Abstract 470: Motility of human colorectal cancer cells is promoted by H1047R kinase mutation of PI3K p110-alpha

Abstract

Abstract INTRODUCTION: Mutations in the catalytic subunit p110α of Class 1A phosphatidyinositol 3-kinase (PI3K) occur in nearly 1/3 human colorectal cancer (CRC). In vivo studies have demonstrated that cell lines bearing the p110α mutation are more metastatic than wild type PI3K cells. The most frequent cancer-specific mutations in p110α are the kinase domain mutation H1047R and the helical domain mutation E542K/E545K. Our group has previously shown that the two hotspot mutations in PI3K in either the helical or kinase domains have a significantly different metastatic potential in an orthotopic murine model. The aim of this study was to compare the difference in cell motility between the helical and kinase domain mutation bearing human CRC cell lines. METHODS: Wound healing Assay was used to determine the motility of human CRC cells in vitro. Effect of PI3K inhibition on cell motility was tested under the treatments with 0.1 and 1.0 µM of wortmannin, which is a class 1 PI3K inhibitor, and PIK75, which is the specific inhibitor of p110α. RESULTS: Our data indicate that H1047R-p110α increases cell motility more than E545K-p110α and the inhibition of PI3K significantly delayed or abrogated the migration of CRC cells. Immuno-blotting analysis showed increased downstream survival signaling pathway activation of PI3K in the cells bearing H1047R-p110α knase domain mutation compared to the cells which have E545K-p110α helical domain mutation. CONCLUSION: The PI3K-p110α kinase mutation bearing CRC cells were more motile as compared to the helical domain mutation bearing cells. This data supports our previous in vivo data that kinase domain mutations have a greater metastatic capability than helical domain bearing mutants. Cell motility was abrogated by both nonspecific and p110α directed PI3K inhibition suggesting that the activation of PI3K is necessary for CRC cell motility. This data supports the efforts to target the PI3K pathway in patients with advanced CRC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 470. doi:1538-7445.AM2012-470