GW6471

GW6471 is a potent PPARα antagonist. IC50 & Target:PPARα^[1] In Vitro:In a cell-based reporter assay, GW6471 completely inhibits GW409544-induced activation of PPARα with an IC₅₀ of 0.24 μM^[1]. The functional role of PPARα is evaluated on renal cell carcinoma (RCC) cell viability by MTT assay. Both Caki-1 (VHL wild type) and 786-O (VHL mutated) cells are incubated separately with a specific PPARα agonist, WY14,643, or a specific PPARα antagonist, GW6471 at concentrations from 12.5 to 100 μM for 72 hours, and cell viability is assessed. While WY14,643 either has no affect on, or slightly increased, cell viability, GW6471 significantly and dose-dependently inhibits cell viability (up to approximately 80%) in both cell lines^[2]. In Vivo:To test the antitumor activity of PPARα antagonism in vivo, a subcutaneous xenograft mouse model is used. Caki-1 cells are implanted subcutaneously in nude (Nu/Nu) mice. After tumor masses reach ～5 mm in diameter, GW6471 is administrated intraperitoneally every other day for 4 wk at a dose (20 mg/kg mouse body wt) that is described to be effective in an in vivo dose-response study and confirmed here to be efficacious. There are significant differences in tumor growth between vehicle- and GW6471-treated animals. No toxicity is observed at the doses of GW6471 based on weights of the animals, and laboratory values, including kidney and liver function tests, are not adversely affected. To demonstrate on-target effects of GW6471, c-Myc levels are evaluated in the tumors, which show significant decreases in the GW6471-treated animals^[3].