Abstract 527: Identification of novel target mRNAs of microRNA-143 in glioblastoma cells

Abstract

The purpose of this study is to assess the biological role of microRNA-143 (miR-143) in Glioblastoma multiforme (GBM). In the United States, the incidence of GBM is about 17% of all primary brain tumors and about 60-75% of all Astrocytomas. Many patients recur even after therapy with a median survival rate of 15 months. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally. Deregulated miRNAs have been identified in cancer including GBM. In this study, we aim to thoroughly uncover the role of miR-143 by using GBM cell lines, mouse models, and patient samples. Previous qPCR data from FFPE samples of Puerto Rican GBM patients showed a higher relative expression of miR-143 in GBM patients compared to control individuals and paired surrounding non-cancerous tissue suggesting an oncogenic role. Moreover, in vitro data of transient transfections of a miR-143 oligonucleotide inhibitor in GBM cells showed reduced cell proliferation (clonogenic assay), increased apoptosis and cell cycle arrest in the G0/G1-S phase (flow cytometry and western blot analysis). Furthermore, we want to identify novel target mRNAs of miR-143 in GBM cells that may explain these results. Using in silico analysis tools and a qPCR analysis we identified 5 candidate genes as potential miR-143 targets. Western blot analysis of the proteins encoded by these genes using miR-143 overexpressing cells showed that the Integral membrane protein 2B (ITM2B) and Zinc transporter 8 (SLC30A8) protein levels were reduced and when miR-143 was transiently inhibited their protein levels where increased. These results suggest that miR-143 targets these mRNAs. Ongoing luciferase reporter assays will determine direct binding of miR-143 to the 3'UTR of these mRNAs in GBM cells. Citation Format: Eunice Lozada-Delgado, Fatma Valiyeva, Maria Marcos, Pablo Vivas. Identification of novel target mRNAs of microRNA-143 in glioblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 527.