RACK1 to modulate expression of MMP10 via Src/NF-κB pathway in gastric cancer.

Abstract

e15529 Background: Receptor of activated C kinase 1 (RACK1) is regarded as a scaffolding protein in multiple intracellular signal transduction pathways. Our previous works had demonstrated that RACK1 might involve in progression of gastric cancer, and could be a criterion to predict the good prognosis for the patients after surgical resection. The aim of this study is to explore the regulatory role of RACK1 in matrix metalloproteinase 10 (MMP10) autocrine, and which may be involved in invasion of gastric cancer. Methods: RACK1 knockdown gastric cell lines were established by shRNA. Secretion of cytokines secretion, as well as MMP10 was measured by antibody arrays and enzyme-linked immunosorbent assay. Cell migration and invasion was compared between normal and RACK1 knockdown cells. Pharmacological inhibitors were employed in searching specific signaling pathway. The correlation of RACK1 and MMP10 expression in gastric cancer samples was analyzed by Spearman’s ρ test. Results: Expression of MMP10 was substantially enhanced after knockdown of RACK1 in vitro, which contributed to enhanced migration and invasiveness of gastric cancer cells in autocrine manner. Specific inhibitors of NF-κB and c-Src, as well as overexpression of dominant-negative c-Src mutant, could suppress the expression of MMP10. Finally, an inverse correlation of RACK1 and IL-8 expression was confirmed in gastric cancer samples. Conclusions: Down-regulation of RACK1 resulted in the up-regulation of MMP10 in gastric cancer, which might enhance invasiveness via Src/NF-κB pathway partially.