Background: Phenylacetate (PA), an aromatic fatty acid, is now undergoing evaluation as a potential anticancer reagent. Our previous study showed that PA induces cell growth inhibition in prostate cancer cells. Here, we investigated whether PA is effective against three renal cancer cell lines in vitro.
Materials and methods: The cell viability of PA-treated renal carcinoma cell lines (Caki-1, Os-RC-2 and RCC10) was assessed by trypan-blue exclusion and cell cycle distribution by flow cytometry. The cell cycle-regulatory protein expression was evaluated by Western blot, immunoprecipitation and kinase assay.
Results: Growth inhibition occurred with PA treatment at a dose of 2-5 mM and an increased percentage of cells in G1 after 24 hours of exposure. Reduced phosphorylation of the retinoblastoma protein (Rb) and CDK2 activity, increased expression of p21Cip1 and enhanced binding of p21Cip1 to CDK2 were observed following treatment with PA.
Conclusion: Overall, these results suggest that p21Cip1 is a critical target in PA-mediated cell growth inhibition in RCC cells playing a key role in CDK2 inactivation, hypophosphorylation of pRb and subsequent G1 cell cycle arrest.