pGPU6/GFP/Neo-hTERT-shRNA对结直肠癌SW480细胞裸鼠移植瘤的抑制

目的:研究靶向hTERT基因的重组质粒pGPU6/GFP/Neo-hTERT-shRNA对人结直肠癌SW480细胞裸鼠移植瘤的治疗作用。方法:于裸鼠右侧腋下皮下注射人结直肠癌SW480细胞建立结直肠癌移植瘤动物模型,随机分为生理盐水组(NS组)、pGPU6/GFP/Neo-NC-shRNA组(NC-shRNA组)和pGPU6/GFP/Neo-hTERT-shRNA组(hTERT-shRNA组),各组连续进行相应治疗6次后,观察肿瘤的生长状况,测量肿瘤体积并绘制肿瘤生长曲线,H-E染色观察肿瘤组织形态学变化,免疫组织化学法检测移植瘤组织中hTERT蛋白的表达,TUNEL法检肿瘤组织中细胞凋亡情况,RT-PCR法检测瘤组织中hTERT mR-NA的表达。结果:与NC-shRNA组和NS组比较,hTERT-shRNA组移植瘤体积增长速度减慢;hTERT-shRNA组移植瘤组织中见肿瘤细胞形态明显改变,凋亡细胞数明显增多[(36.30±5.05)%vs(5.25±1.06)%、(6.95±1.07)%,P<0.01];hTERT-shRNA组hTERT的mRNA和蛋白表达均明显受到抑制(171.42±30.94 vs 146.89±21.43、137.35±25.49,P<0.01;0.39±0.09 vs 0.81±0.335、0.750±0.206,P<0.05)。结论:重组质粒pGPU6/GFP/Neo-hTERT-shRNA通过下调hTERT mRNA和蛋白水平的表达促进肿瘤细胞的凋亡,抑制结直肠癌移植瘤的生长。

Inhibition of pGPU6/GFP/Neo-hTERT-shRNA on colorectal cancer SW480 cell xenograft in nude mice

Objective:To investigate the treatment effect of recombinant plasmid pGPU6/GFP/Neo-hTERT-shRNA targeting hTERT gene on human colorectal cancer SW480 cell xenograft in nude mice.Methods: Human colorectal cancer SW480 cells were subcutaneously implanted under the skin of the right armpit to establish nude mice model of colorectal cancer,after the tumors grew to a definite size.The mice were randomly divided into three groups: normal saline(NS group),pGPU6/GFP/Neo-NC-shRNA group(NC-shRNA group)and pGPU6/GFP/Neo-hTERT-shRNA group(hTERT-shRNA group).After each group was treated for 6 consecutive times,the growth status of the tumor was observed,tumor volume was measured,tumor growth curve was drawn,tumor tissue morphology was observed with H-E staining,the expression of hTERT protein in the tumors was detected by immunohistochemistry,cell apoptosis was inspected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling(TUNEL),and the expression of hTERT mRNA was checked by RT-PCR.Results: The growth of tumor volume became slower in hTERT-shRNA group than did that in NS group and NC-shRNA group.Compared with NS group and NC-shRNA group,the tumor cell morphology changed obviously and the number of apoptotic cells increased significantly in the transplanted tumor tissues in hTERT-shRNA group([36.3±5.05]% vs [5.25±1.06]%,[6.95±1.07]%,P<0.01).Compared with NS group and NC-shRNA group,the expression of hTERT protein was significantly inhibited in hTERT-shRNA group([171.42±30.94] vs [146.89±21.43],[137.35±25.49],P<0.01).Compared with NS group and NC-shRNA group,the expression of hTERT mRNA was significantly inhibited in hTERT-shRNA group(0.39±0.09 vs 0.81±0.34,0.75±0.21,P<0.05).Conclusion: Recombinant plasmid pGPU6/GFP/Neo-hTERT-shRNA promotes apoptosis of implanted human colorectal cancer by down-regulating the expression of hTERT mRNA and hTERT protein in tumor tissues,thus inhibiting the growth.