The Pattern of Expression of Phospholipase C-gamma in Benign and Malignant Tumors of the Breast

ABSTRACT

PURPOSE: The activation of phospholipase C (PLC) is one of the early events in various growth processes, including malignant transformation. Among PLC-isozymes, PLC-gamma is activated through direct interaction with growth factor receptor tyrosine kinase. In this study, we evaluated the patterns of PLC-gamma expression in benign and malignant tumors of the breast and compared the patterns with their normal counterpart. METHODS: Using immunoblot assay, we evaluated the patterns of expression in PLC-gamma in 20 breast cancer tissues, 13 fibroadenoma tissues, and normal tissues. The level of expression was analyzed by densitometry. RESULTS: All of 20 breast cancer tissues and 13 fibroadenoma tissues showed overexpression of PLC-gamma when compared with their normal counterparts. The level of the PLC-gamma expression was 3.9-fold and 17.3-fold higher in fibroadenomas and breastcancers, respectively, than in normal tissues. CONCLUSION: The result suggested that the level of PLC-gamma expression increases as the normal tissue undergoes progression to fibroadenoma, and finally to carcinoma. The pattern of expression of PLC-gamma in breast tissue implies that the PLC-gamma-mediated signal transduction may play a significant role in the progression of breast cancer from normal tissue.