OSI‐027 inhibits the tumorigenesis of colon cancer through mediation of c‐Myc/FOXO3a/PUMA axis

Colon cancer is a gastrointestinal malignancy that is one of the leading causes of tumor-associated deaths. It has been reported that the mammalian target of rapamycin (mTOR) can lead to the progression of colon cancer. However, the mechanism by which mTOR inhibitor (OSI-027) mediates the tumorigenesis of colon cancer remains largely unknown. Cell function of colon cancer was investigated by cell counting kit-8 flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. In addition, quantitative real-time polymerase chain reaction and Western blot were used to investigate the mechanism underlying the function of OSI-027 in colon cancer. OSI-027 dose-dependently reduced colon cancer cell viability by inducing cell apoptosis. In addition, OSI-027 induced the apoptosis of colon cancer cells via upregulation of PUMA. OSI-027 promoted the expression of PUMA by activation of forkhead box protein O3a (FOXO3a), and c-Myc knockdown partially increased FOXO3a and PUMA levels. Moreover, OSI-027 attenuated the tumor growth of colon cancer through the mediation of the mTOR/c-Myc/FOXO3a axis. OSI-027 attenuates colon cancer progression through the mediation of the c-Myc/FOXO3a/PUMA axis. Thereby, this study might shed new insights on exploring the strategies against colon cancer.