Medical Cell Biology Commons^™

Ocular Adnexal Metastases From Renal Cell Carcinoma: An Update And Comprehensive Literature Review, Tejal Magan, Tejus Pradeep, Madalina Tuluc, Jurij R. Bilyk, Tatyana Milman

Wills Eye Hospital Papers

PURPOSE: The purpose of this study was to review the clinical presentation, systemic work-up, and outcomes of all previously reported ocular adnexal (OA) metastases from renal cell carcinoma (RCC). METHODS: This was a literature review. PubMed and Google Scholar databases were searched for all well-documented cases of OA metastases from RCC. RESULTS: Final analysis identified 44 patients with either biopsy-confirmed (41/44, 93%) or treatment response-documented (3/44, 6%) OA metastases from RCC. Thirty-four (77%) patients were male. The median age was 60 years (mean: 60, range: 22-87 years). The most common presenting signs were proptosis (19/44, 43%) and OA mass (14/44, …

Interferon Gamma Release Assay Mitogen Responses In Covid-19, Dagan Coppock, Claire E. Zurlo, Jenna M. Meloni, Sara L. Goss, John J. Zurlo, Matthew A. Pettengill

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background

Elevated cytokine release and T cell exhaustion have been associated with COVID-19 disease severity. T cell activity may be indirectly measured through interferon gamma release assays (IGRAs), which use mitogen stimulation of T lymphocytes as a positive control. In our institution, an unexpectedly high rate of indeterminate IGRAs was noted in COVID-19–positive patients. We aimed to evaluate the clinical characteristics associated with indeterminate IGRA results and the difference in mitogen responses between COVID-19–positive and COVID-19–negative patients.

Methods

We reviewed all patients, regardless of COVID status, who were admitted between March 1, 2020, and May 31, 2020, and for whom …

Dysregulation Of Mir-21-Associated Mirna Regulatory Networks By Chronic Ethanol Consumption Impairs Liver Regeneration., Austin Parrish, Ankita Srivastava, Egle Juskeviciute, Jan B Hoek, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Impaired liver regeneration has been considered as a hallmark of progression of alcohol-associated liver disease. Our previous studies demonstrated that in vivo inhibition of the microRNA (miRNA) miR21 can restore regenerative capacity of the liver in chronic ethanol-fed animals. The present study focuses on the role of microRNA regulatory networks that are likely to mediate the miR-21 action. Rats were chronically fed an ethanol-enriched diet along with pair-fed control animals and treated with AM21 (anti-miR-21), a locked nucleic acid antisense to miR-21. Partial hepatectomy (PHx) was performed and miRNA expression profiling over the course of liver regeneration was assessed. Our …

Mapping The Little Brain At The Heart By An Interdisciplinary Systems Biology Team., Rajanikanth Vadigepalli, James S. Schwaber

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

No abstract provided.

Impaired 26s Proteasome Assembly Precedes Neuronal Loss In Mutant Ubqln2 Rats., Wenjuan Zhang, Bo Huang, Limo Gao, Cao Huang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Proteasomal dysfunction is known to be associated with amyotrophic lateral sclerosis and frontotemporal degeneration (ALS/FTD). Our previous reports have shown that a mutant form of ubiquilin-2 (UBQLN2) linked to ALS/FTD leads to neurodegeneration accompanied by accumulations of the proteasome subunit Rpt1 in transgenic rats, but the precise pathogenic mechanisms of how this mutation impairs the proteasome remains to be elucidated. Here, we reveal that this UBQLN2 mutation in rats disrupted the proteasome integrity prior to neurodegeneration, that it dissociated the 26S proteasome in vitro, and that its depletion did not affect 26S proteasome assembly. During both disease progression and in …

Characterization And Clinical Significance Of Eif1ax Mutations And Co-Mutations In Cytologically Indeterminate Thyroid Nodules: A 5-Year Retrospective Analysis., Stacey Gargano, Nitika Badjatia, Yanina Nikolaus, Stephen C Peiper, Zi-Xuan Wang, Phd

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

OBJECTIVE: Mutations in the EIF1AX gene have been recently detected in a small percentage of benign and malignant thyroid lesions. We sought to investigate the prevalence and clinical significance of EIF1AX mutations and co-mutations in cytologically indeterminate thyroid nodules at our institution.

MATERIALS AND METHODS: A 5-year retrospective analysis was performed on thyroid nodules with a cytologic diagnosis of Bethesda category III or IV, which had undergone testing by our in-house next generation sequencing panel. Surgically resected nodules with EIF1AX mutations were identified, and mutation type and presence of co-mutations were correlated with histopathologic diagnosis.

RESULTS: 41/904 (4.5%) cases overall …

Resident Immune Cells Of The Avascular Lens: Mediators Of The Injury And Fibrotic Response Of The Lens., A. Menko, Jodirae Dedreu, Caitlin M. Logan, Heather Paulson, Alex V Levin, Janice L Walker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Tissues typically harbor subpopulations of resident immune cells that function as rapid responders to injury and whose activation leads to induction of an adaptive immune response, playing important roles in repair and protection. Since the lens is an avascular tissue, it was presumed that it was absent of resident immune cells. Our studies now show that resident immune cells are a shared feature of the human, mouse, and chicken lens epithelium. These resident immune cells function as immediate responders to injury and rapidly populate the wound edge following mock cataract surgery to function as leader cells. Many of these resident …

Discoidin Domain Receptor 1 Functionally Interacts With The Igf-I System In Bladder Cancer, Simone Buraschi, Alaide Morcavallo, Thomas Neill, Manuela Stefanello, Chiara Palladino, Shi-Qiong Xu, Antonino Belfiore, Renato V. Iozzo, Andrea Morrione

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

No abstract provided.

Single-Cell Gene Expression Analysis Identifies Chronic Alcohol-Mediated Shift In Hepatocyte Molecular States After Partial Hepatectomy., Sirisha Achanta, Aalap Verma, Ankita Srivastava, Harshavardhan Nilakantan, Jan B. Hoek, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The analysis of molecular states of individual cells, as defined by their mRNA expression profiles and protein composition, has gained widespread interest in studying biological phenomena ranging from embryonic development to homeostatic tissue function and genesis and evolution of cancers. Although the molecular content of individual cells in a tissue can vary widely, their molecular states tend to be constrained within a transcriptional landscape partly described by the canonical archetypes of a population of cells. In this study, we sought to characterize the effects of an acute (partial hepatectomy) and chronic (alcohol consumption) perturbation on the molecular states of individual …

Single-Cell Transcriptional Analysis Reveals Novel Neuronal Phenotypes And Interaction Networks Involved In The Central Circadian Clock., James Park, Haisun Zhu, Sean O'Sullivan, Babatunde A Ogunnaike, David R Weaver, James S. Schwaber, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Single-cell heterogeneity confounds efforts to understand how a population of cells organizes into cellular networks that underlie tissue-level function. This complexity is prominent in the mammalian suprachiasmatic nucleus (SCN). Here, individual neurons exhibit a remarkable amount of asynchronous behavior and transcriptional heterogeneity. However, SCN neurons are able to generate precisely coordinated synaptic and molecular outputs that synchronize the body to a common circadian cycle by organizing into cellular networks. To understand this emergent cellular network property, it is important to reconcile single-neuron heterogeneity with network organization. In light of recent studies suggesting that transcriptionally heterogeneous cells organize into distinct cellular …

Mirna-145 Increases Therapeutic Sensibility To Gemcitabine Treatment Of Pancreatic Adenocarcinoma Cells., Yong Lin, Xin Ge, Yiyang Wen, Zhu-Mei Shi, Qiu-Dan Chen, Min Wang, Ling-Zhi Liu, Bing-Hua Jiang, Yuan Lu

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Pancreatic adenocarcinoma is one of the most leading causes of cancer-related deaths worldwide. Although recent advances provide various treatment options, pancreatic adenocarcinoma has poor prognosis due to its late diagnosis and ineffective therapeutic multimodality. Gemcitabine is the effective first-line drug in pancreatic adenocarcinoma treatment. However, gemcitabine chemoresistance of pancreatic adenocarcinoma cells has been a major obstacle for limiting its treatment effect. Our study found that p70S6K1 plays an important role in gemcitabine chemoresistence. MiR-145 is a tumor suppressor which directly targets p70S6K1 for inhibiting its expression in pancreatic adenocarcinoma, providing new therapeutic scheme. Our findings revealed a new mechanism underlying …

Gaining Competencies During Early Medical Training: Medical Students As Teaching Assistants In Dissection-Based Anatomy Course, Martin T. Brown, Bruce Fenderson, Guiyan Zhang

Department of Pathology, Anatomy, and Cell Biology Posters

Introduction and Objectives

• In 2002, ACGME identified six ACGME Core Competencies: patient care; medical knowledge; practice-based learning and improvement; interpersonal and communication skills; professionalism; and systems-based practice.
• AAMC recommended lists of similar competencies for the curricula of medical schools. Competency based curricula have been widely implemented in medical schools.
• Effective shifting in the graduate medical educational programs has been reported in various clinical specialties.
• There is a lack of reported efforts and development on competency training in early preclinical years of medical education.

Objectives:

• To explore methods for strengthening medical students’ competency training during preclinical undergraduate medical education.
• To measure …

Micu1 Regulation Of Mitochondrial Ca(2+) Uptake Dictates Survival And Tissue Regeneration., Anil Noronha Antony, Melanie Paillard, Cynthia Moffat, Egle Juskeviciute, Jason Correnti, Brad Bolon, Emanual Rubin, Md, György Csordás, Erin L Seifert, Jan B. Hoek, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondrial Ca(2+) uptake through the recently discovered Mitochondrial Calcium Uniporter (MCU) is controlled by its gatekeeper Mitochondrial Calcium Uptake 1 (MICU1). However, the physiological and pathological role of MICU1 remains unclear. Here we show that MICU1 is vital for adaptation to postnatal life and for tissue repair after injury. MICU1 knockout is perinatally lethal in mice without causing gross anatomical defects. We used liver regeneration after partial hepatectomy as a physiological stress response model. Upon MICU1 loss, early priming is unaffected, but the pro-inflammatory phase does not resolve and liver regeneration fails, with impaired cell cycle entry and extensive necrosis. …

Cells Activated For Wound Repair Have The Potential To Direct Collective Invasion Of An Epithelium., Brigid M Bleaken, A Sue Menko, Janice Walker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mechanisms regulating how groups of cells are signaled to move collectively from their original site and invade surrounding matrix are poorly understood. Here we develop a clinically relevant ex vivo injury invasion model to determine whether cells involved in directing wound healing have invasive function and whether they can act as leader cells to direct movement of a wounded epithelium through a three-dimensional (3D) extracellular matrix (ECM) environment. Similar to cancer invasion, we found that the injured cells invade into the ECM as cords, involving heterotypical cell-cell interactions. Mesenchymal cells with properties of activated repair cells that typically locate to …

In-Silico Identification Of Prognostically Inversely Correlated Mirnas And Mrnas (Pic’S) In Multiple Cancers, Chirayu Pankaj Goswami, Zi-Xuan Wang

Department of Pathology, Anatomy, and Cell Biology Posters

Despite numerous methods available to identify potential mRNA targets for miRNAs, prognostic relationship of these molecules in diseases like cancers where deregulation of gene expression is a major pathogenic factor, has not yet been emphasized. We performed in-silico identification of prognostically inversely correlated miRNA - mRNA pairs (PIC’s) in multiple cancers using expression data from The Cancer Genome Atlas. Partners in a PIC show inverse correlation of expression and opposite hazard implication. Using a three step approach, we identified a total of 1,253,443 PIC’s from 23 cancer types, several of which have previously been shown to have a predicted or …

Intracellular Information Processing Through Encoding And Decoding Of Dynamic Signaling Features., Hirenkumar K Makadia, James S. Schwaber, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cell signaling dynamics and transcriptional regulatory activities are variable within specific cell types responding to an identical stimulus. In addition to studying the network interactions, there is much interest in utilizing single cell scale data to elucidate the non-random aspects of the variability involved in cellular decision making. Previous studies have considered the information transfer between the signaling and transcriptional domains based on an instantaneous relationship between the molecular activities. These studies predict a limited binary on/off encoding mechanism which underestimates the complexity of biological information processing, and hence the utility of single cell resolution data. Here we pursue a …

Gsk-3Β Regulates Tumor Growth And Angiogenesis In Human Glioma Cells., Peng Zhao, Qi Li, Zhumei Shi, Charlie Li, Lin Wang, Xue Liu, Chengfei Jiang, Xu Qian, Yongping You, Ning Liu, Ling-Zhi Liu, Lianshu Ding, Bing-Hua Jiang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Glioma accounts for the majority of primary malignant brain tumors in adults.

METHODS: Glioma specimens and normal brain tissues were analyzed for the expression levels of GSK-3β and p-GSK-3β (Ser9) by tissue microarray analysis (TMA) and Western blotting. Glioma cells over-expressing GSK-3β were used to analyze biological functions both in vitro and in vivo.

RESULTS: The levels of p-GSK-3β (Ser9), but not total GSK-3β, are significantly up-regulated in glioma tissues compared to normal tissues, and are significantly correlated with the glioma grades. Ectopic expression of GSK-3β decreased the phosphorylation levels of mTOR and p70S6K1; and inhibited β-catenin, HIF-1α and …

Mir-497 Decreases Cisplatin Resistance In Ovarian Cancer Cells By Targeting Mtor/P70s6k1., Shaohua Xu, Guang-Bo Fu, Zhen Tao, Jun Ouyang, Fanfei Kong, Bing-Hua Jiang, Xiaoping Wan, Ke Chen

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The mechanism of cisplatin resistance in ovarian cancer is not clearly understood. In the present investigation, we found that the expression levels of miR-497 were reduced in chemotherapy-resistant ovarian cancer cells and tumor tissues due to hypermethylation of miR-497 promoter. Low miR-497 expression levels were associated with chemo-resistant phonotype of ovarian cancer. By analyzing the expression levels of miR-497, mTOR and p70S6K1 in a clinical gene-expression array dataset, we found that mTOR and p70S6K1, two proteins correlated to chemotherapy-resistance in multiple types of human cancers, were inversely correlated with miR-497 levels in ovarian cancer tissues. By using an orthotopic ovarian …

Disseminated Histiocytoses Biomarkers Beyond Brafv600e: Frequent Expression Of Pd-L1., Nurija Bilalovic, Juan P. Palazzo, Ryan P Bender, Jeffrey Swensen, Sherri Z Millis, Semir Vranic, Daniel Von Hoff, Robert J Arceci, Zoran Gatalica

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The histiocytoses are rare tumors characterized by the primary accumulation and tissue infiltration of histiocytes and dendritic cells. Identification of the activating BRAFV600E mutation in Erdheim-Chester disease (ECD) and Langerhans cell histiocytosis (LCH) cases provided the basis for the treatment with BRAF and/or MEK inhibitors, but additional treatment options are needed. Twenty-four cases of neoplastic histiocytic diseases [11 extrapulmonary LCH, 4 ECD, 4 extranodal Rosai-Dorfman disease (RDD), 3 follicular dendritic cell sarcoma (FDCS), 1 histiocytic sarcoma (HS) and 1 blastic plasmacytoid dendritic cell neoplasm (BPDCN)] were analyzed using immunohistochemical and mutational analysis in search of biomarkers for targeted therapy. BRAF …

Hormone-Induced Calcium Oscillations Depend On Cross-Coupling With Inositol 1,4,5-Trisphosphate Oscillations., Lawrence D Gaspers, Paula J Bartlett, Antonio Politi, Paul Burnett, Walson Metzger, Jane Johnston, Suresh K Joseph, Thomas Höfer, Andrew P Thomas

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Receptor-mediated oscillations in cytosolic Ca(2+) concentration ([Ca(2+)]i) could originate either directly from an autonomous Ca(2+) feedback oscillator at the inositol 1,4,5-trisphosphate (IP3) receptor or as a secondary consequence of IP3 oscillations driven by Ca(2+) feedback on IP3 metabolism. It is challenging to discriminate these alternatives, because IP3 fluctuations could drive Ca(2+) oscillations or could just be a secondary response to the [Ca(2+)]i spikes. To investigate this problem, we constructed a recombinant IP3 buffer using type-I IP3 receptor ligand-binding domain fused to GFP (GFP-LBD), which buffers IP3 in the physiological range. This IP3 buffer slows hormone-induced [IP3] dynamics without changing steady-state …

Loss Of Miro1-Directed Mitochondrial Movement Results In A Novel Murine Model For Neuron Disease., Tammy T Nguyen, Sang S Oh, David Weaver, Agnieszka Lewandowska, Dane Maxfield, Max-Hinderk Schuler, Nathan K Smith, Jane Macfarlane, Gerald Saunders, Cheryl A Palmer, Valentina Debattisti, Takumi Koshiba, Stefan Pulst, Eva L Feldman, György Hajnóczky, Janet M Shaw

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Defective mitochondrial distribution in neurons is proposed to cause ATP depletion and calcium-buffering deficiencies that compromise cell function. However, it is unclear whether aberrant mitochondrial motility and distribution alone are sufficient to cause neurological disease. Calcium-binding mitochondrial Rho (Miro) GTPases attach mitochondria to motor proteins for anterograde and retrograde transport in neurons. Using two new KO mouse models, we demonstrate that Miro1 is essential for development of cranial motor nuclei required for respiratory control and maintenance of upper motor neurons required for ambulation. Neuron-specific loss of Miro1 causes depletion of mitochondria from corticospinal tract axons and progressive neurological deficits mirroring …

Proline-Rich Tyrosine Kinase 2 (Pyk2) Regulates Igf-I-Induced Cell Motility And Invasion Of Urothelial Carcinoma Cells, Marco Genua, Shi-Qiong Xu, Simone Buraschi, Stephen C. Peiper, Leonard G. Gomella, Antonio Belfiore, Renato V. Iozzo, Andrea Morrione

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The insulin-like growth factor receptor I (IGF-IR) plays an essential role in transformation by promoting cell growth and protecting cancer cells from apoptosis. We have recently demonstrated that the IGF-IR is overexpressed in invasive bladder cancer tissues and promotes motility and invasion of urothelial carcinoma cells. These effects require IGF-I-induced Akt- and MAPK-dependent activation of paxillin. The latter co-localizes with focal adhesion kinases (FAK) at dynamic focal adhesions and is critical for promoting motility of urothelial cancer cells. FAK and its homolog Proline-rich tyrosine kinase 2 (Pyk2) modulate paxillin activation; however, their role in regulating IGF-IR-dependent signaling and motility in …

Genetic Polymorphism In A Vegf-Independent Angiogenesis Gene Angpt1 And Overall Survival Of Colorectal Cancer Patients After Surgical Resection, Jingyao Dai, Shaogui Wan, Feng Zhou, Ronald E. Myers, Xu Guo, Bingshan Li, Xiaoying Fu, Juan P. Palazzo, Kefeng Dou, Hushan Yang, Jinliang Xing

Kimmel Cancer Center Faculty Papers

Background

The VEGF-independent angiogenic signaling plays an important role in the development of colorectal cancer (CRC). However, its implication in the clinical outcome of CRC has not been reported. This study aimed to investigate the association between genetic variations in several major VEGF-independent signaling pathway genes and the overall survival of CRC patients.

Methods

Seven single nucleotide polymorphisms (SNPs) in four important VEGF-independent angiogenic genes (ANGPT1, AMOT, DLL4 and ENG) were genotyped in a Chinese population with 408 CRC patients.

Results

One SNP, rs1954727 in ANGPT1, was significantly associated with CRC overall survival. Compared to …

Uterine Dysfunction In Biglycan And Decorin Deficient Mice Leads To Dystocia During Parturition., Zhiping Wu, Abraham W Aron, Elyse E Macksoud, Renato V Iozzo, Chi-Ming Hai, Beatrice E Lechner

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cesarean birth rates are rising. Uterine dysfunction, the exact mechanism of which is unknown, is a common indication for Cesarean delivery. Biglycan and decorin are two small leucine-rich proteoglycans expressed in the extracellular matrix of reproductive tissues and muscle. Mice deficient in biglycan display a mild muscular dystrophy, and, along with mice deficient in decorin, are models of Ehlers-Danlos Syndrome, a connective tissue anomaly associated with uterine rupture. As a variant of Ehlers-Danlos Syndrome is caused by a genetic mutation resulting in abnormal biglycan and decorin secretion, we hypothesized that biglycan and decorin play a role in uterine function. Thus, …

Blood-Brain Barrier Abnormalities Caused By Hiv-1 Gp120: Mechanistic And Therapeutic Implications., Jean-Pierre Louboutin, David S Strayer

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The blood-brain barrier (BBB) is compromised in many systemic and CNS diseases, including HIV-1 infection of the brain. We studied BBB disruption caused by HIV-1 envelope glycoprotein 120 (gp120) as a model. Exposure to gp120, whether acute [by direct intra-caudate-putamen (CP) injection] or chronic [using SV(gp120), an experimental model of ongoing production of gp120] disrupted the BBB, and led to leakage of vascular contents. Gp120 was directly toxic to brain endothelial cells. Abnormalities of the BBB reflect the activity of matrix metalloproteinases (MMPs). These target laminin and attack the tight junctions between endothelial cells and BBB basal laminae. MMP-2 and …

Graft Versus Host Disease Of The Brain Following Allogeneic Stem Cell Transplant For Myelodysplastic Syndrome, Janet Yoo, Lindsay Simon, Zi-Xuan Wang, Phd, Lawrence C. Kenyon

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Graft-versus-host disease (GVHD) is a frequent cause of morbidity and mortality following bone marrow transplantation (BMT). GVHD occurs when immune cells transplanted from a non-identical donor (the graft) recognize the transplant recipient (the host) as foreign, thereby initiating an immune reaction that causes disease in the transplant recipient. GVHD, which can present either acutely or chronically, typically involves the skin, gastrointestinal tract, and liver. In contrast, GVHD involving other organs such as the heart and kidney is highly uncommon and involvement of the central nervous system has only very rarely been described in the literature. We report an unusual case …

Cns Recruitment Of Cd8+ T Lymphocytes Specific For A Peripheral Virus Infection Triggers Neuropathogenesis During Polymicrobial Challenge., Christine M Matullo, Kevin J O'Regan, Mark Curtis, Glenn F Rall

Department of Microbiology and Immunology Faculty Papers

Although viruses have been implicated in central nervous system (CNS) diseases of unknown etiology, including multiple sclerosis and amyotrophic lateral sclerosis, the reproducible identification of viral triggers in such diseases has been largely unsuccessful. Here, we explore the hypothesis that viruses need not replicate in the tissue in which they cause disease; specifically, that a peripheral infection might trigger CNS pathology. To test this idea, we utilized a transgenic mouse model in which we found that immune cells responding to a peripheral infection are recruited to the CNS, where they trigger neurological damage. In this model, mice are infected with …

Switches, Excitable Responses And Oscillations In The Ring1b/Bmi1 Ubiquitination System., Lan K Nguyen, Javier Muñoz-García, Helene Maccario, Aaron Ciechanover, Walter Kolch, Boris N Kholodenko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

In an active, self-ubiquitinated state, the Ring1B ligase monoubiquitinates histone H2A playing a critical role in Polycomb-mediated gene silencing. Following ubiquitination by external ligases, Ring1B is targeted for proteosomal degradation. Using biochemical data and computational modeling, we show that the Ring1B ligase can exhibit abrupt switches, overshoot transitions and self-perpetuating oscillations between its distinct ubiquitination and activity states. These different Ring1B states display canonical or multiply branched, atypical polyubiquitin chains and involve association with the Polycomb-group protein Bmi1. Bistable switches and oscillations may lead to all-or-none histone H2A monoubiquitination rates and result in discrete periods of gene (in)activity. Switches, overshoots …

Role And Mechanism Of Arsenic In Regulating Angiogenesis., Ling-Zhi Liu, Yue Jiang, Richard L Carpenter, Yi Jing, Stephen C Peiper, Bing-Hua Jiang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Arsenic is a wide spread carcinogen associated with several kinds of cancers including skin, lung, bladder, and liver cancers. Lung is one of the major targets of arsenic exposure. Angiogenesis is the pivotal process during carcinogenesis and chronic pulmonary diseases, but the role and mechanism of arsenic in regulating angiogenesis remain to be elucidated. In this study we show that short time exposure of arsenic induces angiogenesis in both human immortalized lung epithelial cells BEAS-2B and adenocarcinoma cells A549. To study the molecular mechanism of arsenic-inducing angiogenesis, we find that arsenic induces reactive oxygen species (ROS) generation, which activates AKT …

Mitostatin Is Down-Regulated In Human Prostate Cancer And Suppresses The Invasive Phenotype Of Prostate Cancer Cells., Matteo Fassan, Domenico D'Arca, Juraj Letko, Andrea Vecchione, Marina P Gardiman, Peter Mccue, Bernadette Wildemore, Massimo Rugge, Dolores Shupp-Byrne, Leonard G Gomella, Andrea Morrione, Renato V Iozzo, Raffaele Baffa

Kimmel Cancer Center Faculty Papers

MITOSTATIN, a novel putative tumor suppressor gene induced by decorin overexpression, is expressed in most normal human tissues but is markedly down-regulated in advanced stages of mammary and bladder carcinomas. Mitostatin negatively affects cell growth, induces cell death and regulates the expression and activation levels of Hsp27. In this study, we demonstrated that ectopic expression of Mitostatin in PC3, DU145, and LNCaP prostate cancer cells not only induced a significant reduction in cell growth, but also inhibited migration and invasion. Moreover, Mitostatin inhibited colony formation in soft-agar of PC3 and LNCaP cells as well as tumorigenicity of LNCaP cells in …