Effect of silencing Survivin gene expression by RNA interference on the radiosensitivity of cervical carcinoma cell line SiHa / 肿瘤

ABSTRACT

Objective: To explore the influence of silencing Survivin expression by RNA interference on the radiosensitivity of cervical carcinoma SiHa cells. Methods: The recombinant eukaryotic expression plasmid pSurvivin-shRNA was constructed and transfected into SiHa cells. The mRNA and protein expressions of Survivin were determined by RT-PCR and Western blotting, respectively. The activity of caspase-3 was measured by kinase activity determination method. The apoptotic rate was determined by flow cytometry. The changes of radiosensitivity were explored by colony formation test. Results: Compared with SiHa cells transfected with pNeg-shRNA (SiHa/ pNeg-shRNA cells) and untransfected SiHa cells, the expressions of survivin in the cells transfected with pSurvivin-shRNA (Si-Ha/ pSurvivin-shRNA cells) were inhibited significantly at both mRNA and protein levels. The activity of caspase-3 in SiHa/pSurvivin-shRNA cells was significantly enhanced, and the D405 was 1.34 ± 0.05 (P < 0.05). The apoptotic rate of SiHa/pSurvivin-shRNA cells was (5.13 ± 0.81)% and (11.27 ± 1.89)% after 24 hand 48 h X-ray irradiation at 6 MV and 8 Gy, respectively, which was significantly higher than SiHa/pNeg-shRNA cells and untransfected cells (P < 0.05). The colony formation ability of SiHa/pSurvivin-shRNA cells was markedly decreased after irradiation (P < 0.05), which indicated that the sensitivity of SiHa/pSurvivin-shRNA cells was enhanced. Conclusion: The inhibition of Survivin by RNAi could enhance the radiosensitivity of SiHa cells by increasing caspase-3 activity and inducing apoptosis.