Presence of estrogen receptors in human myeloid monocytic cells (THP-1 cell line)

Objective: To test THP-1 cells for the presence of estrogen receptors (ER) since studies have demonstrated in viva and irt vitro, the influence of est rogens on cells involved in immune response (i.e. macrophages), and since i t has been demonstrated that human myeloid monocytic THP-1. cell acquire ph enotypic and functional macrophage-like features after incubation with seve ral cytokines or pharmacological agents. Design: Stimulation of THP-1 cells with phorbol myristate acetate (PMA) to prompt their differentiation into macrophage-like cells and evaluation of the possible induction of ER, Metho ds: The expression of ER was: analyzed by immunocytochemical assay, reverse transcriptase polymerase chain reaction(RT-PCR) and Western blot analysis. Results: After stimulation by PMA, the human myeloid monocytic THP-I cells showed the presence of ER, together with markers of monocytic cell differe ntiation such as CD68, CD54 and HLA-DR, Conclusion: Estrogen effects may be exerted directly through ER on monocytes/macrophages. PMA-treated THP-1 ce lls may constitute a useful in vitro model to determine the effects of estr ogens on macrophage;like cells and their implications in the inflammatory a nd immune processes.