Bleomycin induces the hsp 70 heat shock promoter in cultured cells

Bleomycin-induced lung disease is characterized by cell injury followed by fibroblast proliferation. Cells respond to injury by synthesizing a family of heat shock proteins. These proteins are critical to cell survival, and those of the 70,000 MW group (hsp 70) are essential for cell division and proliferation. To evaluate the effect of bleomycin on heat shock gene expression, we transfected a gene construct containing the hsp 70 heat shock gene promoter into fibroblasts. Doses of bleomycin, which have previously been shown to augment lung fibroblast proliferation, induce the hsp 70 heat shock promoter in the transfected cells. Bleomycin did not induce the expression of a non-hsp promoter placed in cells as a control of nonspecific gene activation. These observations suggest that bleomycin exposure may cause significant alterations in important DNA promoter regions such as the hsp 70 promoter and point to new ways to assess bleomycin-induced changes in cells.