22 results on '"Flashner S"'
Search Results
2. Lactate Suppresses Growth of Esophageal Adenocarcinoma Patient-Derived Organoids through Alterations in Tumor NADH/NAD+ Redox State.
- Author
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Su SH, Mitani Y, Li T, Sachdeva U, Flashner S, Klein-Szanto A, Dunbar KJ, Abrams J, Nakagawa H, and Gabre J
- Subjects
- Humans, Glycolysis drug effects, Barrett Esophagus metabolism, Barrett Esophagus pathology, Tumor Microenvironment, Esophageal Neoplasms metabolism, Esophageal Neoplasms pathology, Adenocarcinoma metabolism, Adenocarcinoma pathology, Oxidation-Reduction, Organoids metabolism, Organoids drug effects, NAD metabolism, Lactic Acid metabolism, Cell Proliferation drug effects
- Abstract
Barrett's esophagus (BE) is a common precancerous lesion that can progress to esophageal adenocarcinoma (EAC). There are significant alterations in the esophageal microbiome in the progression from healthy esophagus to BE to EAC, including an increased abundance of a variety of lactate-producing bacteria and an increase of lactate in the tumor microenvironment, as predicted by metabolic modeling. The role of bacterial lactate in EAC is unknown. Here, we utilize patient-derived organoid (PDO) models of EAC and demonstrate that lactate inhibits the growth and proliferation of EAC PDOs through alterations in the tumor NADH/NAD+ redox state. Further RNA sequencing of EAC PDOs identifies ID1 and RSAD2 as potential regulatory molecules crucial in mediating lactate's ability to suppress glycolysis and proliferation. Gene ontology analysis also identifies the activation of inflammatory and immunological pathways in addition to alterations in the metabolic pathways in EAC PDOs exposed to lactate, suggesting a multi-faceted role for lactate in the pathogenesis of EAC.
- Published
- 2024
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3. Modeling Epithelial Homeostasis and Perturbation in Three-Dimensional Human Esophageal Organoids.
- Author
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Shimonosono M, Morimoto M, Hirose W, Tomita Y, Matsuura N, Flashner S, Ebadi MS, Okayasu EH, Lee CY, Britton WR, Martin C, Wuertz BR, Parikh AS, Sachdeva UM, Ondrey FG, Atigadda VR, Elmets CA, Abrams JA, Muir AB, Klein-Szanto AJ, Weinberg KI, Momen-Heravi F, and Nakagawa H
- Subjects
- Humans, Epidermal Growth Factor pharmacology, Epidermal Growth Factor metabolism, Keratinocytes metabolism, Keratinocytes drug effects, Keratinocytes cytology, Signal Transduction drug effects, Epithelial Cells metabolism, Epithelial Cells drug effects, Models, Biological, Cell Line, Cell Proliferation drug effects, Receptors, Transforming Growth Factor beta metabolism, Organoids drug effects, Organoids metabolism, Esophagus metabolism, Esophagus pathology, Esophagus drug effects, Homeostasis
- Abstract
Background: Esophageal organoids from a variety of pathologies including cancer are grown in Advanced Dulbecco's Modified Eagle Medium-Nutrient Mixture F12 (hereafter ADF). However, the currently available ADF-based formulations are suboptimal for normal human esophageal organoids, limiting the ability to compare normal esophageal organoids with those representing a given disease state. Methods: We have utilized immortalized normal human esophageal epithelial cell (keratinocyte) lines EPC1 and EPC2 and endoscopic normal esophageal biopsies to generate three-dimensional (3D) organoids. To optimize the ADF-based medium, we evaluated the requirement of exogenous epidermal growth factor (EGF) and inhibition of transforming growth factor-(TGF)-β receptor-mediated signaling, both key regulators of the proliferation of human esophageal keratinocytes. We have modeled human esophageal epithelial pathology by stimulating esophageal 3D organoids with interleukin (IL)-13, an inflammatory cytokine, or UAB30, a novel pharmacological activator of retinoic acid signaling. Results: The formation of normal human esophageal 3D organoids was limited by excessive EGF and intrinsic TGFβ-receptor-mediated signaling. Optimized HOME0 improved normal human esophageal organoid formation. In the HOME0-grown organoids, IL-13 and UAB30 induced epithelial changes reminiscent of basal cell hyperplasia, a common histopathologic feature in broad esophageal disease conditions including eosinophilic esophagitis. Conclusions: HOME0 allows modeling of the homeostatic differentiation gradient and perturbation of the human esophageal epithelium while permitting a comparison of organoids from mice and other organs grown in ADF-based media.
- Published
- 2024
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4. Cancer-associated DNA hypermethylation of Polycomb targets requires DNMT3A dual recognition of histone H2AK119 ubiquitination and the nucleosome acidic patch.
- Author
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Gretarsson KH, Abini-Agbomson S, Gloor SL, Weinberg DN, McCuiston JL, Kumary VUS, Hickman AR, Sahu V, Lee R, Xu X, Lipieta N, Flashner S, Adeleke OA, Popova IK, Taylor HF, Noll K, Windham CL, Maryanski DN, Venters BJ, Nakagawa H, Keogh MC, Armache KJ, and Lu C
- Subjects
- Humans, Polycomb-Group Proteins metabolism, Polycomb-Group Proteins genetics, Promoter Regions, Genetic, Cryoelectron Microscopy, Cell Line, Tumor, DNA Methylation, DNA Methyltransferase 3A, Nucleosomes metabolism, Histones metabolism, DNA (Cytosine-5-)-Methyltransferases metabolism, DNA (Cytosine-5-)-Methyltransferases genetics, Ubiquitination, CpG Islands, Protein Binding, Neoplasms genetics, Neoplasms metabolism, Neoplasms pathology
- Abstract
During tumor development, promoter CpG islands that are normally silenced by Polycomb repressive complexes (PRCs) become DNA-hypermethylated. The molecular mechanism by which de novo DNA methyltransferase(s) [DNMT(s)] catalyze CpG methylation at PRC-regulated regions remains unclear. Here, we report a cryo-electron microscopy structure of the DNMT3A long isoform (DNMT3A1) amino-terminal region in complex with a nucleosome carrying PRC1-mediated histone H2A lysine-119 monoubiquitination (H2AK119Ub). We identify regions within the DNMT3A1 amino terminus that bind H2AK119Ub and the nucleosome acidic patch. This bidentate interaction is required for effective DNMT3A1 engagement with H2AK119Ub-modified chromatin in cells. Further, aberrant redistribution of DNMT3A1 to Polycomb target genes recapitulates the cancer-associated DNA hypermethylation signature and inhibits their transcriptional activation during cell differentiation. This effect is rescued by disruption of the DNMT3A1-acidic patch interaction. Together, our analyses reveal a binding interface critical for mediating promoter CpG island DNA hypermethylation, a major molecular hallmark of cancer.
- Published
- 2024
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5. Epithelial overexpression of IL-33 induces eosinophilic esophagitis dependent on IL-13.
- Author
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Masuda MY, Pyon GC, Luo H, LeSuer WE, Putikova A, Dao A, Ortiz DR, Schulze AR, Fritz N, Kobayashi T, Iijima K, Klein-Szanto AJ, Shimonosono M, Flashner S, Morimoto M, Pai RK, Rank MA, Nakagawa H, Kita H, Wright BL, and Doyle AD
- Subjects
- Animals, Humans, Mice, Disease Models, Animal, Eosinophils immunology, Esophageal Mucosa pathology, Esophageal Mucosa immunology, Esophagus pathology, Esophagus immunology, Interleukin-1 Receptor-Like 1 Protein genetics, Interleukin-1 Receptor-Like 1 Protein metabolism, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Eosinophilic Esophagitis immunology, Eosinophilic Esophagitis genetics, Eosinophilic Esophagitis pathology, Interleukin-13 genetics, Interleukin-13 immunology, Interleukin-13 metabolism, Interleukin-33 genetics, Interleukin-33 immunology, Interleukin-33 metabolism
- Abstract
Background: Eosinophilic esophagitis (EoE) is an increasingly common inflammatory condition of the esophagus; however, the underlying immunologic mechanisms remain poorly understood. The epithelium-derived cytokine IL-33 is associated with type 2 immune responses and elevated in esophageal biopsy specimens from patients with EoE., Objective: We hypothesized that overexpression of IL-33 by the esophageal epithelium would promote the immunopathology of EoE., Methods: We evaluated the functional consequences of esophageal epithelial overexpression of a secreted and active form of IL-33 in a novel transgenic mouse, EoE33. EoE33 mice were analyzed for clinical and immunologic phenotypes. Esophageal contractility was assessed. Epithelial cytokine responses were analyzed in three-dimensional organoids. EoE33 phenotypes were further characterized in ST2
-/- , eosinophil-deficient, and IL-13-/- mice. Finally, EoE33 mice were treated with dexamethasone., Results: EoE33 mice displayed ST2-dependent, EoE-like pathology and failed to thrive. Esophageal tissue remodeling and inflammation included basal zone hyperplasia, eosinophilia, mast cells, and TH 2 cells. Marked increases in levels of type 2 cytokines, including IL-13, and molecules associated with immune responses and tissue remodeling were observed. Esophageal organoids suggested reactive epithelial changes. Genetic deletion of IL-13 in EoE33 mice abrogated pathologic changes in vivo. EoE33 mice were responsive to steroids., Conclusions: IL-33 overexpression by the esophageal epithelium generated immunopathology and clinical phenotypes resembling human EoE. IL-33 may play a pivotal role in the etiology of EoE by activating the IL-13 pathway. EoE33 mice are a robust experimental platform for mechanistic investigation and translational discovery., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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6. ALDH2 dysfunction and alcohol cooperate in cancer stem cell enrichment.
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Flashner S, Shimonosono M, Tomita Y, Matsuura N, Ohashi S, Muto M, Klein-Szanto AJ, Alan Diehl J, Chen CH, Mochly-Rosen D, Weinberg KI, and Nakagawa H
- Subjects
- Humans, Mice, Animals, Aldehyde Dehydrogenase genetics, Aldehyde Dehydrogenase metabolism, Risk Factors, Alcohol Drinking genetics, Cisplatin pharmacology, Aldehyde Dehydrogenase, Mitochondrial genetics, Ethanol metabolism, Acetaldehyde metabolism, Cell Transformation, Neoplastic, Neoplastic Stem Cells pathology, Alcohol Dehydrogenase genetics, Esophageal Squamous Cell Carcinoma genetics, Esophageal Neoplasms pathology
- Abstract
The alcohol metabolite acetaldehyde is a potent human carcinogen linked to esophageal squamous cell carcinoma (ESCC) initiation and development. Aldehyde dehydrogenase 2 (ALDH2) is the primary enzyme that detoxifies acetaldehyde in the mitochondria. Acetaldehyde accumulation causes genotoxic stress in cells expressing the dysfunctional ALDH2E487K dominant negative mutant protein linked to ALDH2*2, the single nucleotide polymorphism highly prevalent among East Asians. Heterozygous ALDH2*2 increases the risk for the development of ESCC and other alcohol-related cancers. Despite its prevalence and link to malignant transformation, how ALDH2 dysfunction influences ESCC pathobiology is incompletely understood. Herein, we characterize how ESCC and preneoplastic cells respond to alcohol exposure using cell lines, three-dimensional organoids and xenograft models. We find that alcohol exposure and ALDH2*2 cooperate to increase putative ESCC cancer stem cells with high CD44 expression (CD44H cells) linked to tumor initiation, repopulation and therapy resistance. Concurrently, ALHD2*2 augmented alcohol-induced reactive oxygen species and DNA damage to promote apoptosis in the non-CD44H cell population. Pharmacological activation of ALDH2 by Alda-1 inhibits this phenotype, suggesting that acetaldehyde is the primary driver of these changes. Additionally, we find that Aldh2 dysfunction affects the response to cisplatin, a chemotherapeutic commonly used for the treatment of ESCC. Aldh2 dysfunction facilitated enrichment of CD44H cells following cisplatin-induced oxidative stress and cell death in murine organoids, highlighting a potential mechanism driving cisplatin resistance. Together, these data provide evidence that ALDH2 dysfunction accelerates ESCC pathogenesis through enrichment of CD44H cells in response to genotoxic stressors such as environmental carcinogens and chemotherapeutic agents., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
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7. Experimental Modeling of Host-Bacterial Interactions in Head and Neck Squamous Cell Carcinoma.
- Author
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Okolo O, Honzel E, Britton WR, Yu VX, Flashner S, Martin C, Nakagawa H, and Parikh AS
- Abstract
The microscopic species colonizing the human body, collectively referred to as the microbiome, play a crucial role in the maintenance of tissue homeostasis, immunity, and the development of disease. There is evidence to suggest associations between alterations in the microbiome and the development of head and neck squamous cell carcinomas (HNSCC). The use of two-dimensional (2D) modeling systems has made significant strides in uncovering the role of microbes in carcinogenesis; however, direct mechanistic links remain in their infancy. Patient-derived three-dimensional (3D) HNSCC organoid and organotypic models have recently been described. Compared to 2D models, 3D organoid culture systems effectively capture the genetic and epigenetic features of parent tissue in a patient-specific manner and may offer a more nuanced understanding of the role of host-microbe responses in carcinogenesis. This review provides a topical literature review assessing the current state of the field investigating the role of the microbiome in HNSCC; including in vivo and in vitro modeling methods that may be used to characterize microbiome-epithelial interactions.
- Published
- 2023
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8. Protocol for tumor dissociation and fluorescence-activated cell sorting of human head and neck cancers.
- Author
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Okolo O, Yu V, Flashner S, Martin C, Nakagawa H, Lin DT, Puram SV, and Parikh AS
- Abstract
Tumors originating from the head and neck represent diverse histologies and are comprised of several cell types, including malignant cells, cancer-associated fibroblasts, endothelial cells, and immune cells. In this protocol, we describe a step-by-step approach for the dissociation of fresh human head and neck tumor specimens, followed by isolation of viable single cells using fluorescence-activated cell sorting. Our protocol facilitates the effective downstream use of techniques, including single-cell RNA sequencing and generation of three-dimensional patient-derived organoids. For complete details on the use and execution of this protocol, please refer to Puram et al. (2017)
1 and Parikh et al. (2022).2 ., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)- Published
- 2023
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9. Patient-derived three-dimensional culture techniques model tumor heterogeneity in head and neck cancer.
- Author
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Parikh AS, Yu VX, Flashner S, Okolo OB, Lu C, Henick BS, Momen-Heravi F, Puram SV, Teknos T, Pan Q, and Nakagawa H
- Subjects
- Humans, Squamous Cell Carcinoma of Head and Neck pathology, Culture Techniques, Organoids pathology, Stromal Cells, Tumor Microenvironment, Head and Neck Neoplasms pathology
- Abstract
Head and neck squamous cell carcinoma (HNSCC) outcomes remain stagnant, in part due to a poor understanding of HNSCC biology. The importance of tumor heterogeneity as an independent predictor of outcomes and treatment failure in HNSCC has recently come to light. With this understanding, 3D culture systems, including patient derived organoids (PDO) and organotypic culture (OTC), that capture this heterogeneity may allow for modeling and manipulation of critical subpopulations, such as p-EMT, as well as interactions between cancer cells and immune and stromal cells in the microenvironment. Here, we review work that has been done using PDO and OTC models of HNSCC, which demonstrates that these 3D culture models capture in vivo tumor heterogeneity and can be used to model tumor biology and treatment response in a way that faithfully recapitulates in vivo characteristics. As such, in vitro 3D culture models represent an important bridge between 2D monolayer culture and in vivo models such as patient derived xenografts., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: B.S.H. is advisor/consultant to AstraZeneca, Ideaya, Jazz Pharmaceuticals, Sorrento Therapeutics, Genentech-Roche, OncLive, Veeva, Athenium, Boxer, Dava Oncology., (Copyright © 2023. Published by Elsevier Ltd.)
- Published
- 2023
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10. Detergent exposure induces epithelial barrier dysfunction and eosinophilic inflammation in the esophagus.
- Author
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Doyle AD, Masuda MY, Pyon GC, Luo H, Putikova A, LeSuer WE, Flashner S, Rank MA, Nakagawa H, Kita H, and Wright BL
- Subjects
- Animals, Mice, Epithelial Cells metabolism, Hyperplasia pathology, Inflammation metabolism, Interleukin-33 metabolism, Detergents adverse effects, Eosinophilic Esophagitis
- Abstract
Background: Eosinophilic esophagitis (EoE) is a chronic allergic disease associated with type 2 inflammation and epithelial barrier dysfunction. The etiology is unknown, however, genetic heritability studies suggest environmental factors play a key role in pathogenesis. Detergents, such as sodium dodecyl sulfate (SDS), are common ingredients in household products such as dish soap and toothpaste. We hypothesized detergent exposure decreases epithelial barrier function and induces esophageal inflammation., Methods: Immortalized esophageal epithelial cells (EPC2) were cultured in air-liquid interface (ALI) and exposed to SDS. Barrier function/activity was assessed by transepithelial electrical resistance (TEER), FITC-dextran flux, and RT-PCR. Additionally, SDS-treated mouse esophageal organoids were evaluated for morphology. To investigate the effects of SDS in vivo, mice were treated with 0.5% SDS in drinking water for 14 days. Esophagi were assessed by gross morphology, histopathology, protein expression, and bulk RNA sequencing., Results: When EPC2 cells were exposed to SDS (5 μg/ml) for 96 h, TEER decreased (p = 0.03), and FITC-dextran flux increased (p = 0.0002). mRNA expression of IL-33 increased 4.5-fold (p = 0.02) at 6 h and DSG1 decreased (p < 0.0001) by 72 h. Disrupted epithelial integrity was noted in SDS-treated esophageal organoids. When mice were exposed to SDS, they showed increased esophageal width, chemokine, and metalloprotease levels. Mice treated with SDS also showed increased IL-33 protein expression, basal zone hyperplasia, CD4
+ cell infiltration, and esophageal eosinophilia. RNA sequencing revealed upregulation of immune response pathway genes., Conclusion: Exposure to SDS decreases esophageal barrier integrity, stimulates IL-33 production, and promotes epithelial hyperplasia and tissue eosinophilia. Detergents may be a key environmental trigger in EoE pathogenesis., (© 2022 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)- Published
- 2023
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11. Modeling Oral-Esophageal Squamous Cell Carcinoma in 3D Organoids.
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Flashner S, Martin C, Matsuura N, Shimonosono M, Tomita Y, Morimoto M, Okolo O, Yu VX, Parikh AS, Klein-Szanto AJP, Yan K, Gabre JT, Lu C, Momen-Heravi F, Rustgi AK, and Nakagawa H
- Subjects
- Humans, Mice, Animals, Squamous Cell Carcinoma of Head and Neck, Organoids metabolism, Cell Line, Tumor, Cell Proliferation, Esophageal Squamous Cell Carcinoma, Esophageal Neoplasms pathology, Carcinoma, Squamous Cell pathology, Mouth Neoplasms, Head and Neck Neoplasms
- Abstract
Esophageal squamous cell carcinoma (ESCC) is prevalent worldwide, accounting for 90% of all esophageal cancer cases each year, and is the deadliest of all human squamous cell carcinomas. Despite recent progress in defining the molecular changes accompanying ESCC initiation and development, patient prognosis remains poor. The functional annotation of these molecular changes is the necessary next step and requires models that both capture the molecular features of ESCC and can be readily and inexpensively manipulated for functional annotation. Mice treated with the tobacco smoke mimetic 4-nitroquinoline 1-oxide (4NQO) predictably form ESCC and esophageal preneoplasia. Of note, 4NQO lesions also arise in the oral cavity, most commonly in the tongue, as well as the forestomach, which all share the stratified squamous epithelium. However, these mice cannot be simply manipulated for functional hypothesis testing, as generating isogenic mouse models is time- and resource-intensive. Herein, we overcome this limitation by generating single cell-derived three-dimensional (3D) organoids from mice treated with 4NQO to characterize murine ESCC or preneoplastic cells ex vivo. These organoids capture the salient features of ESCC and esophageal preneoplasia, can be cheaply and quickly leveraged to form isogenic models, and can be utilized for syngeneic transplantation experiments. We demonstrate how to generate 3D organoids from normal, preneoplastic, and SCC murine esophageal tissue and maintain and cryopreserve these organoids. The applications of these versatile organoids are broad and include the utilization of genetically engineered mice and further characterization by flow cytometry or immunohistochemistry, the generation of isogeneic organoid lines using CRISPR technologies, and drug screening or syngeneic transplantation. We believe that the widespread adoption of the techniques demonstrated in this protocol will accelerate progress in this field to combat the severe burden of ESCC.
- Published
- 2022
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12. Tumor suppressor mediated ubiquitylation of hnRNPK is a barrier to oncogenic translation.
- Author
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Mucha B, Qie S, Bajpai S, Tarallo V, Diehl JN, Tedeschi F, Zhou G, Gao Z, Flashner S, Klein-Szanto AJ, Hibshoosh H, Masataka S, Chajewski OS, Majsterek I, Pytel D, Hatzoglou M, Der CJ, Nakagawa H, Bass AJ, Wong KK, Fuchs SY, Rustgi AK, Jankowsky E, and Diehl JA
- Subjects
- Humans, Ubiquitination, RNA-Binding Proteins genetics, RNA-Binding Proteins metabolism, Oncogenes, RNA, Messenger metabolism, Heterogeneous-Nuclear Ribonucleoprotein K genetics, Heterogeneous-Nuclear Ribonucleoprotein K metabolism, Carcinogenesis genetics
- Abstract
Heterogeneous Nuclear Ribonucleoprotein K (hnRNPK) is a multifunctional RNA binding protein (RBP) localized in the nucleus and the cytoplasm. Abnormal cytoplasmic enrichment observed in solid tumors often correlates with poor clinical outcome. The mechanism of cytoplasmic redistribution and ensuing functional role of cytoplasmic hnRNPK remain unclear. Here we demonstrate that the SCF
Fbxo4 E3 ubiquitin ligase restricts the pro-oncogenic activity of hnRNPK via K63 linked polyubiquitylation, thus limiting its ability to bind target mRNA. We identify SCFFbxo4 -hnRNPK responsive mRNAs whose products regulate cellular processes including proliferation, migration, and invasion. Loss of SCFFbxo4 leads to enhanced cell invasion, migration, and tumor metastasis. C-Myc was identified as one target of SCFFbxo4 -hnRNPK. Fbxo4 loss triggers hnRNPK-dependent increase in c-Myc translation, thereby contributing to tumorigenesis. Increased c-Myc positions SCFFbxo4 -hnRNPK dysregulated cancers for potential therapeutic interventions that target c-Myc-dependence. This work demonstrates an essential role for limiting cytoplasmic hnRNPK function in order to maintain translational and cellular homeostasis., (© 2022. The Author(s).)- Published
- 2022
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13. Transcription factor Sp1 regulates mitotic chromosome assembly and segregation.
- Author
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Flashner S, Swift M, Sowash A, Fahmy AN, and Azizkhan-Clifford J
- Subjects
- Aneuploidy, Animals, Centromere, Humans, Mammals genetics, Transcription Factors genetics, Chromosome Segregation, Mitosis, Sp1 Transcription Factor genetics
- Abstract
Aneuploidy is a pervasive feature of cancer cells that results from chromosome missegregation. Several transcription factors have been associated with aneuploidy; however, no studies to date have demonstrated that mammalian transcription factors directly regulate chromosome segregation during mitosis. Here, we demonstrate that the ubiquitously expressed transcription factor specificity protein 1 (Sp1), which we have previously linked to aneuploidy, has a mitosis-specific role regulating chromosome segregation. We find that Sp1 localizes to mitotic centromeres and auxin-induced rapid Sp1 degradation at mitotic onset results in chromosome segregation errors and aberrant mitotic progression. Furthermore, rapid Sp1 degradation results in anomalous mitotic chromosome assembly characterized by loss of condensin complex I localization to mitotic chromosomes and chromosome condensation defects. Consistent with these defects, Sp1 degradation results in reduced chromosome passenger complex activity and histone H3 serine 10 phosphorylation during mitosis, which is essential for condensin complex I recruitment and chromosome condensation. Together, these data provide the first evidence of a mammalian transcription factor acting specifically during mitosis to regulate chromosome segregation., (© 2022. The Author(s).)
- Published
- 2022
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14. 3D Organoids: An Untapped Platform for Studying Host-Microbiome Interactions in Esophageal Cancers.
- Author
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Flashner S, Yan KS, and Nakagawa H
- Abstract
The microbiome is an emerging key co-factor in the development of esophageal cancer, the sixth leading cause of cancer death worldwide. However, there is a paucity of data delineating how the microbiome contributes to the pathobiology of the two histological subtypes of esophageal cancer: esophageal squamous cell carcinoma and esophageal adenocarcinoma. This critical knowledge gap is partially due to inadequate modeling of host-microbiome interactions in the etiology of esophageal cancers. Recent advances have enabled progress in this field. Three dimensional (3D) organoids faithfully recapitulate the structure and function of the normal, preneoplastic, and neoplastic epithelia of the esophagus ex vivo and serve as a platform translatable for applications in precision medicine. Elsewhere in the gastrointestinal (GI) tract, the co-culture of 3D organoids with the bacterial microbiome has fostered insight into the pathogenic role of the microbiome in other GI cancers. Herein, we will summarize our current understanding of the relationship between the microbiome and esophageal cancer, discuss 3D organoid models of esophageal homeostasis, review analogous models of host-microbiome interactions in other GI cancers, and advocate for the application of these models to esophageal cancers. Together, we present a promising, novel approach with the potential to ameliorate the burden of esophageal cancer-related morbidity and mortality via improved prevention and therapeutic interventions.
- Published
- 2021
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15. Alcohol Metabolism Enriches Squamous Cell Carcinoma Cancer Stem Cells That Survive Oxidative Stress via Autophagy.
- Author
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Shimonosono M, Tanaka K, Flashner S, Takada S, Matsuura N, Tomita Y, Sachdeva UM, Noguchi E, Sangwan V, Ferri L, Momen-Heravi F, Yoon AJ, Klein-Szanto AJ, Diehl JA, and Nakagawa H
- Subjects
- Alcohol Drinking metabolism, Animals, Apoptosis, Cell Line, Tumor, Cell Proliferation, Cell Survival, Humans, Hyaluronan Receptors metabolism, Membrane Potential, Mitochondrial, Mice, SCID, Mitochondria metabolism, Organoids pathology, Oxidation-Reduction, Mice, Autophagy, Carcinoma, Squamous Cell metabolism, Carcinoma, Squamous Cell pathology, Ethanol metabolism, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Oxidative Stress
- Abstract
Background: Alcohol (ethanol) consumption is a major risk factor for head and neck and esophageal squamous cell carcinomas (SCCs). However, how ethanol (EtOH) affects SCC homeostasis is incompletely understood., Methods: We utilized three-dimensional (3D) organoids and xenograft tumor transplantation models to investigate how EtOH exposure influences intratumoral SCC cell populations including putative cancer stem cells defined by high CD44 expression (CD44H cells)., Results: Using 3D organoids generated from SCC cell lines, patient-derived xenograft tumors, and patient biopsies, we found that EtOH is metabolized via alcohol dehydrogenases to induce oxidative stress associated with mitochondrial superoxide generation and mitochondrial depolarization, resulting in apoptosis of the majority of SCC cells within organoids. However, CD44H cells underwent autophagy to negate EtOH-induced mitochondrial dysfunction and apoptosis and were subsequently enriched in organoids and xenograft tumors when exposed to EtOH. Importantly, inhibition of autophagy increased EtOH-mediated apoptosis and reduced CD44H cell enrichment, xenograft tumor growth, and organoid formation rate., Conclusions: This study provides mechanistic insights into how EtOH may influence SCC cells and establishes autophagy as a potential therapeutic target for the treatment of EtOH-associated SCC.
- Published
- 2021
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16. Understanding the cellular origin and progression of esophageal cancer using esophageal organoids.
- Author
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Sachdeva UM, Shimonosono M, Flashner S, Cruz-Acuña R, Gabre JT, and Nakagawa H
- Subjects
- Adenocarcinoma genetics, Adenocarcinoma metabolism, Animals, Cell Communication, Cell Culture Techniques, Cell Transformation, Neoplastic genetics, Cell Transformation, Neoplastic metabolism, Cell Transformation, Neoplastic pathology, Esophageal Neoplasms genetics, Esophageal Neoplasms metabolism, Esophageal Squamous Cell Carcinoma genetics, Esophageal Squamous Cell Carcinoma metabolism, Gene Expression Regulation, Neoplastic, Humans, Mice, Neoplastic Stem Cells metabolism, Organoids, Phenotype, Precancerous Conditions genetics, Precancerous Conditions metabolism, Signal Transduction, Tumor Cells, Cultured, Tumor Microenvironment, Adenocarcinoma pathology, Cell Lineage, Esophageal Neoplasms pathology, Esophageal Squamous Cell Carcinoma pathology, Neoplastic Stem Cells pathology, Precancerous Conditions pathology
- Abstract
Three-dimensional (3D) organoids are a novel tool to model epithelial cell biology and human diseases of the esophagus. 3D organoid culture systems have been utilized to investigate the pathobiology of esophageal cancer, including both squamous cell carcinoma and adenocarcinoma. Additional organoid-based approaches for study of esophageal development and benign esophageal diseases have provided key insights into esophageal keratinocyte differentiation and mucosal regeneration. These investigations have implications for the identification of esophageal cancer stem cells, as well as the potential to halt malignant progression through induction of differentiation pathways. Patient-derived organoids (PDOs) from human tissue samples allow for unique and faithful in vitro modeling of esophageal cancers, and provide an exciting platform for investigation into personalized medicine and targeted treatment approaches, as well as new models for understanding therapy resistance and recurrent disease. Future directions include high-throughput genomic screening using PDOs, and study of tumor-microenvironmental interactions through co-culture with immune and stromal cells and novel extracellular matrix complexes., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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17. DSB repair pathway choice is regulated by recruitment of 53BP1 through cell cycle-dependent regulation of Sp1.
- Author
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Swift ML, Beishline K, Flashner S, and Azizkhan-Clifford J
- Subjects
- Cell Line, Tumor, Cyclin A metabolism, Cyclin-Dependent Kinase 2 metabolism, Humans, Phosphorylation, Cell Cycle, DNA Breaks, Double-Stranded, DNA End-Joining Repair, Sp1 Transcription Factor metabolism, Tumor Suppressor p53-Binding Protein 1 metabolism
- Abstract
Although many of the factors, epigenetic changes, and cell cycle stages that distinguish repair of double-strand breaks (DSBs) by homologous recombination (HR) from non-homologous end joining (NHEJ) are known, the underlying mechanisms that determine pathway choice are incompletely understood. Previously, we found that the transcription factor Sp1 is recruited to DSBs and is necessary for repair. Here, we demonstrate that Sp1 localizes to DSBs in G1 and is necessary for recruitment of the NHEJ repair factor, 53BP1. Phosphorylation of Sp1-S59 in early S phase evicts Sp1 and 53BP1 from the break site; inhibition of that phosphorylation results in 53BP1 and Sp1 remaining at DSBs in S phase cells, precluding BRCA1 binding and suppressing HR. Expression of Sp1-S59A increases sensitivity of BRCA1
+/+ cells to poly (ADP-ribose) polymerase (PARP) inhibition similar to BRCA1 deficiency. These data demonstrate how Sp1 integrates the cell cycle and DSB repair pathway choice to favor NHEJ., Competing Interests: Declaration of interests The authors declare no competing interest., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2021
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18. Caspase cleavage of transcription factor Sp1 enhances apoptosis.
- Author
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Torabi B, Flashner S, Beishline K, Sowash A, Donovan K, Bassett G, and Azizkhan-Clifford J
- Subjects
- Animals, Apoptosis drug effects, Apoptosis radiation effects, Bleomycin pharmacology, Camptothecin pharmacology, Caspase 3 genetics, Cell Cycle drug effects, Cell Cycle genetics, Cell Cycle radiation effects, Cell Line, Cell Line, Tumor, DNA Damage, Dogs, Doxorubicin pharmacology, Fibroblasts cytology, Fibroblasts drug effects, Fibroblasts metabolism, Fibroblasts radiation effects, Gene Expression Regulation, HEK293 Cells, Humans, MCF-7 Cells, Madin Darby Canine Kidney Cells, Mutation, Osteoblasts drug effects, Osteoblasts pathology, Osteoblasts radiation effects, Protein Stability, Proteolysis, RNA, Small Interfering genetics, RNA, Small Interfering metabolism, Signal Transduction, Sp1 Transcription Factor genetics, TNF-Related Apoptosis-Inducing Ligand pharmacology, Ultraviolet Rays adverse effects, Apoptosis genetics, Caspase 3 metabolism, Osteoblasts metabolism, Sp1 Transcription Factor metabolism
- Abstract
Sp1 is a ubiquitous transcription factor that regulates many genes involved in apoptosis and senescence. Sp1 also has a role in the DNA damage response; at low levels of DNA damage, Sp1 is phosphorylated by ATM and localizes to double-strand break sites where it facilitates DNA double-strand-break repair. Depletion of Sp1 increases the sensitivity of cells to DNA damage, whereas overexpression of Sp1 can drive cells into apoptosis. In response to a variety of stimuli, Sp1 can be regulated through proteolytic cleavage by caspases and/or degradation. Here, we show that activation of apoptosis through DNA damage or TRAIL-mediated activation of the extrinsic apoptotic pathway induces caspase-mediated cleavage of Sp1. Cleavage of Sp1 was coincident with the appearance of cleaved caspase 3, and produced a 70 kDa Sp1 product. In vitro analysis revealed a novel caspase cleavage site at aspartic acid 183. Mutation of aspartic acid 183 to alanine conferred resistance to cleavage, and ectopic expression of the Sp1 D183A rendered cells resistant to apoptotic stimuli, indicating that Sp1 cleavage is involved in the induction of apoptosis. The 70 kDa product resulting from caspase cleavage of Sp1 comprises amino acids 184-785. This truncated form, designated Sp1-70C, which retains transcriptional activity, induced apoptosis when overexpressed in normal epithelial cells, whereas Sp1D183A induced significantly less apoptosis. Together, these data reveal a new caspase cleavage site in Sp1 and demonstrate for the first time that caspase cleavage of Sp1 promotes apoptosis.
- Published
- 2018
- Full Text
- View/download PDF
19. The use of analgesics in patients with acute abdominal pain.
- Author
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LoVecchio F, Oster N, Sturmann K, Nelson LS, Flashner S, and Finger R
- Subjects
- Acute Disease, Adult, Emergencies, Female, Humans, Male, Middle Aged, Prospective Studies, Abdominal Pain diagnosis, Abdominal Pain drug therapy, Analgesics, Opioid therapeutic use, Morphine therapeutic use
- Abstract
Analgesics in patients with acute abdominal pain are often withheld for fear that they may change physical examination findings and thus may be unsafe. We conducted a randomized, prospective, placebo-controlled trial to investigate changes in physical examination following the administration of placebo, 5 mg, or 10 mg of morphine to 49 patients with acute abdominal pain. One patient was withdrawn secondary to inadequate documentation. Of the 48 patients who completed the trial, a statistically significant change in physical examination was noted in both groups receiving analgesics, but not in the placebo group. No adverse events or delays in diagnosis were attributed to the administration of analgesics. We conclude that physical examination does change after the administration of analgesics in patients with acute abdominal pain and that a larger study is needed to evaluate analgesic safety in this subpopulation of emergency department patients.
- Published
- 1997
- Full Text
- View/download PDF
20. An experimental model of neonatal testicular torsion: evidence against an exclusively extravaginal etiology.
- Author
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Friedman RM, Flashner SC, Akwari OE, and King LR
- Subjects
- Animals, Male, Rats, Rats, Sprague-Dawley, Spermatic Cord Torsion etiology, Spermatic Cord Torsion pathology, Testis pathology, Disease Models, Animal, Spermatic Cord Torsion congenital
- Abstract
The present study was designed to determine whether extravaginal torsion of the spermatic cord (EVT) can be distinguished from intravaginal torsion (IVT) on the basis of gross and histologic examination of the testis. It is traditionally believed that EVT, postulated to occur only in neonates, can be grossly distinguished from IVT, which occurs in older patients, on the basis of adherence between testis and tunica vaginalis. Such adherence is felt to be present in EVT but not IVT. This concept that the two types of torsion can be distinguished in the operating room has important clinical ramifications. In cases of EVT, contralateral orchidopexy theoretically need not be performed, since adhesions develop between tunica vaginalis and dartos by a few weeks of age. This is in contrast to IVT, in which contralateral orchidopexy is necessary due to the bilateral nature of the bell clapper deformity. Using a rat model, we first demonstrated that IVT could produce adherence of the tunica vaginalis to testis. Then, eight rats were operated on, producing right IVT and left EVT. Animals were then sacrificed at intervals of up to one month. Gross and histologic examination showed involvement of the tunica vaginalis in an ischemic and inflammatory response in a majority of testes, regardless of the type of torsion. Attempts to distinguish EVT from IVT on the basis of grossly evident adhesions between tunica vaginalis and testis are of questionable validity. Early contralateral orchidopexy is therefore recommended in all cases of neonatal torsion.
- Published
- 1993
- Full Text
- View/download PDF
21. Endoscopic release of retained Penrose drains: a simple solution for an old problem.
- Author
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Beshai AZ, Flashner SC, and Walther PJ
- Subjects
- Adult, Child, Endoscopy, Equipment Design, Humans, Pelvis surgery, Urology methods, Drainage instrumentation, Foreign Bodies therapy, Postoperative Complications therapy, Urology instrumentation
- Abstract
The Penrose drain internally tethered by a fascial suture is a surgical complication with medical and legal implications. Correction of this problem usually has required open reexploration. A technique of endoscopic release of such a drain through the drain tract is described. Since this procedure can be performed with the patient under local anesthesia, additional hospitalization and patient discomfort are minimized. This technique has broad applicability for the management of this wound complication following most abdominal explorations requiring drain placement for urological, gynecological or general surgical indications.
- Published
- 1992
- Full Text
- View/download PDF
22. Effectiveness of a handsewn nipple valve for reflux prevention in bladder reconstruction.
- Author
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Friedman RM, Flashner SC, and King LR
- Subjects
- Child, Female, Humans, Ileum surgery, Male, Methods, Reoperation, Ureter surgery, Urinary Bladder Calculi etiology, Urinary Reservoirs, Continent adverse effects, Vesico-Ureteral Reflux etiology, Postoperative Complications prevention & control, Urinary Bladder surgery, Vesico-Ureteral Reflux prevention & control
- Abstract
The intussuscepted nipple has proved to be a versatile mechanism to provide continence or prevent reflux in urological reconstructive surgery. Early in its use detussusception of the nipple was recognized as a common complication, which was usually prevented by using several rows of staples to stabilize the nipple. The use of staples has reduced the rate of reoperation for eversion or obstruction but it has led to a higher stone formation rate, ranging from 10 to 18% in recent series. Since 1983 we have used a handsewn intussuscepted ileal nipple stabilized without staples as our antireflux mechanism in bladder augmentations and continent diversions. This technique has been performed in 30 patients with an average followup of greater than 3 years. A small bladder stone developed in only 1 (3%) of the patients, who was completely dependent on intermittent catheterization, while 4 (13%) required reoperation due to eversion of the nipple. This incidence compares well with nipple reoperation rates in recent series, which range from 7 to 28%. We conclude that absorbable sutures are as effective as staples in stabilizing the antireflux nipple, and that they result in a lower incidence of subsequent stone formation.
- Published
- 1992
- Full Text
- View/download PDF
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