Antiproliferativ e prostaglandins activate heatshock transcription factor

Treatment ofhumanK562erythroleukemia cells withtheantiproliferativ e prostaglandin A1results inthe elevated transcription oftwoheatshockgenes, HSP70and HSP90. Parallel withincreased heat shock genetrnscription is theactivation ofheatshocktranscription factor. Heatshock transcription factor levels areinduced within 60minafter pros- tagandin Aladdition tolevels similar tothat achieved during heat shock. Therequirement forprotein synthesis forprostaglandin AI activation ofheat shock transcription factor suggests that effects onnascent protein synthesis maybeinvolved inthesigaling mechanism. Although itisunclear whether theactivation ofaheat shock response byprostalandins isrelevant tothebiochemical properties ofthese natural substances, cells pretreated with prostaglandin Alareprotected against asubsequent heat shock, indicative ofathermotolerant state.