[miR-449b and miR-34c on inducing down-regulation of cell cycle-related proteins and cycle arrests in SKOV3-ipl cell, an ovarian cancer cell line].

Objective: To investigate the effects of miR-449 and miR-34 on cell growth, cell cycle and target gene expression based on these miRNA different expressions in ovarian cancer cell lines SKOV3 and SKOV3-ipl both with mutation of p53.

Methods: The expressions of miR-449a/b and miR-34b,c in SKOV3 and SKOV3-ipl were detected by RT-PCR. miR-449a,b and miR-34b,c were ectopically expressed by transfection of SKOV3-ipl. The cell growth rate was assayed by MTS method. The changes of cell cycle were measured by FCM. The changes of expression of cell cycle related proteins were detected by Western blot.

Results: Ectopic expression of miR-449b and miR-34c resulted in lowered adhesion activities by 28%-34%, and in cell cycle arrests with increased cell number of 15.62% and 15.71% in G1 and with decreased cell number of 15.96% and 16.56% in S. Cell cycle related proteins CDK6 and CDC25A were down-regulated. The decreases of CDK6 and CDC25A by miR-449b were 39% and 22% respecyively; 49% and 32% by miR-34c respectively. The more decreases were seen in co-action by miR-449b and miR-34c with decreases of 69% in CDK6, 86% in CDC25A, and 59% in CyclinA.

Conclusion: miR-449b and miR-34c resulted in cell cycle arrests and down-regulation of CDK6, CDC25A and CyclinA in high malignant ovarian cancer cell line SKOV3-ipl.