Expression of E-cadherin, β-catenin, matrix metalloproteinase-7 and its correlation to invasion/metastasis of hereditary non-polyposis colorectal cancer

AIM: To detect expression of E-cadherin (E-cad), β-catenin (β-cat) and matrix metalloproteinase-7 (MMP-7) in hereditary non-polyposis colorectal cancer (HNPCC) and sporadic colorectal cancer (CRC), and to analyze its relationship to the biological behavior of HNPCC. METHODS: Protein expression of E-cad, β-cat and MMP-7 in 30 specimens of HNPCC, 30 of sporadic CRC and eight of normal colorectal tissues was detected by SP immunohistochemistry. Their corresponding clinical data were analyzed retrospectively. RESULTS: The positive expression rates of E-cad and membrane β-cat in HNPCC patients were higher than those in sporadic CRC (E-cad, 86.7% vs 60.0%; membrane β-cat, 83.3% vs 50.0%, all P < 0.05). The positive expression rates of cytoplasm β-cat and MMP-7 in HNPCC patients were lower than those in sporadic CRC patients (cytoplasm β-cat, 46.7% vs 80.0%; MMP-7, 46.7% vs 86.7%; both P > 0.05). Positive rates of E-cad, β-cat and MMP-7 in the two groups were significantly related to depth of invasion and lymph node metastasis (r = 0.732, P < 0.05), but not to sex or the size or position of the tumor. Protein expression of E-cad was positively correlated with expression of membrane β-cat (r = 0.477, P < 0.05), however, expression of membrane β-cat was negatively correlated with expression of cytoplasmic β-cat (r = -0.419, P < 0.05), while expression of cytoplasm β-cat was positively correlated with expression of MMP-7 (r = 0.380, P < 0.05). CONCLUSION: There are remarkable differences in expressions of E-cad, β-cat and MMP-7 between HNPCC and sporadic CRC. This could be the reason that HNPCC tumors are less invasive and have less metastatic potential compared to sporadic cancers.