生长抑素受体2基因转染抑制胰腺肿瘤细胞生长机制的探讨  

Mechanisms of inhibition of growth of human pancreatic carcinoma implanted in nude mice by somatostatin receptor subtype 2

作　　者：Kumar Manoj 刘正人[1] 田锐[1] 秦仁义[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院外科,武汉430030

出　　处：《中华医学杂志》2004年第9期760-765,共6页National Medical Journal of China

基　　金：国家自然科学基金资助项目 (3 0 2 714 73 )

摘　　要：目的　探讨生长抑素受体 2 (SSTR2 )基因转染抑制体内胰腺肿瘤生长的效果及其机制。方法　利用lipofectAMINE将人类SSTR2全长cDNA转染导入胰腺癌细胞株PC 3中 ,G4 18筛选出阳性克隆 ;免疫组织化学SABC法和RT PCR检测生长抑素受体 2的稳定表达。分别将表达生长抑素受体2的PC 3细胞 (实验组 )和空载体对照组及阴性对照组的PC 3细胞异种移植到无胸腺小鼠体内。TUNEL法测定这些细胞形成的胰腺肿瘤细胞凋亡指数 (AI) ;免疫组织化学SP法测定凋亡相关基因Bcl 2和Bax的表达 ,以及肿瘤微血管密度 (MVD)。另外 ,比较 3组裸鼠之间胰腺肿瘤的大小和重量。结果　实验组胰腺肿瘤细胞AI(3 39%± 0 84 % )显著高于空载体对照组 (0 6 9%± 0 0 8% )和阴性对照组 (0 6 8%± 0 0 9% ) (P <0 0 5 )。与空载体对照组和阴性对照组相比 ,实验组Bcl 2蛋白表达显著降低 ,Bax蛋白的表达则显著升高 (P <0 0 5 ) ;实验组MVD(6 3± 1 7)显著低于空载体对照组 (12 6±1 7)和阴性对照组 (13 5± 1 9) (P <0 0 5 )。另外 ,实验组胰腺肿瘤的大小和重量也显著低于空载体对照组和阴性对照组 (P <0 0 5 )。空载体对照组与阴性对照组之间未观测到任何有差异的指标 (P >0 0 5 )。结论　大多数人胰腺癌细胞中缺失SSTR2基因 ,生长抑?Objective To investigate the antitumor effect of somatostatin receptor subtype 2 (SSTR2) gene transfection into pancreatic cancer cell line PC-3,and the mechanisms involved in this effect. Methods The full-length human SSTR2 cDNA was introduced into the pancreatic cancer cell line PC-3 by lipofect amine-mediated transfection. Positive clones were screened by G418 and stable expression of SSTR2 was detected by immunocytochemistry SABC method and RT-PCR. Fifteen athymic mice were randomly divided into 3 groups of 5 mice to be xenografted with SSTR2-expressing cells (experimental group),empty vector control group,and control group cells respectively. The weight of mice and the size of tumor were measured every week. Eight weeks later the mice were killed and the tumors were taken out. TUNEL assay was used to determine the apoptotic index (AI) in these tumors. Immunohistochemistry SP method was used to determine the expressions of apoptosis regulating genes,Bcl-2 and Bax,and intratumoral.microvessel density (MVD). Moreover,the tumor volume and weight were compared among these three groups. Results The AI was significantly higher in the experimental group (3.39%±0.84%) compared with the empty vector control group (0.69%±0.08%) and control group (0.68%±0.09%) (both P <0.05). The significant decrease in Bcl-2,and increase in Bax protein expressions were detected in the experimental group compared with the empty vector control group and control group (both P <0.05). MVD was significantly lower in the experimental group (6.3±1.7) than those in the empty vector control group (12.6±1.7) and control group (13.5±1.9) ( P <0.05). Moreover,the tumor volume and weight were significantly lower in the experimental group as compared with the empty vector control group and control group ( P <0.05). However,no significant differences in all the indicators were observed between the empty vector control group and the control group (both P >0.05). Conclusions Re-expression of SSTR2 gene,the expression of which is frequently lost i

关 键 词：生长抑素受体2 基因转染 胰腺肿瘤 细胞生长 SSTR2 癌细胞 

分 类 号：R735.9[医药卫生—肿瘤]