Impact of RNAi targeting survivin gene on tumor growth， apoptosis and chemosensitivity to cisplatin in nude mice xenograft of human cervical carcinoma

Abstract

Objective To observe the impact of RNAi targeting survivin gene on tumor growth， apoptosis and chemosensitivity to cisplatin in nude mice xenograft of human cervical carcinoma. MethodsHeLa-s2，HeLa-NC，HeLa-U6 neo and HeLa cells were inoculated respectively in flank subcutaneous tissue of 24 female nude mice randomly to establish xenograft models of human cervical carcinoma， observed the tumor growth status. The tumor volume were measured termly and the tumor weight were investigated after they were killed to observe the impact of RNAi targeting survivin gene on tumor growth. The expression of survivin protein in tumor tissues were examined by immunohistochemistry SP method. Cell apoptosis in tumor tissues were observed by TUNEL method and counted out AI. To observe the impact of RNAi targeting survivin gene on tumor chemosensitivity after delt with cisplatin， measured the tumor volume termly and drew the tumor growth curve， investigated the tumor weight after they were killed and examined cell apoptosis by TUNEL method. Results Establish 4 groups of xenograft models of human cervical carcinoma. The tumor volume of HeLa-s2 group was obviously less than that of HeLa group at every checkpoint. At the terminal of observation， the tumor weight of HeLa-s2 group was obviously lower than that of HeLa group， and they were(0.369±0.043)g and (1.150±0.136)g respectively(P<0.05).The tumor growth inhibitive rate of HeLa-s2 group was 67.9%. The expression of survivin protein examined by immunohistochemistry in tumor tissues of HeLa-s2 group decreased sharply. Apoptotic cells increased in tumor tissues of HeLa-s2 group examined by TUNEL method， AI was (22.73±1.37)%. The tumor volume of HeLa-s2 group was obviously less than that of HeLa group at every checkpoint after delt with cisplatin and the tumor gowth was inhibited. At the terminal of observation，the tumor weight of HeLa-s2 group was obviously lower than that of HeLa group，they were(0.323±0.058)g and(1.347±0.173)g respectively(P<0.05)；cell apoptosis increased in tumor tissues of HeLa-s2 group，and compared with HeLa group， AI of HeLa-s2 group rose up notably，they were(37.38±1.01)% and(5.19±0.61)%(P<0.05). Conclusions Survivin gene RNAi can inhibit tumor growth and accelerate cell apoptosis in xenograft by inhibiting survivin protein expression， and through increasing cell apoptosis induced by cisplatin， can enhance its inhibitive efficiency， consequently improve tumor chemosensitivity to cisplatin.