细胞周期蛋白G2在胃癌组织中的表达和其对胃癌细胞株体外增殖影响的研究

Expression of cyclin G2 in gastric carcinoma tissue and study of its effect on in vitro proliferation of gastric carcinoma cell strain

目的研究G型细胞周期蛋白(cyclin)家族中的新成员cyclinG2在胃癌组织中的表达和其对胃癌细胞株SGC7901体外增殖的影响。方法通过免疫组织化学技术检测40例胃癌标本中cyclinG2蛋白的表达情况并进行显微图像分析;利用阳离子介导的脂质体转染试剂将包含有cyclinG2的真核表达载体pIRESG2转染SGC7901,经G418克隆筛选后获得稳定表达cyclinG2的细胞克隆,噻唑蓝法(MTT)比色法测定转染后细胞增殖活性的改变。结果①CyclinG2在非癌组织、分化型癌和差分化型癌组织中的阳性率和表达强度逐渐下降且差异有统计学意义(P<0.01)。②转染pIRESG2获得的克隆细胞的体外增殖能力降低(P<0.01)。结论CyclinG2基因很可能是一种候选的抑癌基因,随着胃癌恶性程度的增加其表达水平降低;外源性基因转染导致的cyclinG2异常性高表达可显著抑制胃癌细胞株的体外增殖能力。

Objective To survey the expression in gastric cancer of a new member cyclin G2 (belonging to G typed cyclin family) and its influence on cell strain SGC 7901.Methods Forty case gastric cancer specimens were examined by immunohistochemical technology to observe cyclin G2 expression and analyze the positive rates and average gray value′s change by micro image analysis system;the pIRES G2 plasmid was transferred into SGC 7901 cell line through cation lipofectamine reagent;cell clones were chosen by G418;pick up cell clone and enlarge culture to test cell proliferative ability by MTT assay (thiazolyl blue method).Results ①The positive rates of cyclin G2 in non cancer tissue, differentiation and low differentiation type cancer were 90%,83 3% and 22 7% (P<0.01).The average gray values of cyclin G2 in non cancer tissue,differentiation type and low differentiation type cancer were 166±13,191±16 and 219±13 (P<0.01).② The average absorbency of clone cell obtained by stable transfection pIRES G2 at 570 nm was 1.70±0.21,the average absorbency of clone cell obtained by stable transfection pIRESneo at 570 nm was 2 1±0 4,there was statistical differential notability between them (P<0.01).Conclusion The expression level of cyclin G2 was associated with the differentiation degree of gastric carcinoma,it may serve as a biological marker in the evaluation of the malignancy of tumor,it can inhibit SGC 7901 cell proliferation ability obviously.