SND1 mediated downregulation of PTPN23 in HCC

SND1 MEDIATED DOWNREGULATION OF PTPN23 IN HEPATOCELLULAR CARCINOMA By Nidhi Jariwala, MS A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University, 2014. ADVISOR: Dr. Devanand Sarkar Associate Professor, Department of Human and Molecular Genetics Blick Scholar Associate Scientific Director, Cancer Therapeutics VCU Institute of Molecular Medicine Massey Cancer Center ABSTRACT Staphyloccocal nuclease domain containing protein 1 (SND1) is identified as an oncogene in multiple cancers, including hepatocellular carcinoma (HCC). SND1 regulates gene expression at transcriptional as well as post-transcriptional level and mediates molecular pathways that culminate into carcinogenesis. SND1 is a component of RNA-induced silencing complex (RISC) and functions as a nuclease for RNAi-mediated mRNA degradation. On the other hand SND1 also binds to specific mRNAs, increasing their stability and hence expression. The aim of the present study is to identify mRNAs to which SND1 binds and modulates them either by degradation or increasing stability which might facilitate promotion of HCC by SND1. We performed RNA immunoprecipitation followed by RNA sequencing (RIP-Seq) using anti-SND1 antibody and human HCC cell line QGY-7703. More than 350 mRNAs were identified to be interacting with SND1, of which Protein tyrosine phosphatase non-receptor 23 (PTPN23) was of particular interest, since PTPN23 has been identified to be a tumor suppressor and its role in HCC has not been studied. We document that SND1 can bind to PTPN23 mRNA and induce its degradation. There is an inverse correlation between SND1 and PTPN23 levels in human HCC cell lines and PTPN23 level is downregulated in HCC. Our study thus identifies a novel mechanism by which SND1 promotes hepatocarcinogenesis and identifies PTPN23 as a potential tumor suppressor in HCC. Further studies need to be performed to explore the relationship of these two molecules in in vivo models and to develop PTPN23 overexpression as a potential therapeutic approach for HCC

Small molecule inhibitors of Late SV40 Factor (LSF) abrogate hepatocellular carcinoma (HCC): evaluation using an endogenous HCC model

Hepatocellular carcinoma (HCC) is a lethal malignancy with high mortality and poor prognosis. Oncogenic transcription factor Late SV40 Factor (LSF) plays an important role in promoting HCC. A small molecule inhibitor of LSF, Factor Quinolinone Inhibitor 1 (FQI1), significantly inhibited human HCC xenografts in nude mice without harming normal cells. Here we evaluated the efficacy of FQI1 and another inhibitor, FQI2, in inhibiting endogenous hepatocarcinogenesis. HCC was induced in a transgenic mouse with hepatocyte-specific overexpression of c-myc (Alb/c-myc) by injecting N-nitrosodiethylamine (DEN) followed by FQI1 or FQI2 treatment after tumor development. LSF inhibitors markedly decreased tumor burden in Alb/c-myc mice with a corresponding decrease in proliferation and angiogenesis. Interestingly, in vitro treatment of human HCC cells with LSF inhibitors resulted in mitotic arrest with an accompanying increase in CyclinB1. Inhibition of CyclinB1 induction by Cycloheximide or CDK1 activity by Roscovitine significantly prevented FQI-induced mitotic arrest. A significant induction of apoptosis was also observed upon treatment with FQI. These effects of LSF inhibition, mitotic arrest and induction of apoptosis by FQI1s provide multiple avenues by which these inhibitors eliminate HCC cells. LSF inhibitors might be highly potent and effective therapeutics for HCC either alone or in combination with currently existing therapies.The present study was supported in part by grants from The James S. McDonnell Foundation, National Cancer Institute Grant R01 CA138540-01A1 (DS), National Institutes of Health Grant R01 CA134721 (PBF), the Samuel Waxman Cancer Research Foundation (SWCRF) (DS and PBF), National Institutes of Health Grants R01 GM078240 and P50 GM67041 (SES), the Johnson and Johnson Clinical Innovation Award (UH), and the Boston University Ignition Award (UH). JLSW was supported by Alnylam Pharmaceuticals, Inc. DS is the Harrison Endowed Scholar in Cancer Research and Blick scholar. PBF holds the Thelma Newmeyer Corman Chair in Cancer Research. The authors acknowledge Dr. Lauren E. Brown (Dept. Chemistry, Boston University) for the synthesis of FQI1 and FQI2, and Lucy Flynn (Dept. Biology, Boston University) for initially identifying G2/M effects caused by FQI1. (James S. McDonnell Foundation; R01 CA138540-01A1 - National Cancer Institute; R01 CA134721 - National Institutes of Health; R01 GM078240 - National Institutes of Health; P50 GM67041 - National Institutes of Health; Samuel Waxman Cancer Research Foundation (SWCRF); Johnson and Johnson Clinical Innovation Award; Boston University Ignition Award; Alnylam Pharmaceuticals, Inc.)Published versio

Characterization of Staphylococcal nuclease and tudor domain containing protein 1 (SND1) as a molecular target in Hepatocellular carcinoma and Non-alcoholic steatohepatitis

CHARACTERIZATION OF STAPHYLOCOCCAL NUCLEASE AND TUDOR DOMAIN CONTAINING PROTEIN 1 (SND1) AS A MOLECULAR TARGET IN HEPATOCELLULAR CARCINOMA AND NON-ALCOHOLIC STEATOHEPATITIS Nidhi Jariwala, PhD A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Integrative Life Sciences Virginia Commonwealth University, 2017 Devanand Sarkar, M.B.B.S., PhD. Associate Professor, Department of Human and Molecular Genetics Virginia Commonwealth University Richmond, Virginia SND1, a subunit of the miRNA regulatory complex RISC, has been implicated as an oncogene in hepatocellular carcinoma (HCC). Oncoprotein SND1 regulates gene expression at a post-transcriptional level in multiple cancers including hepatocellular carcinoma (HCC). In the present study, we characterize oncogenic functions of SND1 in HCC employing a novel transgenic mouse model (Alb/SND1) and present SND1 as a potential molecular target in HCC management. We show that Alb/SND1 mice develop spontaneous HCC with partial penetrance and exhibit more highly aggressive HCC induced by chemical carcinogenesis. Livers from Alb/SND1 mice exhibit a relative increase in inflammatory markers and spheroid-generating tumor initiating cells (TiC). Mechanistic investigations defined roles for Akt and NF-κB signaling pathways in promoting TiC formation in Alb/SND1 mice. Intravenous administration of the selective SND1 inhibitor 3\u27, 5\u27-deoxythymidine bisphosphate (pdTp) inhibited tumor formation without effects on body weight or liver function. We conclude that SND1 drives pro-oncogenic transcriptomic and proteomic changes in hepatocyte resulting in aggressive HCC. SND1 specific RNA interactome is identified with RNA immunoprecipitation sequencing (RIPSeq) approach. With an adjusted p value of2-fold enrichment over control, 282 mRNAs were identified to significantly associate with SND1 protein. We focused on the tumor suppressor Protein Tyrosine Phosphatase non-receptor type 23 (PTPN23) because its regulation by SND1 and its role in HCC are not known. In current study, we confirm that SND1 post-transcriptionally downregulates PTPN23. Pursuing functional studies with tetracycline inducible overexpression system, we validate that PTPN23 inhibits tyrosine kinase signaling, proliferation, epithelial to mesenchymal transition, migration, invasion and in vivo tumorigenesis. Alb/SND1 mice also manifest steatosis and fibrosis at one year of age. Coupled with a pro-inflammatory hepatic phenotype, we conclude that Alb/SND1 livers present NASH. High fat diet causes severe NASH and aggressive NASH induced HCC in Alb/SND1 mice. Serum and hepatic lipid profiling shows that hepatocyte specific SND1 overexpression associate with elevated triglyceride and cholesterol LDL levels. Contrarily, hepatocyte specific deletion of SND1 (SND1ΔHEP) in vivo, significantly protects against age dependent steatosis. Association of SND1 in NASH pathology is novel discovery and we present preliminary evidence confirming role of SND1 in promoting NASH

MODELLING OF PMSM AND FOC OF PMSM BASED ON SPWM WITH MATLAB/SIMULINK

ABSTARCT: Permanent-magnet-synchronous-machine (PMSM) drives have been increasingly applied in a variety of industrial applications which require fast dynamic response and accurate control over wide speed ranges. Permanent magnet (PM) synchronous motors are widely used in low and mid power applications such as computer peripheral equipments, robotics, adjustable speed drives and electric vehicles. The mathematical model of PMSM is analyzed and the system model of FOC vector control has been established. The control system has been also simulated by MATLAB/Simulink