Medicine and Health Sciences Commons^™

The Janus Kinase 1 Is Critical For Pancreatic Cancer Initiation And Progression, Hridaya Shrestha, Patrick Rädler, Rayane Dennaoui, Madison Wicker, Nirakar Rajbhandari, Yunguang Sun, Amy Peck, Kerry Vistisen, Aleata Triplett, Rafic Beydoun, Esta Sterneck, Dieter Saur, Hallgeir Rui, Kay-Uwe Wagner

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Interleukin-6 (IL-6)-class inflammatory cytokines signal through the Janus tyrosine kinase (JAK)/signal transducer and activator of transcription (STAT) pathway and promote the development of pancreatic ductal adenocarcinoma (PDAC); however, the functions of specific intracellular signaling mediators in this process are less well defined. Using a ligand-controlled and pancreas-specific knockout in adult mice, we demonstrate in this study that JAK1 deficiency prevents the formation of KRAS^G12D-induced pancreatic tumors, and we establish that JAK1 is essential for the constitutive activation of STAT3, whose activation is a prominent characteristic of PDAC. We identify CCAAT/enhancer binding protein δ (C/EBPδ) as a biologically relevant …

Xpo1 Blockade With Kpt-330 Promotes Apoptosis In Cutaneous T-Cell Lymphoma By Activating The P53-P21 And P27 Pathways, Nitin Chakravarti, Amy Boles, Rachel Burzinski, Paola Sindaco, Colleen Isabelle, Kathleen Mcconnell, Anjali Mishra, Pierluigi Porcu

Kimmel Cancer Center Faculty Papers

Dysregulated nuclear-cytoplasmic trafficking has been shown to play a role in oncogenesis in several types of solid tumors and hematological malignancies. Exportin 1 (XPO1) is responsible for the nuclear export of several proteins and RNA species, mainly tumor suppressors. KPT-330, a small molecule inhibitor of XPO1, is approved for treating relapsed multiple myeloma and diffuse large B-cell lymphoma. Cutaneous T-cell lymphoma (CTCL) is an extranodal non-Hodgkin lymphoma with an adverse prognosis and limited treatment options in advanced stages. The effect of therapeutically targeting XPO1 with KPT-330 in CTCL has not been established. We report that XPO1 expression is upregulated in …

Nf-Κb As An Inducible Regulator Of Inflammation In The Central Nervous System, Sudha Anilkumar, Elizabeth Wright-Jin

Department of Medicine Faculty Papers

The NF-κB (nuclear factor K-light-chain-enhancer of activated B cells) transcription factor family is critical for modulating the immune proinflammatory response throughout the body. During the resting state, inactive NF-κB is sequestered by IκB in the cytoplasm. The proteasomal degradation of IκB activates NF-κB, mediating its translocation into the nucleus to act as a nuclear transcription factor in the upregulation of proinflammatory genes. Stimuli that initiate NF-κB activation are diverse but are canonically attributed to proinflammatory cytokines and chemokines. Downstream effects of NF-κB are cell type-specific and, in the majority of cases, result in the activation of pro-inflammatory cascades. Acting as …

Stat5 Induces Androgen Receptor (Ar) Gene Transcription In Prostate Cancer And Offers A Druggable Pathway To Target Ar Signaling, Cristina Maranto, Lavannya Sabharwal, Vindhya Udhane, Samuel P. Pitzen, Braedan Mccluskey, Songyan Qi, Christine O'Connor, Savita Devi, Scott Johnson, Kenneth Jacobsohn, Anjishnu Banerjee, Kenneth A. Iczkowski, Liang Wang, Scott M. Dehm, Marja T. Nevalainen

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Androgen receptor (AR) drives prostate cancer (PC) growth and progression, and targeting AR signaling is the mainstay of pharmacological therapies for PC. Resistance develops relatively fast as a result of refueled AR activity. A major gap in the field is the lack of understanding of targetable mechanisms that induce persistent AR expression in castrate-resistant PC (CRPC). This study uncovers an unexpected function of active Stat5 signaling, a known promoter of PC growth and clinical progression, as a potent inducer of AR gene transcription. Stat5 suppression inhibited AR gene transcription in preclinical PC models and reduced the levels of wild-type, mutated, …

Extended-Synaptotagmin-1 And -2 Control T Cell Signaling And Function, Nathalia Benavides, Claudio G. Giraudo

Department of Microbiology and Immunology Faculty Papers

Upon T-cell activation, the levels of the secondary messenger diacylglycerol (DAG) at the plasma membrane need to be controlled to ensure appropriate T-cell receptor signaling and T-cell functions. Extended-Synaptotagmins (E-Syts) are a family of inter-organelle lipid transport proteins that bridge the endoplasmic reticulum and the plasma membrane. In this study, we identify a novel regulatory mechanism of DAG-mediated signaling for T-cell effector functions based on E-Syt proteins. We demonstrate that E-Syts downmodulate T-cell receptor signaling, T-cell-mediated cytotoxicity, degranulation, and cytokine production by reducing plasma membrane levels of DAG. Mechanistically, E-Syt2 predominantly modulates DAG levels at the plasma membrane in resting-state …

Targeting The Αvβ3/Ngr2 Pathway In Neuroendocrine Prostate Cancer, Anna Testa, Fabio Quaglia, Nicole M. Naranjo, Cecilia E. Verrillo, Christopher D. Shields, Stephen Lin, Maxwell W. Pickles, Drini F. Hamza, Tami Von Schalscha, David A. Cheresh, Benjamin E Leiby, Qin Liu, Jianyi Ding, William K. Kelly, D. Craig Hooper, Eva Corey, Edward F. Plow, Dario C. Altieri, Lucia R. Languino

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Highly aggressive, metastatic, neuroendocrine prostate cancer, which typically develops from prostate cancer cells acquiring resistance to androgen deprivation therapy, is associated with limited treatment options and hence poor prognosis. We have previously demonstrated that the αVβ3 integrin is over-expressed in neuroendocrine prostate cancer. We now show that LM609, a monoclonal antibody that specifically targets the human αVβ3 integrin, hinders the growth of neuroendocrine prostate cancer patient-derived xenografts in vivo. Our group has recently identified a novel αVβ3 integrin binding partner, NgR2, responsible for regulating the expression of neuroendocrine markers and for inducing neuroendocrine differentiation in prostate cancer cells. Through in …

Identification Of A Β-Arrestin-Biased Negative Allosteric Modulator For The Β2-Adrenergic Receptor, Michael Ippolito, Francesco De Pascali, Nathan Hopfinger, Konstantin E. Komolov, Daniela Laurinavichyute, Poli Adi Narayana Reddy, Leon A. Sakkal, Kyle Z. Rajkowski, Ajay P. Nayak, Justin Lee, Jordan Lee, Gaoyuan Cao, Preston S. Donover, Melvin Reichman, Stevens. An, Joseph M. Salvino, Raymond B. Penn, Roger S S. Armen, Charles P. Scott, Jeffrey L. Benovic

Department of Biochemistry and Molecular Biology Faculty Papers

Catecholamine-stimulated β2-adrenergic receptor (β2AR) signaling via the canonical Gs–adenylyl cyclase–cAMP–PKA pathway regulates numerous physiological functions, including the therapeutic effects of exogenous β-agonists in the treatment of airway disease. β2AR signaling is tightly regulated by GRKs and β-arrestins, which together promote β2AR desensitization and internalization as well as downstream signaling, often antithetical to the canonical pathway. Thus, the ability to bias β2AR signaling toward the Gs pathway while avoiding β-arrestin-mediated effects may provide a strategy to improve the functional consequences of β2AR activation. Since attempts to develop Gs-biased agonists and allosteric modulators for the β2AR have been largely unsuccessful, here we …

Abaloparatide Maintains Normal Rat Blood Calcium Level In Part Via 1,25-Dihydroxyvitamin D/Osteocalcin Signaling Pathway, Yanmei Yang, Wei-Ju Louis Tseng, Bin Wang

Center for Translational Medicine Faculty Papers

The PTH-related peptide(1-34) analog, abaloparatide (ABL), is the second anabolic drug available for the treatment of osteoporosis. Previous research demonstrated that ABL had a potent anabolic effect but caused hypercalcemia at a significantly lower rate. However, the mechanism by which ABL maintains the stability of blood calcium levels remains poorly understood. Our in vivo data showed that ABL treatment (40 µg/kg/day for 7 days) significantly increased rat blood level of 1,25-dihydroxyvitamin D [1,25-(OH)2D] without raising the blood calcium value. ABL also significantly augmented the carboxylated osteocalcin (Gla-Ocn) in the blood and bone that is synthesized by osteoblasts, and increased noncarboxylated …

Scutellaria Baicalensis Enhances 5-Fluorouracil-Based Chemotherapy Via Inhibition Of Proliferative Signaling Pathways, Haizhou Liu, Hui Liu, Zhiyi Zhou, Jessica Chung, Guojing Zhang, Jin Chang, Robert A Parise, Edward Chu, John C Schmitz

Abington Jefferson Health Papers

Fluoropyridine-based chemotherapy remains the most widely used treatment for colorectal cancer (CRC). In this study, we investigated the mechanism by which the natural product Scutellaria baicalensis (Huang Qin; HQ) and one of its main components baicalin enhanced 5-fluorouracil (5-FU) antitumor activity against CRC. Cell proliferation assays, cell cycle analysis, reverse-phase protein array (RPPA) analysis, immunoblot analysis, and qRT-PCR were performed to investigate the mechanism(s) of action of HQ and its active components on growth of CRC cells. HQ exhibited in vitro antiproliferative activity against drug resistant human CRC cells, against human and mouse CRC cells with different genetic backgrounds and …

Pimt Is A Novel And Potent Suppressor Of Endothelial Activation, Chen Zhang, Zhifu Guo, Wennan Liu, Kyosuke Kazama, Louis Hu, Xiaobo Sun, Lu Wang, Hyoungjoo Lee, Lin Lu, Xiao-Feng Yang, Ross Summer, Jianxin Sun

Division of Pulmonary and Critical Care Medicine Faculty Papers

Proinflammatory agonists provoke the expression of cell surface adhesion molecules on endothelium in order to facilitate leukocyte infiltration into tissues. Rigorous control over this process is important to prevent unwanted inflammation and organ damage. Protein L-isoaspartyl O-methyltransferase (PIMT) converts isoaspartyl residues to conventional methylated forms in cells undergoing stress-induced protein damage. The purpose of this study was to determine the role of PIMT in vascular homeostasis. PIMT is abundantly expressed in mouse lung endothelium and PIMT deficiency in mice exacerbated pulmonary inflammation and vascular leakage to LPS(lipopolysaccharide). Furthermore, we found that PIMT inhibited LPS-induced toll-like receptor signaling through its interaction …

Intestinal Neuropod Cell Gucy2c Regulates Visceral Pain, Joshua R. Barton, Annie K. Londregran, Tyler D. Alexander, Ariana A. Entezari, Shely Bar-Ad, Lan Cheng, Angelo C. Lepore, Adam E. Snook, Manuel Covarrubias, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Visceral pain (VP) is a global problem with complex etiologies and limited therapeutic options. Guanylyl cyclase C (GUCY2C), an intestinal receptor producing cyclic GMP(cGMP), which regulates luminal fluid secretion, has emerged as a therapeutic target for VP. Indeed, FDA-approved GUCY2C agonists ameliorate VP in patients with chronic constipation syndromes, although analgesic mechanisms remain obscure. Here, we revealed that intestinal GUCY2C was selectively enriched in neuropod cells, a type of enteroendocrine cell that synapses with submucosal neurons in mice and humans. GUCY2Chi neuropod cells associated with cocultured dorsal root ganglia neurons and induced hyperexcitability, reducing the rheobase and increasing the resulting …

Ctpathway: A Crosstalk-Based Pathway Enrichment Analysis Method For Cancer Research, Haizhou Liu, Mengqin Yuan, Ramkrishna Mitra, Xu Zhou, Min Long, Wanyue Lei, Shunheng Zhou, Yu-E Huang, Fei Hou, Christine M. Eischen, Wei Jiang

Department of Cancer Biology Faculty Papers

Background: Pathway enrichment analysis (PEA) is a common method for exploring functions of hundreds of genes and identifying disease-risk pathways. Moreover, different pathways exert their functions through crosstalk. However, existing PEA methods do not sufficiently integrate essential pathway features, including pathway crosstalk, molecular interactions, and network topologies, resulting in many risk pathways that remain uninvestigated.

Methods: To overcome these limitations, we develop a new crosstalk-based PEA method, CTpathway, based on a global pathway crosstalk map (GPCM) with >440,000 edges by combing pathways from eight resources, transcription factor-gene regulations, and large-scale protein-protein interactions. Integrating gene differential expression and crosstalk effects in …

Serpinb3 Drives Cancer Stem Cell Survival In Glioblastoma, Adam Lauko, Josephine Volovetz, Soumya M Turaga, Defne Bayik, Daniel J Silver, Kelly Mitchell, Erin E Mulkearns-Hubert, Dionysios C Watson, Kiran Desai, Manav Midha, Jing Hao, Kathleen Mccortney, Alicia Steffens, Ulhas Naik, Manmeet S Ahluwalia, Shideng Bao, Craig Horbinski, Jennifer S Yu, Justin D Lathia

Department of Medicine Faculty Papers

Despite therapeutic interventions for glioblastoma (GBM), cancer stem cells (CSCs) drive recurrence. The precise mechanisms underlying CSC resistance, namely inhibition of cell death, are unclear. We built on previous observations that the high cell surface expression of junctional adhesion molecule-A drives CSC maintenance and identified downstream signaling networks, including the cysteine protease inhibitor SerpinB3. Using genetic depletion approaches, we found that SerpinB3 is necessary for CSC maintenance, survival, and tumor growth, as well as CSC pathway activation. Knockdown of SerpinB3 also increased apoptosis and susceptibility to radiation therapy. SerpinB3 was essential to buffer cathepsin L-mediated cell death, which was enhanced …

Retinoids As Chemo-Preventive And Molecular-Targeted Anti-Cancer Therapies., Victoria O. Hunsu, Caroline O.B. Facey, Jeremy Z. Fields, Bruce M. Boman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Retinoic acid (RA) agents possess anti‐tumor activity through their ability to induce cellular differentiation. However, retinoids have not yet been translated into effective systemic treatments for most solid tumors. RA signaling is mediated by the following two nuclear retinoic receptor subtypes: the retinoic acid receptor (RAR) and the retinoic X receptor (RXR), and their isoforms. The identification of mutations in retinoid receptors and other RA signaling pathway genes in human cancers offers opportunities for target discovery, drug design, and personalized medicine for distinct molecular retinoid subtypes. For example, chromosomal translocation involving RARA occurs in acute promyelocytic leukemia (APL), and all‐trans …

Sars-Cov-2 Viral Proteins Nsp1 And Nsp13 Inhibit Interferon Activation Through Distinct Mechanisms, Christine Vazquez, Sydnie E Swanson, Seble G Negatu, Mark Dittmar, Jesse Miller, Holly Ramage, Sara Cherry, Kellie A Jurado

Department of Microbiology and Immunology Faculty Papers

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a devastating global pandemic, infecting over 43 million people and claiming over 1 million lives, with these numbers increasing daily. Therefore, there is urgent need to understand the molecular mechanisms governing SARS-CoV-2 pathogenesis, immune evasion, and disease progression. Here, we show that SARS-CoV-2 can block IRF3 and NF-κB activation early during virus infection. We also identify that the SARS-CoV-2 viral proteins NSP1 and NSP13 can block interferon activation via distinct mechanisms. NSP1 antagonizes interferon signaling by suppressing host mRNA translation, while NSP13 downregulates interferon and NF-κB promoter signaling by limiting TBK1 …

Ap-1 And Nf-Κb Synergize To Transcriptionally Activate Latent Hiv Upon T-Cell Receptor Activation., Joseph Hokello, Adhikarimayum Lakhikumar Sharma, Mudit Tyagi

Center for Translational Medicine Faculty Papers

Latent HIV-1 proviruses are capable of reactivating productive lytic infection, but the precise molecular mechanisms underlying emergence from latency are poorly understood. In this study, we determined the contribution of the transcription factors NF-κB, NFAT, and AP-1 in the reactivation of latent HIV following T-cell receptor (TCR) activation using Jurkat T-cell clones harboring single latent HIV proviruses. Our findings demonstrate that during reactivation from latency, NF-κB enhances HIV transcription while NFAT inhibits it by competing with NF-κB for overlapping binding sites on the HIV long terminal repeat (LTR). We have also demonstrated for the first time the molecular contribution of …

C1q/Tnf-Related Protein 5 Contributes To Diabetic Vascular Endothelium Dysfunction Through Promoting Nox-1 Signaling., Jing Liu, Zhijun Meng, Lu Gan, Rui Guo, Jia Gao, Caihong Liu, Di Zhu, Demin Liu, Ling Zhang, Zhen Zhang, Dina Xie, Xiangying Jiao, Wayne Bond Lau, Bernard L. Lopez, Theodore A. Christopher, Xin-Liang Ma, Jimin Cao, Yajing Wang

Department of Emergency Medicine Faculty Papers

OBJECTIVE: Dysregulated adipokine profiles contribute to the pathogenesis of diabetic cardiovascular complications. Endothelial cell (EC) dysfunction, a common pathological alteration in cardiovascular disorders, is exaggerated in diabetes. However, it is unclear whether and how dysregulated adipokines may contribute to diabetic EC dysfunction.

METHODS AND RESULTS: Serum C1q/TNF-Related Protein 5 (CTRP5) were determined in control/diabetes patients, and control/diabetic mice (high-fat diet, HFD). We observed for the first time that serum total CTRP5 was increased, high molecular weight (HMW) form was decreased, but the globular form (gCTRP5) was significantly increased in diabetic patients. These pathological alterations were reproduced in diabetic mice. To …

Nk Cell-Derived Gm-Csf Potentiates Inflammatory Arthritis And Is Negatively Regulated By Cis, Cynthia Louis, Fernando Souza-Fonseca-Guimaraes, Yuyan Yang, Damian D'Silva, Tobias Kratina, Laura Dagley, Soroor Hediyeh-Zadeh, Jai Rautela, Seth Lucian Masters, Melissa J Davis, Jeffrey J Babon, Bogoljub Ciric, Eric Vivier, Warren S Alexander, Nicholas D Huntington, Ian P Wicks

Department of Neurology Faculty Papers

Despite increasing recognition of the importance of GM-CSF in autoimmune disease, it remains unclear how GM-CSF is regulated at sites of tissue inflammation. Using GM-CSF fate reporter mice, we show that synovial NK cells produce GM-CSF in autoantibody-mediated inflammatory arthritis. Synovial NK cells promote a neutrophilic inflammatory cell infiltrate, and persistent arthritis, via GM-CSF production, as deletion of NK cells, or specific ablation of GM-CSF production in NK cells, abrogated disease. Synovial NK cell production of GM-CSF is IL-18–dependent. Furthermore, we show that cytokine-inducible SH2-containing protein (CIS) is crucial in limiting GM-CSF signaling not only during inflammatory arthritis but also …

Evolution Of Cortical Neurogenesis In Amniotes Controlled By Robo Signaling Levels., Adrián Cárdenas, Ana Villalba, Camino De Juan Romero, Esther Picó, Christina Kyrousi, Athanasia C Tzika, Marc Tessier-Lavigne, Le Ma, Micha Drukker, Silvia Cappello, Víctor Borrell

Department of Neuroscience Faculty Papers

Cerebral cortex size differs dramatically between reptiles, birds, and mammals, owing to developmental differences in neuron production. In mammals, signaling pathways regulating neurogenesis have been identified, but genetic differences behind their evolution across amniotes remain unknown. We show that direct neurogenesis from radial glia cells, with limited neuron production, dominates the avian, reptilian, and mammalian paleocortex, whereas in the evolutionarily recent mammalian neocortex, most neurogenesis is indirect via basal progenitors. Gain- and loss-of-function experiments in mouse, chick, and snake embryos and in human cerebral organoids demonstrate that high Slit/Robo and low Dll1 signaling, via Jag1 and Jag2, are necessary and …

Pepducins As A Potential Treatment Strategy For Asthma And Copd., Reynold A. Panettieri, Tonio Pera, Stephen B B. Liggett, Jeffrey L. Benovic, Raymond B. Penn

Center for Translational Medicine Faculty Papers

Current therapies to treat asthma and other airway diseases primarily include anti-inflammatory agents and bronchodilators. Anti-inflammatory agents target trafficking and resident immunocytes and structural cells, while bronchodilators act to prevent or reverse shortening of airway smooth muscle (ASM), the pivotal tissue regulating bronchomotor tone. Advances in our understanding of the biology of G protein-coupled receptors (GPCRs) and biased agonism offers unique opportunities to modulate GPCR function that include the use of pepducins and allosteric modulators. Recent evidence suggests that small molecule inhibitors of Gα _q as well as pepducins targeting G _q -coupled receptors can broadly inhibit contractile agonist-induced ASM …

Cigarette Smoke Initiates Oxidative Stress-Induced Cellular Phenotypic Modulation Leading To Cerebral Aneurysm Pathogenesis., Robert M. Starke, John W. Thompson, Muhammad S. Ali, Crissey L. Pascale, Alejandra Martinez Lege, Dale Ding, Nohra Chalouhi, David M. Hasan, Pascal Jabbour, Gary K Owens, Michal Toborek, Joshua M. Hare, Aaron S. Dumont

Department of Neurosurgery Faculty Papers

OBJECTIVE: Cigarette smoke exposure (CSE) is a risk factor for cerebral aneurysm (CA) formation, but the molecular mechanisms are unclear. Although CSE is known to contribute to excess reactive oxygen species generation, the role of oxidative stress on vascular smooth muscle cell (VSMC) phenotypic modulation and pathogenesis of CAs is unknown. The goal of this study was to investigate whether CSE activates a NOX (NADPH oxidase)-dependent pathway leading to VSMC phenotypic modulation and CA formation and rupture.

APPROACH AND RESULTS: In cultured cerebral VSMCs, CSE increased expression of NOX1 and reactive oxygen species which preceded upregulation of proinflammatory/matrix remodeling genes …

Mir-181a Increases Foxo1 Acetylation And Promotes Granulosa Cell Apoptosis Via Sirt1 Downregulation., Mei Zhang, Qun Zhang, Yali Hu, Lu Xu, Yue Jiang, Chunxue Zhang, Lijun Ding, Ruiwei Jiang, Jianxin Sun, Haixiang Sun, Guijun Yan

Center for Translational Medicine Faculty Papers

Oxidative stress impairs follicular development by inducing granulosa cell (GC) apoptosis, which involves enhancement of the transcriptional activity of the pro-apoptotic factor Forkhead box O1 (FoxO1). However, the mechanism by which oxidative stress promotes FoxO1 activity is still unclear. Here, we found that miR-181a was upregulated in hydrogen peroxide (H

Decorin-Evoked Paternally Expressed Gene 3 (Peg3) Is An Upstream Regulator Of The Transcription Factor Eb (Tfeb) In Endothelial Cell Autophagy., Thomas Neill, Catherine Sharpe, Rick T. Owens, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Macroautophagy is a fundamental and evolutionarily conserved catabolic process that eradicates damaged and aging macromolecules and organelles in eukaryotic cells. Decorin, an archetypical small leucine-rich proteoglycan, initiates a protracted autophagic program downstream of VEGF receptor 2 (VEGFR2) signaling that requires paternally expressed gene 3 (PEG3). We have discovered that PEG3 is an upstream transcriptional regulator of transcription factor EB (TFEB), a master transcription factor of lysosomal biogenesis, for decorin-evoked endothelial cell autophagy. We found a functional requirement of PEG3 for TFEB transcriptional induction and nuclear translocation in human umbilical vein endothelial and PAER2 cells. Mechanistically, inhibiting VEGFR2 or AMP-activated protein …

Gucy2c Signaling Opposes The Acute Radiation-Induced Gi Syndrome., Peng Li, Evan Wuthrick, Jeff A. Rappaport, Crystal Kraft, Jieru E. Lin, Glen Marszalowicz, Adam E. Snook, Tingting Zhan, Terry M. Hyslop, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

High doses of ionizing radiation induce acute damage to epithelial cells of the gastrointestinal (GI) tract, mediating toxicities restricting the therapeutic efficacy of radiation in cancer and morbidity and mortality in nuclear disasters. No approved prophylaxis or therapy exists for these toxicities, in part reflecting an incomplete understanding of mechanisms contributing to the acute radiation-induced GI syndrome (RIGS). Guanylate cyclase C (GUCY2C) and its hormones guanylin and uroguanylin have recently emerged as one paracrine axis defending intestinal mucosal integrity against mutational, chemical, and inflammatory injury. Here, we reveal a role for the GUCY2C paracrine axis in compensatory mechanisms opposing RIGS. …

Cyclin D1 Restrains Oncogene-Induced Autophagy By Regulating The Ampk-Lkb1 Signaling Axis., Mathew C. Casimiro, Gabriele Disante, Agnese Di Rocco, Emanuele Loro, Claudia Pupo, Timothy G. Pestell, Sara Bisetto, Marco A. Velasco-Velázquez, Xuanmao Jiao, Zhiping Li, Christine M. Kusminski, Erin L. Seifert, Chenguang Wang, Daniel Ly, Bin Zheng, Che-Hung Shen, Philipp E. Scherer, Richard Pestell

Department of Cancer Biology Faculty Papers

Autophagy activated after DNA damage or other stresses mitigates cellular damage by removing damaged proteins, lipids, and organelles. Activation of the master metabolic kinase AMPK enhances autophagy. Here we report that cyclin D1 restrains autophagy by modulating the activation of AMPK. In cell models of human breast cancer or in a cyclin D1-deficient model, we observed a cyclin D1-mediated reduction in AMPK activation. Mechanistic investigations showed that cyclin D1 inhibited mitochondrial function, promoted glycolysis, and reduced activation of AMPK (pT172), possibly through a mechanism that involves cyclin D1-Cdk4/Cdk6 phosphorylation of LKB1. Our findings suggest how AMPK activation by cyclin D1 …

Dysregulated Gpcr Signaling And Therapeutic Options In Uveal Melanoma., Vivian Chua, Dominic Lapadula, Clinita Randolph, Jeffrey L. Benovic, Philip B. Wedegaertner, Andrew E. Aplin

Department of Biochemistry and Molecular Biology Faculty Papers

Uveal melanoma is the most common primary intraocular malignant tumor in adults and arises from the transformation of melanocytes in the uveal tract. Even after treatment of the primary tumor, up to 50% of patients succumb to metastatic disease. The liver is the predominant organ of metastasis. There is an important need to provide effective treatment options for advanced stage uveal melanoma. To provide the preclinical basis for new treatments, it is important to understand the molecular underpinnings of the disease. Recent genomic studies have shown that mutations within components of G protein-coupled receptor (GPCR) signaling are early events associated …

Co-Targeting Hgf/Cmet Signaling With Mek Inhibitors In Metastatic Uveal Melanoma., Hanyin Cheng, Vivian Chua, Connie Liao, Timothy J. Purwin, Mizue Terai, Ken Kageyama, Michael A. Davies, Takami Sato, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

Patients with metastatic uveal melanoma usually die within 1 year of diagnosis, emphasizing an urgent need to develop new treatment strategies. The liver is the most common site of metastasis. Mitogen-activated protein kinase kinase (MEK) inhibitors improve survival in V600 BRAF-mutated cutaneous melanoma patients but have limited efficacy in patients with uveal melanoma. Our previous work showed that hepatocyte growth factor (HGF) signaling elicits resistance to MEK inhibitors in metastatic uveal melanoma. In this study, we demonstrate that expression of two BH3-only family proteins, Bim-EL and Bmf, contributes to HGF-mediated resistance to MEK inhibitors. Targeting HGF/cMET signaling with LY2875358, a …

Proteoglycan Neofunctions: Regulation Of Inflammation And Autophagy In Cancer Biology., Liliana Schaefer, Claudia Tredup, Maria A. Gubbiotti, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Inflammation and autophagy have emerged as prominent issues in the context of proteoglycan signaling. In particular, two small, leucine-rich proteoglycans, biglycan and decorin, play pivotal roles in the regulation of these vital cellular pathways and, as such, are intrinsically involved in cancer initiation and progression. In this minireview, we will address novel functions of biglycan and decorin in inflammation and autophagy, and analyze new emerging signaling events triggered by these proteoglycans, which directly or indirectly modulate these processes. We will critically discuss the dual role of proteoglycan-driven inflammation and autophagy in tumor biology, and delineate the potential mechanisms through which …

V-Src Oncogene Induces Trop2 Proteolytic Activation Via Cyclin D1., Xiaoming Ju, Xuanmao Jiao, Adam Ertel, Mathew C. Casimiro, Gabriele Disante, Shengqiong Deng, Zhiping Li, Agnese Di Rocco, Tingting Zhan, Adam Hawkins, Tanya Stoyanova, Sebastiano Andò, Alessandro Fatatis, Michael P. Lisanti, Leonard G. Gomella, Lucia R. Languino, Richard G. Pestell

Department of Cancer Biology Faculty Papers

Proteomic analysis of castration-resistant prostate cancer demonstrated the enrichment of Src tyrosine kinase activity in approximately 90% of patients. Src is known to induce cyclin D1, and a cyclin D1-regulated gene expression module predicts poor outcome in human prostate cancer. The tumor-associated calcium signal transducer 2 (TACSTD2/Trop2/M1S1) is enriched in the prostate, promoting prostate stem cell self-renewal upon proteolytic activation via a γ-secretase cleavage complex (PS1, PS2) and TACE (ADAM17), which releases the Trop2 intracellular domain (Trop2 ICD). Herein, v-Src transformation of primary murine prostate epithelial cells increased the proportion of prostate cancer stem cells as characterized by gene expression, …

Mitochondrial Akt Regulation Of Hypoxic Tumor Reprogramming., Young Chan Chae, Valentina Vaira, M. Cecilia Caino, Hsin-Yao Tang, Jae Ho Seo, Andrew V. Kossenkov, Luisa Ottobrini, Cristina Martelli, Giovanni Lucignani, Irene Bertolini, Marco Locatelli, Kelly G. Bryant, Jagadish C. Ghosh, Sofia Lisanti, Bonsu Ku, Silvano Bosari, Lucia R. Languino, David W. Speicher, Dario C. Altieri

Department of Cancer Biology Faculty Papers

Hypoxia is a universal driver of aggressive tumor behavior, but the underlying mechanisms are not completely understood. Using a phosphoproteomics screen, we now show that active Akt accumulates in the mitochondria during hypoxia and phosphorylates pyruvate dehydrogenase kinase 1 (PDK1) on Thr346 to inactivate the pyruvate dehydrogenase complex. In turn, this pathway switches tumor metabolism toward glycolysis, antagonizes apoptosis and autophagy, dampens oxidative stress, and maintains tumor cell proliferation in the face of severe hypoxia. Mitochondrial Akt-PDK1 signaling correlates with unfavorable prognostic markers and shorter survival in glioma patients and may provide an "actionable" therapeutic target in cancer.