细胞凋亡在结肠腺癌组织中的变化及其相关蛋白的表达

Apoptosis and expression of apoptosis-related proteins Bcl-2,Bcl-xL and Bcl-w in human colon adenocarcinoma

目的:观察结肠腺癌组织细胞凋亡的变化,探讨抑制凋亡蛋白Bcl-2、Bcl-xL及Bcl-w在结肠腺癌中的作用.方法:收集14例我院手术切除结肠腺癌标本,肠镜取正常结肠黏膜组织27例,所有标本均经病理明确诊断.用TUNEL法检测其组织细胞凋亡水平,并用免疫组织化学PV法检测蛋白Bcl-2、Bcl-xL及Bcl-w的表达水平.结果:正常结肠黏膜组织的细胞凋亡指数明显高于结肠腺癌,有统计学显著性差异(t=3.35,P=0.002);结肠腺癌中Bcl-xL与Bcl-w的表达均高于正常结肠黏膜组织,有统计学差异(92.86%vs11.11%;85.71%vs0%,P<0.01或P<0.05);Bcl-2的表达与正常结肠黏膜组织没有统计学差异(P>0.05).结论:结肠腺癌的组织细胞凋亡明显低于正常结肠组织;结肠腺癌中抑制凋亡蛋白Bcl-xL与Bcl-w的高表达可能发挥了重要的作用.

AIM： To examine the occurrence of apoptosis in colon adenocarcinoma and investigate the role of Bcl-2, Bcl-xL and Bcl-w as mediators of apoptosis.METHODS： Fourteen human colon adenocarcinoma specimens were obtained by surgical resection and pathologically confirmed. Twentyseven normal colon tissue specimens were obtained by colonoscopic biopsy. Apoptosis was detected using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） assay. The expression of Bcl-2, Bcl-xL and Bcl-w proteins was measured by immunohistochemistry.RESULTS： Compared with normal colon tis-sues, the apoptosis index （AI） in colon adenocarcinoma tissues significantly decreased （t = 3.35, P = 0.002）. The expression levels of Bcl-xL and Bcl-w proteins were significantly higher in colon adenocarcinoma tissues than in normal colon tissues （92.86% vs 11.11% and 85.71% vs 0%, respectively; P 〈 0.01 and 0.05）, whereas no significant difference was noted in the expression level of Bcl-2 protein between adenocarcinoma and normal colon tissues （P 〉 0.05）.CONCLUSION： Apoptosis occurs in normal colon tissue but decreases in colon adenocarcinoma. Both Bcl-xL and Bcl-w proteins, rather than Bcl-2 protein, may play an important role in the suppression of apoptosis in colon adenocarcinoma.