Expression of phospholipase C-gamma 1 and its transcriptional regulators in breast cancer tissues

Abstract

Background: PLC-gamma 1 is activated through direct interaction with growth factor receptor tyrosine kinase but little is known about the mechanisms controlling PLC-gamma 1 expression and its biological significance. Materials and methods: Using immunoblotting, we evaluated PLC-gamma 1 protein overexpression in twenty breast cancer tissues. The expression of binding protein to GES1, GES2 and GES3, located in transcriptional regulator (GPE1) was found by electrophoretic mobility shift assay (EMSA). We also determined whether there was any correlation between prognostic factors (numbers of metastatic axillary nodes, histologic grade, c-erbB2, p53, and E-cadherin) and the overexpression of PLC-gamma 1 protein. Result: On immunoblotting, 17 of 20 breast cancer tissues showed overexpression of PLC-gamma 1, a result of which was corresponded to that of immunohistochemistry. The binding proteins to GES1, GES2 and GES3 were overexpressed only when PLC-gamma 1 protein overexpression was apparent. Positive expression of E-cadherin only was significantly associated with PLC-gamma 1 protein overexpression (x = 0.607, p=0.045). Conclusion: GPE1 binding proteins might be the transcriptional regulator in PLC-gamma 1 overexpression and the relationship between expression of PLC-gamma 1 and E-cadherin would require further elucidation.