Abstract 2317: Oct4 impacts migration of breast cancer via Epithelial-to-mesenchymal transition related manner

Abstract

Abstract Recent studys suggest that Oct4, a key regulator in maintenance of the embryonic stem cell pluripotency and proliferation, is relevant with the malignant characteristic of breast cancer. This study aims to investigate the role of OCT4 in the mechanism underlying the migration of breast cancer. We compared Oct4 expression in cultured MCF-7 and MDA-MB-231 cell, both of them are original from breast dust epithelial cell while the migration capacity of MDA-MB-231 cell is strikingly higher than that of MCF-7 cell. Result of western blot showed that expression level of Oct4 in MCF-7 cell was much higher than that in MDA-MB-231 cell. Then, we abolished Oct4 expression MCF-7 cell using siRNA technology. Trans-well assay result showed Oct4 down-regulation significantly increased the number of migrated cells. The expressions of E-cadherin andα-SMA, accepted epithelial and mesenchymal marker separately, were examined by western blot method. Upon down-regulation of Oct4, E-cadherin expression was inhibited whileα-SMA expression was significantly up-regulated. Real-time PCR result showed Fibronetin mRNA expression was also significantly up-regulated after Oct4 down-regulation. Further, we added TGF-β1 to cultured MCF-7 cell and then examined Oct4, E-cadherin and α-SMA expression level with Western blot. The results showed that TGF-β1 significantly inhibited E-cadherin while induced α-SMA expression in both time- and dose-dependent manner. At the same time, Oct4 expression was also highly down-regulated with the treatment of TGF-β1. Interestingly, Snail expression, which is a critical transcription factor in epithelium to mesenchymal transition (EMT) program, is significantly increased with the down-regulation of Oct-4 expression. Our study seemed to implicate transcription factor OCT4 in migration of breast cancer via EMT-related manner and this effect is likely associated with the impact of Oct-4 on the expression of Snail. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. 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 2317.