超声微泡靶向破坏转染shRNA沉默Survivin表达诱导裸鼠宫颈癌移植瘤凋亡的研究

目的 通过超声微泡靶向破坏(UTMD)对靶向存活素的短发夹状重组质粒(Survivin-shRNA)进行转染,探讨其凋亡诱导效应、增殖抑制作用及其安全性.方法 将荷人宫颈癌(Hela)裸鼠随机分为三组:质粒+超声辐照(P+US)组,注入质粒溶液后予以超声辐照;质粒+微泡+超声辐照(P+UTMD)组,注入质粒/微泡复合物后辐照;对照组,不予任何处理.对组织样本行组织学检查,采用免疫组化SABC法检测移植瘤增殖细胞核抗原(PCNA)、Survivin、Bcl-2、Bax、Caspase-3、Ki-67、核干细胞因子(NS)、p53蛋白在各组肿瘤标本中的表达.结果 P+UTMD组的PCNA、Ki-67、Bcl-2、Survivin及NS蛋白表达下降,而Bax、Caspase-3、p53蛋白表达明显增加,与对照组及P+US组比较差异均有统计学意义(P＜0.05).结论 UTMD联合Survivin-shRNA能有效沉默Survivin基因表达,具有抑制增殖和促分化的作用,并诱发细胞凋亡,无明显副作用,为癌症基因疗法提供一种高效、无创、有前景的新方法.

Study of UTMD associated with shRNA techniques to silence Survivin expression and induce cell apoptosis

Objective To investigate the gene silencing,apoptosis induction and the suppression of proliferation in vivo transfected by UTMD techniques associated with shRNA techniques. Methods The survivin-shRNA expression vector was constructed. Nude mice were randomly arranged into 3 groups:control group, plasmid injection and ultrasound (P + US), P + UTMD group. Histological examination were evaluated. Protein expressions of Survivin and proliferating cell nuclear antigen (PCNA), Bcl-2, Bax,Caspase-3, Ki-67, nucleostemin (NS), p53 were investigated by immunohistochemistry. Results In transplanted tumors experiment, comparing with those in C and P + US groups, protein expressions of PCNA,Ki-67,Bcl-2, Survivin, NS were down-regulated markedly, while those of Bax, Caspase-3 and P53 were up-regulated significantly ( P ＜ 0.05). Conclusions UTMD combined with shRNA technique can induce apoptosis and inhibit proliferation significantly, without causing any apparently adverse effect,representing a new,promising technology that can be used in the tumor gene therapy and research.