Medicine and Health Sciences Commons^™

Oncogene-Dependent Regulation Of Autophagic Flux In Melanoma, Kirsten Anne Meyer White

Biomedical Sciences ETDs

Skin cancer is the one of the most diagnosed cancers in the United States with increasing incidence of 6% every year. In 2015, it is estimated 73,870 new cases of melanoma will be identified and 9,480 individuals will die of their disease. While melanoma only accounts for approximately 2.4% of all cancer related deaths and is the 5th leading diagnosed cancer (US) it is the one of the most common cancers in young adults, age 25-29, particularly for young women. Of particular importance, the mean survival rate of patients diagnosed with metastatic melanoma is six months, with five-year survival rates …

Antioncogenic And Oncogenic Properties Of Nrf2 In Arsenic-Induced Carcinogenesis, Young-Ok Son, Poyil Pratheeshkumar, Ram Vinod Roy, Andrew Hitron, Lei Wang, Sasidharan Padmaja Divya, Mei Xu, Jia Luo, Gang Chen, Zhuo Zhang, Xianglin Shi

Center for Research on Environmental Disease Faculty Publications

Arsenic (As³⁺) is a carcinogen with considerable environmental and occupational relevancy. The present study shows that As³⁺-transformed human lung bronchial epithelial BEAS-2B cells (AsT cells) exhibit the property of apoptosis resistance. The level of basal reactive oxygen species (ROS) is very low in AsT cells in correlation with elevated expressions of both antioxidant enzymes and antiapoptotic proteins. Nuclear factor erythroid 2-related factor (Nrf2) and p62 are constitutively expressed. These two proteins up-regulate antioxidant enzymes and antiapoptotic proteins. The knockdown of Nrf2 or p62 by small interfering RNA (siRNA) enhanced both ROS levels and As³⁺-induced …

Dendritic Cell Autophagy Contributes To Herpes Simplex Virus-Driven Stromal Keratitis And Immunopathology, Yike Jiang, Xiaotang Yin, Patrick M. Stuart, David A. Leib

Dartmouth Scholarship

Herpetic stromal keratitis (HSK) is a blinding ocular disease that is initiated by HSV-1 and characterized by chronic inflammation in the cornea. Although HSK immunopathology of the cornea is well documented in animal models, events preceding this abnormal inflammatory cascade are poorly understood. In this study, we have examined the activation of pathological CD4T cells in the development of HSK. Dendritic cell autophagy (DC-autophagy) is an important pathway regulating ma- jor histocompatibility complex class II (MHCII)-dependent antigen presentation and proper CD4T cell activation during infectious diseases. Using DC-autophagy-deficient mice, we found that DC-autophagy significantly and specifically contributes to HSK disease …

The Role Of Perlecan And Endorepellin In The Control Of Tumor Angiogenesis And Endothelial Cell Autophagy., Stephen Douglass, Atul Goyal, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

During tumor growth and angiogenesis there is a dynamic remodeling of tissue architecture often accompanied by the release of extracellular matrix constituents full of biological activity. One of the key constituents of the tumor microenvironment is the large heparan sulfate proteoglycan perlecan. This proteoglycan, strategically located at cell surfaces and within basement membranes, is a well-defined pro-angiogenic molecule when intact. However, when partially processed by proteases released during cancer remodeling and invasion, the C-terminal fragment of perlecan, known as endorepellin, has opposite effects than its parent molecule. Endorepellin is a potent inhibitor of angiogenesis by exerting a dual receptor antagonism …

Beclin-1 Expression Is Retained In High-Grade Serous Ovarian Cancer Yet Is Not Essential For Autophagy Induction In Vitro, Rohann J.M. Correa, Yudith R. Valdes, Trevor G. Shepherd, Gabriel E. Dimattia

Anatomy and Cell Biology Publications

Background: Autophagy is a conserved cellular self-digestion mechanism that can either suppress or promote cancer in a context-dependent manner. In ovarian cancer, prevalent mono-allelic deletion of BECN1 (a canonical autophagy-inducer) suggests that autophagy is impaired to promote carcinogenesis and that Beclin-1 is a haploinsufficient tumor suppressor. Nonetheless, autophagy is known to be readily inducible in ovarian cancer cells. We sought to clarify whether Beclin-1 expression is in fact disrupted in ovarian cancer and whether this impacts autophagy regulation.

Methods: BECN1 expression levels were assessed using The Cancer Genome Atlas (TCGA) datasets from 398 ovarian high-grade serous cystadenocarcinomas (HGSC) and protein …

Truncating Mutation In The Autophagy Gene Uvrag Confers Oncogenic Properties And Chemosensitivity In Colorectal Cancers, Shanshan He, Zhen Zhao, Yongfei Yang, Douglas O'Connell, Xiaowei Zhang, Soohwan Oh, Binyun Ma, Joo-Hyung Lee, Tian Zhang, Bino Varghese, Janae Yip, Sara Dolatshahi Pirooz, Ming Li, Yong Zhang, Guo-Min Li, Sue Ellen Martin, Keigo Machida, Chengyu Liang

Toxicology and Cancer Biology Faculty Publications

Autophagy-related factors are implicated in metabolic adaptation and cancer metastasis. However, the role of autophagy factors in cancer progression and their effect in treatment response remain largely elusive. Recent studies have shown that UVRAG, a key autophagic tumour suppressor, is mutated in common human cancers. Here we demonstrate that the cancer-related UVRAG frameshift (FS), which does not result in a null mutation, is expressed as a truncated UVRAG^FS in colorectal cancer (CRC) with microsatellite instability (MSI), and promotes tumorigenesis. UVRAG^FS abrogates the normal functions of UVRAG, including autophagy, in a dominant-negative manner. Furthermore, expression of UVRAG^FS can …

Paradoxical Effects Of The Autophagy Inhibitor 3-Methyladenine On Docetaxel-Induced Toxicity In Pc-3 And Lncap Prostate Cancer Cells, Rebecca Pickard, Briohny Spencer, Amelia Mcfarland, Nijole Bernaitis, Andrew Davey, Russ Chess-Williams, Catherine Mcdermott, Amanda Forbes, David Christie, Shailendra Anoopkumar-Dukie

Russ Chess-Williams

Survival time in patients with androgen-resistant prostate cancer. However, it provides only a modest increase in survival and is associated with significant toxicity. Therefore, there is an urgent need to identify potential adjunct therapies. Given the key role of autophagy in both tumour survival and chemoresistance, the impact of autophagy modulation on docetaxel toxicity was tested in vitro. PC-3 and LNCaP cells were pre-treated with the autophagy inhibitor 3- methyladenine (5 mM) and then exposed to various concentrations (0–100 μM) of docetaxel. Cytoxic effects of docetaxel were measured using resazurin reduction to resorufin, whilst autophagy and apoptosis was measured using …

Paradoxical Effects Of The Autophagy Inhibitor 3-Methyladenine On Docetaxel-Induced Toxicity In Pc-3 And Lncap Prostate Cancer Cells, Rebecca Pickard, Briohny Spencer, Amelia Mcfarland, Nijole Bernaitis, Andrew Davey, Russ Chess-Williams, Catherine Mcdermott, Amanda Forbes, David Christie, Shailendra Anoopkumar-Dukie

Catherine M. McDermott

Survival time in patients with androgen-resistant prostate cancer. However, it provides only a modest increase in survival and is associated with significant toxicity. Therefore, there is an urgent need to identify potential adjunct therapies. Given the key role of autophagy in both tumour survival and chemoresistance, the impact of autophagy modulation on docetaxel toxicity was tested in vitro. PC-3 and LNCaP cells were pre-treated with the autophagy inhibitor 3- methyladenine (5 mM) and then exposed to various concentrations (0–100 μM) of docetaxel. Cytoxic effects of docetaxel were measured using resazurin reduction to resorufin, whilst autophagy and apoptosis was measured using …

Paradoxical Role Of 3-Methyladenine In Pyocyanin-Induced Toxicity In 1321n1 Astrocytoma And Sh-Sy5y Neuroblastoma Cells, Amelia Mcfarland, Gary Grant, Anthony Perkins, Cameron Flegg, Andrew Davey, Tristan Allsopp, Gillian Renshaw, Justin Kavanagh, Catherine Mcdermott, Shailendra Anoopkumar-Dukie

Catherine M. McDermott

The role of autophagy in pyocyanin (PCN)-induced toxicity in the central nervous system (CNS) remains unclear, with only evidence from our group identifying it as a mechanism underlying toxicity in 1321N1 astrocytoma cells. Therefore, the aim of this study was to further examine the role of autophagy in PCN-induced toxicity in the CNS. To achieve this, we exposed 1321N1 astrocytoma and SH-SY5Y neuroblastoma cells to PCN (0-100 μmol/L) and tested the contribution of autophagy by measuring the impact of the autophagy inhibitor 3-methyladenine (3-MA) using a series of biochemical and molecular markers. Pretreatment of 1321N1 astrocytoma cells with 3-MA (5 …

Association Of Autophagy In The Cell Death Mediated By Dihydrotestosterone In Autoreactive T Cells Independent Of Antigenic Stimulation, Ting Jia, Annandurai Anandhan, Chandirasegaran Massilamany, Rajkumar A. Rajasekaran, Rodrigo Franco, Jay Reddy

School of Veterinary and Biomedical Sciences: Faculty Publications

Gender disparity is well documented in the mouse model of experimental autoimmune encephalomyelitis (EAE) induced with proteolipid protein (PLP) 139–151, in which female, but not male, SJL mice show a chronic relapsing-remitting paralysis. Furthermore, dihydrotestosterone (DHT) has been shown to ameliorate the severity of EAE, but the underlying mechanisms of its protective effects are unclear. Using major histocompatibility complex (MHC) class II dextramers for PLP 139-151, we tested the hypothesis that DHT selectively modulates the expansion and functionalities of antigen-specific T cells. Unexpectedly, we noted that DHT induced cell death in antigen-specific, autoreactive T cells, but the effects were not …

Differing Roles Of Autophagy In Hiv-Associated Neurocognitive Impairment And Encephalitis With Implications For Morphine Co-Exposure, Seth M. Dever, Myosotys Rodriguez, Jessica Lapierre, Blair N. Costin, Nazira El-Hage

Pharmacology and Toxicology Publications

We investigated the role of autophagy in HIV-infected subjects with neurocognitive impairment (NCI) ± HIV encephalitis (HIVE), many of which had a history of polysubstance abuse/dependence, using post-mortem brain tissues to determine whether differences in autophagy related factors may be more associated with NCI or NCI-encephalitis. Using qRT-PCR, we detected significant differences in gene expression levels with SQSTM1, LAMP1 higher in HIV-infected subjects without NCI while ATG5, SQSTM1 were then lower in HIV infection/NCI and ATG7, SQSTM1 being higher in NCI-HIVE. Immunohistochemical labeling of these autophagy associated proteins (also including Beclin 1 and LC3B) in Iba1-positive microglial cells showed generally …

Targeting Autophagy In Multiple Myeloma, Yun Dai

Theses and Dissertations

Apoptosis (Type I) and autophagy (Type II) represent two major forms of programmed cell death. Numerous anticancer agents employed in standard chemotherapy or novel targeted therapy induce both apoptosis and autophagy. Of note, a cytoprotective autophagic response often counteracts apoptosis triggered by such agents, potentially contributing to drug-resistance. Mechanistically, autophagy and apoptosis share molecular regulatory mechanisms primarily governed by the Bcl-2 family proteins. However, since autophagy acts as the double-edge sword in cancer, whether autophagy should be inhibited or activated in cancer treatment remains the subject of debate. Here we report a) a novel autophagy-targeted strategy that targeting the adaptor …

Amla Enhances Autophagy And Modulates Beta Amyloid Metabolism In An In Vitro Model Of Alzheimer’S Disease, Elham Teimouri, Prashant Bharadwaj, Stephanie R. Rainey-Smith, Paul Fraser, Giuseppe Verdile, Ralph N. Martins

ECU Posters

Alzheimer’s disease (AD) is a progressive, fatal neurodegenerative disease characterized by extensive neuronal loss associated with increased accumulation of the beta amyloid (Aβ) protein. Reducing production, preventing aggregation and improving clearance of Aβare areas of active research in the development of therapeutic agents to ameliorate neurodegeneration in AD. The Indian plant amla (Emblicaofficinalis), commonly known as Indian gooseberry, has widely been utilized in traditional Ayurvedic medicine preparations in the treatment of a variety of disease conditions including cardiovascular disease and diabetes: accumulating evidence also suggests that amla may be beneficial in AD. Amla exhibits antioxidant, anti-inflammatory, and anti-apoptotic mechanisms and …

Role Of Autophagy In The Pathogenesis Of Alzheimer Disease, Muhammet Cemal Kizilarslanoğlu, Zekeri̇ya Ülger

Turkish Journal of Medical Sciences

Alzheimer disease (AD) is the most common progressive neurodegenerative disorder causing increased morbidity and mortality. It is characterized by accumulation of amyloid-β in neurons. As there is no known definitive treatment of this disorder, studies trying to determine its exact pathogenetic pathways and target therapies for these specific pathways are being rapidly conducted. Autophagy is one of the areas of interest in studies on the pathogenesis of AD. It is a process of self-digestion that is thought to be a response to stressors and allows cells to adapt to environmental changes. There is accumulating evidence showing an association between autophagy …

Linking Adiponectin And Autophagy In The Regulation Of Breast Cancer Metastatic Potential, Emily Libby

All ETDs from UAB

Curative approaches for metastatic breast cancer remain elusive. Adiponectin is the most abundant of the adipocyte-secreted adipokines, and there is recent interest in development of adiponectin-based therapies for this disease. Yet, while multiple epidemiological studies have indicated that low levels of circulating plasma adiponectin portend poorer prognosis, recent work has reported that elevated adiponectin expression in breast tissue correlates with advanced disease. Further, isoform-specific roles of this molecule are not well understood. Thus, the overarching purpose of this work was to elucidate how adiponectin isoforms contribute to the microenvironmental regulation of the early steps of breast cancer metastasis. We show …

Changes In Gene Expression During Nitrogen Starvation Are Mediated By Targeted Degradation Of Translation And Mrna Decay Factors In Saccharomyces Cerevisiae, Shane Patrick Kelly

All ETDs from UAB

Autophagy is the cellular mechanism of recruitment and decay of cytoplasmic molecules, proteins, and organelles that are obsolete for a particular growth condition. Autophagic degradation is distinct from proteasomal degradation by the formation of a de-novo double membrane which engulfs its cargo to be delivered for degradation to the yeast vacuole. Once thought to be only a general phenomenon of bulk decay, several autophagic pathways have demonstrated selectivity. In the following work we show that during nitrogen starvation (a potent inducer of autophagy) in the yeast Saccharomyces cerevisiae, a subset of translation factors are degraded selectively and rapidly. We go …

Metabolic And Oxidative Regulation Of Neuronal Autophagy And Survival, Matthew Dodson

All ETDs from UAB

Neurodegenerative diseases, such as Parkinson's disease, Alzheimer's disease and Huntington's disease are all characterized by metabolic dysfunction, increased oxidative damage to proteins and organelles, formation of proteinaceous inclusions, decreased autophagic and proteasomal function, and eventual neuronal and glial cell death. While our understanding of the mechanisms that underlie many of these pathologies is constantly growing, their exact cause, onset, interplay and progression still remain unclear. The gap between the description of disease pathologies and understanding the fundamental mechanisms of disease pathogenesis, progression and potential therapeutics to mitigate disease progression is still large. Based on the observation that altered glucose utilization, …

Potential Role Of Protein Kinase Cbeta In High Fat Diet-Induced Adipose Dysfunction By Regulating Autophagy Levels, Neil Mehta

Williams Honors College, Honors Research Projects

Obesity is the most common nutritional disorder in the United States and worldwide. Public health efforts and other anti-obesity measures clearly have not controlled the obesity epidemic. There is a great need to understand the pathogenic mechanisms underlying fat accumulation. Research of the past decade supports a prominent role for diet-induced adipose tissue dysfunction in the development and/or progression of obesity and associated insulin resistance. Potential mechanisms for the development of adipose tissue dysfunction include ectopic (visceral) fat accumulation, genetic factors, and alterations in autophagy and inflammatory processes. However, the molecular mechanisms linking dietary fat intake with alterations in adipose …