PP2A的肿瘤抑制功能及与凋亡因子Noxa的关系

PP2A's suppressing tumor function and its relationship with apoptosis factor Noxa

目的检测PP2A及Noxa蛋白在大肠癌癌组织和癌旁组织中的表达,探讨PP2A、Noxa在大肠癌发生、发展中的作用以及二者的相关性。方法采用免疫组织化学法检测40例大肠癌患者的癌组织(大肠癌组)及癌旁组织(癌旁组)PP2A、Noxa蛋白表达情况,采用TUNEL法检测细胞凋亡情况。结果大肠癌组PP2A与Noxa蛋白阳性表达率(90%、82.5%)明显低于癌旁组(95%、88.1%),P<0.05;大肠癌组PP2A、Noxa蛋白阳性表达在大肠癌组织分化程度、淋巴结转移差异有统计学意义(P<0.05);40例大肠癌组织中PP2A蛋白与Noxa蛋白表达之间呈正相关(r=0.229,P<0.05)。大肠癌癌细胞凋亡指数在癌细胞分化程度、淋巴结转移及临床分期上差异有统计学意义(P<0.05);大肠癌组PP2A、Noxa表达阴性者癌细胞凋亡指数均明显低于表达阳性者(P<0.05)。结论 PP2A、Noxa蛋白可能相互协同,在结直肠癌的发生、发展过程中发挥抑制作用。

Objective To detect PP2 A and Noxa expression in colorectal carcinoma tissues and paracarcinoma tissues , and to explore the function and the correlation between PP 2A and Noxa in colorectal carcinoma .Methods PP2 A and Noxa protein in 40 colorectal carcinoma tissues and 40 paracancerous tissues were detected by immunohistochemical technique .The cell apop-tosis was detected by TUNEL .Results The positive expression of PP2A protein in colorectal cancer tissues was 90%, which was significantly lower than that of paracancerous tissues （95%）（P〈0.05 ）;Noxa protein positive expression was 82.5% in colorectal cancer tissues vs 88.1%in paracarcinoma tissues （P〈0.05）.The rates of PP2A, Noxa protein expression was associated with the tumor differentiation , lymph node metastasis（P〈0.05）.Expression of PP2A protein and Noxa protein in 40 cases of colorectal carcinomas tissues showed a positivelinear correlation （r =0.229,P 〈0.05）.The apoptosic index of colorectal cancer was statisti -cally significant in cell differentiation, lymph node metastasis and clinical stage.The apoptosicindex in PP2A, Noxa negative expression group was much lower than that in the positive group（P 〈0.05）.Conclusion PP2A, Noxa proteins may play negative roles in the incidence anddevelopment of colorectal cancer, the correlation analysis between them is positive .