survivin基因RNA干涉对宫颈癌裸鼠移植瘤生长及凋亡和顺铂化疗敏感性的影响

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

目的观察survivin基因RNAi对宫颈癌裸鼠移植瘤生长、凋亡和化疗敏感性的影响。方法随机选择雌性BALB/C-nu/nu裸小鼠24只,细胞接种法建立4组人宫颈癌裸鼠皮下移植瘤模型,每天观察裸鼠一般状况及肿瘤生长情况,通过绘制肿瘤生长曲线并计算肿瘤生长抑制率,观察survivin基因RNAi对人宫颈癌裸鼠皮下移植瘤生长的影响;通过免疫组化SP法检测各组移植瘤组织中survivin蛋白表达情况,TUNEL染色观察survivin基因RNAi对人宫颈癌裸鼠皮下移植瘤凋亡的影响;当肿瘤体积达0.2cm3时给予顺铂化疗以观察survivin基因RNAi对人宫颈癌裸鼠皮下移植瘤化疗敏感性的影响。结果成功建立4组人宫颈癌裸鼠皮下移植瘤模型,接种HeLa-s2组裸鼠肿瘤体积在每个检测点均明显小于接种HeLa组;观察结束时,接种HeLa-s2组裸鼠瘤重明显小于接种HeLa组,分别为:(0.369±0.043)g和(1.150±0.136)g(P<0.05);接种HeLa-s2组裸鼠肿瘤生长抑制率为67.9%。免疫组化结果显示:接种HeLa-s2组裸鼠survivin蛋白表达显著下降;TUNEL染色结果显示:接种HeLa-s2组裸鼠细胞凋亡明显增多,凋亡指数(AI)值达(22.73±1.37)%。顺铂化疗后不同检测点接种HeLa-s2组裸鼠肿瘤体积明显小于接种HeLa组,肿瘤生长明显受抑;观察结束后,接种HeLa-s2组裸鼠瘤重明显小于接种HeLa组,分别为:(0.323±0.058)g和(1.347±0.173)g(P<0.05);接种HeLa-s2组裸鼠肿瘤细胞凋亡明显增多,与接种HeLa组AI比较,接种HeLa-S2组AI明显升高,分别为:(37.38±1.01)%和(5.19±0.61)%(P<0.05)。结论 survivin基因RNAi可通过下调移植瘤组织survivin蛋白表达抑制移植瘤生长并促进其凋亡,并通过增加顺铂化疗诱导的细胞凋亡,增强顺铂化疗对移植瘤的生长抑制,进而提高移植瘤对顺铂化疗的敏感性。

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.Methods HeLa-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.