumor growth locally and muscle function systemically.
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- 2016
17. Loss of Asxl1 Alters Self-Renewal and Cell Fate of Bone Marrow Stromal Cell, Leading to Bohring-Opitz-like Syndrome in Mice
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Feng Chun Yang, Shi Chen, Fuhong He, Steven D. Rhodes, Qianfei Wang, Caihong Xing, Mingjiang Xu, Khalid S. Mohammad, Lihn Nguyen, Zhaomin Li, Yongzheng He, Peng Zhang, Omar Abdel-Wahab, Caiying Zhu, Yuan Zhou, Kai Deng, and Theresa A. Guise
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0301 basic medicine ,bone marrow stromal cell ,Bohring-Opitz syndrome ,Cellular differentiation ,Gene Expression ,Biochemistry ,Mice ,Osteogenesis ,Transduction, Genetic ,Adipocytes ,10. No inequality ,lcsh:QH301-705.5 ,lcsh:R5-920 ,skeletal development ,Cell Differentiation ,Nanog Homeobox Protein ,medicine.anatomical_structure ,Stem cell ,lcsh:Medicine (General) ,Homeobox protein NANOG ,Stromal cell ,Primary Cell Culture ,Bone Marrow Cells ,Biology ,Cell fate determination ,Article ,03 medical and health sciences ,Craniosynostoses ,Intellectual Disability ,Genetics ,medicine ,Animals ,Humans ,Progenitor cell ,Cell Proliferation ,Osteoblasts ,Sequence Analysis, RNA ,Mesenchymal stem cell ,Genetic Complementation Test ,Lentivirus ,Mesenchymal Stem Cells ,Cell Biology ,self-renewal and differentiation ,ASXL1 mutation ,Repressor Proteins ,Disease Models, Animal ,030104 developmental biology ,lcsh:Biology (General) ,Cancer research ,Bone marrow ,Octamer Transcription Factor-3 ,Developmental Biology - Abstract
Summary De novo ASXL1 mutations are found in patients with Bohring-Opitz syndrome, a disease with severe developmental defects and early childhood mortality. The underlying pathologic mechanisms remain largely unknown. Using Asxl1-targeted murine models, we found that Asxl1 global loss as well as conditional deletion in osteoblasts and their progenitors led to significant bone loss and a markedly decreased number of bone marrow stromal cells (BMSCs) compared with wild-type littermates. Asxl1−/− BMSCs displayed impaired self-renewal and skewed differentiation, away from osteoblasts and favoring adipocytes. RNA-sequencing analysis revealed altered expression of genes involved in cell proliferation, skeletal development, and morphogenesis. Furthermore, gene set enrichment analysis showed decreased expression of stem cell self-renewal gene signature, suggesting a role of Asxl1 in regulating the stemness of BMSCs. Importantly, re-introduction of Asxl1 normalized NANOG and OCT4 expression and restored the self-renewal capacity of Asxl1−/− BMSCs. Our study unveils a pivotal role of ASXL1 in the maintenance of BMSC functions and skeletal development., Graphical Abstract, Highlights • Asxl1 loss impairs BMSC self-renewal and cell fate • Asxl1 loss leads to dramatic bone loss • Asxl1 loss alters the expression of genes critical for cell fates of BMSCs • Re-introducing Asxl1 restores self-renewal and lineage commitment in Asxl1−/− BMSCs, In this article, Yang, Wang, and colleagues show that loss of Asxl1 led to multiple skeletal developmental defects, closely reminiscent of Bohring-Opitz syndrome. They identified that the skeletal defects were associated with an impaired self-renewal and skewed lineage commitment of bone marrow stromal cells (BMSCs). These findings indicate a pivotal role of ASXL1 in the maintenance of BMSC functions and skeletal development.
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- 2016
18. Growth factor independence 1 expression in myeloma cells enhances their growth, survival, and osteoclastogenesis
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Deborah L. Galson, Daniela N. Petrusca, Judith L. Anderson, Rebecca Silbermann, Feng-Ming Wang, Quanhong Sun, Nicola Giuliani, Khalid S. Mohammad, Cheolkyu Park, Noriyoshi Kurihara, Dan Zhou, Silvia Marino, Denise Toscani, Colin D. Crean, and G. David Roodman
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0301 basic medicine ,p53 ,Cancer Research ,Programmed cell death ,Stromal cell ,Gfi1 ,medicine.medical_treatment ,Apoptosis ,lcsh:RC254-282 ,Apoptosis and osteolysis ,03 medical and health sciences ,Mice ,Osteoclast ,Multiple myeloma ,Osteogenesis ,Bone disease ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Molecular Biology ,Cell growth ,Chemistry ,lcsh:RC633-647.5 ,Growth factor ,Research ,Osteoblast ,Cell Differentiation ,Hematology ,lcsh:Diseases of the blood and blood-forming organs ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,3. Good health ,DNA-Binding Proteins ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,Cell culture ,Cancer research ,Female ,Bone marrow ,Transcription Factors - Abstract
Background In spite of major advances in treatment, multiple myeloma (MM) is currently an incurable malignancy due to the emergence of drug-resistant clones. We previously showed that MM cells upregulate the transcriptional repressor, growth factor independence 1 (Gfi1), in bone marrow stromal cells (BMSCs) that induces prolonged inhibition of osteoblast differentiation. However, the role of Gfi1 in MM cells is unknown. Methods Human primary CD138+ and BMSC were purified from normal donors and MM patients’ bone marrow aspirates. Gfi1 knockdown and overexpressing cells were generated by lentiviral-mediated shRNA. Proliferation/apoptosis studies were done by flow cytometry, and protein levels were determined by Western blot and/or immunohistochemistry. An experimental MM mouse model was generated to investigate the effects of MM cells overexpressing Gfi1 on tumor burden and osteolysis in vivo. Results We found that Gfi1 expression is increased in patient’s MM cells and MM cell lines and was further increased by co-culture with BMSC, IL-6, and sphingosine-1-phosphate. Modulation of Gfi1 in MM cells had major effects on their survival and growth. Knockdown of Gfi1 induced apoptosis in p53-wt, p53-mutant, and p53-deficient MM cells, while Gfi1 overexpression enhanced MM cell growth and protected MM cells from bortezomib-induced cell death. Gfi1 enhanced cell survival of p53-wt MM cells by binding to p53, thereby blocking binding to the promoters of the pro-apoptotic BAX and NOXA genes. Further, Gfi1-p53 binding could be blocked by HDAC inhibitors. Importantly, inoculation of MM cells overexpressing Gfi1 in mice induced increased bone destruction, increased osteoclast number and size, and enhanced tumor growth. Conclusions These results support that Gfi1 plays a key role in MM tumor growth, survival, and bone destruction and contributes to bortezomib resistance, suggesting that Gfi1 may be a novel therapeutic target for MM. Electronic supplementary material The online version of this article (10.1186/s13045-018-0666-5) contains supplementary material, which is available to authorized users.
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- 2018
19. Osteolytic Breast Cancer Causes Skeletal Muscle Weakness in an Immunocompetent Syngeneic Mouse Model
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Khalid S. Mohammad, David L. Waning, Carter Mikesell, Andrew R. Marks, Steven Reiken, Haifang Xu, Theresa A. Guise, and Jenna N. Regan
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0301 basic medicine ,Endocrinology, Diabetes and Metabolism ,Myostatin ,syngeneic tumor model ,lcsh:Diseases of the endocrine glands. Clinical endocrinology ,Cachexia ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,breast cancer ,osteolytic disease ,medicine ,Original Research ,muscle weakness ,RYR1 ,lcsh:RC648-665 ,biology ,Ryanodine receptor ,business.industry ,Skeletal muscle ,Muscle weakness ,NOX4 ,medicine.disease ,Muscle atrophy ,3. Good health ,immune competent ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,biology.protein ,Cancer research ,medicine.symptom ,business - Abstract
Muscle weakness and cachexia are significant paraneoplastic syndromes of many advanced cancers. Osteolytic bone metastases are common in advanced breast cancer and are a major contributor to decreased survival, performance, and quality of life for patients. Pathologic fracture caused by osteolytic cancer in bone (OCIB) leads to a significant (32%) increased risk of death compared to patients without fracture. Since muscle weakness is linked to risk of falls which are a major cause of fracture, we have investigated skeletal muscle response to OCIB. Here, we show that a syngeneic mouse model of OCIB (4T1 mammary tumor cells) leads to cachexia and skeletal muscle weakness associated with oxidation of the ryanodine receptor and calcium (Ca2+) release channel (RyR1). Muscle atrophy follows known pathways via both myostatin signaling and expression of muscle-specific ubiquitin ligases, atrogin-1 and MuRF1. We have identified a mechanism for skeletal muscle weakness due to increased oxidative stress on RyR1 via NAPDH oxidases [NADPH oxidase 2 (Nox2) and NADPH oxidase 4 (Nox4)]. In addition, SMAD3 phosphorylation is higher in muscle from tumor-bearing mice, a critical step in the intracellular signaling pathway that transmits TGFβ signaling to the nucleus. This is the first time that skeletal muscle weakness has been described in a syngeneic model of OCIB and represents a unique model system in which to study cachexia and changes in skeletal muscle.
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- 2017
20. Bone-induced expression of integrin β3 enables targeted nanotherapy of breast cancer metastases
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Yalin Xu, Dipanjan Pan, Grace Hu, Gregory C. Fox, Khalid S. Mohammad, Xiaoxia Yang, Joshua S. Novack, Deborah V. Novack, Alison K. Esser, Thomas J. Walsh, James A. J. Fitzpatrick, Anne H. Schmieder, Graham A. Colditz, Gabriel H. Lukaszewicz, David L. Waning, Katherine N. Weilbaecher, Gregory M. Lanza, Elizabeth Cordell, Xinming Su, Theresa A. Guise, and Michael H. Ross
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0301 basic medicine ,CA15-3 ,Oncology ,Cancer Research ,medicine.medical_specialty ,Mice, Nude ,Bone Neoplasms ,Breast Neoplasms ,Docetaxel ,Article ,Metastasis ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,Transforming Growth Factor beta ,Internal medicine ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Molecular Targeted Therapy ,Mice, Inbred BALB C ,biology ,business.industry ,Integrin beta3 ,Cancer ,Transforming growth factor beta ,medicine.disease ,Integrin alphaVbeta3 ,Metastatic breast cancer ,Xenograft Model Antitumor Assays ,Gene Expression Regulation, Neoplastic ,Mice, Inbred C57BL ,030104 developmental biology ,030220 oncology & carcinogenesis ,Cancer cell ,biology.protein ,Nanoparticles ,Female ,Taxoids ,business ,medicine.drug ,Signal Transduction - Abstract
Bone metastases occur in approximately 70% of metastatic breast cancer patients, often leading to skeletal injuries. Current treatments are mainly palliative and underscore the unmet clinical need for improved therapies. In this study, we provide preclinical evidence for an antimetastatic therapy based on targeting integrin β3 (β3), which is selectively induced on breast cancer cells in bone by the local bone microenvironment. In a preclinical model of breast cancer, β3 was strongly expressed on bone metastatic cancer cells, but not primary mammary tumors or visceral metastases. In tumor tissue from breast cancer patients, β3 was significantly elevated on bone metastases relative to primary tumors from the same patient (n = 42). Mechanistic investigations revealed that TGFβ signaling through SMAD2/SMAD3 was necessary for breast cancer induction of β3 within the bone. Using a micelle-based nanoparticle therapy that recognizes integrin αvβ3 (αvβ3-MPs of ∼12.5 nm), we demonstrated specific localization to breast cancer bone metastases in mice. Using this system for targeted delivery of the chemotherapeutic docetaxel, we showed that bone tumor burden could be reduced significantly with less bone destruction and less hepatotoxicity compared with equimolar doses of free docetaxel. Furthermore, mice treated with αvβ3-MP-docetaxel exhibited a significant decrease in bone-residing tumor cell proliferation compared with free docetaxel. Taken together, our results offer preclinical proof of concept for a method to enhance delivery of chemotherapeutics to breast cancer cells within the bone by exploiting their selective expression of integrin αvβ3 at that metastatic site. Cancer Res; 77(22); 6299–312. ©2017 AACR.
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- 2017
21. Heparin-like polysaccharides reduce osteolytic bone destruction and tumor growth in a mouse model of breast cancer bone metastasis
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Jussi M. Halleen, Khalid S. Mohammad, Sanna Maria Käkönen, Anni Wärri, Merja Perälä, Anne Marjamäki, Marjo Pihlavisto, Theresa A. Guise, Rami Käkönen, Olli Kallioniemi, Jukka P. Rissanen, Sirkku Pollari, and Liisa Nissinen
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Cancer Research ,Mice, Nude ,Osteoclasts ,Bone Neoplasms ,Breast Neoplasms ,Bone resorption ,Glycosaminoglycan ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Breast cancer ,SDG 3 - Good Health and Well-being ,Transforming Growth Factor beta ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Bone Resorption ,RNA, Small Interfering ,Molecular Biology ,Bacterial Capsules ,030304 developmental biology ,0303 health sciences ,business.industry ,Heparin ,Cancer ,Bone metastasis ,Heparan sulfate ,medicine.disease ,Interleukin-11 ,3. Good health ,Interleukin 11 ,Gene Expression Regulation, Neoplastic ,Oncology ,chemistry ,030220 oncology & carcinogenesis ,Cancer research ,Female ,Sulfotransferases ,business ,medicine.drug - Abstract
TGF-β regulates several steps in cancer metastasis, including the establishment of bone metastatic lesions. TGF-β is released from bone during osteoclastic bone resorption and it stimulates breast cancer cells to produce osteolytic factors such as interleukin 11 (IL-11). We conducted a cell-based siRNA screen and identified heparan sulfate 6-O-sulfotransferase 2 (HS6ST2) as a critical gene for TGF-β–induced IL-11 production in highly bone metastatic MDA-MB-231(SA) breast cancer cells. HS6ST2 attaches sulfate groups to glucosamine residues in heparan sulfate glycosaminoglycans. We subsequently showed how heparin and a high-molecular-weight Escherichia coli K5-derived heparin-like polysaccharide (K5-NSOS) inhibited TGF-β–induced IL-11 production in MDA-MB-231(SA) cells. In addition, K5-NSOS inhibited bone resorption activity of human osteoclasts in vitro. We evaluated the therapeutic potential of K5-NSOS and fragmin in a mouse model of breast cancer bone metastasis. MDA-MB-231(SA) cells were inoculated into the left cardiac ventricle of athymic nude mice which were treated with fragmin, K5-NSOS, or vehicle once a day for four weeks. Both heparin-like glycosaminoglycans inhibited weight reduction, decreased osteolytic lesion area, and reduced tumor burden in bone. In conclusion, our data imply novel mechanisms involved in TGF-β induction and support the critical role of heparan sulfate glycosaminoglycans in cancer metastasis as well as indicate that K5-NSOS is a potential antimetastatic and antiresorptive agent for cancer therapy. This study illustrates the potential to translate in vitro siRNA screening results toward in vivo therapeutic concepts. Mol Cancer Res; 10(5); 597–604. ©2012 AACR.
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- 2012
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22. Regulation of Postnatal Trabecular Bone Formation by the Osteoblast Endothelin A Receptor
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Katrina L. Clines, Gregory A. Clines, Christopher R. McKibbin, Maria Niewolna, Jessica M. Grunda, Larry J. Suva, Theresa A. Guise, C. Ryan McKenna, Masashi Yanagisawa, Khalid S. Mohammad, and John M. Chirgwin
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musculoskeletal diseases ,Male ,medicine.medical_specialty ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,SEX STEROIDS ,Biology ,Polymerase Chain Reaction ,Bone remodeling ,ENDOTHELIN A RECEPTOR ,03 medical and health sciences ,Mice ,0302 clinical medicine ,ENDOTHELIN-1 ,Internal medicine ,medicine ,Animals ,Orthopedics and Sports Medicine ,Receptor ,OSTEOBLAST ,030304 developmental biology ,DNA Primers ,Mice, Knockout ,0303 health sciences ,Bone Development ,Osteoblasts ,Base Sequence ,Osteoblast ,Original Articles ,3T3 Cells ,Androgen ,Receptor, Endothelin A ,Endothelin 1 ,Immunohistochemistry ,medicine.anatomical_structure ,Endocrinology ,030220 oncology & carcinogenesis ,Dihydrotestosterone ,Female ,Endothelin receptor ,BONE ,Homeostasis ,medicine.drug - Abstract
Endothelin-1 (ET-1) is a potent vasoconstrictor that also stimulates cells in the osteoblast lineage by binding to the endothelin A receptor (ETAR). ET-1 ligand is widely secreted, particularly by the vasculature. However, the contributions of ETAR signaling to adult bone homeostasis have not been defined. ETAR was inactivated in osteoblasts by crossing ETAR-floxed and osteocalcin-Cre mice. Histomorphometric analyses were performed on 4-, 8-, and 12-week-old osteoblast-targeted ETAR knockout (KO) and wild-type (WT) male and female mice. Tibial trabecular bone volume was significantly lower from 12 weeks in KO versus WT mice in both males and females. Bone-formation rate, osteoblast density, and in vitro osteoblast differentiation were reduced by targeted inactivation of ETAR. A separate longitudinal analysis was performed between 8 and 64 weeks to examine the effect of aging and castration on bone metabolism in ETAR KO mice. Hypogonadism did not change the rate of bone accrual in WT or KO females. However, eugonadal KO males had a significantly larger increase in tibial and femoral bone acquisition than WT mice. Male mice castrated at 8 weeks of age showed the reverse: KO mice had reduced rates of tibial and femoral BMD acquisition compared with WT mice. In vitro, ET-1 increased osteoblast proliferation, survival, and differentiation. Dihydrotestosterone also increased osteoblast differentiation using a mechanism distinct from the actions of ET-1. These results demonstrate that endothelin signaling in osteoblasts is an important regulator of postnatal trabecular bone remodeling and a modulator of androgen effects on bone. © 2011 American Society for Bone and Mineral Research
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- 2011
23. TGFβ-Mediated induction of SphK1 as a potential determinant in human MDA-MB-231 breast cancer cell bone metastasis
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Justin K. Mack, Theresa A. Guise, Donna Cerabona, Keith R. Stayrook, Hai H Bui, Maria Niewolna, Khalid S. Mohammad, Daniel F. Edwards, Pierrick G.J. Fournier, and David L. Waning
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medicine.medical_specialty ,Sphingosine ,Bone metastasis ,Biology ,medicine.disease ,Article ,3. Good health ,Metastasis ,chemistry.chemical_compound ,Breast cancer ,Circulating tumor cell ,Endocrinology ,chemistry ,Internal medicine ,medicine ,Cancer research ,General Earth and Planetary Sciences ,SPHK1 Gene ,Protein kinase A ,General Environmental Science ,Transforming growth factor - Abstract
Mechanistic understanding of the preferential homing of circulating tumor cells to bone and their perturbation on bone metabolism within the tumor-bone microenvironment remains poorly understood. Alteration in both transforming growth factor β (TGFβ) signaling and sphingolipid metabolism results in the promotion of tumor growth and metastasis. Previous studies using MDA-MB-231 human breast cancer-derived cell lines of variable metastatic potential were queried for changes in sphingolipid metabolism genes to explore correlations between TGFβ dependence and bone metastatic behavior. Of these genes, only sphingosine kinase-1 (SPHK1) was identified to be significantly increased following TGFβ treatment. Induction of SPHK1 expression correlated to the degree of metastatic capacity in these MDA-MB-231-derived cell lines. We demonstrate that TGFβ mediates the regulation of SPHK1 gene expression, protein kinase activity and is critical to MDA-MB-231 cell viability. Furthermore, a bioinformatic analysis of human breast cancer gene expression supports SPHK1 as a hallmark TGFβ target gene that also bears the genetic fingerprint of the basal-like/triple-negative breast cancer molecular subtype. These data suggest a potential new signaling axis between TGFβ/SphK1 that may have a role in the development, prognosis or the clinical phenotype associated with tumor-bone metastasis.
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- 2015
24. Oxygen-sensing PHDs regulate bone homeostasis through the modulation of osteoprotegerin
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Amato J. Giaccia, Alesha B. Castillo, Steven D. Rhodes, Colleen Wu, Tremika L.S. Wilson, Khalid S. Mohammad, Edward L. LaGory, Theresa A. Guise, Rebecca E. Andersen, Erinn B. Rankin, Ernestina Schipani, Laura Castellini, and Javier Fernandez-Alcudia
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musculoskeletal diseases ,medicine.medical_specialty ,Bone disease ,Osteoporosis ,Osteoclasts ,Cell Communication ,Biology ,Bone and Bones ,Prolyl Hydroxylases ,Bone resorption ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Genetics ,medicine ,Animals ,Homeostasis ,Gene Silencing ,Bone Resorption ,Endochondral ossification ,Cells, Cultured ,030304 developmental biology ,0303 health sciences ,Osteoblasts ,Stem Cells ,Osteoprotegerin ,Oxygen transport ,3T3 Cells ,medicine.disease ,Cell Hypoxia ,Oxygen tension ,Cell biology ,Enzyme Activation ,Oxygen ,Endocrinology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Erythropoiesis ,Female ,Hypoxia-Inducible Factor 1 ,Bone marrow ,Corrigendum ,Signal Transduction ,Developmental Biology ,Research Paper - Abstract
Bone development and homeostasis are achieved through an intricate balance between osteoblastic bone formation and osteoclastic bone resorption (Zaidi 2007; Khosla et al. 2008). Mammalian bone develops through endochondral ossification, a process that requires the coordination of osteoblasts and blood vessel invasion into the cartilaginous template to trigger the formation of the primary ossification center, highlighting the importance of angiogenesis during bone formation (Kronenberg 2003; Provot and Schipani 2005; Maes 2013). Maintenance of bone homeostasis is achieved by coupling bone formation with osteoblastic bone resorption. In particular, the RANK/RANKL/osteoprotegerin (OPG) axis contributes to this process by facilitating osteoblast-mediated osteoclastogenesis (Boyle et al. 2003). Deregulation of bone homeostasis is a hallmark of pathophysiological bone disease and occurs due to imbalances in osteogenic–angiogenic coupling or between bone-forming osteoblasts and bone resorption by osteoclasts. Increased bone results in osteopetrosis, whereas osteoporosis is associated with bone loss (Teitelbaum and Ross 2003; Seeman and Delmas 2006). Elucidating the molecular mechanisms that control bone homeostasis within the bone microenvironment is needed in order to identify novel therapeutic strategies to generate functional bone to treat chronic metabolic bone disorders where the options for treatment are still limited. The bone microenvironment is a particularly hypoxic microenvironment. Most adult tissues are well vascularized, allowing for the promotion of oxygen transport with normal median interstitial oxygen tension (pO2) values ranging from 3% to 9% (Vaupel et al. 1989). In contrast, pO2 levels in the bone range from 5%, the PHD enzymes regulate HIF protein stability by catalyzing the hydroxylation of HIF transcription factors on conserved proline residues, targeting them for proteosomal degradation by the von Hippel-Lindau (pVHL) ubiquitin ligase complex. When oxygen tensions fall below 5%, PHD enzyme activity is diminished, and HIF-1α and HIF-2α are stabilized and activate the expression of genes involved in diverse physiological conditions ranging from erythropoiesis to metabolism to angiogenesis (Semenza 2012). Thus, PHD enzymes provide a direct link between oxygen availability and the regulation of HIF transcriptional activity. While the PHD isoforms have nearly ubiquitous tissue expression, the tissue-specific role of each isoform in regulating HIF protein levels remains poorly defined. Here, we sought to dissect the physiologic role of oxygen-sensing PHD1, PHD2, and PHD3 enzymes in the regulation of bone homeostasis. For this purpose, we used a genetic approach to specifically inactivate Phd1, Phd2, and Phd3 in cells of the osteoblastic lineage using Cre-loxP-mediated recombination. In addition to coordinating osteoblastic–angiogenic coupling, we identified a previously unknown role for the PHD/HIF signaling pathway in the osteoblastic regulation of osteoclastogenesis through the direct regulation of OPG. Importantly, inactivation of selective PHD isoforms within the cells of the osteoblastic lineage inhibited bone loss in ovariectomized mice. Thus, molecular oxygen, through the PHD/HIF signaling pathway, plays a central role in bone homeostasis by controlling both angiogenesis and osteoclastogenesis, and therapeutic targeting of PHD enzymes can potentially be used for the treatment of bone disorders.
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- 2015
25. Dystrophic spinal deformities in a neurofibromatosis type 1 murine model
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Khalid S. Mohammad, Xianlin Yang, Xiaohua Wu, Hao Yang, Xiaohong Li, Shi Chen, Amanda L. Bergner, Feng Chun Yang, Theresa A. Guise, Wei Zhang, Dalong Yang, David A. Stevenson, and Steven D. Rhodes
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Pathology ,medicine.medical_specialty ,Neurofibromatosis 1 ,medicine.medical_treatment ,lcsh:Medicine ,Mice, Transgenic ,Scoliosis ,Thoracic Vertebrae ,Bone remodeling ,Mice ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Vertebral fusion ,medicine ,Animals ,Humans ,Neurofibromatosis ,Child ,lcsh:Science ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,business.industry ,lcsh:R ,Intervertebral disc ,Anatomy ,medicine.disease ,Spine ,Disease Models, Animal ,medicine.anatomical_structure ,Spinal fusion ,Thoracic vertebrae ,Cervical Vertebrae ,Female ,lcsh:Q ,Bone Remodeling ,business ,030217 neurology & neurosurgery ,Research Article ,Cervical vertebrae - Abstract
Despite the high prevalence and significant morbidity of spinal anomalies in neurofibromatosis type 1 (NF1), the pathogenesis of these defects remains largely unknown. Here, we present two murine models: Nf1flox/-;PeriCre and Nf1flox/-;Col.2.3Cre mice, which recapitulate spinal deformities seen in the human disease. Dynamic histomorphometry and microtomographic studies show recalcitrant bone remodeling and distorted bone microarchitecture within the vertebral spine of Nf1flox/-;PeriCre and Nf1flox/-;Col2.3Cre mice, with analogous histological features present in a human patient with dystrophic scoliosis. Intriguingly, 36-60% of Nf1flox/-;PeriCre and Nf1flox/-;Col2.3Cre mice exhibit segmental vertebral fusion anomalies with boney obliteration of the intervertebral disc (IVD). While analogous findings have not yet been reported in the NF1 patient population, we herein present two case reports of IVD defects and interarticular vertebral fusion in patients with NF1. Collectively, these data provide novel insights regarding the pathophysiology of dystrophic spinal anomalies in NF1, and provide impetus for future radiographic analyses of larger patient cohorts to determine whether IVD and vertebral fusion defects may have been previously overlooked or underreported in the NF1 patient population.
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- 2015
26. Generation of the first Autosomal Dominant Osteopetrosis Type II (ADO2) disease models
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Marta Capannolo, Michael J. Econs, Maurizio Muraca, Khalid S. Mohammad, Antonio Maurizi, Kang Chu, Amie K. Gray, Shoji Ichikawa, Imranul Alam, Mattia Capulli, Andrea Del Fattore, and Anna Teti
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Male ,Heterozygote ,Histology ,Physiology ,Endocrinology, Diabetes and Metabolism ,Molecular Sequence Data ,Osteoclasts ,CLCN7 Gene ,Osteopetrosis ,Chloride channel ,Osteoclast ,Article ,Bone and Bones ,Mice ,Bone Density ,Chloride Channels ,medicine ,Missense mutation ,Animals ,Gene Knock-In Techniques ,Gene ,Cells, Cultured ,Genes, Dominant ,Genetics ,Neurons ,biology ,Base Sequence ,Homozygote ,Heterozygote advantage ,X-Ray Microtomography ,medicine.disease ,Penetrance ,Mice, Inbred C57BL ,Disease Models, Animal ,medicine.anatomical_structure ,Phenotype ,biology.protein ,Female ,CLCN7 ,Biomarkers - Abstract
Autosomal dominant osteopetrosis type II (ADO2) is a heritable osteosclerotic disorder dependent on osteoclast impairment. In most patients it results from heterozygous missense mutations in the chloride channel 7 (CLCN7) gene, encoding for a 2Cl(-)/1H(+) antiporter. By a knock-in strategy inserting a missense mutation in the Clcn7 gene, our two research groups independently generated mouse models of ADO2 on different genetic backgrounds carrying the homolog of the most frequent heterozygous mutation (p.G213R) in the Clcn7 gene found in humans. Our results demonstrate that the heterozygous model holds true presenting with higher bone mass, increased numbers of poorly resorbing osteoclasts and a lethal phenotype in the homozygous state. Considerable variability is observed in the heterozygous mice according with the mouse background, suggesting that modifier genes could influence the penetrance of the disease gene.
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- 2013
27. RANKL/RANK/MMP-1 molecular triad contributes to the metastatic phenotype of breast and prostate cancer cells in vitro
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Theresa A. Guise, Joana Tato-Costa, Ricardo A. Pires, Khalid S. Mohammad, Sandra Casimiro, Rui Pedro A. G. Teixeira, Allan Lipton, Luis Costa, Antonio J. F. Carvalho, Sofia Ribeiro, Irina Alho, and Repositório da Universidade de Lisboa
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Male ,lcsh:Medicine ,Biochemistry ,Metastasis ,Bone remodeling ,Mice ,0302 clinical medicine ,Cell Movement ,Molecular Cell Biology ,Basic Cancer Research ,lcsh:Science ,0303 health sciences ,Multidisciplinary ,biology ,Receptor Activator of Nuclear Factor-kappa B ,Prostate Cancer ,Bone metastasis ,Obstetrics and Gynecology ,Cell migration ,Immunohistochemistry ,medicine.anatomical_structure ,Oncology ,RANKL ,030220 oncology & carcinogenesis ,Medicine ,Female ,Matrix Metalloproteinase 1 ,Research Article ,musculoskeletal diseases ,medicine.medical_specialty ,Bone and Mineral Metabolism ,Blotting, Western ,Bone Neoplasms ,Breast Neoplasms ,Real-Time Polymerase Chain Reaction ,Bone resorption ,Cell Line ,03 medical and health sciences ,Rheumatology ,Osteoclast ,Internal medicine ,Cell Line, Tumor ,Breast Cancer ,medicine ,Animals ,Humans ,Biology ,030304 developmental biology ,RANK Ligand ,lcsh:R ,Prostatic Neoplasms ,Cancers and Neoplasms ,medicine.disease ,Genitourinary Tract Tumors ,Endocrinology ,Metabolism ,Cancer cell ,Cancer research ,biology.protein ,lcsh:Q - Abstract
Copyright: © 2013 Casimiro et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited., The osteolytic nature of bone metastasis results from a tumor-driven increased bone resorption. Bone remodeling is orchestrated by the molecular triad RANK-RANKL-OPG. This process is dysregulated in bone metastases, mostly via induction of RANKL by tumor-derived factors. These factors increase expression of RANKL, which induce osteoclast formation, function, and survival, thereby increasing bone resorption. RANK is unexpectedly expressed by cancer cells, and the activation of RANKL-RANK pathway correlates with an increased invasive phenotype. To investigate the interaction between RANK expression in human breast and prostate cancer cells and their pro-metastatic phenotype we analyzed the activation of RANKL-RANK pathway and its effects on cell migration, invasion, gene expression in vitro, and osteolysis-inducing ability in vivo. RANKL activates kinase signaling pathways, stimulates cell migration, increases cell invasion, and up-regulates MMP-1 expression. In vivo, MMP-1 knockdown resulted in smaller x-ray osteolytic lesions and osteoclastogenesis, and decreased tumor burden. Therefore, RANKL inhibition in bone metastatic disease may decrease the levels of the osteoclastogenesis inducer MMP-1, contributing to a better clinical outcome., The work was supported in part by grants from the National Institutes of Health (National Cancer Institute) CA69158 and CA143057 (to TAG and KM); and FCT Fellowships SFRH/BPD/34801/2007, SFRH/BD/45219/2008 and SFRH/BD/44716/2008 (to SC, JT-C and IA).
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- 2013
28. Decreased autocrine EGFR signaling in metastatic breast cancer cells inhibits tumor growth in bone and mammary fat pad
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John Foley, Jennifer L. Gilmore, Nicole K. Nickerson, Theresa A. Guise, Angela Bruzzaniti, Erin Crismore, and Khalid S. Mohammad
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Anatomy and Physiology ,lcsh:Medicine ,Fat pad ,Mice ,Osteogenesis ,Molecular Cell Biology ,Basic Cancer Research ,Epidermal growth factor receptor ,Phosphorylation ,RNA, Small Interfering ,skin and connective tissue diseases ,lcsh:Science ,Musculoskeletal System ,Multidisciplinary ,biology ,Obstetrics and Gynecology ,Metastatic breast cancer ,ErbB Receptors ,Oncology ,Intercellular Signaling Peptides and Proteins ,Medicine ,Female ,Signal Transduction ,Research Article ,medicine.medical_specialty ,EGF Family of Proteins ,Mice, Nude ,Breast Neoplasms ,Amphiregulin ,Bone and Bones ,Paracrine signalling ,Breast cancer ,Mammary Glands, Animal ,Internal medicine ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Autocrine signalling ,Biology ,Glycoproteins ,lcsh:R ,Cancer ,Cancers and Neoplasms ,X-Ray Microtomography ,medicine.disease ,Endocrinology ,Cancer research ,biology.protein ,lcsh:Q - Abstract
Breast cancer metastasis to bone triggers a vicious cycle of tumor growth linked to osteolysis. Breast cancer cells and osteoblasts express the epidermal growth factor receptor (EGFR) and produce ErbB family ligands, suggesting participation of these growth factors in autocrine and paracrine signaling within the bone microenvironment. EGFR ligand expression was profiled in the bone metastatic MDA-MB-231 cells (MDA-231), and agonist-induced signaling was examined in both breast cancer and osteoblast-like cells. Both paracrine and autocrine EGFR signaling were inhibited with a neutralizing amphiregulin antibody, PAR34, whereas shRNA to the EGFR was used to specifically block autocrine signaling in MDA-231 cells. The impact of these was evaluated with proliferation, migration and gene expression assays. Breast cancer metastasis to bone was modeled in female athymic nude mice with intratibial inoculation of MDA-231 cells, and cancer cell-bone marrow co-cultures. EGFR knockdown, but not PAR34 treatment, decreased osteoclasts formed in vitro (p
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- 2012
29. c-Fms signaling mediates neurofibromatosis Type-1 osteoclast gain-in-functions
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Xianqi Li, Xiaohua Wu, Jin Yuan, Naoyuki Takahashi, Yongzheng He, Mingjiang Xu, Xianlin Yang, Feng Chun Yang, Li Jiang, Shi Chen, Theresa A. Guise, Steven D. Rhodes, and Khalid S. Mohammad
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Mouse ,Bone density ,Osteopenia and Osteoporosis ,Osteoporosis ,Osteoclasts ,lcsh:Medicine ,Biochemistry ,Intracellular Receptors ,Mice ,0302 clinical medicine ,Cell Movement ,Molecular Cell Biology ,Signaling in Cellular Processes ,Enzyme Inhibitors ,Biochemistry Simulations ,Extracellular Signal-Regulated MAP Kinases ,lcsh:Science ,Cells, Cultured ,0303 health sciences ,Neurofibromin 1 ,Multidisciplinary ,Animal Models ,medicine.anatomical_structure ,Medicine ,Female ,Cellular Types ,Signal transduction ,Research Article ,Signal Transduction ,Macrophage colony-stimulating factor ,musculoskeletal diseases ,medicine.medical_specialty ,congenital, hereditary, and neonatal diseases and abnormalities ,Histology ,Hematopoietic Progenitor Cells ,Bone Marrow Cells ,Ras Signaling ,Receptor, Macrophage Colony-Stimulating Factor ,Biology ,Ribosomal Protein S6 Kinases, 90-kDa ,Bone resorption ,03 medical and health sciences ,Model Organisms ,Osteoclast ,Internal medicine ,Genetics ,Cell Adhesion ,medicine ,Animals ,Humans ,Bone Resorption ,neoplasms ,030304 developmental biology ,Blood Cells ,Macrophage Colony-Stimulating Factor ,lcsh:R ,Proteins ,medicine.disease ,eye diseases ,nervous system diseases ,Mice, Inbred C57BL ,Osteopenia ,Endocrinology ,Genetics of Disease ,biology.protein ,Women's Health ,lcsh:Q ,Gene Deletion ,030217 neurology & neurosurgery - Abstract
Skeletal abnormalities including osteoporosis and osteopenia occur frequently in both pediatric and adult neurofibromatosis type 1 (NF1) patients. NF1 (Nf1) haploinsufficient osteoclasts and osteoclast progenitors derived from both NF1 patients and Nf1(+/-) mice exhibit increased differentiation, migration, and bone resorptive capacity in vitro, mediated by hyperactivation of p21(Ras) in response to limiting concentrations of macrophage-colony stimulating factor (M-CSF). Here, we show that M-CSF binding to its receptor, c-Fms, results in increased c-Fms activation in Nf1(+/) (-) osteoclast progenitors, mediating multiple gain-in-functions through the downstream effectors Erk1/2 and p90RSK. PLX3397, a potent and selective c-Fms inhibitor, attenuated M-CSF mediated Nf1(+/-) osteoclast migration by 50%, adhesion by 70%, and pit formation by 60%. In vivo, we administered PLX3397 to Nf1(+/-) osteoporotic mice induced by ovariectomy (OVX) and evaluated changes in bone mass and skeletal architecture. We found that PLX3397 prevented bone loss in Nf1(+/-)-OVX mice by reducing osteoclast differentiation and bone resorptive activity in vivo. Collectively, these results implicate the M-CSF/c-Fms signaling axis as a critical pathway underlying the aberrant functioning of Nf1 haploinsufficient osteoclasts and may provide a potential therapeutic target for treating NF1 associated osteoporosis and osteopenia.
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- 2012
30. The haploinsufficient hematopoietic microenvironment is critical to the pathological fracture repair in murine models of neurofibromatosis type 1
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Xianlin Yang, Paige Snider, Grzegorz Nalepa, Xiaohong Li, Li Jiang, Theresa A. Guise, Simon J. Conway, Yongzheng He, Xiaohua Wu, Khalid S. Mohammad, D. Wade Clapp, Shi Chen, Alexander G. Robling, Steven D Rhodes, and Feng Chun Yang
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Pathology ,Anatomy and Physiology ,Mouse ,lcsh:Medicine ,Haploinsufficiency ,Mice ,0302 clinical medicine ,Bone Density ,Bone Marrow ,Immune Physiology ,Molecular Cell Biology ,Bone Marrow and Stem Cell Transplantation ,lcsh:Science ,Musculoskeletal System ,Fracture Healing ,0303 health sciences ,Multidisciplinary ,Stem Cells ,Animal Models ,Hematology ,medicine.anatomical_structure ,Autosomal Dominant ,Medicine ,Cellular Types ,Research Article ,medicine.medical_specialty ,congenital, hereditary, and neonatal diseases and abnormalities ,Neurofibromatosis 1 ,Tumor suppressor gene ,Immunology ,030209 endocrinology & metabolism ,Mice, Transgenic ,Bone healing ,Biology ,03 medical and health sciences ,Model Organisms ,Genes, Neurofibromatosis 1 ,medicine ,Genetics ,Animals ,Progenitor cell ,Neurofibromatosis ,Bone ,neoplasms ,Crosses, Genetic ,Germ-Line Mutation ,030304 developmental biology ,Phenocopy ,Clinical Genetics ,Osteoblasts ,lcsh:R ,Mesenchymal Stem Cells ,Human Genetics ,Bone fracture ,medicine.disease ,Hematopoietic Stem Cells ,beta-Galactosidase ,eye diseases ,nervous system diseases ,Disease Models, Animal ,Immune System ,Clinical Immunology ,lcsh:Q ,Bone marrow ,Neurofibromatosis Type 1 ,Developmental Biology - Abstract
Germline mutations in the NF1 tumor suppressor gene cause neurofibromatosis type 1 (NF1), a complex genetic disorder with a high predisposition of numerous skeletal dysplasias including short stature, osteoporosis, kyphoscoliosis, and fracture non-union (pseudoarthrosis). We have developed murine models that phenocopy many of the skeletal dysplasias observed in NF1 patients, including reduced bone mass and fracture non-union. We also show that the development of these skeletal manifestations requires an Nf1 haploinsufficient background in addition to nullizygous loss of Nf1 in mesenchymal stem/progenitor cells (MSCs) and/or their progenies. This is replicated in two animal models of NF1, PeriCre(+);Nf1(flox/-) and Col2.3Cre(+);Nf1(flox/-) mice. Adoptive transfer experiments demonstrate a critical role of the Nf1+/- marrow microenvironment in the impaired fracture healing in both models and adoptive transfer of WT bone marrow cells improves fracture healing in these mice. To our knowledge, this is the first demonstration of a non-cell autonomous mechanism in non-malignant NF1 manifestations. Collectively, these data provide evidence of a combinatory effect between nullizygous loss of Nf1 in osteoblast progenitors and haploinsufficiency in hematopoietic cells in the development of non-malignant NF1 manifestations.
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- 2011
31. Hypoxia and TGF-β Drive Breast Cancer Bone Metastases through Parallel Signaling Pathways in Tumor Cells and the Bone Microenvironment
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John M. Chirgwin, Khalid S. Mohammad, Pierrick G.J. Fournier, C. Ryan McKenna, Xiang Hong Peng, Lauren K. Dunn, Theresa A. Guise, Holly W. Davis, and Maria Niewolna
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Vascular Endothelial Growth Factor A ,lcsh:Medicine ,Diabetes and Endocrinology/Bone and Mineral Metabolism ,Metastasis ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Transforming Growth Factor beta ,Biochemistry/Cell Signaling and Trafficking Structures ,CXC chemokine receptors ,Neoplasm Metastasis ,lcsh:Science ,Hypoxia ,Women's Health/Breast Cancer ,0303 health sciences ,Multidisciplinary ,biology ,Bone metastasis ,Osteoblast ,3. Good health ,Vascular endothelial growth factor ,Gene Expression Regulation, Neoplastic ,Vascular endothelial growth factor A ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Oncology/Breast Cancer ,Female ,Research Article ,Signal Transduction ,medicine.medical_specialty ,Receptors, CXCR4 ,Bone Neoplasms ,Breast Neoplasms ,Bone resorption ,Bone and Bones ,03 medical and health sciences ,Internal medicine ,Cell Line, Tumor ,medicine ,Animals ,Humans ,030304 developmental biology ,business.industry ,lcsh:R ,Transforming growth factor beta ,medicine.disease ,Hypoxia-Inducible Factor 1, alpha Subunit ,Endocrinology ,chemistry ,Cancer research ,biology.protein ,lcsh:Q ,business - Abstract
Background Most patients with advanced breast cancer develop bone metastases, which cause pain, hypercalcemia, fractures, nerve compression and paralysis. Chemotherapy causes further bone loss, and bone-specific treatments are only palliative. Multiple tumor-secreted factors act on the bone microenvironment to drive a feed-forward cycle of tumor growth. Effective treatment requires inhibiting upstream regulators of groups of prometastatic factors. Two central regulators are hypoxia and transforming growth factor (TGF)- β. We asked whether hypoxia (via HIF-1α) and TGF-β signaling promote bone metastases independently or synergistically, and we tested molecular versus pharmacological inhibition strategies in an animal model. Methodology/Principal Findings We analyzed interactions between HIF-1α and TGF-β pathways in MDA-MB-231 breast cancer cells. Only vascular endothelial growth factor (VEGF) and the CXC chemokine receptor 4 (CXCR4), of 16 genes tested, were additively increased by both TGF-β and hypoxia, with effects on the proximal promoters. We inhibited HIF-1α and TGF-β pathways in tumor cells by shRNA and dominant negative receptor approaches. Inhibition of either pathway decreased bone metastasis, with no further effect of double blockade. We tested pharmacologic inhibitors of the pathways, which target both the tumor and the bone microenvironment. Unlike molecular blockade, combined drug treatment decreased bone metastases more than either alone, with effects on bone to decrease osteoclastic bone resorption and increase osteoblast activity, in addition to actions on tumor cells. Conclusions/Significance Hypoxia and TGF-β signaling in parallel drive tumor bone metastases and regulate a common set of tumor genes. In contrast, small molecule inhibitors, by acting on both tumor cells and the bone microenvironment, additively decrease tumor burden, while improving skeletal quality. Our studies suggest that inhibitors of HIF-1α and TGF-β may improve treatment of bone metastases and increase survival.
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- 2009
32. DICKKOPF HOMOLOG 1 MEDIATES ENDOTHELIN-1-STIMULATED NEW BONE FORMATION*
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John D. Shaughnessy, John M. Chirgwin, Khalid S. Mohammad, Yongde Bao, Gregory A. Clines, Owen W. Stephens, Larry J. Suva, Jay W. Fox, and Theresa A. Guise
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musculoskeletal diseases ,medicine.medical_treatment ,Biology ,Article ,Mice ,Endocrinology ,Organ Culture Techniques ,Osteogenesis ,medicine ,Animals ,Molecular Biology ,Cells, Cultured ,Oligonucleotide Array Sequence Analysis ,Osteoblasts ,Endothelin-1 ,Interleukin-6 ,Reverse Transcriptase Polymerase Chain Reaction ,Growth factor ,Skull ,Wnt signaling pathway ,Bone metastasis ,Osteoblast ,General Medicine ,Tissue inhibitor of metalloproteinase ,medicine.disease ,Molecular biology ,Cell biology ,CTGF ,Wnt Proteins ,medicine.anatomical_structure ,DKK1 ,Animals, Newborn ,Gene Expression Regulation ,CYR61 ,Intercellular Signaling Peptides and Proteins ,Female - Abstract
Tumor-produced endothelin-1 (ET-1) stimulates osteoblasts to form new bone and is an important mediator of osteoblastic bone metastasis. The anabolic actions of ET-1 in osteoblasts were investigated by gene microarray analyses of murine neonatal calvarial organ cultures. Targets of ET-1 action were validated by real-time RT-PCR in murine primary osteoblast cultures. IL-6, IL-11, the CCN (CYR61, CTGF, NOV) family members cysteine-rich protein 61 and connective tissue growth factor, inhibin beta-A, serum/glucocorticoid regulated kinase, receptor activator of nuclear factor kappaB ligand, snail homolog 1, tissue inhibitor of metalloproteinase 3, and TG-interacting factor transcripts were increased by ET-1. ET-1 decreased the transcript for the Wnt signaling pathway inhibitor, dickkopf homolog 1 (Dkk1). Calvarial organ cultures treated with ET-1 had lower concentrations of DKK1 protein in conditioned media than control cultures. High DKK1 concentrations in bone marrow suppress bone formation in multiple myeloma. We hypothesized that the converse occurs in osteoblastic bone metastasis, where ET-1 stimulates osteoblast activity by reducing autocrine production of DKK1. Recombinant DKK1 blocked ET-1-mediated osteoblast proliferation and new bone formation in calvarial organ cultures, whereas a DKK1-neutralizing antibody increased osteoblast numbers and new bone formation. ET-1 directed nuclear translocation of beta-catenin in osteoblasts, indicating activation of the Wnt signaling pathway. The data suggest that ET-1 increases osteoblast proliferation and new bone formation by activating the Wnt signaling pathway through suppression of the Wnt pathway inhibitor DKK1.
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- 2006
33. IMPROVING COMPATIBILITY OF RECYCLED NITRILE RUBBER (rNBR) AND ETHYLENE VINYL ACETATE (EVA) BLENDS BY ELECTRON BEAM IRRADIATION.
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Norshafini, M. Z., Ratnam, C. T., Chuah, A. Luqman, and Khalid, S. Mohammad
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NITRILE rubber ,VINYL acetate ,COPOLYMERS ,RECYCLED products ,ELECTRON beams ,IRRADIATION ,ARTIFICIAL rubber - Abstract
Blends of ethylene vinyl acetate (EVA) copolymer and recycled nitrile rubber (rNBR) were prepared using an internal mixer. N,N'-m-phenylenedimaleimide (HVA-2) was added into the blend composed of 70 wt % of EVA and 30 wt % of rNBR, and served as a crosslinking agent. The HVA-2 concentration was varied from 0 to 5 phr. The changes in the compatibility of the blends were investigated before and after electron beam irradiation by means of physical and morphological tests. The results obtained from these tests were then analysed, namely tensile strength (TS), modulus 100 (M100), elongation at break, gel content and scanning electron microscopy (SEM). The results showed that the TS and elongation at break had decreased with increasing in HVA-2 concentration and electron beam irradiation dose, while the M100 had increased. It is believed that the blends had undergone early crosslinking reaction during mixing. Hence, the brittleness of the materials had increased upon exposure to electron beam irradiation due to the excessive crosslinking bonds. This observation was supported by the gel content and SEM micrographs. [ABSTRACT FROM AUTHOR]
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- 2016
34. The TGF-β Signaling Regulator PMEPA1 Suppresses Prostate Cancer Metastases to Bone
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Hun Soo Kim, Holly W. Walton, Gregory A. Clines, Theresa A. Guise, John M. Chirgwin, Patricia Juárez, Maria Niewolna, C. Xiang Hong Peng, Yunlong Liu, Clark D. Wells, Pierrick G.J. Fournier, Khalid S. Mohammad, and Guanglong Jiang
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PCA3 ,Male ,Cancer Research ,medicine.medical_specialty ,Cancer Model ,Mice, Nude ,Bone Neoplasms ,Article ,Mice ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Transforming Growth Factor beta ,Cell Line, Tumor ,Internal medicine ,Chlorocebus aethiops ,medicine ,Animals ,Humans ,030304 developmental biology ,0303 health sciences ,Gene knockdown ,biology ,business.industry ,Pteridines ,Cancer ,Membrane Proteins ,Prostatic Neoplasms ,Hep G2 Cells ,Cell Biology ,Transforming growth factor beta ,medicine.disease ,Disease Models, Animal ,Endocrinology ,Oncology ,Gene Knockdown Techniques ,030220 oncology & carcinogenesis ,COS Cells ,Cancer research ,biology.protein ,Signal transduction ,business ,Signal Transduction ,Transforming growth factor - Abstract
SummaryTransforming growth factor-β (TGF-β) regulates the expression of genes supporting breast cancer cells in bone, but little is known about prostate cancer bone metastases and TGF-β. Our study reveals that the TGFBR1 inhibitor SD208 effectively reduces prostate cancer bone metastases. TGF-β upregulates in prostate cancer cells a set of genes associated with cancer aggressiveness and bone metastases, and the most upregulated gene was PMEPA1. In patients, PMEPA1 expression decreased in metastatic prostate cancer and low Pmepa1 correlated with decreased metastasis-free survival. Only membrane-anchored isoforms of PMEPA1 interacted with R-SMADs and ubiquitin ligases, blocking TGF-β signaling independently of the proteasome. Interrupting this negative feedback loop by PMEPA1 knockdown increased prometastatic gene expression and bone metastases in a mouse prostate cancer model.
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35. Tumor-expressed adrenomedullin accelerates breast cancer bone metastasis
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Xianghong Peng, Attaya Suvannasankha, Theresa A. Guise, Holly W. Davis, Lisa L. Wessner, Valerie A. Siclari, John M. Chirgwin, Douglas R. Tompkins, Khalid S. Mohammad, Maria Niewolna, and C. Ryan McKenna
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medicine.medical_specialty ,Angiogenesis ,Mice, Nude ,Bone Neoplasms ,Breast Neoplasms ,Adenocarcinoma ,Bone and Bones ,Adrenomedullin ,Mice ,03 medical and health sciences ,Paracrine signalling ,0302 clinical medicine ,Osteoclast ,Cell Line, Tumor ,Internal medicine ,Bone cell ,medicine ,Animals ,Humans ,RNA, Messenger ,030304 developmental biology ,Medicine(all) ,0303 health sciences ,business.industry ,Bone metastasis ,medicine.disease ,Metastatic breast cancer ,3. Good health ,Endocrinology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Disease Progression ,Female ,business ,Neoplasm Transplantation ,Ex vivo ,Research Article - Abstract
Introduction Adrenomedullin (AM) is secreted by breast cancer cells and increased by hypoxia. It is a multifunctional peptide that stimulates angiogenesis and proliferation. The peptide is also a potent paracrine stimulator of osteoblasts and bone formation, suggesting a role in skeletal metastases—a major site of treatment-refractory tumor growth in patients with advanced disease. Methods The role of adrenomedullin in bone metastases was tested by stable overexpression in MDA-MB-231 breast cancer cells, which cause osteolytic bone metastases in a standard animal model. Cells with fivefold increased expression of AM were characterized in vitro, inoculated into immunodeficient mice and compared for their ability to form bone metastases versus control subclones. Bone destruction was monitored by X-ray, and tumor burden and osteoclast numbers were determined by quantitative histomorphometry. The effects of AM overexpression on tumor growth and angiogenesis in the mammary fat pad were determined. The effects of AM peptide on osteoclast-like multinucleated cell formation were tested in vitro. A small-molecule AM antagonist was tested for its effects on AM-stimulated ex vivo bone cell cultures and co-cultures with tumor cells, where responses of tumor and bone were distinguished by species-specific real-time PCR. Results Overexpression of AM mRNA did not alter cell proliferation in vitro, expression of tumor-secreted factors or cell cycle progression. AM-overexpressing cells caused osteolytic bone metastases to develop more rapidly, which was accompanied by decreased survival. In the mammary fat pad, tumors grew more rapidly with unchanged blood vessel formation. Tumor growth in the bone was also more rapid, and osteoclasts were increased. AM peptide potently stimulated bone cultures ex vivo; responses that were blocked by small-molecule adrenomedullin antagonists in the absence of cellular toxicity. Antagonist treatment dramatically suppressed tumor growth in bone and decreased markers of osteoclast activity. Conclusions The results identify AM as a target for therapeutic intervention against bone metastases. Adrenomedullin potentiates osteolytic responses in bone to metastatic breast cancer cells. Small-molecule antagonists can effectively block bone-mediated responses to tumor-secreted adrenomedullin, and such agents warrant development for testing in vivo. Electronic supplementary material The online version of this article (doi:10.1186/s13058-014-0458-y) contains supplementary material, which is available to authorized users.
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36. Growth factor independence 1 expression in myeloma cells enhances their growth, survival, and osteoclastogenesis
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Daniela N Petrusca, Denise Toscani, Feng-Ming Wang, Cheolkyu Park, Colin D Crean, Judith L Anderson, Silvia Marino, Khalid S Mohammad, Dan Zhou, Rebecca Silbermann, Quanhong Sun, Noriyoshi Kurihara, Deborah L Galson, Nicola Giuliani, and G David Roodman
- Subjects
Gfi1 ,Multiple myeloma ,p53 ,Bone disease ,Apoptosis and osteolysis ,Diseases of the blood and blood-forming organs ,RC633-647.5 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background In spite of major advances in treatment, multiple myeloma (MM) is currently an incurable malignancy due to the emergence of drug-resistant clones. We previously showed that MM cells upregulate the transcriptional repressor, growth factor independence 1 (Gfi1), in bone marrow stromal cells (BMSCs) that induces prolonged inhibition of osteoblast differentiation. However, the role of Gfi1 in MM cells is unknown. Methods Human primary CD138+ and BMSC were purified from normal donors and MM patients’ bone marrow aspirates. Gfi1 knockdown and overexpressing cells were generated by lentiviral-mediated shRNA. Proliferation/apoptosis studies were done by flow cytometry, and protein levels were determined by Western blot and/or immunohistochemistry. An experimental MM mouse model was generated to investigate the effects of MM cells overexpressing Gfi1 on tumor burden and osteolysis in vivo. Results We found that Gfi1 expression is increased in patient’s MM cells and MM cell lines and was further increased by co-culture with BMSC, IL-6, and sphingosine-1-phosphate. Modulation of Gfi1 in MM cells had major effects on their survival and growth. Knockdown of Gfi1 induced apoptosis in p53-wt, p53-mutant, and p53-deficient MM cells, while Gfi1 overexpression enhanced MM cell growth and protected MM cells from bortezomib-induced cell death. Gfi1 enhanced cell survival of p53-wt MM cells by binding to p53, thereby blocking binding to the promoters of the pro-apoptotic BAX and NOXA genes. Further, Gfi1-p53 binding could be blocked by HDAC inhibitors. Importantly, inoculation of MM cells overexpressing Gfi1 in mice induced increased bone destruction, increased osteoclast number and size, and enhanced tumor growth. Conclusions These results support that Gfi1 plays a key role in MM tumor growth, survival, and bone destruction and contributes to bortezomib resistance, suggesting that Gfi1 may be a novel therapeutic target for MM.
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- 2018
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37. Dystrophic spinal deformities in a neurofibromatosis type 1 murine model.
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Steven D Rhodes, Wei Zhang, Dalong Yang, Hao Yang, Shi Chen, Xiaohua Wu, Xiaohong Li, Xianlin Yang, Khalid S Mohammad, Theresa A Guise, Amanda L Bergner, David A Stevenson, and Feng-Chun Yang
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Medicine ,Science - Abstract
Despite the high prevalence and significant morbidity of spinal anomalies in neurofibromatosis type 1 (NF1), the pathogenesis of these defects remains largely unknown. Here, we present two murine models: Nf1flox/-;PeriCre and Nf1flox/-;Col.2.3Cre mice, which recapitulate spinal deformities seen in the human disease. Dynamic histomorphometry and microtomographic studies show recalcitrant bone remodeling and distorted bone microarchitecture within the vertebral spine of Nf1flox/-;PeriCre and Nf1flox/-;Col2.3Cre mice, with analogous histological features present in a human patient with dystrophic scoliosis. Intriguingly, 36-60% of Nf1flox/-;PeriCre and Nf1flox/-;Col2.3Cre mice exhibit segmental vertebral fusion anomalies with boney obliteration of the intervertebral disc (IVD). While analogous findings have not yet been reported in the NF1 patient population, we herein present two case reports of IVD defects and interarticular vertebral fusion in patients with NF1. Collectively, these data provide novel insights regarding the pathophysiology of dystrophic spinal anomalies in NF1, and provide impetus for future radiographic analyses of larger patient cohorts to determine whether IVD and vertebral fusion defects may have been previously overlooked or underreported in the NF1 patient population.
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- 2015
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38. RANKL/RANK/MMP-1 molecular triad contributes to the metastatic phenotype of breast and prostate cancer cells in vitro.
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Sandra Casimiro, Khalid S Mohammad, Ricardo Pires, Joana Tato-Costa, Irina Alho, Rui Teixeira, António Carvalho, Sofia Ribeiro, Allan Lipton, Theresa A Guise, and Luis Costa
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Medicine ,Science - Abstract
The osteolytic nature of bone metastasis results from a tumor-driven increased bone resorption. Bone remodeling is orchestrated by the molecular triad RANK-RANKL-OPG. This process is dysregulated in bone metastases, mostly via induction of RANKL by tumor-derived factors. These factors increase expression of RANKL, which induce osteoclast formation, function, and survival, thereby increasing bone resorption. RANK is unexpectedly expressed by cancer cells, and the activation of RANKL-RANK pathway correlates with an increased invasive phenotype. To investigate the interaction between RANK expression in human breast and prostate cancer cells and their pro-metastatic phenotype we analyzed the activation of RANKL-RANK pathway and its effects on cell migration, invasion, gene expression in vitro, and osteolysis-inducing ability in vivo. RANKL activates kinase signaling pathways, stimulates cell migration, increases cell invasion, and up-regulates MMP-1 expression. In vivo, MMP-1 knockdown resulted in smaller x-ray osteolytic lesions and osteoclastogenesis, and decreased tumor burden. Therefore, RANKL inhibition in bone metastatic disease may decrease the levels of the osteoclastogenesis inducer MMP-1, contributing to a better clinical outcome.
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- 2013
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39. Decreased autocrine EGFR signaling in metastatic breast cancer cells inhibits tumor growth in bone and mammary fat pad.
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Nicole K Nickerson, Khalid S Mohammad, Jennifer L Gilmore, Erin Crismore, Angela Bruzzaniti, Theresa A Guise, and John Foley
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Medicine ,Science - Abstract
Breast cancer metastasis to bone triggers a vicious cycle of tumor growth linked to osteolysis. Breast cancer cells and osteoblasts express the epidermal growth factor receptor (EGFR) and produce ErbB family ligands, suggesting participation of these growth factors in autocrine and paracrine signaling within the bone microenvironment. EGFR ligand expression was profiled in the bone metastatic MDA-MB-231 cells (MDA-231), and agonist-induced signaling was examined in both breast cancer and osteoblast-like cells. Both paracrine and autocrine EGFR signaling were inhibited with a neutralizing amphiregulin antibody, PAR34, whereas shRNA to the EGFR was used to specifically block autocrine signaling in MDA-231 cells. The impact of these was evaluated with proliferation, migration and gene expression assays. Breast cancer metastasis to bone was modeled in female athymic nude mice with intratibial inoculation of MDA-231 cells, and cancer cell-bone marrow co-cultures. EGFR knockdown, but not PAR34 treatment, decreased osteoclasts formed in vitro (p
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- 2012
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40. c-Fms signaling mediates neurofibromatosis Type-1 osteoclast gain-in-functions.
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Yongzheng He, Steven D Rhodes, Shi Chen, Xiaohua Wu, Jin Yuan, Xianlin Yang, Li Jiang, Xianqi Li, Naoyuki Takahashi, Mingjiang Xu, Khalid S Mohammad, Theresa A Guise, and Feng-Chun Yang
- Subjects
Medicine ,Science - Abstract
Skeletal abnormalities including osteoporosis and osteopenia occur frequently in both pediatric and adult neurofibromatosis type 1 (NF1) patients. NF1 (Nf1) haploinsufficient osteoclasts and osteoclast progenitors derived from both NF1 patients and Nf1(+/-) mice exhibit increased differentiation, migration, and bone resorptive capacity in vitro, mediated by hyperactivation of p21(Ras) in response to limiting concentrations of macrophage-colony stimulating factor (M-CSF). Here, we show that M-CSF binding to its receptor, c-Fms, results in increased c-Fms activation in Nf1(+/) (-) osteoclast progenitors, mediating multiple gain-in-functions through the downstream effectors Erk1/2 and p90RSK. PLX3397, a potent and selective c-Fms inhibitor, attenuated M-CSF mediated Nf1(+/-) osteoclast migration by 50%, adhesion by 70%, and pit formation by 60%. In vivo, we administered PLX3397 to Nf1(+/-) osteoporotic mice induced by ovariectomy (OVX) and evaluated changes in bone mass and skeletal architecture. We found that PLX3397 prevented bone loss in Nf1(+/-)-OVX mice by reducing osteoclast differentiation and bone resorptive activity in vivo. Collectively, these results implicate the M-CSF/c-Fms signaling axis as a critical pathway underlying the aberrant functioning of Nf1 haploinsufficient osteoclasts and may provide a potential therapeutic target for treating NF1 associated osteoporosis and osteopenia.
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- 2012
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41. The haploinsufficient hematopoietic microenvironment is critical to the pathological fracture repair in murine models of neurofibromatosis type 1.
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Xiaohua Wu, Shi Chen, Yongzheng He, Steven D Rhodes, Khalid S Mohammad, Xiaohong Li, Xianlin Yang, Li Jiang, Grzegorz Nalepa, Paige Snider, Alexander G Robling, D Wade Clapp, Simon J Conway, Theresa A Guise, and Feng-Chun Yang
- Subjects
Medicine ,Science - Abstract
Germline mutations in the NF1 tumor suppressor gene cause neurofibromatosis type 1 (NF1), a complex genetic disorder with a high predisposition of numerous skeletal dysplasias including short stature, osteoporosis, kyphoscoliosis, and fracture non-union (pseudoarthrosis). We have developed murine models that phenocopy many of the skeletal dysplasias observed in NF1 patients, including reduced bone mass and fracture non-union. We also show that the development of these skeletal manifestations requires an Nf1 haploinsufficient background in addition to nullizygous loss of Nf1 in mesenchymal stem/progenitor cells (MSCs) and/or their progenies. This is replicated in two animal models of NF1, PeriCre(+);Nf1(flox/-) and Col2.3Cre(+);Nf1(flox/-) mice. Adoptive transfer experiments demonstrate a critical role of the Nf1+/- marrow microenvironment in the impaired fracture healing in both models and adoptive transfer of WT bone marrow cells improves fracture healing in these mice. To our knowledge, this is the first demonstration of a non-cell autonomous mechanism in non-malignant NF1 manifestations. Collectively, these data provide evidence of a combinatory effect between nullizygous loss of Nf1 in osteoblast progenitors and haploinsufficiency in hematopoietic cells in the development of non-malignant NF1 manifestations.
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- 2011
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42. Hypoxia and TGF-beta drive breast cancer bone metastases through parallel signaling pathways in tumor cells and the bone microenvironment.
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Lauren K Dunn, Khalid S Mohammad, Pierrick G J Fournier, C Ryan McKenna, Holly W Davis, Maria Niewolna, Xiang Hong Peng, John M Chirgwin, and Theresa A Guise
- Subjects
Medicine ,Science - Abstract
Most patients with advanced breast cancer develop bone metastases, which cause pain, hypercalcemia, fractures, nerve compression and paralysis. Chemotherapy causes further bone loss, and bone-specific treatments are only palliative. Multiple tumor-secreted factors act on the bone microenvironment to drive a feed-forward cycle of tumor growth. Effective treatment requires inhibiting upstream regulators of groups of prometastatic factors. Two central regulators are hypoxia and transforming growth factor (TGF)- beta. We asked whether hypoxia (via HIF-1alpha) and TGF-beta signaling promote bone metastases independently or synergistically, and we tested molecular versus pharmacological inhibition strategies in an animal model.We analyzed interactions between HIF-1alpha and TGF-beta pathways in MDA-MB-231 breast cancer cells. Only vascular endothelial growth factor (VEGF) and the CXC chemokine receptor 4 (CXCR4), of 16 genes tested, were additively increased by both TGF-beta and hypoxia, with effects on the proximal promoters. We inhibited HIF-1alpha and TGF-beta pathways in tumor cells by shRNA and dominant negative receptor approaches. Inhibition of either pathway decreased bone metastasis, with no further effect of double blockade. We tested pharmacologic inhibitors of the pathways, which target both the tumor and the bone microenvironment. Unlike molecular blockade, combined drug treatment decreased bone metastases more than either alone, with effects on bone to decrease osteoclastic bone resorption and increase osteoblast activity, in addition to actions on tumor cells.Hypoxia and TGF-beta signaling in parallel drive tumor bone metastases and regulate a common set of tumor genes. In contrast, small molecule inhibitors, by acting on both tumor cells and the bone microenvironment, additively decrease tumor burden, while improving skeletal quality. Our studies suggest that inhibitors of HIF-1alpha and TGF-beta may improve treatment of bone metastases and increase survival.
- Published
- 2009
- Full Text
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43. Pharmacologic inhibition of the TGF-beta type I receptor kinase has anabolic and anti-catabolic effects on bone.
- Author
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Khalid S Mohammad, Carol G Chen, Guive Balooch, Elizabeth Stebbins, C Ryan McKenna, Holly Davis, Maria Niewolna, Xiang Hong Peng, Daniel H N Nguyen, Sophi S Ionova-Martin, John W Bracey, William R Hogue, Darren H Wong, Robert O Ritchie, Larry J Suva, Rik Derynck, Theresa A Guise, and Tamara Alliston
- Subjects
Medicine ,Science - Abstract
During development, growth factors and hormones cooperate to establish the unique sizes, shapes and material properties of individual bones. Among these, TGF-beta has been shown to developmentally regulate bone mass and bone matrix properties. However, the mechanisms that control postnatal skeletal integrity in a dynamic biological and mechanical environment are distinct from those that regulate bone development. In addition, despite advances in understanding the roles of TGF-beta signaling in osteoblasts and osteoclasts, the net effects of altered postnatal TGF-beta signaling on bone remain unclear. To examine the role of TGF-beta in the maintenance of the postnatal skeleton, we evaluated the effects of pharmacological inhibition of the TGF-beta type I receptor (TbetaRI) kinase on bone mass, architecture and material properties. Inhibition of TbetaRI function increased bone mass and multiple aspects of bone quality, including trabecular bone architecture and macro-mechanical behavior of vertebral bone. TbetaRI inhibitors achieved these effects by increasing osteoblast differentiation and bone formation, while reducing osteoclast differentiation and bone resorption. Furthermore, they induced the expression of Runx2 and EphB4, which promote osteoblast differentiation, and ephrinB2, which antagonizes osteoclast differentiation. Through these anabolic and anti-catabolic effects, TbetaRI inhibitors coordinate changes in multiple bone parameters, including bone mass, architecture, matrix mineral concentration and material properties, that collectively increase bone fracture resistance. Therefore, TbetaRI inhibitors may be effective in treating conditions of skeletal fragility.
- Published
- 2009
- Full Text
- View/download PDF
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