9 results on '"Saab ST"'
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2. Functional tumor cell-intrinsic STING, not host STING, drives local and systemic antitumor immunity and therapy efficacy following cryoablation.
- Author
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Alshebremi M, Tomchuck SL, Myers JT, Kingsley DT, Eid S, Abiff M, Bonner M, Saab ST, Choi SH, and Huang AY
- Subjects
- Animals, Mice, Mice, Inbred C57BL, Adaptive Immunity, Cytokines, Tumor Microenvironment, Cryosurgery, Lung Neoplasms
- Abstract
Background: Despite its potential utility in delivering direct tumor killing and in situ whole-cell tumor vaccination, tumor cryoablation produces highly variable and unpredictable clinical response, limiting its clinical utility. The mechanism(s) driving cryoablation-induced local antitumor immunity and the associated abscopal effect is not well understood., Methods: The aim of this study was to identify and explore a mechanism of action by which cryoablation enhances the therapeutic efficacy in metastatic tumor models. We used the subcutaneous mouse model of the rhabdomyosarcoma (RMS) cell lines RMS 76-9
STINGwt or RMS 76-9STING-/- , along with other murine tumor models, in C57BL/6 or STING-/- ( TMEM173-/- ) mice to evaluate local tumor changes, lung metastasis, abscopal effect on distant tumors, and immune cell dynamics in the tumor microenvironment (TME)., Results: The results show that cryoablation efficacy is dependent on both adaptive immunity and the STING signaling pathway. Contrary to current literature dictating an essential role of host-derived STING activation as a driver of antitumor immunity in vivo, we show that local tumor control, lung metastasis, and the abscopal effect on distant tumor are all critically dependent on a functioning tumor cell-intrinsic STING signaling pathway, which induces inflammatory chemokine and cytokine responses in the cryoablated TME. This reliance extends beyond cryoablation to include intratumoral STING agonist therapy. Additionally, surveys of gene expression databases and tissue microarrays of clinical tumor samples revealed a wide spectrum of expressions among STING-related signaling components., Conclusions: Tumor cell-intrinsic STING pathway is a critical component underlying the effectiveness of cryoablation and suggests that expression of STING-related signaling components may serve as a potential therapy response biomarker. Our data also highlight an urgent need to further characterize tumor cell-intrinsic STING pathways and the associated downstream inflammatory response evoked by cryoablation and other STING-dependent therapy approaches., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)- Published
- 2023
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3. Ischial osteochondroma as an unusual source of pregnancy-related sciatic pain: a case report.
- Author
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Trager RJ, Prosak SE, Getty PJ, Barger RL, Saab ST, and Dusek JA
- Subjects
- Adult, Female, Humans, Lumbar Vertebrae, Lumbosacral Region, Pregnancy, Low Back Pain etiology, Low Back Pain therapy, Osteochondroma complications, Osteochondroma diagnostic imaging, Sciatica diagnosis, Sciatica etiology, Sciatica therapy
- Abstract
Background: While most cases of sciatica result from degenerative conditions of the low back, some cases result from conditions of the hip and pelvic region. Sciatica developing in relation to pregnancy or labor also presents unique considerations., Case Presentation: A 37-year-old African American woman with a history of hypertension and polycystic ovary syndrome presented to a chiropractor at a hospital-based outpatient clinic with a seven-week history of low back pain with radiation into the right lower extremity which began during labor. The chiropractor performed a brief trial of care, yet when the patient's symptoms worsened, ordered lumbar spine radiographs, followed by lumbar magnetic resonance imaging (MRI), which were both normal. The chiropractor then ordered hip radiographs, which were suggestive of ischial osteochondroma, and referred the patient to an orthopedic oncologist. MRI findings were compatible with an osteochondroma with associated adventitial bursitis and mass effect on the sciatic nerve. The patient initially chose conservative management with bursa aspiration and therapeutic injection. Despite initial relief, there was eventual return of symptoms. The patient elected to undergo surgical removal, with a positive outcome., Conclusion: The key distinguishing features that led to a diagnosis of osteochondroma in this case included attention to the patient-reported symptoms and history, worsening of symptoms despite conservative care, and lack of explanatory findings on lumbar imaging. This case highlights the benefit of evaluating the hip and pelvis when the clinical features of sciatica cannot be ascribed to a lumbar etiology. This case also illustrates the role of a chiropractor working in an integrative health system to facilitate timely imaging and referrals to resolve a challenging diagnosis., (© 2022. The Author(s).)
- Published
- 2022
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4. Four major patterns of placental injury: a stepwise guide for understanding and implementing the 2016 Amsterdam consensus.
- Author
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Redline RW, Ravishankar S, Bagby CM, Saab ST, and Zarei S
- Subjects
- Consensus Development Conferences as Topic, Female, Humans, Pregnancy, Pathology, Surgical standards, Placenta injuries, Placenta Diseases classification, Placenta Diseases diagnosis
- Abstract
The Amsterdam classification system defines four major patterns of placental injury, maternal vascular malperfusion, fetal vascular malperfusion, acute chorioamnionitis, and villitis of unknown etiology, and lists the histologic findings that characterize each. However, there continues to be uncertainty regarding specific definitions, histologic mimics, grading and staging, and what combination of findings is required to diagnose each pattern of injury in a reproducible fashion. The purpose of this review is to clarify some of these issues by suggesting a stepwise approach to more fully realize the potential of this new classification system. In our view, the critical steps for correctly identifying and communicating each pattern of injury are (1) familiarity with the underlying pathophysiology and known clinical associations, (2) incorporation of important gross findings, (3) learning to recognize underlying architectural alterations and defining features at low power, (4) using higher magnification to narrow the differential diagnosis and assess severity (grading) and duration (staging), and (5) adopting a template for generating standardized placental reports that succinctly provide useful information for patient care and research applications.
- Published
- 2021
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5. A Novel Homozygous Missense Mutation in the YARS Gene: Expanding the Phenotype of YARS Multisystem Disease.
- Author
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Zeiad RKHM, Ferren EC, Young DD, De Lancy SJ, Dedousis D, Schillaci LA, Redline RW, Saab ST, Crespo M, Bhatti TR, Ackermann AM, Bedoyan JK, and Wood JR
- Abstract
Aminoacyl-tRNA synthetases (ARSs) are crucial enzymes for protein translation. Mutations in genes encoding ARSs are associated with human disease. Tyrosyl-tRNA synthetase is encoded by YARS which is ubiquitously expressed and implicated in an autosomal dominant form of Charcot-Marie-Tooth and autosomal recessive YARS- related multisystem disease. We report on a former 34-week gestational age male who presented at 2 months of age with failure to thrive (FTT) and cholestatic hepatitis. He was subsequently diagnosed with hyperinsulinemic hypoglycemia with a negative congenital hyperinsulinism gene panel and F-DOPA positron-emission tomography (PET) scan that did not demonstrate a focal lesion. Autopsy findings were notable for overall normal pancreatic islet size and morphology. Trio whole exome sequencing identified a novel homozygous variant of uncertain significance in YARS (c.611A > C, p.Tyr204Cys) with each parent a carrier for the YARS variant. Euglycemia was maintained with diazoxide (max dose, 18 mg/kg/day), and enteral dextrose via gastrostomy tube (G-Tube). During his prolonged hospitalization, the patient developed progressive liver disease, exocrine pancreatic insufficiency, acute renal failure, recurrent infections, ichthyosis, hematologic concerns, hypotonia, and global developmental delay. Such multisystem features have been previously reported in association with pathogenic YARS mutations. Although hypoglycemia has been associated with pathogenic YARS mutations, this report provides more conclusive data that a YARS variant can cause hyperinsulinemic hypoglycemia. This case expands the allelic and clinical heterogeneity of YARS -related disease. In addition, YARS -related disease should be considered in the differential of hyperinsulinemic hypoglycemia associated with multisystem disease., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society.)
- Published
- 2021
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6. Fibrous hamartoma of infancy: a clinicopathologic analysis of 60 cases.
- Author
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Saab ST, McClain CM, and Coffin CM
- Subjects
- Adipose Tissue chemistry, Adipose Tissue pathology, Adolescent, Age Factors, Biomarkers, Tumor analysis, Biopsy, Child, Child, Preschool, Female, Fibrosis, Hamartoma chemistry, Humans, Immunohistochemistry, Infant, Infant, Newborn, Male, Mesoderm chemistry, Mesoderm pathology, Predictive Value of Tests, Soft Tissue Neoplasms chemistry, Tumor Burden, Hamartoma pathology, Soft Tissue Neoplasms pathology
- Abstract
Fibrous hamartoma of infancy is a benign soft tissue tumor with a characteristic triphasic organoid histologic appearance. It typically occurs within the first 2 years of life. The usual anatomic locations include the upper extremities, axilla, and upper back. Diagnostic challenges occur when this tumor arises in older children, outside of the usual anatomic sites, or when unusual histologic features are encountered. This study reports 60 cases of fibrous hamartoma of infancy from institutional and consultation files. All had a triphasic organoid histologic pattern, but half also displayed an unusual pseudoangiomatous histologic pattern. The male to female ratio was 2.0 (40 boys, 20 girls), with a mean age of 1.5 years (range, 16 d to 8 y) at diagnosis. Tumor size ranged from 0.5 to 9 cm, with a mean of 3.7 cm. Sites included the trunk (40 cases), extremities (17 cases), and head and neck (3 cases). All cases had triphasic elements of mature fibrous tissue, mature adipose tissue, and immature mesenchymal tissue in varying proportions, with the additional pseudoangiomatous pattern in 32 cases. Immunohistochemical analysis demonstrated reactivity for smooth muscle actin and CD34 in the mature fibrous tissue, S100 protein in the mature adipose tissue, and variable CD34 reactivity in immature mesenchymal and pseudoangiomatous foci. Ki-67 proliferative activity was noted in the immature mesenchymal and pseudoangiomatous foci, and Bcl-2 reactivity was restricted to mesenchymal and pseudoangiomatous foci. Follow-up information in 12 cases revealed no evidence of recurrence in 10 patients and local recurrence in 2 patients, each at 3.5 years after primary excision. This study demonstrates an expanded age range (up to 8 y) and anatomic distribution (30 cases outside of the classic locations of the upper extremities, axilla, and upper back) of fibrous hamartoma of infancy. The pseudoangiomatous morphologic variation can lead to challenges in diagnosis and may reflect a maturational phenomenon from the immature mesenchymal component.
- Published
- 2014
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7. RAMP1 is a direct NKX3.1 target gene up-regulated in prostate cancer that promotes tumorigenesis.
- Author
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Logan M, Anderson PD, Saab ST, Hameed O, and Abdulkadir SA
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- Animals, Carcinogenesis genetics, Cell Line, Tumor, Cell Proliferation, Down-Regulation, Gene Expression Regulation, Neoplastic, Gene Knockdown Techniques, Genes, Neoplasm, Humans, MAP Kinase Signaling System, Male, Mice, Mice, Nude, Prostate metabolism, Prostate pathology, Prostatic Neoplasms enzymology, Protein Binding genetics, Receptor Activity-Modifying Protein 1 metabolism, Carcinogenesis pathology, Homeodomain Proteins metabolism, Prostatic Neoplasms genetics, Prostatic Neoplasms pathology, Receptor Activity-Modifying Protein 1 genetics, Transcription Factors metabolism, Up-Regulation genetics
- Abstract
The homeodomain-containing transcription factor, NKX3.1, plays an important role in the suppression of prostate tumorigenesis. Herein, we identify the receptor activity-modifying protein 1 (RAMP1) as a direct NKX3.1 target gene through analysis of chromatin immunoprecipitation coupled to massively parallel sequencing and gene expression data. RAMP1 is a coreceptor for certain G-protein-coupled receptors, such as the calcitonin gene-related peptide receptor, to the plasma membrane. We found that RAMP1 expression is specifically elevated in human prostate cancer relative to other tumor types. Furthermore, RAMP1 mRNA and protein levels are significantly higher in human prostate cancer compared with benign glands. We identified multiple NKX3.1 binding sites in the RAMP1 locus in human prostate cancer cells and in the normal mouse prostate. Analyses of Nkx3.1 knockout mice and human prostate cancer cell lines indicate that NKX3.1 represses RAMP1 expression. Knockdown of RAMP1 by shRNA decreased prostate cancer cell proliferation and tumorigenicity in vitro and in vivo. By using gene expression profiling and pathway analyses, we identified several cancer-related pathways that are significantly altered in RAMP1 knockdown cells, including the mitogen-activated protein kinase signaling pathway. Further experiments confirmed a reduction in MAP2KI (MEK1) expression and phosphorylated-extracellular signal-regulated kinase 1/2 levels in RAMP1 knockdown cells. These data provide novel insights into the role of RAMP1 in promoting prostate tumorigenesis and support the potential of RAMP1 as a novel biomarker and possible therapeutic target in prostate cancer., (Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2013
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8. IgG4 plasma cells in inflammatory myofibroblastic tumor: inflammatory marker or pathogenic link?
- Author
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Saab ST, Hornick JL, Fletcher CD, Olson SJ, and Coffin CM
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- Adolescent, Adult, Anaplastic Lymphoma Kinase, Biomarkers analysis, Child, Child, Preschool, Diagnosis, Differential, Female, Granuloma, Plasma Cell pathology, Humans, Immunohistochemistry, Infant, Male, Myofibroblasts pathology, Plasma Cells pathology, Predictive Value of Tests, Receptor Protein-Tyrosine Kinases analysis, Scleroderma, Systemic pathology, Young Adult, Granuloma, Plasma Cell immunology, Immunoglobulin G analysis, Myofibroblasts immunology, Plasma Cells immunology, Scleroderma, Systemic immunology
- Abstract
Inflammatory myofibroblastic tumor is a rare mesenchymal neoplasm that harbors an anaplastic lymphoma kinase (ALK) gene rearrangement in the majority of cases. It is composed of fibroblastic-myofibroblastic cells with a characteristic inflammatory infiltrate that consists predominantly of plasma cells. In contrast, IgG4-related sclerosing disease is a recently described multisystem disorder with a histological appearance similar to inflammatory myofibroblastic tumor. The plasma cell infiltrate is characteristic in IgG4-related sclerosing disease and has been studied as a tool to render this diagnosis. Histologically, the two disorders overlap, although there are significant clinical differences. This study analyzes the histological appearance of 36 inflammatory myofibroblastic tumors, compares them with IgG4-related sclerosing disease, and assesses the plasma cell profile using immunohistochemistry to determine the range and proportion of IgG4 plasma cells. The majority of patients were children and young adults, mainly with solitary masses and no clinical manifestations of IgG4-related sclerosing disease. ALK-1 positivity was present in 23 cases (64%). None showed obliterative phlebitis or prominent lymphoid aggregates. Of 36 inflammatory myofibroblastic tumors, 15 cases showed an IgG4/IgG ratio ≥0.10, a cutoff described in the literature as supportive of IgG4-related sclerosing disease and up to 33 IgG4-positive plasma cells per high-power field indicating a mild-to-moderate increase as compared with IgG4-related sclerosing disease. Currently, the diagnostic recognition of inflammatory myofibroblastic tumor is based on clinicopathological features and diagnostic adjuncts, such as ALK-1 reactivity and genetic tests. Although inflammatory myofibroblastic tumor and IgG4-related sclerosing disease are distinct entities, a subset of inflammatory myofibroblastic tumors exhibit an IgG4/IgG ratio that is within the range for IgG4-related sclerosing disease. Therefore, the ratio alone cannot be used as a reliable discriminator between these two entities and other clinical and pathologic features must always be taken into account.
- Published
- 2011
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9. Therapy-induced selective loss of leukemia-initiating activity in murine adult T cell leukemia.
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El Hajj H, El-Sabban M, Hasegawa H, Zaatari G, Ablain J, Saab ST, Janin A, Mahfouz R, Nasr R, Kfoury Y, Nicot C, Hermine O, Hall W, de Thé H, and Bazarbachi A
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- Animals, Arsenic Trioxide, Arsenicals administration & dosage, Cell Cycle drug effects, Gene Products, tax genetics, Human T-lymphotropic virus 1 genetics, Humans, In Situ Nick-End Labeling, Interferon-alpha administration & dosage, Leukemia-Lymphoma, Adult T-Cell pathology, Leukemia-Lymphoma, Adult T-Cell virology, Mice, Mice, SCID, Mice, Transgenic, Organ Size drug effects, Oxides administration & dosage, Reverse Transcriptase Polymerase Chain Reaction, Spleen drug effects, Spleen metabolism, Spleen pathology, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Apoptosis drug effects, Human T-lymphotropic virus 1 drug effects, Leukemia-Lymphoma, Adult T-Cell drug therapy
- Abstract
Chronic HTLV-I (human T cell lymphotropic virus type I) infection may cause adult T cell leukemia/lymphoma (ATL), a disease with dismal long-term prognosis. The HTLV-I transactivator, Tax, initiates ATL in transgenic mice. In this study, we demonstrate that an As(2)O(3) and IFN-α combination, known to trigger Tax proteolysis, cures Tax-driven ATL in mice. Unexpectedly, this combination therapy abrogated initial leukemia engraftment into secondary recipients, whereas the primary tumor bulk still grew in the primary hosts, only to ultimately abate later on. This loss of initial transplantability required proteasome function. A similar regimen recently yielded unprecedented disease control in human ATL. Our demonstration that this drug combination targeting Tax stability abrogates tumor cell immortality but not short-term growth may foretell a favorable long-term efficiency of this regimen in patients.
- Published
- 2010
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