凋亡诱导因子和caspase-3在结直肠腺瘤-癌序列中的表达及相关性

目的探讨非caspase依赖凋亡途径的凋亡诱导因子（AIF）与caspase依赖凋亡途径的caspase-3在结直肠腺瘤．癌序列中的表达变化及两种蛋白之间的相关性。方法采用免疫组织化学染色检测18例正常黏膜、84例结直肠腺瘤和72例结直肠癌中AIF及caspase-3的表达情况。结果结直肠腺瘤组织中AIF及caspase-3的阳性表达率均明显高于正常黏膜组织（P〈0．05）；腺瘤组织中AIF阳性表达率与腺癌之间的差异无统计学意义（P〉0．05），而caspase-3阳性表达率则明显高于腺癌组织（P〈0．05）；腺瘤组内绒毛状腺瘤AIF阳性表达率明显低于管状腺瘤（P〈0．05），而caspase-3阳性表达率在两种腺瘤之间的差异无统计学意义（P〉0．05）。相关分析显示，AIF表达与caspase-3表达无显著相关性（P〉0．05）。结论AIF代表的非caspase依赖凋亡途径异常发生在腺瘤向癌突变早期．而caspase依赖途径的凋亡失控可能是更重要的促进结直肠癌发生的因素之一。非caspase依赖的凋亡途径与caspase依赖的凋亡途径是肿瘤发生中两条相对独立的细胞凋亡途径。

Expression of AIF and caspase-3 in colorectai carcinoma, adenoma, and normal mncosa and its correlation

Objective To investigate the expression differenees of apeptosis-indueing factor (AIF) and easpase-3 among coloreetal carcinoma, adenoma and normal mucosa, and to identify the relationship between AIF and caspase-3 expression in coloreetal adenoma-careinoma sequence.Methods Formalin-fixed paraffin embedded colorectal tissues from 174 cases, including 84 adenomas,72 carcinomas, and 18 normal mucosa, were examined for expression of AIF and easpase-3 by streptavidin-peroxidase(SP) immunohistoehemistry. Results The positive rates of AIF and caspase-3 in coloreetal adenoma were higher than those in normal mueosa (P<0.05). The positive rate of AIF in adenoma showed no significant difference compared to coloreetal carcinoma (P>0.05). However, caspase-3 expression in adenomas was significantly higher than that in carcinoma (P0.05). AIF expression had no prominent correlation with the caspase-3 expression (P>0.05). Conclusions The dysregnlation of caspase-independent pathway of apoptosis may be an early event in the development of coloreetal carcinogenesis, while the dysregulation of the easpase-dependent pathway of apoptosis may be one of contributing factors of coloreetal carcinogenesis. The easpase-independent pathway of apoptosis and the caspase-dependent pathway of apoptosis are two relatively independent pathways in eoloreetal carcinogenesis.