This proposal aims to identify cellular targets of a grape-skin derived chemical called resveratrol, in regards to its chemopreventive activities against prostate cancer (CAP). The studies described herein expand on our published observations that this dietary polyphenol significantly reduced growth of androgen responsive (AD) and hormone refractory (AI) CaP cells, and profoundly lowered prostate specific antigen (PSA) expression. The slow natural history of CaP and the long latency associated with AD->AI transition present an ideal model for testing whether this specific agent confers chemoprotection in humans. As a requisite to fulfilling this long-term objective, I propose to identify and characterize cellular targets of resveratrol using a novel approach, which I have named resveratrol-capture proteomics. The underpinning of this innovative approach lies in the aromatic stilbene core of resveratrol and its hydrophilic side groups, which I hypothesize to interact with and specifically bind distinct targeting proteins (herein referred to as resveratrol targeting proteins, RTPs). We have devised an innovative, specific strategy to facilitate the identification of RTPs, in the context of CaP progression. The collective goal of this project therefore is to isolate, identify, clone and express RTPs, using cells mimicking different stages of CaP, for comparison with RTPs derived from normal prostate epithelial and stromal cells. Our experimental approach is to couple resveratrol to epoxy-activated agarose beads, forming a resveratrol-capture affinity matrix. We will test its ability to capture cellular targeting proteins. Specificity of capture will be investigated by varying elution conditions (changing salt, pH, displacement ligands etc.). Proteins binding with the strongest affinity to the matrix will be eluted with resveratrol. They will be checked for purity and then analyzed by mass spectrometry, to ascertain whether they comprise of known proteins in the human genome database. Proteins successfully identified by mass spectrometry will be cloned and expressed. These studies should reveal protein candidates with an obligatory or facilitatory function in chemoprevention of CaP by resveratrol, or in the progression of CaP from a treatable AD form to an AI state, currently without curative therapies.
|Hsieh, Tze-chen; Wu, Joseph M (2010) Resveratrol: Biological and pharmaceutical properties as anticancer molecule. Biofactors 36:360-9|
|Hsieh, Tze-Chen (2009) Uptake of resveratrol and role of resveratrol-targeting protein, quinone reductase 2, in normally cultured human prostate cells. Asian J Androl 11:653-61|
|Hsieh, Tze-Chen; Wang, Zhirong; Deng, Haiteng et al. (2008) Identification of glutathione sulfotransferase-pi (GSTP1) as a new resveratrol targeting protein (RTP) and studies of resveratrol-responsive protein changes by resveratrol affinity chromatography. Anticancer Res 28:29-36|
|Hsieh, Tze-chen; Wang, Zhirong; Hamby, Carl V et al. (2005) Inhibition of melanoma cell proliferation by resveratrol is correlated with upregulation of quinone reductase 2 and p53. Biochem Biophys Res Commun 334:223-30|