ABSTRACT
We report the anticarcinogenic, anti-aging polyphenol resveratrol activates the radio- and chemo-inducible cancer gene therapy vector Ad.Egr.TNF, a replication-deficient adenovirus that expresses human tumor necrosis factor alpha (TNF-alpha) under control of the Egr-1 promoter. Like ionizing radiation or chemotherapeutic agents previously shown to activate Ad.Egr.TNF, resveratrol also induces Egr-1 expression from its chromosomal locus with a possible role for Egr-1 promoter CC(A+T)richGG sequences in the expression of TNF-alpha. Resveratrol induction of TNF-alpha in Ad.Egr.TNF-infected tumor xenografts demonstrated antitumor response in human and rat tumor models comparable to that of radio- or chemotherapy-induced TNF-alpha. Although sirtuins are known targets of resveratrol, in vitro inhibition of SIRT1 activity did not abrogate resveratrol induction of Egr-1 expression. This suggests that SIRT1 is not essential to mediate resveratrol induction of Egr-1. Nevertheless, control of transgene expression via resveratrol activation of Egr-1 may extend use of Ad.Egr.TNF to patients intolerant of radiation or cytotoxic therapy and offer a novel tool for development of other inducible gene therapies.
