[Effect of small interference RNA on E6, E7 mRNA of human papillomavirus type-18 in cervical cancer cells].

OBJECTIVE: To study the effect of small interference RNA on E6, E7 mRNA of human papillomavirus type-18 (HPV18) in cervical cancer cells. METHODS: The specific HPV18E6 and E7 siRNA synthesized by in virtro transcription. The cell activity was detected by methyl thiazolyl tetrazolium (MTT) assay to determine the most suitable concentration, then cells were transfected into HPV18 cervical cancer cells by oligofectamine. HPV18E6, E7 mRNA level was examined by semi-quantitative RT-PCR, and the cell cycles were analyzed by flow cytometry. RESULTS: The activity of the HeLa cells had an obvious suppression after transfection to 0.57 +/- 0.05 and 0.62 +/- 0.04 compared with the contrast of 0.87 +/- 0.05. The expression of HPV18E6 mRNA level was 0.63 +/- 0.04 before transfection, decreased to 0.53 +/- 0.04, 0.46 +/- 0.02, 0.56 +/- 0.03 evidently after transfection at 24, 48, 72 hours. The expression of HPV18E7 mRNA level was 0.66 +/- 0.03 before transfection and decreased to 0.60 +/- 0.05, 0.52 +/- 0.04, 0.59 +/- 0.02 after transfection at 24, 48, 72 hours. The number of cells in G(2) phase was increased after HPV18E6 siRNA transfection from (1.4 +/- 1.2)% to (66.9 +/- 3.5)%, S phase was declined from (39.4 +/- 0.4)% to (0 +/- 5.5)%, and they were (47.2 +/- 0.5)% and (5.6 +/- 4.2)% in E7 group. CONCLUSION: RNAi exists in HeLa cells, and its effect has specificity.