Association of increased levels of TGF-β1 and p14ARF in prostate carcinoma cell lines overexpressing Egr-1

Abstract

The present study examined the effect of the overexpression of early growth response gene (Egr-1) on transforming growth factor β-1 (TGF-β1) and p14ARFlevels, in PC-3 and LNCaP prostate carcinoma cell lines. Amplification of EGR-1, TGF-β1 and p14ARFwere observed in the two cell lines treated with different stimuli and resulted in a corresponding mRNA and protein expression. The downregulation of TGF-β1 and the attenuation of p14ARFexpression by siRNA against Egr-1 predominantly suggested that TGF-β1 and p14ARFmay be regulated by the transcription factor EGR-1. A marginal attenuation of cell growth in PC-3 and LNCaP prostate carcinoma cell lines overexpressing p14ARFwas observed. Cells transfected with Egr-1 wild-type were able to grow and avoid cell cycle arrest and apoptosis in the presence or absence of p14ARF. In addition, EGR-1 stimulated the expression of TGF β-l as well as the accumulation of the p14ARFproteins. The results suggested that TGF-β1 and p14ARFactivities in the presen