Research and innovation in the development of everolimus for oncology.

Introduction: The critical role of increased activity of mammalian target of rapamycin (mTOR) in the pathophysiology of multiple diseases is well established. Inhibition of the mTOR pathway may block disease progression and improve patient outcomes. Everolimus, an mTOR inhibitor, began in clinical development as part of a regimen (Certican, Zortress) for prevention of organ transplant rejection and is now an approved oncology agent.

Protein kinase C-{alpha} mediates epidermal growth factor receptor transactivation in human prostate cancer cells.

Progression of human prostate cancer to a malignancy that is refractory to androgen-ablation therapy renders the disease resistant to available treatment options and accounts for the high prostate cancer mortality rate. Epidermal growth factor receptor (EGFR) expression in human prostate cancer specimens increases with disease progression to androgen-refractory prostate cancer, and experimental models implicate EGFR-dependent signaling to Erk1/2 activation in the androgen-refractory prostate cancer phenotype. 12-O-Tetradecanoylphorbol-13-acetate (TPA)-induced Erk1/2 activation in human prostate cancer PC-3 cells is a paradigm of diacylglycerol-induced EGFR transactivation in androgen-independent prostate cancer.

Resveratrol antagonizes EGFR-dependent Erk1/2 activation in human androgen-independent prostate cancer cells with associated isozyme-selective PKC alpha inhibition.

The development of androgen-independent prostate cancer (AI PrCa) involves constitutive Erk1/2 activation sustained by the epidermal growth factor/transforming growth factor-alpha/EGF receptor (EGF/TGFalpha/EGFR) axis and other trophic signaling mechanisms in neoplastic human prostate epithelial cells in vivo. In this report, we show that growth-inhibitory concentrations of the dietary phytochemical resveratrol suppress EGFR-dependent Erk1/2 activation pathways stimulated by EGF and phorbol ester (12- O -tetradecanoyl phorbol 13-acetate, TPA) in human AI PrCa PC-3 cells in vitro. Because protein kinase C (PKC) is the major cellular receptor for phorbol esters and taking into consideration that resveratrol is PKC-inhibitory, we investigated resveratrol effects on cellular PKC isozymes associated with the suppression of TPA-induced Erk1/2 activation.

Resveratrol: a candidate nutritional substance for prostate cancer prevention.

The dietary stilbene resveratrol is a major constituent of a variety of edible plant products, including grapes and peanuts. Resveratrol has been identified as an excellent candidate cancer chemopreventive, based on its safety and efficacy in animal models of carcinogenesis. Resveratrol is a prototype of a plethora of bioactive polyphenols in the food supply that has just begun to be mined for cancer preventive agents.