In the present research, we assumed that reducing the amounts of E6 and E7 oncoproteins by a specific siRNA sequence and recovering p53 and RB proteins, along with the recovery of the FOXO1 protein by applying anti-miR-182, would increase apoptosis and reduce proliferation rate in cancer cells. The HPV16-positive CaSki cervical cancer cell line was used. 48 hours after transfection of siRNA for targeting E6 and E7 oncoproteins and anti-miR-182, expression of its cellular targets p53, p21 and FOXO1 was assessed by real-time PCR, western blot analysis and immunocytofluorescence staining. In all treatments, apoptosis rate and viability were evaluated using Annexin-V-FITC apoptosis detection kits and MTT assays, respectively. Among the designed siRNAs, E6-1 and E7-2 proved the most effective in reducing E6 and E7 expressions by increasing the apoptotic rates to 12.4% and 16%, respectively, after 48 hours. Also, using anti-miR-182 increased apoptotic rate to 12.7% 48 hours after transfection of cervical cancer cells. The combinational use of either E6-1 or E7-2 siRNAs with anti-miR-182 resulted in a rise in apoptosis to 19.3% and 26%, respectively, higher than those obtained from the individual application of either without anti-miR-182. The simultaneous use of siRNA E6-1 and siRNA E7-2 with cisplatin increased sensitivity to cisplatin and reduced the viability of the cancer cells as compared to the use of cisplatin alone. The simultaneous use of cisplatin and anti-miR-182 had no considerable effect on viability or apoptosis rate compared to cisplatin alone.
Keywords: HPV16; anti-miR-182; apoptosis; cervical cancer; siRNA.