Abstract 5118: Rho/ROCK pathway mediates plasticity of scirrhous gastric carcinoma cell motility

Abstract

Abstract The small guanosine triphosphatase (GTPase) Rho and its downstream effector Rho-associated kinase (ROCK) is one of a key mediator involved in controlling focal adhesions and the dynamics of actin stress fibers. This pathway has been shown to play important roles in the regulation of various cellular processes, such as cell shape changes and adhesion dynamics that drive migration. The underlying molecular mechanisms for the function of Rho/ROCK pathway leading to the development and progression in scirrhous gastric carcinoma cells have not been defined. We investigated the role of the Rho/ROCK pathway in the adhesion and invasion of gastric carcinoma cells, using a human scirrhous gastric cancer cell line, OCUM-2MD3. ROCK inhibitor, Y27632 significantly increased the adhesion of OCUM-2MD3 cells to the extracellular metrix (ECM) protein matrigel, but had no effect on attachment to polylysine. Further examination using ECM components showed enhanced binding ability was obtained only in laminin, but not in fibronectin, Type I collagen, and Type IV collagen. Reverse transcriptional (RT)-PCR analysis revealed that integrin subunits α3-integrin was clearly up-regulated by treatment with Y-27632 in OCUM-2MD3 cells, reflecting the specificity of ECM protein showing high adhesiveness property of gastric carcinoma cells. ROCK inhibitor also enhanced the invasion of OCUM-2MD3 cells through matrigel. The fact that Y27632 up-regulated the expression of membrane-type 1 matrix metalloproteinase by RT-PCR suggested the possibility that increased invasion ability of OCUM-2MD3 cells was related to proteolytic activity of extracellular matrices. Time-lapse microscopy showed conversion of OCUM-2MD3 cells from elongated to more round morphology with bleb in the presence of Y27632, suggesting that inhibition of Rho/ROCK pathway undergo a so-called ‘amoeboid to mesenchymal’ transition. Taken together, these data suggests that Rho/ROCK regulate plasticity of metastatic gastric carcinoma via mesenchymal-amoeboid transition, leading to clarify the specific progression of scirrhous gastric carcinoma. 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 5118.