Abstract 662: Role of FAM3B as a novel tumor suppressor gene in gastric cancer.

Abstract

Abstract PANcreatic-DERived factor (PANDER, FAM3B) is a member of the FAM3 family of cytokine molecules. FAM3B expression is originally identified in the endocrine pancreas and also expressed in in colon and stomach. Initial characterization of FAM3B revealed a potential role in pancreatic islet apoptosis. However, the biological function of FAM3B has still remained elusive. Here we show that FAM3B level is decreased in 11 out of 14 cancer tissues samples (78.5%) as well as in gastric cancer cell lines. Ectopic expression of FAM3B leads to inhibition of cell growth and reduction of single cell colony forming activity and tumorigenicity of gastric cancer cells. FAM3B not only induces reduction of AKT phosphorylation, which is involved in cell survival, but also upregulation of p21, an inhibitor of cell cycle progression. We also demonstrated that FAM3B gene is silenced by epigenetic modification in gastric cancer cell lines. MS-275, a synthetic inhibitor of histone deacetylase, induced FAM3B gene expression. In conclusion, our data suggest the role of FAM3B as a putative tumor suppressor through downregulation of oncogenic AKT signaling pathway in gastric cancer. Citation Format: Hyojung Kim, Sujin Park, Jin Muk Kang, Staci Jakyong Kim, Seong-Jin Kim. Role of FAM3B as a novel tumor suppressor gene in gastric cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 662. doi:10.1158/1538-7445.AM2013-662