OBJECTIVETo investigate the relationship between positive expression of Her2 and abnormal expressions of beta-catenin and E-cadherin and its implications.

METHODSImmunohistochemistry was used to detect the expressions of Her2, beta-catenin and E-cadherin in 147 samples of human breast carcinoma. The expressions of beta-catenin and E-cadherin were also detected in 19 tissues adjacent to the carcinoma and 17 benign breast lesions as controls.

RESULTSIn breast carcinoma, positive Her2 expression was associated with lymph node metastasis, advanced clinical stage and negative expression of ER and PR (P<0.05). Abnormal beta-catenin expression was associated with positive lymph node status and high histological grade (P<0.01). Abnormality of E-cadherin expression was related to lymph node metastasis and advanced clinical stage (P<0.05). Abnormal beta-catenin expression was directly correlated with abnormal E-cadherin expression (P<0.01). Her2 positivity showed a direct correlation to abnormal beta-catenin expression (P<0.01), and they cooperated in promoting axillary lymph node metastasis in human breast carcinoma (P<0.01).

CONCLUSIONA direct correlation between positive Her2 expression and abnormal beta-catenin expression exists in human breast carcinoma, and positive Her2 expression may have functional interactions with abnormal activation of Wnt/beta-catenin signaling pathway.