Abstract 3036: Comparison of miRNA expression between human osteoblasts and osteosarcoma cells

Abstract

Abstract Osteosarcoma is the most common primary malignant bone tumor that most frequently affects young adults. There is increasing evidence that miRNAs (miRs) are important modulators of gene expression and their deregulation has been reported in various human tumors. This study investigated differences in miR expression in normal human osteoblast cells versus malignant human osteosarcoma cells differ in their miR expression. Analysis of miRNA expression in normal osteoblast cell lines (hOBc, NHOST, hFOB) and osteosarcoma cell lines (KHOS, Saos, U-2OS) were completed using miR microarray technology with unsupervised hierarchical clustering analysis. The relative expression levels of these miRs were confirmed by real-time quantitative RT-PCR. A number of miRs were found to have different expression in the osteosarcoma cells when compared to normal human osteoblasts. Three miRs, miR-199a-3p, miR-127-3p and miR-376c were significantly decreased in osteosarcoma cell lines while miR-151-3p and miR-191 were increased in osteosarcoma cell lines in comparison to osteoblasts. Because miR-199a-3p has been suggested to play a vital role in lung and liver cancer, we further characterized its biological functional role in osteosarcomas. The precursor (miR-199a-1) of miR-199a-3p was stably transfected into osteosarcoma cell lines KHOS and U-2OS, resulting in a decrease of cellular proliferation. The expression of miR-199a-3p targeted genes in transfected cells was evaluated by Western blot. These targets included MET and mTOR, two genes that were observed to be overexpressed in osteosarcoma tissues and various cell lines. Following miR-199a-3p transfection, a decrease in MET and mTOR expression was observed in KHOS and U-2OS cells. This study demonstrates that various miRs are differentially expressed in osteosarcomas, and miR-199a-3p, in particular may play a functional role in osteosarcoma cell growth and proliferation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3036.