Abstract 4982: N-myc downstream-regulated gene 1/Cap43 expression promotes cell differentiation of human osteosarcoma cells

N-myc downstream regulated gene 1 (NDRG1)/Cap43 is closely associated with cell differentiation, and its expression is induced by hypoxia and increasing intracellular calcium. Whether NDRG1/Cap43 expression in cancer cells is a predictive marker of good or poor prognosis in patients depends upon tumor types and differentiation status. In this study, we examined whether NDRG1/Cap43 expression was involved in differentiation of osteosarcoma cells, and used three osteosarcoma cell lines, MG63, U2OS, and SaOS2. Its expression in MG63 and U2OS was significantly enhanced by vitamin D 3 that also induced production of osteocalcin, a differentiation marker of osteoblasts. Knockdown of NDRG1/Cap43 using siRNA also suppressed the production of osteocalcin and enhanced cell proliferation, accompanying by suppression of p21 expression. Furthermore, acquired invasiveness of osteosarcoma cells during invasion in Matrigel resulted in decreasing expression of NDRG1/Cap43. A possible role of NDRG1/Cap43 in cellular capacity for differentiation and invasion in osteosarcoma cells will be discussed. 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 4982.