Expression of monocyte chemotactic protein-1 in human endometrial cancer cells and the effect of treatment with tamoxifen or buserelin.

Monocyte chemotactic protein-1 (MCP-1) is an important determinant of macrophage infiltration in tumours. This study investigated the effect of tamoxifen and the gonadotrophin-releasing hormone agonist buserelin on MCP-1 in the human endometrial cancer cell line EFE-184. Reverse transcription polymerase chain reaction and Western blot analysis were used to determine MCP-1 mRNA and protein expression, respectively. Immunoreactive MCP-1 in the cell culture media was quantified by enzyme-linked immunosorbent assay. Tamoxifen inhibited MCP-1 mRNA and protein expression in endometrial cancer cells and inhibited MCP-1 secretion in a time- and dose-dependent manner at concentrations of 10(-7) to 10(-5) M. Buserelin had no significant effect on MCP-1 mRNA and protein expression. These results suggest that tamoxifen directly inhibits the expression of MCP-1 in this cell line by blocking the MCP-1 signalling pathways. These findings may contribute to the understanding of the mechanisms underlying the different effects of tamoxifen and gonadotrophin-releasing hormone agonists in the treatment of endometrial cancer.