Repressing IRS1/2 by NT157 inhibits the malignant behaviors of ovarian cancer through inactivating PI3K/AKT/mTOR pathway and inducing autophagy

Abstract Insulin receptor substrate 1 and 2 (IRS1/2) have been found involved in many cancers development and their inhibitors exert significant tumor‐suppressive effects. Here, we tried to explore the function of NT157, an IGF1R‐IRS1/2 inhibitor, in ovarian cancer. We treated ovarian cancer cells with varying doses of NT157. The MTT assay was employed to evaluate cell proliferation and colony formation assay was used for detecting colony‐forming ability. TUNEL assay was adopted to test cell apoptosis. Cell invasion was checked by the Transwell assay. The expression of apoptosis‐related proteins, autophagy markers, IRS1/2, and PI3K/AKT/mTOR pathway was compared by Western blot, immunofluorescence, or qRT‐PCR. As indicated by the data, NT157 abated the viability, proliferation, and induced autophagy of ovarian cancer cells. Overexpressing IRS1/2 attenuated the tumor‐suppressive effect of NT157 and heightened the PI3K/AKT/mTOR pathway activation. Inhibition of the PI3K/AKT/mTOR pathway enhanced the tumor‐suppressive effect of NT157 and facilitated NT157‐mediated autophagy. However, the autophagy inhibitor 3‐MA partly reversed NT‐157‐mediated antitumor effects. In conclusion, this study disclosed that NT157 suppressed the malignant phenotypes of ovarian cancer cells by inducing autophagy and hampering the expression of IRS1/2 and PI3K/AKT/mTOR pathway.