yrdC靶向RNA干扰抑制BGC-823细胞裸鼠体内成瘤的实验研究

Studies on the Growth Inhibition of BGC-823 Cells in Nude Mice by RNA Interference Targeting yrdC

目的检测胃癌组织及癌旁正常组织中的yrdC的mRNA、蛋白表达。构建表达yrdC靶向RNA干扰的重组腺病毒,转染人胃癌细胞株BGC-823,检测干扰后BGC-823细胞yrdC蛋白水平变化,转染后细胞移植裸鼠体内成瘤,观察yrdC沉默后移植瘤生长的变化。方法采用逆转录-聚合酶链反应(RT-PCR)和Western blot法,检测7例胃癌组织及癌旁正常组织中的yrdC的mRNA、蛋白表达。构建表达针对人yrdC的si RNA的重组腺病毒,重组腺病毒Ad-shyrdC转染BGC-823细胞,Western blot检测干扰后BGC-823细胞yrdC蛋白水平变化。裸鼠分3组,分别皮下移植转染Ad-shyrdC、空病毒Ad-Null及未转染的BGC-823细胞(1×107/只),5周后检测裸鼠肿瘤的体积及质量,肿瘤HE染色及yrdC、PCNA、TUNEL免疫组化染色,观察各组yrdC蛋白表达、细胞增殖能力及细胞凋亡的变化。结果胃癌组织中yrdC mRNA及蛋白表达量均比癌旁组织增高。成功构建表达抑制yrdC基因的重组腺病毒Ad-shyrdC,腺病毒介导的yrdC靶向RNA干扰能特异性抑制BGC-823中yrdC蛋白的表达,Ad-shyrdC组肿瘤细胞yrdC蛋白水平明显下降。转染BGC-823细胞后移植裸鼠体内,5周后成瘤体积及质量较Ad-Null组及PBS对照组明显减小(P<0.05);yrdC蛋白表达减少,PCNA染色提示肿瘤细胞增殖活性受抑,TUNEL染色显示凋亡明显增多(P<0.01)。结论腺病毒介导的RNA干扰能有效抑制BGC-823细胞裸鼠体内成瘤,yrdC基因有可能成为胃癌基因治疗的靶点。

Objective To detect the expression of yrdC mRNA and protein in gastric carcinoma tissue and adjacent normal tissue,and to construct recombinant adenovirus carrying human yrdC siRNA and determine the level of endogenous yrdC protein expression and observe the growth of transplanted tumor of BGC-823 in nude mice after the recombinant adenovirus transfection.Methods The expression of yrdC mRNA and protein in gastric carcinoma and adjacent normal tissue in 7 patients were detected by RT-PCR and Western blot.The recombinant adenovirus carrying human yrdC siRNA was constructed and Western blot analyses were performed to determine the levels of endogenous yrdC protein expression.The nude mice were randomly divided into 3 group and the BGC-823 cells transfected with Ad-shyrdC or Ad-Null and non-transfected BGC-823 cells were injected s.c.into the cervix of the nude mice（1×107/mouse）.The volume and weight of tumor were measured 5 weeks later.The expression of yrdC protein and the proliferation and apoptosis of cells were observed by HE staining and immunohistochemical staining for yrdC,PCNA and TUNEL.Results The expression of yrdC mRNA and protein in gastric carcinoma tissue was higher than that in normal tissue and yrdC protein expression was significantly inhibited by RNAi.There was statistical significance in the tumor volume and weight between the group treated with Ad-shyrdC and Ad-Null or PBS control group（P〈0.05）.The expression of yrdC protein was significantly decreased by RNAi treatment.Meanwhile,the cancer cell apoptosis was increased and cell proliferation was inhibited（P〈0.01）.Conclusions Recombinant adenovirus-mediated RNAi could suppress tumor growth derived from BGC-823 cells in vivo,and yrdC may be the new target for gene therapy of gastric carcinoma.