The roles of SHANK1 in the development of colon cancer.

SH3 and multiple ankyrin repeat domains protein 1 (SHANK1) belongs to a family of postsynaptic scaffolding proteins. In this study, we found that SHANK1 was abnormally high expressed in colon cancer tissues compared to normal tissues. Colon cancer patients with low SHANK1 expression had better prognosis. Furthermore, the expression of SHANK1 was knocked down in human colon cancer cell lines HCT116 and HT29 and the role of SHANK1 was investigated in colon cancer tumorigenesis. Our results showed that the knockdown of SHANK1 inhibited the survival and proliferation of both cells. The migration of these two cell lines was significantly reduced and the apoptosis was induced compared with control cells. The Bax/Bcl-2 ratio in both cell lines that SHANK1 was knocked down was increased, which is a signal that the mitochondrial apoptotic pathway was triggered. In addition, we observed that knockdown of SHANK1 reduced the expression of phosphorylated forms of AKT and mTOR. These data suggested that loss of SHANK1 inhibited viability and induced apoptosis of HCT116 and HT29 cells through the AKT/mTOR signaling pathway. Our data revealed that SHANK1 played important roles in the growth of colon cancer cells and may be used as a novel strategy for colon cancer therapy. SIGNIFICANCE OF THE STUDY: Herein, we reported that SHANK1 was abnormally high expressed in colon cancer tissues and associated with worse prognosis of patients. In addition, knockdown of SHANK1 inhibited viability and induced apoptosis in colon cancer cell lines through AKT/mTOR signaling pathways. These data suggest that SHANK1 may be a new oncogene in colon cancer. This study reveals the role of SHANK1 in addition to neuronal development and cognitive development. And it provides a new potential target for the prediction and treatment of colon cancer.