Gene expression profiling of the response to thermal injury in human cells

The genetic response of human cells to sublethal thermal injury was assessed by gene expression profiling, using macroarrays containing 588 complementary known genes. At 1, 4, 8, and 24 h following thermal injury, RNA was isolated, and a cDNA copy was generated incorporating (33)P and hybridized to Atlas arrays. About one-fifth of the genes on the membrane exhibited a significant elevation or depression in expression (>/=2-fold) by 4 h posttreatment. Genes for heat shock proteins (HSPs) were upregulated as well as genes for transcription factors, growth regulation, and DNA repair. Cluster analysis was performed to assess temporal relationships between expression of genes. Translation of mRNA for some expressed genes, including HSP70 and HSP40, was corroborated by Western blotting. Gene expression profiling can be used to determine information about gene responses to thermal injury by retinal pigment epithelium cells following sublethal injury. The induction of gene expression following thermal injury involves a number of genes not previously identified as related to the stress response.