Medical Sciences Commons^™

Hypoxia Regulates Vessel-Modifying Macrophages And Vice Versa In Tumors, Kayla Jo Steinberger

Graduate Theses, Dissertations, and Problem Reports

Hypoxia, or low oxygen, is a common feature of solid tumors correlating with poor survival in cancer patients. Growing tumors need a blood supply to deliver oxygen. Tumors attempt to re-acquire oxygen by forming new blood vessels from nearby, pre-existing vessels, a process known as angiogenesis. Past treatments aimed at preventing this process yielded not only disappointing results in the clinic but sometimes worsened the patient’s prognosis making the tumor more hypoxic, emphasizing the urgent need for novel targets. In tumors, angiogenesis is notoriously dysfunctional resulting in leaky, under-perfused blood vessels which cannot adequately deliver oxygen and exacerbates hypoxia. Emerging …

Complexity Of Progranulin Mechanisms Of Action In Mesothelioma, Elisa Ventura, Christopher Xie, Simone Buraschi, Antonino Belfiore, Renato V. Iozzo, Antonio Giordano, Andrea Morrione

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background: Mesothelioma is an aggressive disease with limited therapeutic options. The growth factor progranulin plays a critical role in several cancer models, where it regulates tumor initiation and progression. Recent data from our laboratories have demonstrated that progranulin and its receptor, EphA2, constitute an oncogenic pathway in bladder cancer by promoting motility, invasion and in vivo tumor formation. Progranulin and EphA2 are expressed in mesothelioma cells but their mechanisms of action are not well defined. In addition, there are no data establishing whether the progranulin/EphA2 axis is tumorigenic for mesothelioma cells.

Methods: The expression of progranulin in various mesothelioma cell …

Bap1 Maintains Hif-Dependent Interferon Beta Induction To Suppress Tumor Growth In Clear Cell Renal Cell Carcinoma., Lauren Langbein, Rayan El Hajjar, Shen He, Eleonora Sementino, Zhijiu Zhong, Wei Jiang, Benjamin E Leiby, Li Li, Robert G Uzzo, Joseph R Testa, Haifeng Yang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BRCA1-associated protein 1 (BAP1) is a deubiquitinase that is mutated in 10-15% of clear cell renal cell carcinomas (ccRCC). Despite the association between BAP1 loss and poor clinical outcome, the critical tumor suppressor function(s) of BAP1 in ccRCC remains unclear. Previously, we found that hypoxia-inducible factor 2α (HIF2α) and BAP1 activate interferon-stimulated gene factor 3 (ISGF3), a transcription factor activated by type I interferons and a tumor suppressor in ccRCC xenograft models. Here, we aimed to determine the mechanism(s) through which HIF and BAP1 regulate ISGF3. We found that in ccRCC cells, loss of the von Hippel-Lindau tumor suppressor (VHL) …

Stem Signatures Associating Sox2 Antibody Helps To Define Diagnosis And Prognosis Prediction With Esophageal Cancer, Zi-Yang Peng, Qing-Shi Wang, Kai Li, Si-Si Chen, Xiang Li, Guo-Dong Xiao, Shou-Ching Tang, Hong Ren, Zhe Wang, Xin Sun

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background: esophageal cancer is one of the deadliest diseases worldwide. Due to the ineffectual screening methods referring to early diagnosis, most people have lost their chance of radical resection when diagnosed with esophageal cancer. This aim of this study was designed to evaluate the latent values of the stem signatures-associated autoantibodies (AABS) in predicting the early diagnosis, and particularly seeking the precise predictive outcomes with sensitive SOX2. We also studied the potential immunotherapeutic targets and prospective long-term prognosis predicators of esophageal cancer.

Methods: The serum concentrations of selective antibodies were quantitated by enzyme-linked immunosorbent assay (ELISA), and a total of …

Comparative Analysis Of Tumor Capsule Thickness And Other Histologic Features In Encapsulated Follicular Variant Of Papillary Thyroid Carcinoma (Efvptc) And Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features (Niftp), Brenda French, Stacey K. Mardekian, Md

Department of Pathology Honors Program Student Research Symposium

Recent reclassification of a subset of non-invasive encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) tumors as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) has led to important changes in the clinical management of patients with these indolent lesions. Although there are established diagnostic criteria to differentiate NIFTP from EFVPTC, our objective was to determine further differences in histological characteristics between NIFTP and noninvasive EFVPTC. Additionally, we sought to identify histological differences between non-invasive and invasive EFVPTC lesions beyond the key finding of invasion. 68 encapsulated follicular lesions with papillary-like nuclear features from patients treated at Thomas Jefferson …

Clinico-Pathological Features And Pd-1/Pd-L1 Expression In Primary Mediastinal Large B Cell Lymphoma, Lydia Glick, Geetha Jagannathan, Md, Guldeep Uppal, Md

Department of Pathology Honors Program Student Research Symposium

Primary Mediastinal Large B Cell Lymphoma (PMBCL) is a distinct subtype of Diffuse Large B Cell Lymphoma (DLBCL) that has been historically reported to have a worse prognosis than DLBCL. Occasional studies have reported PD-L1 expression in PMBCL, which can emerge as an important target for immune-check point therapy. This study aimed to evaluate clinico-pathological features and characterize the expression of PD-1 and PD-L1 in a single cohort of 15 patients with PMBCL.

A total of 15 cases of PMBCL were retrieved from records of the department of Pathology; eleven of these had tissue available for additional immunohistochemistry, specifically, PD-L1 …

Metastatic Lobular Breast Carcinoma In A Meningioma: A Case Study, Sara Chapin, Msii, Lawrence C. Kenyon, Md, Phd

Department of Pathology Honors Program Student Research Symposium

Hormonal relationships between breast carcinoma and meningioma have long been reported in the literature. This association may be related to the widespread expression of progesterone receptors in meningiomas. Indeed, meningiomas are more common in women and may demonstrate increased growth during pregnancy. Women have an increased risk of meningioma following breast carcinoma diagnosis and vice versa. However, much more uncommon is a tumor to tumor metastases of breast carcinoma into a meningioma. We report a case of a 56 year old female with a past medical history of breast cancer, found to have a right sphenoorbital meningioma with metastatic lobular …

Ewing’S Sarcoma, Chris Lucasti, Bs, Bruce A. Fenderson, Phd

Department of Pathology Honors Program Student Research Symposium

Ewing’s sarcoma is the second most common malignant tumor of the bone occurring in children and adolescents. Typically, patients present between the ages of 10 and 20, with the disease having a slight predilection for males.1 Tumors often arise in the mid-shaft with the femur being the most frequently affected bone. The most common chromosome translocation, t(11;22)(q24;q12), occurs between the EWS gene and the FLI-1 gene. This translocation has been implicated in these aggressive and malignant tumors.1–4 Oftentimes, patients present with pain and swelling in the area of the affected bone or joint.5 While there has been some improvement in …

Implications Of Hobnail Features In Anaplastic Thyroid Carcinoma And Precursor Lesions, Caroline Dunne, Ba, Stacey K. Mardekian, Md

Department of Pathology Honors Program Student Research Symposium

Anaplastic thyroid carcinoma (ATC) has the poorest prognosis of all thyroid cancers. Morphologically, it is characterized by pleomorphic undifferentiated cells. In some cases, a differentiated precursor lesion, either papillary thyroid carcinoma (PTC) or follicular thyroid carcinoma, can be identified adjacent to the anaplastic component. There are certain morphological variants of PTC that are known to be associated with more aggressive behavior, but a recently described, understudied variant is the hobnail variant. It is characterized histologically by micropapillary structures lined by cells with abundant eosinophilic cytoplasm and apically-placed bulging nuclei. The aim of this study was to evaluate the frequency of …

Suppression Of Invasion And Metastasis Of Triple-Negative Breast Cancer Lines By Pharmacological Or Genetic Inhibition Of Slug Activity., Giovanna Ferrari-Amorotti, Claudia Chiodoni, Fei Shen, Sara Cattelani, Angela Rachele Soliera, Gloria Manzotti, Giulia Grisendi, Massimo Dominici, Francesco Rivasi, Mario Paolo Colombo, Alessandro Fatatis, Bruno Calabretta

Department of Cancer Biology Faculty Papers

Most triple-negative breast cancers (TNBCs) exhibit gene expression patterns associated with epithelial-to-mesenchymal transition (EMT), a feature that correlates with a propensity for metastatic spread. Overexpression of the EMT regulator Slug is detected in basal and mesenchymal-type TNBCs and is associated with reduced E-cadherin expression and aggressive disease. The effects of Slug depend, in part, on the interaction of its N-terminal SNAG repressor domain with the chromatin-modifying protein lysine demethylase 1 (LSD1); thus, we investigated whether tranylcypromine [also known as trans-2-phenylcyclopropylamine hydrochloride (PCPA) or Parnate], an inhibitor of LSD1 that blocks its interaction with Slug, suppresses the migration, invasion, and metastatic …

Methylseleninic Acid Sensitizes Notch3-Activated Ovca429 Ovarian Cancer Cells To Carboplatin., Tiffany J. Tzeng, Lei Cao, Yangxin Fu, Huawei Zeng, Wen-Hsing Cheng

College of Agriculture & Life Sciences Publications and Scholarship

Ovarian cancer, the deadliest of gynecologic cancers, is usually not diagnosed until advanced stages. Although carboplatin has been popular for treating ovarian cancer for decades, patients eventually develop resistance to this platinum-containing drug. Expression of neurogenic locus notch homolog 3 (Notch3) is associated with chemoresistance and poor overall survival in ovarian cancer patients. Overexpression of NICD3 (the constitutively active form of Notch3) in OVCA429 ovarian cancer cells (OVCA429/NICD3) renders them resistance to carboplatin treatment compared to OVCA429/pCEG cells expressing an empty vector. We have previously shown that methylseleninic acid (MSeA) induces oxidative stress and activates ataxia-telangiectasia mutated and DNA-dependent protein …

Cytoplasmic Localization Of Alteration/Deficiency In Activation 3 (Ada3) Predicts Poor Clinical Outcome In Breast Cancer Patients., Sameer Mirza, Emad A. Rakha, Alaa Alshareeda, Shakur Mohibi, Xiangshan Zhao, Bryan J. Katafiasz, Jun Wang, Channabasavaiah B. Gurumurthy, Aditya Bele, Ian O. Ellis, Andrew R. Green, Hamid Band, Vimla Band

Journal Articles: Genetics, Cell Biology & Anatomy

Transcriptional activation by estrogen receptor (ER) is a key step to breast oncogenesis. Given previous findings that ADA3 is a critical component of HAT complexes that regulate ER function and evidence that overexpression of other ER coactivators such as SRC-3 is associated with clinical outcomes in breast cancer, the current study was designed to assess the potential significance of ADA3 expression/localization in human breast cancer patients. In this study, we analyzed ADA3 expression in breast cancer tissue specimens and assessed the correlation of ADA3 staining with cancer progression and patient outcome. Tissue microarrays prepared from large series of breast cancer …

Expression And Function Of Hypoxia Inducible Factor-1 Alpha In Human Melanoma Under Non-Hypoxic Conditions, Caroline N. Mills, Sandeep S. Joshi, Richard M. Niles

Richard M. Niles

Background Hypoxia inducible factor-1 alpha (HIF-1α) protein is rapidly degraded under normoxic conditions. When oxygen tensions fall HIF-1α protein stabilizes and transactivates genes involved in adaptation to hypoxic conditions. We have examined the normoxic expression of HIF-1α RNA and protein in normal human melanocytes and a series of human melanoma cell lines isolated from radial growth phase (RGP), vertical growth phase (VGP) and metastatic (MET) melanomas. Results HIF-1α mRNA and protein was increased in RGP vs melanocytes, VGP vs RGP and MET vs VGP melanoma cell lines. We also detected expression of a HIF-1α mRNA splice variant that lacks part …

Overexpression Of A Novel Cell Cycle Regulator Ecdysoneless In Breast Cancer: A Marker Of Poor Prognosis In Her2/Neu-Overexpressing Breast Cancer Patients., Xiangshan Zhao, Sameer Mirza, Alaa Alshareeda, Ying Zhang, Channabasavaiah B. Gurumurthy, Aditya Bele, Jun Hyun Kim, Shakur Mohibi, Monica Goswami, Subodh M. Lele, William West, Fang Qiu, Ian O. Ellis, Emad A. Rakha, Andrew R. Green, Hamid Band, Vimla Band

Journal Articles: Genetics, Cell Biology & Anatomy

Uncontrolled proliferation is one of the hallmarks of breast cancer. We have previously identified the human Ecd protein (human ortholog of Drosophila Ecdysoneless, hereafter called Ecd) as a novel promoter of mammalian cell cycle progression, a function related to its ability to remove the repressive effects of Rb-family tumor suppressors on E2F transcription factors. Given the frequent dysregulation of cell cycle regulatory components in human cancer, we used immunohistochemistry of paraffin-embedded tissues to examine Ecd expression in normal breast tissue versus tissues representing increasing breast cancer progression. Initial studies of a smaller cohort without outcomes information showed that Ecd expression …

Autophagy And Senescence In Cancer-Associated Fibroblasts Metabolically Supports Tumor Growth And Metastasis Via Glycolysis And Ketone Production., Claudia Capparelli, Carmela Guido, Diana Whitaker-Menezes, Phd, Gloria Bonuccelli, Renee Balliet, Timothy G Pestell, Allison F Goldberg, Richard Pestell, Anthony Howell, Sharon Sneddon, Ruth Birbe, Aristotelis Tsirigos, Ubaldo E. Martinez-Outshoorn, Federica Sotgia, Michael P. Lisanti

Department of Stem Cell Biology and Regenerative Medicine Faculty Papers & Presentations

Senescent fibroblasts are known to promote tumor growth. However, the exact mechanism remains largely unknown. An important clue comes from recent studies linking autophagy with the onset of senescence. Thus, autophagy and senescence may be part of the same physiological process, known as the autophagy-senescence transition (AST). To test this hypothesis, human fibroblasts immortalized with telomerase (hTERT-BJ1) were stably transfected with autophagy genes (BNIP3, CTSB or ATG16L1). Their overexpression was sufficient to induce a constitutive autophagic phenotype, with features of mitophagy, mitochondrial dysfunction and a shift toward aerobic glycolysis, resulting in L-lactate and ketone body production. Autophagic fibroblasts also showed …

Ctgf Drives Autophagy, Glycolysis And Senescence In Cancer-Associated Fibroblasts Via Hif1 Activation, Metabolically Promoting Tumor Growth., Claudia Capparelli, Diana Whitaker-Menezes, Carmela Guido, Renee Balliet, Timothy G Pestell, Anthony Howell, Sharon Sneddon, Richard Pestell, Ubaldo E. Martinez-Outshoorn, Michael P. Lisanti, Federica Sotgia

Department of Stem Cell Biology and Regenerative Medicine Faculty Papers & Presentations

Previous studies have demonstrated that loss of caveolin-1 (Cav-1) in stromal cells drives the activation of the TGF-β signaling, with increased transcription of TGF-β target genes, such as connective tissue growth factor (CTGF). In addition, loss of stromal Cav-1 results in the metabolic reprogramming of cancer-associated fibroblasts, with the induction of autophagy and glycolysis. However, it remains unknown if activation of the TGF-β / CTGF pathway regulates the metabolism of cancer-associated fibroblasts. Therefore, we investigated whether CTGF modulates metabolism in the tumor microenvironment. For this purpose, CTGF was overexpressed in normal human fibroblasts or MDA-MB-231 breast cancer cells. Overexpression of …

Pv1 Down-Regulation Via Shrna Inhibits The Growth Of Pancreatic Adenocarcinoma Xenografts, Sophie J. Deharvengt, Dan Tse, Olga Sideleva, Caitlin Mcgarry, Jason R. Gunn, Daniel S. Longnecker, Catherine Carriere, Radu V. Stan

Dartmouth Scholarship

PV1 is an endothelial-specific protein with structural roles in the formation of diaphragms in endothelial cells of normal vessels. PV1 is also highly expressed on endothelial cells of many solid tumours. On the basis of in vitro data, PV1 is thought to actively participate in angiogenesis. To test whether or not PV1 has a function in tumour angiogenesis and in tumour growth in vivo, we have treated pancreatic tumour-bearing mice by single-dose intratumoural delivery of lentiviruses encoding for two different shRNAs targeting murine PV1. We find that PV1 down-regulation by shRNAs inhibits the growth of established tumours derived from two …

Contribution Of The Unfolded Protein Response To Vegf Expression, Ethel Rose Pereira

Theses and Dissertations (ETD)

Tumor cells experience a limiting microenvironment due to inadequate vascularization that can affect the normal functioning of intracellular organelles. In the case of the endoplasmic reticulum, the limiting environment is further exacerbated by the high metabolic demands of the tumor cells, which together interfere with the proper maturation of nascent proteins synthesized there. The resultant accumulation of unfolded proteins activates a signal transduction pathway known as the Unfolded Protein Response, which serves primarily to protect the cell during stress and helps restore homeostasis to this organelle. As tumors expand resulting in regions that are a greater distance from functional blood …

Decorin-Mediated Inhibition Of Colorectal Cancer Growth And Migration Is Associated With E-Cadherin In Vitro And In Mice., Xiuli Bi, Nicole M Pohl, Zhibin Qian, George R Yang, Yuan Gou, Grace Guzman, Andre Kajdacsy-Balla, Renato V Iozzo, Wancai Yang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Previous studies have shown that decorin expression is significantly reduced in colorectal cancer tissues and cancer cells, and genetic deletion of the decorin gene is sufficient to cause intestinal tumor formation in mice, resulting from a downregulation of p21, p27(kip1) and E-cadherin and an upregulation of β-catenin signaling [Bi,X. et al. (2008) Genetic deficiency of decorin causes intestinal tumor formation through disruption of intestinal cell maturation. Carcinogenesis, 29, 1435-1440]. However, the regulation of E-cadherin by decorin and its implication in cancer formation and metastasis is largely unknown. Using a decorin knockout mouse model (Dcn(-/-) mice) and manipulated expression of decorin …

Decorin Protein Core Affects The Global Gene Expression Profile Of The Tumor Microenvironment In A Triple-Negative Orthotopic Breast Carcinoma Xenograft Model., Simone Buraschi, Thomas Neill, Rick T Owens, Leonardo A Iniguez, George Purkins, Rajanikanth Vadigepalli, Barry Evans, Liliana Schaefer, Stephen C Peiper, Zi-Xuan Wang, Renato V Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Decorin, a member of the small leucine-rich proteoglycan gene family, exists and functions wholly within the tumor microenvironment to suppress tumorigenesis by directly targeting and antagonizing multiple receptor tyrosine kinases, such as the EGFR and Met. This leads to potent and sustained signal attenuation, growth arrest, and angiostasis. We thus sought to evaluate the tumoricidal benefits of systemic decorin on a triple-negative orthotopic breast carcinoma xenograft model. To this end, we employed a novel high-density mixed expression array capable of differentiating and simultaneously measuring gene signatures of both Mus musculus (stromal) and Homo sapiens (epithelial) tissue origins. We found that …

Kaempferol Nanoparticles Achieve Strong And Selective Inhibition Of Ovarian Cancer Cell Viability., Haitao Luo, Bingbing Jiang, Bingyun Li, Zhaoliang Li, Bing-Hua Jiang, Yi Charlie Chen

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Ovarian cancer is one of the leading causes of cancer death for women throughout the Western world. Kaempferol, a natural flavonoid, has shown promise in the chemoprevention of ovarian cancer. A common concern about using dietary supplements for chemoprevention is their bioavailability. Nanoparticles have shown promise in increasing the bioavailability of some chemicals. Here we developed five different types of nanoparticles incorporating kaempferol and tested their efficacy in the inhibition of viability of cancerous and normal ovarian cells. We found that positively charged nanoparticle formulations did not lead to a significant reduction in cancer cell viability, whereas nonionic polymeric nanoparticles …

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 …

Mir-21 Induced Angiogenesis Through Akt And Erk Activation And Hif-1Α Expression., Ling-Zhi Liu, Chongyong Li, Qi Chen, Yi Jing, Richard Carpenter, Yue Jiang, Hsiang-Fu Kung, Lihui Lai, Bing-Hua Jiang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

MicroRNAs (miRNAs) are endogenous, small noncoding RNAs that play important roles in various cellular functions and tumor development. Recent studies have indicated that miR-21 is one of the important miRNAs associated with tumor growth and metastasis, but the role and molecular mechanism of miR-21 in regulating tumor angiogenesis remain to be elucidated. In this study, miR-21 was overexpressed by transfecting pre-miR-21 into human prostate cancer cells and tumor angiogenesis was assayed using chicken chorioallantoic membrane (CAM). We found that overexpression of miR-21 in DU145 cells increased the expression of HIF-1α and VEGF, and induced tumor angiogenesis. AKT and extracellular regulated …

Proliferation Of Aneuploid Human Cells Is Limited By A P53-Dependent Mechanism, Sarah L. Thompson, Duane A. Compton

Dartmouth Scholarship

Most solid tumors are aneuploid, and it has been proposed that aneuploidy is the consequence of an elevated rate of chromosome missegregation in a process called chromosomal instability (CIN). However, the relationship of aneuploidy and CIN is unclear because the proliferation of cultured diploid cells is compromised by chromosome missegregation. The mechanism for this intolerance of nondiploid genomes is unknown. In this study, we show that in otherwise diploid human cells, chromosome missegregation causes a cell cycle delay with nuclear accumulation of the tumor suppressor p53 and the cyclin kinase inhibitor p21. Deletion of the p53 gene permits the accumulation …

Expression And Function Of Hypoxia Inducible Factor-1 Alpha In Human Melanoma Under Non-Hypoxic Conditions, Caroline N. Mills, Sandeep S. Joshi, Richard M. Niles

Biochemistry and Microbiology

Background

Hypoxia inducible factor-1 alpha (HIF-1α) protein is rapidly degraded under normoxic conditions. When oxygen tensions fall HIF-1α protein stabilizes and transactivates genes involved in adaptation to hypoxic conditions. We have examined the normoxic expression of HIF-1α RNA and protein in normal human melanocytes and a series of human melanoma cell lines isolated from radial growth phase (RGP), vertical growth phase (VGP) and metastatic (MET) melanomas.

Results

HIF-1α mRNA and protein was increased in RGP vs melanocytes, VGP vs RGP and MET vs VGP melanoma cell lines. We also detected expression of a HIF-1α mRNA splice variant that lacks part …

N-Glycosylation Status Of E-Cadherin Controls Cytoskeletal Dynamics Through The Organization Of Distinct Β-Catenin- And Γ-Catenin-Containing Ajs., Basem T Jamal, Mihai Nita-Lazar, Zhennan Gao, Bakr Amin, Janice Walker, Maria A Kukuruzinska

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

N-glycosylation of E-cadherin has been shown to inhibit cell-cell adhesion. Specifically, our recent studies have provided evidence that the reduction of E-cadherin N-glycosylation promoted the recruitment of stabilizing components, vinculin and serine/threonine protein phosphatase 2A (PP2A), to adherens junctions (AJs) and enhanced the association of AJs with the actin cytoskeleton. Here, we examined the details of how N-glycosylation of E-cadherin affected the molecular organization of AJs and their cytoskeletal interactions. Using the hypoglycosylated E-cadherin variant, V13, we show that V13/β-catenin complexes preferentially interacted with PP2A and with the microtubule motor protein dynein. This correlated with dephosphorylation of the microtubule-associated protein …

Interaction With Lc8 Is Required For Pak1 Nuclear Import And Is Indispensable For Zebrafish Development., Christine M Lightcap, Gabor Kari, Luis E Arias-Romero, Jonathan Chernoff, Ulrich Rodeck, John C Williams

Department of Biochemistry and Molecular Biology Faculty Papers

Pak1 (p21 activated kinase 1) is a serine/threonine kinase implicated in regulation of cell motility and survival and in malignant transformation of mammary epithelial cells. In addition, the dynein light chain, LC8, has been described to cooperate with Pak1 in malignant transformation of breast cancer cells. Pak1 itself may aid breast cancer development by phosphorylating nuclear proteins, including estrogen receptor alpha. Recently, we showed that the LC8 binding site on Pak1 is adjacent to the nuclear localization sequence (NLS) required for Pak1 nuclear import. Here, we demonstrate that the LC8-Pak1 interaction is necessary for epidermal growth factor (EGF)-induced nuclear import …

U2os Cells Lacking Chk1 Undergo Aberrant Mitosis And Fail To Activate The Spindle Checkpoint, Laura Carrassa, Yolanda Sanchez, Eugenio Erba, Giovanna Damia

Dartmouth Scholarship

Chk1 is a conserved protein kinase originally identified in fission yeast, required to delay entry of cells with damaged or unreplicated DNA into mitosis. The requirement of Chk1 for both S and G2/M checkpoints has been elucidated while only few studies have connected Chk1 to the mitotic spindle checkpoint. We used a small interference RNA strategy to investigate the role of Chk1 in unstressed conditions. Chk1 depletion in U2OS human osteosarcoma cells inhibited cell proliferation and raised the percentage of cells with a 4N DNA content, which correlated with accumulation of giant polynucleated cells morphologically distinct from apoptotic cells, while …

Stat5 Regulation Of Bcl10 Parallels Constitutive Nfkappab Activation In Lymphoid Tumor Cells., Zsuzsanna S Nagy, Matthew J Lebaron, Jeremy A Ross, Abhisek Mitra, Hallgeir Rui, Robert A Kirken

Department of Cancer Biology Faculty Papers

BACKGROUND: Signal Transducer and Activator of Transcription 5 A and B (STAT5) are key survival factors in cells of the lymphoid lineage. Identification of novel, tissue-specific STAT5 regulated genes would advance the ability to combat diseases due to aberrant STAT5 signaling. In the present work a library of human STAT5 bound genomic elements was created and validated. RESULTS: Of several STAT5 responsive genomic regulatory elements identified, one was located within the first intron of the human BCL10 gene. Chromatin immuno-precipitation reactions confirmed constitutive in vivo STAT5 binding to this intronic fragment in various human lymphoid tumor cell lines. Interestingly, non-phosphorylated …