Effects of PIK3CB gene expression downregulation by RNA interference on the proliferation and apoptosis of colon cancer cell line HCT116

Objective: To explore the effects of expression downregulation of PIK3CB gene induced by RNA interference on the proliferation and apoptosis of colon cancer HCT116 cells. Methods: Three PIK3CB small interfering RNA (siRNA) sequences and one negative control siRNA sequence were designed and synthesized, and then individually transfected into HCT116 cells via lipofectAMINE2000 mediation. The most effective PIK3CB-siRNA was screened by real time PCR and Western blotting. Then the target siRNA was used for CCK-8 assay and JC-1 staining. Results: The expressions of PIK3CB gene and its protein PI3Kp110β were downregulated in HCT116 cells transfected with PIK3CB-siRNA. PIK3CB-siRNA-179 was the most effective, and it led to the highest inhibition rate (80%) of HCT116 cell proliferation. At 24,48 and 72 h after transfection, PIK3CB-siRNA-179 group showed an obvious proliferation arrest compared with the negative control group detected by CCK-8 assay. The mitochondrial membrane potential displayed an obvious decrease detected by JC-1 fluorescence staining at 48 h after transfection. Conclusion: Downregulation of PI3Kp110βprotein expression can depress the proliferation and induce apoptosis of colon cancer cell line HCT116. PIK3CB gene may become the new target of gene therapy for colorectal cancer. DOI:10.3781/j.issn.1000-7431.2011.01.005