Bmi-1 siRNA inhibited ovarian cancer cell line growth and decreased telomerase activity.

The knockdown of Bmi-1 could effectively suppress cancer cell proliferation and tumourigenicity in several cancers. This study aims to investigate whether or not Bmi-1 plays a causative role in the proliferation of ovarian epithelial cancer cells and telomerase activity. The messenger RNA (mRNA) and protein expression levels of Bmi-1 in the human ovarian carcinoma cell line OVCAR-3 were downregulated by Bmi-1 siRNA, as confirmed by real-time polymerase chain reaction (PCR) and Western blot. Cell viability was analysed by MTT assay, and telomerase activity was analysed by a modified telomeric repeat amplification protocol. Targeting Bmi-1 with siRNA inhibited Bmi-1 mRNA over five-fold compared with the control cells, and inhibited Bmi-1 protein expression over three-fold compared with control cells. The viability of the OVCAR-3 ovarian cancer cell line was reduced by Bmi-1 mRNA compared to control cells. Telomerase activity was decreased 22.73% (from 0.33 to 0.255) by Bmi-1 siRNA treatment compared to control cells. As Bmi-1 siRNA depressed telomerase activity, cell immortalisation may be prevented; thus, silencing Bmi-1 may be a potential therapy to manage ovarian cancer.