Levels of the 90kd heat shock protein and resistance to glucocorticoid-mediated cell killing in a range of human and murine lymphocyte cell lines.

The 90kd heat shock protein is associated with the receptors for glucocorticoids and other steroids. The steroid is believed to function by releasing the receptor from hsp90 allowing the receptor to bind to DNA and activate transcription. The levels of hsp90 have been measured in a variety of lymphoid cell lines and compared with their sensitivity to steroid mediating killing. No correlation of high hsp90 levels with steroid resistance was observed. However, increased levels of hsp90 in response to steroid were observed in a number of cell lines. The significance of these findings is discussed in terms of the modulation of the cells response to steroid treatment and the mechanism of steroid resistance.