Retroviral reporter systems for assessing the activity of stress-inducible signal transduction pathways controlled by the p53, HIF-1, and HSF-1 transcription factors

Abstract

Tumor suppressor p53, hypoxia-inducible factor 1 (HIF-1) and heat-shock factor 1 (HSF-1) are involved as the key transcription factors in cellular response to stress, induced by genetic material damage, hypoxia and heat shock respectively. The protein factors listed above also play an integral part in tumor development and progression. Thus, modulation of their activity may be important for treatment of cancer. In our work we obtained the reporter constructs for quantitative assessment of p53, HIF-1 and HSF-1 transcriptional activity on the basis of retro- and lentiviruses, allowing to obtain reporter cell lines almost out of any cell type. Induction of beta-galactosidase reporter gene expression, reflecting the activity of p53 and HIF-1 factors, depends on dose of treatment and also correlates with the induction of the endogenous target genes expression. The observed effect of activating treatments completely disappeared when the expression of p53 and HIF-1 genes was inhibited with specific siRNAs. The obtained reporter constructs may find the application in the screening of chemical and genetic (such as siRNA- and cDNA-libraries) modulators of transcriptional activity along with the investigation of components of signal transduction pathways modulating the transcriptional activity of those factors.