Glucocorticoid receptor in multiple myeloma

Glucocorticoid receptor levels of myeloma cells were quantitated in 7 patients with multiple myeloma. In 4 patients, glucocorticoid receptor levels were less than 10 fmol/106 cells. In 3 patients, receptor levels were from 17.6 to 21.4 fmol/106 cells. We further examined the correlation between glucocorticoid receptor levels and effect of dexamethasone on 14C-thymidine incorporation and cell viability using 2 myeloma cell lines, OPM-1 and OPM-2, established from a patient with multiple myeloma. Glucocorticoid receptor levels of OPM-1 and OPM-2 were 8.5 fmol/106 cells and 63.2 fmol/106 cells, respectively. The sensitivity of OPM-1 to dexamethasone in these studies was lower than that of OPM-2. These results suggest the possibility that the low level of glucocorticoid receptor in myeloma cells may be important for predicting a poor response to glucocorticoid therapy.