凋亡相关基因caspase-9,Bax在大肠腺瘤和大肠癌中的表达及意义

目的 探讨细胞凋亡相关基因caspase-9、Bax在大肠癌发生、发展中的可能作用及相互关系。方法 采用免疫组织化学S-P法和TUNEL技术分别检测20例正常大肠黏膜,48例大肠腺瘤,56例大肠癌中caspase-9,Bax蛋白的表达水平及细胞凋亡。结果 Caspase-9在正常大肠黏膜,腺瘤,癌组织中的表达率分别为5.00％、33.33％、64.29％,三者间有明显差异(P<0.01),在腺瘤和癌组织中其表达均高于正常黏膜;Bax在三者间的表达率分别为5.00％、27.08％、57.14％,三者间亦有明显差异(P<0.01)。大肠癌及大肠腺瘤中的细胞凋亡率显著高于正常黏膜(P<0.01),随着癌组织分化程度的下降,凋亡率逐渐降低。caspase-9,Bax的阳性表达与凋亡指数呈密切相关(P<0.01);Caspase-9,Bax的表达均与癌组织的分化程度有关,与病理因素无关。结论 在大肠癌细胞的凋亡过程中,caspase-9可能参与了大肠癌的凋亡,caspase-9和Bax在细胞凋亡的调节中可能存在密切关系。

Study on expression of caspase-9 and bax protein and their relations with cell apoptosis in human large intestine adenoma and carcinoma

Objective To explore the possible roles of caspase-9 and bax proteins in the development and progression of colorectal carcinoma. Methods Immunohistochemistry and TdT-mediated dUTP rock end labeling (TUNEL) were used to study caspase-9 ,bax and cell apoptosis in 20 cases of normal tissues,48 cases of colorectal adenoma and 56 cases of colorectal carcinoma. Results Caspase-9 expression was detectable in 5.00% of normal mucosas, 33 .33 % of adenoma and 64.29% of cancer specimens. Bax expression rate was 5 .00 % , 27 .08 % and 57 .14 % . There was a significant correlation between the expression of caspase-9 and bax. More apoptotic cells were noticed in well-differentiated carcinoma than in poorly differentiated carcinoma ( P < 0.01) . Conclusion Bax may participate in the apoptosis by regulating caspase-9, and it may indicate a close relationship between these two proteins in apoptosis of colon carcinoma.