Vorinostat enhances gefitinib ‑induced cell death through reactive oxygen species‑dependent cleavage of HSP90 and its clients in non‑small cell lung cancer with the EGFR mutation.

Vorinostat enhances gefitinib‑induced cell death through reactive oxygen species‑dependent cleavage of HSP90 and its clients in non‑small cell lung cancer with the EGFR mutation. Oncol Rep. 2018 Oct 22;: Authors: Park SE, Kim DE, Kim MJ, Lee JS, Rho JK, Jeong SY, Choi EK, Kim CS, Hwang JJ Abstract Although different mechanisms of acquired resistance to epidermal growth factor receptor (EGFR)‑tyrosine kinase inhibitors (TKIs) have been reported in non‑small cell lung cancers (NSCLCs), the optimal treatment for patients with acquired resistance has not been clearly defined. The purpose of this study was to investigate the antitumor effects of gefitinib in combination with vorinostat, a potent histone deacetylase inhibitor (HDACI), and their associated molecular mechanisms in relation to activating apoptosis in NSCLC. The treatment using a combination of vorinostat and gefitinib was more potent in promoting cell death by activating apoptosis than gefitinib alone in parental PC9 cells that harbor an EGFR‑activating mutation (EGFR exon 19 deletion) and gefitinib‑resistant PC9 cells (PC9GR) with an EGFR T790M mutation. This combination induced heat shock protein 90 (HSP90) cleavage and reduced the level of HSP90 client proteins, including EGFR, MET and AKT, in PC9 and PC9GR cells. The addition of 4‑(2‑aminoethyl) benzenesulfonyl fluoride hydrochloride, a scavenger of reactive oxygen species (ROS), inhibited the degradatio...
Source: Oncology Reports - Category: Cancer & Oncology Tags: Oncol Rep Source Type: research