大肠癌中β-连环素和Axin表达的研究

Expressions of Axin and β-catenin in human colorectal cancer

目的探讨Axin和β-连环素在大肠癌中的表达及它们与各临床病理因素的关系。方法采用免疫组织化学SP法对100例大肠癌标本中Axin和β-连环素的表达进行了检测。结果β-连环素的细胞膜表达降低率为80.0%,细胞核表达率为26.0%。高、中分化和低分化大肠癌中,β-连环素的表达降低率分别为70%(35/50)和90%(45/50),差异有统计学意义(P=0.012)。有淋巴结转移和无淋巴结转移中大肠癌β-连环素表达降低率分别为87%(48/55)和71%(32/45),差异有统计学意义(P=0.044)。Axin的阳性表达率为48.0%,高、中分化和低分化大肠癌中Axin的阳性表达率为60%(30/50)和36%(18/50),差异有统计学意义(P=0.016)。在β-连环素核表达阳性的病例中,Axin阳性表达率为15.4%(4/26),低于β-连环素核表达阴性病例的60%(44/74)(P<0.01)。结论β-连环素的膜表达降低与大肠癌的低分化和淋巴结转移相关,Axin的表达与大肠癌的低分化和β-连环素的细胞核蓄积呈负相关。

Objective To investgate axis inhibition protein （Axin） and β-catenin,the exon 3 mutation status of β-catenin and their clinicopathological correlations in human colorectal cancer. Methods A total 100 colorectal cancer samples and their corresponding normal colorectal tissue were obtained from the patients under going surgery in the Taiyuan People＇s Hospital between 2001 and 2007. Protein expressions of Axin and β-catenin were detected by immunohistochemistry. Results A reduced membranous expression rate of β-catenin was observed in 80.0% of the cases （80/ 100） along with a nuclear expression rate 26.0% （26/100）. There was a significant difference in β-catenin expression between well and poorly differentiated colorectal cancer. Well to moderately differentiated colorectal cancer showed a reduced expression rate 70.0% （35/50）, in contrast to 90.9% （45/50） in poorly differentiated tumors （P = 0. 012）. Reduced β-catenin expression rate was 87.3% （48/55） in case with lymph node metastasis, in contrast 71.1% （32/ 45） in cases without lymph node metastasis （P = 0. 044）. The positive expression rate of Axin was 48.0% （48/100）. Well to moderately differentiated colorectal cancer demonstated a 60.0% postive expression rate of Axin was （30/50）, much higher than poorly differentiated tumor [36.0% （18/50） ,P= 0.016]. The positive expression rate of Axin in ^- catenin nuclear expressed colorectal cancer was 15.4% （4/26）, much lower than cases in this study,suggesting that it may function as a nuclrar-cytoplasmic shuttling protein. Conclusion The reduced membranous expression of β-catenin is associated with poorly differentiated and lymph node positive human coloreetal cancer. The expression of Axin is inversely correlated with the degree of tumor differentiation and nuclear expression of β-catenin.