Identification and characterization of glucocorticoid receptors in B16 mouse melanoma cells.

OBJECTIVE To gain better insight into the role of glucocorticoids as modulators of cell growth, as well as to investigate the presence and characteristics of glucocorticoid receptors (GR) in mouse melanoma cells. METHODS In two different B16 mouse melanoma cell clones (B16/F10 and B16/C3) the role of synthetic glucocorticoids (triamcinolone acetonide, TA) as cell growth modulators was investigated. RESULTS The inhibitory effect of TA on B16/F10 cell growth after 8 days in culture was observed. The same hormonal treatment applied on B16/C3 melanoma cells also provoked changes in the cell growth. Dot blot analysis, using monoclonal antirodent glucocorticoid receptor antibodies showed the presence of receptor protein in both cell clones. The analysis of glucocorticoid receptors in B16/F10 and B16/C3 cell cytosol by Scatchard assay and ion-exchange chromatography on DEAE-Sephadex A-50 minicolumn indicated that the changes in melanoma cell growth may be mediated by glucocorticoid receptors and may relieve changes in the GR itself. CONCLUSIONS It was found that B16/C3 melanoma cells exhibited different growth pattern under TA treatment when compared to the results obtained with B16/F10 cells. Such differences may be mediated by glucocorticoid receptors.