OBJECTIVETo investigate the relationship between beta-catenin and matrix metalloproteinase-7 (MMP-7) expression and development/biologic behavior of human colorectal cancer.

METHODSImmunohistochemical study for beta-catenin and MMP-7 was carried out on colorectal adenoma-carcinoma tissue microarrays and results analyzed.

RESULTSThe nuclear beta-catenin expression rate was 35.9% in adenoma with malignant transformation, significantly higher than that in adenoma (16.7%) and carcinoma (19.7%) (both P < 0.05). The cytoplasmic and nuclear beta-catenin expression rate in adenoma with severe dysplasia was significantly higher than that in adenoma with mild dysplasia (both P < 0.05). The nuclear beta-catenin expression rate in adenocarcinomas of the ulcerative type, with lymph node metastasis and in the late tumor stages were all significantly higher than that in adenocarcinomas of the polypoid type, with negative lymph node and in the early tumor stages (P < 0.05 or P < 0.01). The MMP-7 expression rate in adenocarcinoma (69.2%) was significantly higher than that in normal colorectal mucosa (15.0%), adenoma (35.0%) and adenoma with malignant transformation (46.2%, P < 0.05 or P < 0.01). The MMP-7 expression rate in ulcerative type adenocarcinoma with lymph node metastasis and in late tumor stages was significantly higher than that in polypoid type adenocarcinoma with negative lymph node and in early tumor stages (all P < 0.05). The cytoplasmic and nuclear beta-catenin expression was thus in positive correlation with the expression of MMP-7 (both P < 0.01).

CONCLUSIONSThe cytoplasmic and nuclear beta-catenin expression, probably an early event, was related to the development of colorectal cancer. beta-catenin may enhance the degradative function of the target gene MMP-7 through nuclear translocation and may further facilitate local invasion and metastasis by the colorectal cancer cells.