Objective To investigate the effect of PTENP1 on the proliferation and apoptosis of colorectal cancer cells and its molecular mechanism.

Methods We selected 107 cases of colorectal cancer and corresponding adjacent tissues as the research objects. The expression level of PTENP1 was analyzed by fluorescence quantitative PCR. Colon cancer HT29 cells with PTENP1 overexpression (PTENP1 group) and empty vector cell line (control group) were established by lentivirus. The cell proliferation and apoptosis were analyzed by CCK8 and flow cytometry. The PTENP1 target gene was analyzed by bioinformatics and double luciferase reporter genes. The expression level of target protein was analyzed by Western blot.

Results The expression of PTENP1 in colorectal cancer tissues was significantly lower than that in adjacent tissues (P < 0.05). The expression level of PTENP1 in the control group was significantly lower than that in the PTENP1 group (P < 0.05). Compared with the control group, the cell proliferation ability of the PTENP1 group was significantly decreased (P < 0.05), the apoptosis level was significantly increased (P < 0.05). miR-21 was complementary to PTENP1. Compared with the control group, the expression of miR-21 in the PTENP1 group was significantly down-regulated (P < 0.05), and the expression of PTEN protein was significantly up-regulated (P < 0.05).

Conclusion PTENP1 and miR-21 competitively bind to regulate the expression of PTEN, and then affect the proliferation and apoptosis of colorectal cancer cells.