Expression of B-catenin in early colorectal carcinoma and its significance

Objective To investigate the correlation of β catenin expression with the progression of early colorectal carcinoma. Methods High sensitive S Pimmunohistochemical method and in situ hybridization were used to detected the proteins and the mRNA of β catenin expression in clinical specimens from normal muscosas , adenomas, early colorectal cancers to advanced colorectal cancers. Results (1)Abnormal β catenin expression with loss of membranous immunoreactivity or cytoplasmic or nuclear staining was observed in some cases of early colorectal cancers. Tumor cells with abnormal expression of β catenin were distributed heterogeneously in the tumor nest and were often located at the invasive front. (2)The reduced membranous expression , the abnormal cytoplasmic or nuclear staining of β catenin was gradually increased from normal muscosas , adenomas, early colorectal cancers to advanced colorectal cancers (P 0.05). (3) The membranous expression rates of β catenin gradually decreased with tumor cells dedifferentiation(P 0.05). Cytoplasmic or nuclear expression of β catenin was not significantly associated with histological differentiation (P 0.05). The reduced membranous or cytoplasmic or nuclear expression of β catenin in early colorectal cancer was significantly associated with the depth of invasion and metastasis (P 0.05). (4) In the consecutive tissue slices , the location of expression of β catenin protein and its mRNA corresponded. The level of β catenin mRNA gradually increased from normal muscosas, adenomas , early colorectal cancers to advanced colorectal cancers (P 0.05). It was significantly associated with the depth of invasion and metastasis (P 0.05). Conclusion β catenin may play an important role in the carcinogenesis, infiltration and metastasis of early colorectal cancer.