Abstract: Objective To investigate β-catenin and lymphoid enhancing factor 1 (LEF-1) expression in malignant melanoma. Methods β-catenin and LEF-1 protein expression was examined using the PowerVision^TM immunohistochemical method in 25 cases of intradermal nevus and 45 cases of malignant melanoma. Results Comparing malignant melanoma with intradermal nevi, there was a significant difference in the expression of β-catenin (33/45=73% vs. 9/25=36%, respectively;P<0.05) and the expression of LEF-1 (28/45=62.2% vs. 0/25=0%, respectively;P<0.05). LEF-1 expression was correlated with lymphatic metastasis and TNM staging (P<0.05), while β-catenin expression was not. In cancer tissues, the abnormal expression of β-catenin was positively correlated with LEF-1 expression (P<0.05). Conclusion The abnormal expression of β-catenin and LEF-1 may play an important role in the carcinogenesis and progression of malignant melanoma.

Key words: Melanoma, β-catenin, Lymphoid enhancing factor