Heat-shock response of rat hepatoma variant cells.
The effect of mild heat shock on protein synthesis was examined in differentiated and dedifferentiated, glucocorticoid-sensitive and resistant clones of H4IIEC3 rat hepatoma cells by one- and two-dimensional gel electrophoresis of [35S]methionine-labeled proteins. Among the major heat-shock proteins, five were induced in all hepatoma clones. Certain members of the HSP70 family and the corresponding mRNAs were only slightly inducible in the glucocorticoid-resistant variants, but were strongly inducible in the sensitive ones. Three other proteins lacked heat inducibility in the dedifferentiated clones. The constitutive level of one major heat-shock protein was elevated in all dedifferentiated variants. These results show that the stage of differentiation influences the expression of heat-shock genes of hepatoma cells. We found no correlation between the elevated constitutive or induced level of heat-shock proteins and heat resistance.
Institute of Genetics, Hungarian Academy of Sciences, Szeged.
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M
Baranyi
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Hevér-Szabó
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Venetianer
D000818:Animals; D002454:Cell Differentiation; D004351:Drug Resistance; D004591:Electrophoresis, Polyacrylamide Gel; D005938:Glucocorticoids / Q000494:pharmacology; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D006358:Hot Temperature; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008970:Molecular Weight; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014407:Tumor Cells, Cultured
D005938:Glucocorticoids; D006360:Heat-Shock Proteins; D012333:RNA, Messenger