STIL a novel link in Shh and Wnt signaling, endowing oncogenic and stem like attributes to colorectal cancer

Abstract

Discovery of potent gene regulating tumorigenesis and drug resistance is of high clinical importance. STIL is an oncogene, however its molecular insights and role in colorectal oncogenesis are unknown. In this study we have explored role of STIL in tumorigenesis and studied its molecular targets in colorectal cancer (CRC). STIL silencing reduced proliferation and tumor growth in CRC. Further, STIL was found to regulate stemness markers CD133 & CD44 and drug resistant markers Thymidylate synthase, ABCB1 & ABCG2 both in in-vitro and in-vivo CRC models. In addition, over expression of STIL mRNA was found to be associated with reduced disease free survival in CRC cases. To our surprise we observed an Shh independent regulation of stemness and drug resistant genes mediated by STIL. Interestingly, we found an Shh independent regulation of {beta}-catenin mediated by STIL via p-AKT, which partially answers Shh independent regulatory mechanism of CSC markers by STIL. Our study suggest an instrumental role of STIL in molecular manifestation of CRC and progression.