title: Enhanced suppression of tumor growth by concomitant treatment of human lung cancer cells with suberoylanilide hydroxamic acid and arsenic trioxide.
abstract: The efficacy of arsenic trioxide (ATO) against acute promyelocytic leukemia (APL) and relapsed APL has been well documented. ATO may cause DNA damage by generating reactive oxygen intermediates. Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, modulates gene and protein expression via histone-dependent or -independent pathways that may result in chromatin decondensation, cell cycle arrest, differentiation, and apoptosis. We investigated whether ATO and SAHA act synergistically to enhance the death of cancer cells. Our current findings showed that combined treatment with ATO and SAHA resulted in enhanced suppression of non-small-cell lung carcinoma in vitro in H1299 cells and in vivo in a xenograft mouse model. Flow cytometric analysis of annexin V+ cells showed that apoptotic cell death was significantly enhanced after combined treatment with ATO and SAHA. At the doses used, ATO did not interfere with cell cycle progression, but SAHA induced p21 expression and led to G1 arrest. A Comet assay demonstrated that ATO, but not SAHA, induced DNA strand breaks in H1299 cells; however, co-treatment with SAHA significantly increased ATO-induced DNA damage. Moreover, SAHA enhanced acetylation of histone H3 and sensitized genomic DNA to DNase I digestion. Our results suggest that SAHA may cause chromatin relaxation and increase cellular susceptibility to ATO-induced DNA damage. Combined administration of SAHA and ATO may be an effective approach to the treatment of lung cancer.
authors: Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors: Chia-Wen
authors: CW
authors: Chien
authors: Ju-Hsien
authors: JH
authors: Yao
authors: Shih-Yu
authors: SY
authors: Chang
authors: Pei-Chih
authors: PC
authors: Lee
authors: Te-Chang
authors: TC
authors: Lee
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000008:administration & dosage / Q000627:therapeutic use*; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005434:Flow Cytometry; D006801:Humans; D006877:Hydroxamic Acids / Q000008:administration & dosage / Q000627:therapeutic use*; D008175:Lung Neoplasms / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010087:Oxides / Q000008:administration & dosage / Q000627:therapeutic use*; D000077337:Vorinostat
chemical_list: D000970:Antineoplastic Agents; D001152:Arsenicals; D006877:Hydroxamic Acids; D010087:Oxides; D000077337:Vorinostat; D000077237:Arsenic Trioxide