Medicine and Health Sciences Commons^™

Absence Of Chordin-Like 1 Aids Motor Recovery In A Mouse Model Of Stroke, Eileen Collyer, Bridget R Boyle, Yolanda Gomez-Galvez, Lorraine Iacovitti, Elena Blanco-Suarez

Farber Institute for Neuroscience Faculty Papers

Chordin-like 1 (Chrdl1) is an astrocyte-secreted protein that regulates synaptic maturation, and limits plasticity via GluA2-containing AMPA receptors (AMPARs). It was demonstrated that Chrdl1 expression is very heterogeneous throughout the brain, and it is enriched in astrocytes in cortical layers 2/3, with peak expression in the visual cortex at postnatal day 14. In response to ischemic stroke, Chrdl1 is upregulated during the acute and sub-acute phases in the peri-infarct region, potentially hindering recovery after stroke. Here, we used photothrombosis to model ischemic stroke in the motor cortex of adult male and female mice. In this study, we demonstrate that elimination …

Lysosomal Lipid Peroxidation Regulates Tumor Immunity, Monika Bhardwaj, Jennifer J Lee, Amanda M Versace, Sandra L Harper, Aaron R Goldman, Mary Ann S Crissey, Vaibhav Jain, Mahendra Pal Singh, Megane Vernon, Andrew E. Aplin, Seokwoo Lee, Masao Morita, Jeffrey D Winkler, Qin Liu, David W Speicher, Ravi K Amaravadi

Department of Surgery Faculty Papers

Lysosomal inhibition elicited by palmitoyl-protein thioesterase 1 (PPT1) inhibitors such as DC661 can produce cell death, but the mechanism for this is not completely understood. Programmed cell death pathways (autophagy, apoptosis, necroptosis, ferroptosis, and pyroptosis) were not required to achieve the cytotoxic effect of DC661. Inhibition of cathepsins, or iron or calcium chelation, did not rescue DC661-induced cytotoxicity. PPT1 inhibition induced lysosomal lipid peroxidation (LLP), which led to lysosomal membrane permeabilization and cell death that could be reversed by the antioxidant N-acetylcysteine (NAC) but not by other lipid peroxidation antioxidants. The lysosomal cysteine transporter MFSD12 was required for intralysosomal transport …

Reduced Er-Mitochondria Connectivity Promotes Neuroblastoma Multidrug Resistance., Jorida Çoku, David M. Booth, Jan Skoda, Madison C Pedrotty, Jennifer Vogel, Kangning Liu, Annette Vu, Erica L Carpenter, Jamie C Ye, Michelle A Chen, Peter Dunbar, Elizabeth Scadden, Taekyung D Yun, Eiko Nakamaru-Ogiso, Estela Area-Gomez, Yimei Li, Kelly C Goldsmith, C Patrick Reynolds, György Hajnóczky, Michael D Hogarty

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Most cancer deaths result from progression of therapy resistant disease, yet our understanding of this phenotype is limited. Cancer therapies generate stress signals that act upon mitochondria to initiate apoptosis. Mitochondria isolated from neuroblastoma cells were exposed to tBid or Bim, death effectors activated by therapeutic stress. Multidrug-resistant tumor cells obtained from children at relapse had markedly attenuated Bak and Bax oligomerization and cytochrome c release (surrogates for apoptotic commitment) in comparison with patient-matched tumor cells obtained at diagnosis. Electron microscopy identified reduced ER-mitochondria-associated membranes (MAMs; ER-mitochondria contacts, ERMCs) in therapy-resistant cells, and genetically or biochemically reducing MAMs in therapy-sensitive …

Ivermectin Induces Apoptosis Of Esophageal Squamous Cell Carcinoma Via Mitochondrial Pathway, Nana Xu, Mengmeng Lu, Jiaxin Wang, Yujia Li, Xiaotian Yang, Xiajie Wei, Jiaoyang Si, Jingru Han, Xiaojuan Yao, Juanmei Zhang, Junqi Liu, Yanming Li, Hushan Yang, Dengke Bao

Department of Medical Oncology Faculty Papers

Background: Esophageal squamous cell carcinoma (ESCC) is the most predominant primary malignant tumor among worldwide, especially in China. To date, the successful treatment remains a mainly clinical challenge, it is imperative to develop successful therapeutic agents.

Methods: The anti-proliferative effect of ivermectin on ESCC is investigated in cell model and in nude mice model. Cell apoptosis was assessed using flow cytometry, TUNEL assay and western blotting. Mitochondrial dysfunction was determined by reactive oxygen species accumulation, mitochondrial membrane potential and ATP levels.

Results: Our results determined that ivermectin significantly inhibited the proliferation of ESCC cells in vitro and in vivo. Furthermore, …

Targeting The Cdk6 Dependence Of Ph+ Acute Lymphoblastic Leukemia, Patrizia Porazzi, Marco De Dominici, Joseph Salvino, Bruno Calabretta

Department of Cancer Biology Faculty Papers

Ph+ ALL is a poor-prognosis leukemia subtype driven by the BCR-ABL1 oncogene, either the p190-or the p210-BCR/ABL isoform in a 70:30 ratio. Tyrosine Kinase inhibitors (TKIs) are the drugs of choice in the therapy of Ph+ ALL. In combination with standard chemotherapy, TKIs have markedly improved the outcome of Ph+ ALL, in particular if this treatment is followed by bone marrow transplantation. However, resistance to TKIs develops with high frequency, causing leukemia relapse that results in

Multiple Autonomous Cell Death Suppression Strategies Ensure Cytomegalovirus Fitness, Pratyusha Mandal, Lynsey Nagrani, Liliana Hernandez, Anita Louise Mccormick, Christopher Dillon, Heather Koehler, Linda Roback, Emad S Alnemri, Douglas Green, Edward Mocarski

Department of Biochemistry and Molecular Biology Faculty Papers

Programmed cell death pathways eliminate infected cells and regulate infection-associated inflammation during pathogen invasion. Cytomegaloviruses encode several distinct suppressors that block intrinsic apoptosis, extrinsic apoptosis, and necroptosis, pathways that impact pathogenesis of this ubiquitous herpesvirus. Here, we expanded the understanding of three cell autonomous suppression mechanisms on which murine cytomegalovirus relies: (i) M38.5-encoded viral mitochon-drial inhibitor of apoptosis (vMIA), a BAX suppressor that functions in concert with M41.1-encoded viral inhibitor of BAK oligomerization (vIBO), (ii) M36-encoded viral inhibitor of caspase-8 activation (vICA), and (iii) M45-encoded viral inhibitor of RIP/RHIM activation (vIRA). Following infection of bone marrow-derived macrophages, the virus initially …

Simultaneous Ck2/Tnik/Dyrk1 Inhibition By 108600 Suppresses Triple Negative Breast Cancer Stem Cells And Chemotherapy-Resistant Disease., Katsutoshi Sato, Amol A. Padgaonkar, Stacey J. Baker, Stephen C. Cosenza, Olga Rechkoblit, D.R.C. Venkata Subbaiah, Josep Domingo-Domenech, Alison Bartkowski, Elisa R. Port, Aneel K. Aggarwal, M. V. Ramana Reddy, Hanna Y. Irie, E. Premkumar Reddy

Department of Medical Oncology Faculty Papers

Triple negative breast cancer (TNBC) remains challenging because of heterogeneous responses to chemotherapy. Incomplete response is associated with a greater risk of metastatic progression. Therefore, treatments that target chemotherapy-resistant TNBC and enhance chemosensitivity would improve outcomes for these high-risk patients. Breast cancer stem cell-like cells (BCSCs) have been proposed to represent a chemotherapy-resistant subpopulation responsible for tumor initiation, progression and metastases. Targeting this population could lead to improved TNBC disease control. Here, we describe a novel multi-kinase inhibitor, 108600, that targets the TNBC BCSC population. 108600 treatment suppresses growth, colony and mammosphere forming capacity of BCSCs and induces G2M arrest …

Autophagy, Apoptosis, The Unfolded Protein Response, And Lung Function In Idiopathic Pulmonary Fibrosis, Pawan Sharma, Javad Alizadeh, Maya Juarez, Afshin Samali, Andrew J Halayko, Nicholas J Kenyon, Saeid Ghavami, Amir A Zeki

Center for Translational Medicine Faculty Papers

Autophagy, apoptosis, and the unfolded protein response (UPR) are fundamental biological processes essential for manifold cellular functions in health and disease. Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal pulmonary disorder associated with aging that has limited therapies, reflecting our incomplete understanding. We conducted an observational study linking molecular markers of cell stress response pathways (UPR: BiP, XBP1; apoptosis: cleaved caspase-3; autophagy: LC3β) in lung tissues from IPF patients and correlated the expression of these protein markers to each subject's lung function measures. We hypothesized that changes in lung tissue expression of apoptosis, autophagy, and UPR markers correlate with …

Mir-21 Plays A Dual Role In Tumor Formation And Cytotoxic Response In Breast Tumors, Tu Dan, Anuradha A. Shastri, Ajay Palagani, Simone Buraschi, Thomas Neill, Jason E Savage, Aastha Kapoor, Tiziana Deangelis, Sankar Addya, Kevin Camphausen, Renato V. Iozzo, Nicole L Simone

Department of Radiation Oncology Faculty Papers

Breast cancer (BrCa) relies on specific microRNAs to drive disease progression. Oncogenic miR-21 is upregulated in many cancers, including BrCa, and is associated with poor survival and treatment resistance. We sought to determine the role of miR-21 in BrCa tumor initiation, progression and treatment response. In a triple-negative BrCa model, radiation exposure increased miR-21 in both primary tumor and metastases. In vitro, miR-21 knockdown decreased survival in all BrCa subtypes in the presence of radiation. The role of miR-21 in BrCa initiation was evaluated by implanting wild-type miR-21 BrCa cells into genetically engineered mouse models where miR-21 was intact, heterozygous …

Distinct Mechanisms Control Genome Recognition By P53 At Its Target Genes Linked To Different Cell Fates., Marina Farkas, Hideharu Hashimoto, Yingtao Bi, Ramana V Davuluri, Lois Resnick-Silverman, James J. Manfredi, Erik W. Debler, Steven B. Mcmahon

Department of Biochemistry and Molecular Biology Faculty Papers

The tumor suppressor p53 integrates stress response pathways by selectively engaging one of several potential transcriptomes, thereby triggering cell fate decisions (e.g., cell cycle arrest, apoptosis). Foundational to this process is the binding of tetrameric p53 to 20-bp response elements (REs) in the genome (RRRCWWGYYYN_0-13RRRCWWGYYY). In general, REs at cell cycle arrest targets (e.g. p21) are of higher affinity than those at apoptosis targets (e.g., BAX). However, the RE sequence code underlying selectivity remains undeciphered. Here, we identify molecular mechanisms mediating p53 binding to high- and low-affinity REs by showing that key determinants of the code are embedded …

Translocase Of The Outer Mitochondrial Membrane Complex Subunit 20 (Tomm20) Facilitates Cancer Aggressiveness And Therapeutic Resistance In Chondrosarcoma., Megan E Roche, Zhao Lin, Diana Whitaker-Menezes, Tingting Zhan, Karoly Szuhai, Judith V M G Bovee, John A Abraham, Wei Jiang, Ubaldo Martinez-Outschoorn, Atrayee Basu-Mallick

Department of Medical Oncology Faculty Papers

Chondrosarcoma is the second most common primary bone malignancy, representing one fourth of all primary bone sarcomas. It is typically resistant to radiation and chemotherapy treatments. However, the molecular mechanisms that contribute to cancer aggressiveness in chondrosarcomas remain poorly characterized. Here, we studied the role of mitochondrial transporters in chondrosarcoma aggressiveness including chemotherapy resistance. Histological grade along with stage are the most important prognostic biomarkers in chondrosarcoma. We found that high-grade human chondrosarcoma tumors have higher expression of the mitochondrial protein, translocase of the outer mitochondrial membrane complex subunit 20 (TOMM20), compared to low-grade tumors. TOMM20 overexpression in human chondrosarcoma …

The Short Variant Of Optic Atrophy 1 (Opa1) Improves Cell Survival Under Oxidative Stress., Hakjoo Lee, Sylvia B Smith, Shey-Shing Sheu, Yisang Yoon

Center for Translational Medicine Faculty Papers

Optic atrophy 1 (OPA1) is a dynamin protein that mediates mitochondrial fusion at the inner membrane. OPA1 is also necessary for maintaining the cristae and thus essential for supporting cellular energetics. OPA1 exists as membrane-anchored long form (L-OPA1) and short form (S-OPA1) that lacks the transmembrane region and is generated by cleavage of L-OPA1. Mitochondrial dysfunction and cellular stresses activate the inner membrane-associated zinc metallopeptidase OMA1 that cleaves L-OPA1, causing S-OPA1 accumulation. The prevailing notion has been that L-OPA1 is the functional form, whereas S-OPA1 is an inactive cleavage product in mammals, and that stress-induced OPA1 cleavage causes mitochondrial fragmentation …

Gasdermins In Apoptosis: New Players In An Old Game., Corey Rogers, Emad S. Alnemri

Department of Biochemistry and Molecular Biology Faculty Papers

Apoptosis is a form of programmed cell death (PCD) that plays critical physiological roles in removing superfluous or dangerous cell populations that are unneeded or threatening to the health of the host organism. Although the molecular pathways leading to activation of the apoptotic program have been extensively studied and characterized starting in the 1970s, new evidence suggests that members of the gasdermin superfamily are novel pore-forming proteins that augment apoptosis by permeabilizing the mitochondria and participate in the final stages of the apoptotic program by inducing secondary necrosis/pyroptosis. These findings may explain outstanding questions in the field such as why …

Irisin Functions To Inhibit Malignant Growth Of Human Pancreatic Cancer Cells Via Downregulation Of The Pi3k/Akt Signaling Pathway., Deguo Zhang, Ping Zhang, Luan Li, Nan Tang, Fei Huang, Xianguo Kong, Xueying Tan, Guangjun Shi

Department of Medicine Faculty Papers

Introduction: Irisin is a newly identified cytokine that has gained increasing attention because of its potential therapeutic applications in metabolic diseases and human cancers. Recently, accumulating evidence indicates that irisin plays an important role in the development and metastasis of various tumors. The aim of this study was to evaluate the effects and underlying mechanisms of irisin on malignant growth of pancreatic cancer cells.

Materials and methods: The anti-proliferative effect of irisin was examined using the CCK-8 assay. Irisin-induced apoptosis was determined by the annexin V-FITC/PI staining assay. The effects of irisin on cell migration and invasion were assessed using …

Interaction Between The Bag1s Isoform And Hsp70 Mediates The Stability Of Anti-Apoptotic Proteins And The Survival Of Osteosarcoma Cells Expressing Oncogenic Myc., Victoria J. Gennaro, Helen Wedegaertner, Steven B. Mcmahon

Department of Biochemistry and Molecular Biology Faculty Papers

BACKGROUND: The oncoprotein MYC has the dual capacity to drive cell cycle progression or induce apoptosis, depending on the cellular context. BAG1 was previously identified as a transcriptional target of MYC that functions as a critical determinant of this cell fate decision. The BAG1 protein is expressed as multiple isoforms, each having an array of distinct biochemical functions; however, the specific effector function of BAG1 that directs MYC-dependent cell survival has not been defined.

METHODS: In our studies the human osteosarcoma line U2OS expressing a conditional MYC-ER allele was used to induce oncogenic levels of MYC. We interrogated MYC-driven survival …

Targeting The Bcl-2 Family In B Cell Lymphoma., Clare M. Adams, Sean Clark-Garvey, Pierluigi Porcu, Christine M. Eischen

Department of Medical Oncology Faculty Papers

Although lymphoma is a very heterogeneous group of biologically complex malignancies, tumor cells across all B cell lymphoma subtypes share a set of underlying traits that promote the development and sustain malignant B cells. One of these traits, the ability to evade apoptosis, is essential for lymphoma development. Alterations in the Bcl-2 family of proteins, the key regulators of apoptosis, is a hallmark of B cell lymphoma. Significant efforts have been made over the last 30 years to advance knowledge of the biology, molecular mechanisms, and therapeutic potential of targeting Bcl-2 family members. In this review, we will highlight the …

Inflammatory Serine Proteases Play A Critical Role In The Early Pathogenesis Of Diabetic Cardiomyopathy., Mikhail A Kolpakov, Kunal Sikder, Amrita Sarkar, Shaswati Chaki, Sanket K Shukla, Xinji Guo, Zhao Qi, Carlos Barbery, Abdelkarim Sabri, Khadija Rafiq

Center for Translational Medicine Faculty Papers

BACKGROUND/AIMS: Diabetic cardiomyopathy (DCM) is characterized by structural and functional alterations that can lead to heart failure. Several mechanisms are known to be involved in the pathogenesis of DCM, however, the molecular mechanism that links inflammation to DCM is incompletely understood. To learn about this mechanism, we investigated the role of inflammatory serine proteases (ISPs) during the development of DCM.

METHODS: Eight weeks old mice with deletion of dipeptidyl peptidase I (DPPI), an enzyme involved in the maturation of major ISPs, and wild type (WT) mice controls were injected with streptozotocin (50 mg/kg for 5 days intraperitoneally) and studied after …

Targeting The Stat5 Pathway In Ph+ Acute Lymphoblastic Leukemia, Valentina Minieri, Marco De Dominici, Marja T. Nevalainen, Bruno Calabretta

Department of Cancer Biology Faculty Papers

No abstract provided.

3,3'-Diindolylmethane Enhances Apoptosis In Docetaxel-Treated Breast Cancer Cells By Generation Of Reactive Oxygen Species., Susan Lanza-Jacoby, Guanjun Cheng

Department of Surgery Faculty Papers

CONTEXT: A major problem in the treatment of cancer is the development of toxic side effects and resistance to chemotherapy. The use of plant compounds to overcome resistance and prevent toxicity is a potential strategy for treatment.

OBJECTIVE: We evaluated whether 3,3'-diindolylmethane (DIM) enhanced the sensitivity of breast cancer cells to docetaxel (DOC).

MATERIALS AND METHODS: MDA-MB231 and Sk-BR-3 cells were treated with and without 25 or 50 µM of DIM and 1 nM of DOC for 48 and 72 h, respectively. MTT assay was used to measure cell survival. Apoptosis and intracellular reactive oxygen species (ROS) were determined by …

Transcriptional Up-Regulation Of Relaxin-3 By Nur77 Attenuates Β-Adrenergic Agonist-Induced Apoptosis In Cardiomyocytes., Xiaohua You, Zhifu Guo, Fang Cheng, Bing Yi, Fan Yang, Xinzhu Liu, Ni Zhu, Xianxian Zhao, Guijun Yan, Xin-Liang Ma, Jianxin Sun

Center for Translational Medicine Faculty Papers

The relaxin family peptides have been shown to exert several beneficial effects on the heart, including anti-apoptosis, anti-fibrosis, and anti-hypertrophy activity. Understanding their regulation might provide new opportunities for therapeutic interventions, but the molecular mechanism(s) coordinating relaxin expression in the heart remain largely obscured. Previous work demonstrated a role for the orphan nuclear receptor Nur77 in regulating cardiomyocyte apoptosis. We therefore investigated Nur77 in the hopes of identifying novel relaxin regulators. Quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) data indicated that ectopic expression of orphan nuclear receptor Nur77 markedly increased the expression of latexin-3 (RLN3), but not relaxin-1 …

Targeting Cdk6 And Bcl2 Exploits The "Myb Addiction" Of Ph+ Acute Lymphoblastic Leukemia, Marco De Dominici, Patrizia Porazzi, Angela Rachele Soliera, Samanta A. Mariani, Sankar Addya, Paolo Fortina, Luke F. Peterson, Orietta Spinelli, Alessandro Rambaldi, Giovanni Martinelli, Anna Ferrari, Ilaria Iacobucci, Bruno Calabretta

Department of Cancer Biology Faculty Papers

Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph^þ ALL) is currently treated with BCR-ABL1 tyrosine kinase inhibitors (TKI) in combination with chemotherapy. However, most patients develop resistance to TKI through BCR-ABL1–dependent and –independent mechanisms. Newly developed TKI can target Ph^þ ALL cells with BCR-ABL1–dependent resistance; however, overcoming BCR-ABL1–independent mechanisms of resistance remains challenging because transcription factors, which are difficult to inhibit, are often involved. We show here that (i) the growth of Ph^þ ALL cell lines and primary cells is highly dependent on MYB-mediated transcriptional upregulation of CDK6, cyclin D3, and BCL2, and (ii) restoring their expression in MYB-silenced …

Response And Resistance To Paradox-Breaking Braf Inhibitor In Melanomas, Edward J. Hartsough, Curtis H. Kugel, Michael J. Vido, Adam C. Berger, Timothy J. Purwin, Allison F. Goldberg, Michael A. Davies, Matthew J. Schiewer, Karen E. Knudsen, Gideon Bollag, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

FDA-approved BRAF inhibitors produce high response rates and improve overall survival in patients with BRAF V600E/K-mutant melanoma, but are linked to pathologies associated with paradoxical ERK1/2 activation in wild-type BRAF cells. To overcome this limitation, a next-generation paradox-breaking RAF inhibitor (PLX8394) has been designed. Here, we show that by using a quantitative reporter assay, PLX8394 rapidly suppressed ERK1/2 reporter activity and growth of mutant BRAF melanoma xenografts. Ex vivo treatment of xenografts and use of a patient-derived explant system (PDeX) revealed that PLX8394 suppressed ERK1/2 signaling and elicited apoptosis more effectively than the FDA-approved BRAF inhibitor, vemurafenib. Furthermore, PLX8394 was …

Non-Hodgkin And Hodgkin Lymphomas Select For Overexpression Of Bclw., Clare M. Adams, Ramkrishna Mitra, Jerald Z. Gong, Md, Christine M. Eischen

Department of Cancer Biology Faculty Papers

Purpose: B-cell lymphomas must acquire resistance to apoptosis during their development. We recently discovered BCLW, an antiapoptotic BCL2 family member thought only to contribute to spermatogenesis, was overexpressed in diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma. To gain insight into the contribution of BCLW to B-cell lymphomas and its potential to confer resistance to BCL2 inhibitors, we investigated the expression of BCLW and the other antiapoptotic BCL2 family members in six different B-cell lymphomas. Experimental Design: We performed a large-scale gene expression analysis of datasets comprising approximately 2,300 lymphoma patient samples, including non-Hodgkin and Hodgkin lymphomas as well as …

Chemokine Signaling During Midline Epithelial Seam Disintegration Facilitates Palatal Fusion, Christiaan M. Suttorp, Niels A. Cremers, René E. Van Rheden, Raymond F. Regan, Pia Helmich, Sven Van Kempen, Anne Marie Kuijpers-Jagtman, Frank Wagener

Department of Emergency Medicine Faculty Papers

Disintegration of the midline epithelial seam (MES) is crucial for palatal fusion, and failure results in cleft palate. Palatal fusion and wound repair share many common signaling pathways related to epithelial-mesenchymal cross-talk. We postulate that chemokine CXCL11, its receptor CXCR3, and the cytoprotective enzyme heme oxygenase (HO), which are crucial during wound repair, also play a decisive role in MES disintegration. Fetal growth restriction and craniofacial abnormalities were present in HO-2 knockout (KO) mice without effects on palatal fusion. CXCL11 and CXCR3 were highly expressed in the disintegrating MES in both wild-type and HO-2 KO animals. Multiple apoptotic DNA fragments …

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

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. …

Posttranscriptional Regulation Of Parg Mrna By Hur Facilitates Dna Repair And Resistance To Parp Inhibitors, Saswati N. Chand, Mahsa Zarei, M. J. Schiewer, Akshay R. Sanan, Carmella Romeo, Shruti Lal, Joseph A. Cozzitorto, Avinoam Nevler, Laura Scolaro, Eric R. Londin, Wei Jiang, Nicole Meisner-Kober, Michael J. Pishvaian, Karen E. Knudsen, Charles Yeo, John M Pascal, Jordan M. Winter, Jonathan R. Brody

Department of Surgery Faculty Papers

The majority of pancreatic ductal adenocarcinomas (PDAC) rely on the mRNA stability factor HuR (ELAV-L1) to drive cancer growth and progression. Here, we show that CRISPR-Cas9–mediated silencing of the HuR locus increases the relative sensitivity of PDAC cells to PARP inhibitors (PARPi). PDAC cells treated with PARPi stimulated translocation of HuR from the nucleus to the cytoplasm, specifically promoting stabilization of a new target, poly (ADP-ribose) glycohydrolase (PARG) mRNA, by binding a unique sequence embedded in its 3⁰ untranslated region. HuR-dependent upregulation of PARG expression facilitated DNA repair via hydrolysis of polyADP-ribose on related repair proteins. Accordingly, strategies to …

Danshen-Chuanxiong-Honghua Ameliorates Cerebral Impairment And Improves Spatial Cognitive Deficits After Transient Focal Ischemia And Identification Of Active Compounds., Xianhua Zhang, Wan Zheng, Tingrui Wang, Ping Ren, Fushun Wang, Xin-Liang Ma, Jian Wang, Xi Huang

Department of Emergency Medicine Faculty Papers

Previously, we only apply a traditional Chinese medicine (TCM) Danshen-Chuanxiong-Honghua (DCH) for cardioprotection via anti-inflammation in rats of acute myocardial infarction by occluding coronary artery. Presently, we select not only DCH but also its main absorbed compound ferulic acid (FA) for cerebra protection via similar action of mechanism above in animals of the transient middle cerebral artery occlusion (tMCAO). We investigated whether oral administration of DCH and FA could ameliorate MCAO-induced brain lesions in animals. By using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we analyzed four compounds, including tanshinol, salvianolic acid B, hydroxysafflor yellow A and especially FA as the putative …

Not So Fast: Cultivating Mirs As Kinks In The Chain Of The Cell Cycle., Matthew J. Schiewer, Karen E. Knudsen

Department of Cancer Biology Faculty Papers

In this issue of Cancer Cell, Hydbring and colleagues define a novel class of microRNAs (miRNAs), deemed "cell-cycle-targeting miRNAs," that target several cyclins/CDKs, reduce tumor cell growth, and induce apoptosis. These miRNAs effectively suppressed chemoresistant patient-derived xenograft growth in vivo, and efficacy could be prospectively predicted with an expression-based algorithm.

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 …