Divergent effects of hyperosmolality on stress-response (heat shock) protein expression in cultured human tumor cells: an immunocytochemical study.

Exposing cells to adverse conditions usually elicits expression of stress-response (heat shock) proteins (srp). Here we show that hyperosmolar growth conditions do not uniformly affect srp expression in MCF-7 and HeLa S3 cells, derived from carcinoma of the breast and cervix, respectively. Thus, whereas srp 27 expression was increased in MCF-7, but not in HeLa S3, the opposite was the case with srp 72. On the other hand, hyperosmolality did not induce alpha B-crystallin or ubiquitin in either cell line. These findings show that srp expression by the human tumor cells studied is non-coordinate, suggesting that each srp is independently modulated.