Suberoylanilide hydroxamic Acid, a histone deacetylase inhibitor, alters multiple signaling pathways in hepatocellular carcinoma cell lines

Introduction: Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, has preclinical efficacy in hepatocellular carcinoma (HCC), despite an unclear molecular mechanism. We sought to further investigate the effects of SAHA on HCC. We hypothesize SAHA will inhibit HCC cellular proliferation through apoptosis and aid in further profiling SAHA's effect on HCC oncogenic pathways. Methods: HCC cell lines were treated with various concentrations of SAHA. Cell proliferation was determined by MTT and colonogenic assays. Cell lysates were analyzed via Western blotting for apoptotic and oncogenic pathway markers. Caspase glo-3/7 was used to assess apoptosis. Results: SAHA treatment demonstrated significant (<0.05) reduction in cell growth and colony formation through apoptosis and cell cycle arrest. Western analysis showed reduction in Notch, pAKT and pERK1/2 proteins. Interestingly, phosphorylated STAT3 was increased in all cell lines. Conclusions: SAHA inhibits Notch, AKT, and Raf-1 pathways but not the STAT3 pathway. We believe that STAT3 may lead to cancer cell progression, reducing SAHA efficacy in HCC. Therefore, combination of SAHA and STAT or Notch inhibition may be a strategy for HCC treatment. (C) 2016 Elsevier Inc. All rights reserved.