To investigate the effect of CD147 expression on the proliferation and apoptosis of colon cancer cells and the potential underlying molecular mechanism.

The expression level of BSG gene (encoding CD147 protein) in colon cancer was analyzed in the UCSC database, and the relationship between BSG expression and survival outcome was evaluated based on the Kaplan-Meier Plotter database. The expression of CD147 in HCT116 and HCoEPiC cells was detected by Western blot. Then, lentivirus-mediated shRNA transfection was used to down-regulate the expression of CD147 in HCT116 cells using shRNA against CD147 (shCD147), with the empty vector (sh-NON) used as the negative control. CCK-8 assay, plate clone formation assay, and Hoechst 33342 staining were used to detect cell proliferation and apoptosis. The expression of MAPK, p-MAPK, C-MYC, BAX, and BCL-2 was detected by Western blot. The correlation between the expression of BSG and MAPK1, MYC, BAX, and BCL-2 in colon cancer was analyzed based on the TIMER2.0 database.

The expression of CD147 in colon cancer tissues was higher than that in normal tissues (P<0.01), and the prognosis of patients with overexpression of CD147 was poor. Western blot analysis showed that the expression of CD147 protein in HCT116 cells was increased compared with that in HCoEPiC cells (P<0.001). Under the fluorescence microscope, the fluorescence expression abundance in the shCD147 low expression group and sh-NON group could reach 90%. Western blot analysis showed that compared with untransfected HCT116 cells, the expression of CD147 protein in the shCD147 group was decreased (P<0.001). After down-regulation of CD147, cell proliferation and colony formation in the sh-CD147 group were decreased compared with untransfected HCT116 cells. The results of Hoechst 33342 staining showed that the nuclear staining of apoptosis in the shCD147 group was stronger and the fluorescence was brighter than that of untransfected HCT116 cells (P<0.001). Compared with untransfected HCT116 cells, the expression of p-MAPK, C-MYC, and BCL-2 in the sh-CD147 group was decreased, but the expression of BAX was increased. Correlation analysis based on the TIMER 2.0 database showed that the expression level of BSG in colon cancer tissue was positively correlated with the expression of MAPK1, MYC, and BCL-2, but negatively correlated with the expression of BAX (P<0.001).

Down-regulation of CD147 expression reduces the proliferation of colon cancer cells and promotes apoptosis, which may be related to the inhibition of the MAPK signaling pathway.