Aspirin has a better effect on PIK3CA mutant colorectal cancer cells by PI3K/Akt/Raptor pathway.

backgroundAspirin, as a non-steroidal anti-inflammatory drug, can improve the survival rate of patients with colorectal cancer, while aspirin is effective in patients with PIK3CA mutant colorectal cancer (CRC). However, the mechanism of aspirin in the treatment of PIK3CA mutated CRC patients remains unclear.

methodsIn this study, immunohistochemistry was used to detect the expression levels of PI3K and Raptor in colorectal cancer patients with PIK3CA mutation and PIK3CA wild-type patients. To demonstrate that aspirin has a better effect on the CRC of PIK3CA mutations in association with the PI3K/Akt/Raptor pathway, we used aspirin to treat PIK3CA mutant CRC cells (HCT-116 and RKO). Subsequently, the CCK8 assay and flow cytometry assay were used to detect the apoptosis of PIK3CA mutant CRC cells before and after aspirin use. Western blot was used to detect the changes of PI3K/Akt/Raptor-associated protein, autophagy protein microtubule associated protein 1 light chain 3 alpha (MAP1LC3A, LC3), beclin 1 (BECN1) and apoptosis protein BCL2-associated X protein/ BCL2 apoptosis regulator (Bax/Bcl2), Caspase 3 after treatment of CRC cells with PIK3CA mutation by aspirin.

resultsPhosphoinositide-3-kinase (PI3K) and regulatory associated protein of MTOR complex 1 (Raptor) protein expression levels were higher in PIK3CA-mutant patients than in IK3CA wild-type patients. The expression of Bax/Bcl2 increased after treatment indicates that aspirin can induce apoptosis of PIK3CA-mutant CRC cells. The expression level of MAP1LC3 (LC3) in cells increases with the concentration of aspirin demonstrates that aspirin can induce autophagy in CRC cells. After 48 h of treatment with aspirin, the phosphorylation of eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1) and ribosomal protein S6 kinase B1 (S6K1) was reduced, cell proliferation has been inhibited. After treatment with aspirin, as phosphorylation of PI3K and Protein kinase B (PKB, Akt) was decreased, Raptor expression was also decreased.

conclusionAspirin can regulate the proliferation, apoptosis and autophagy of CRC cells through the PI3K/Akt/Raptor pathway, affecting PIK3CA-mutant CRC.