A VARIANT GLUCOCORTICOID RECEPTOR MESSENGER-RNA IS EXPRESSED IN MULTIPLE-MYELOMA PATIENTS

In multiple myeloma cells resistant to glucocorticoids, we have previo usly identified a variant glucocorticoid receptor (GR) transcript (P. A. Moalli et at, Cancer Res., 53: 3877-3879, 1993). Here, we report a reverse transcription-PCR assay to assess whether this aberrant GR tra nscript is present in myeloma patients, We detected both the wild-type and variant GR transcripts in the patient isolate that was the source of our myeloma cell lines, in patients refractory to steroid treatmen t, and in healthy control subjects, Simultaneous amplification of wild -type and variant GR mRNAs indicates that the variant GR is more highl y expressed in cells that are resistant to glucocorticoids, We hypothe size that the variant GR is a normal mRNA transcript that acts to modu late glucocorticoid responsiveness, and increased expression contribut es to a resistant phenotype.