Histone deacetylase inhibitor pre-treatment enhances the efficacy of DNA-interacting chemotherapeutic drugs in gastric cancer

Figure 3 Histone deacetylase inhibitor-dependent sensitization of gastric cancer cells decreases the dose of chemotherapeutic drugs to attain maximum efficacy. AGS cells were treated with chemotherapeutic drugs (cisplatin, oxaliplatin and epirubicin) and histone deacetylase (HDAC) inhibitors [valproic acid (VPA), trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA)] for 24 h each in three different combinations: (i) concurrent (HDACi + Drug), (ii) pre- (HDACi Drug) and (iii) post- (Drug HDACi) at the combined dose (as mentioned in Supplementary Table 1), and : 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed. Fraction-affected dose response curve of A: Cisplatin; B: Oxaliplatin; and C: Epirubicin in different combinations with VPA, TSA or SAHA. TSA: Trichostatin A; VPA: Valproic acid; SAHA: Suberoylanilide hydroxamic acid.