TY - JOUR T1 - Effects of Arsenic Compounds on Growth, Cell-Cycle Distribution and Apoptosis of Tretinoin-resistant Human Promyelocytic Leukemia Cells JF - Anticancer Research JO - Anticancer Res SP - 6489 LP - 6494 VL - 34 IS - 11 AU - CHIZUKO SAKAI AU - MARIKO ARAI AU - SACHIKO TANAKA AU - KENJI ONDA AU - KENTARO SUGIYAMA AU - TOSHIHIKO HIRANO Y1 - 2014/11/01 UR - http://ar.iiarjournals.org/content/34/11/6489.abstract N2 - Background/Aim: The effects of inorganic and organic arsenicals on proliferation, cell-cycle distribution, and apoptosis of all-transretinoic acid (ATRA)-resistant human promyelocytic leukemia HL-60 (HL-60-R2) cells were herein investigated. Materials and Methods: Cell proliferation was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell-cycle distribution and apoptotic cells were analyzed by flow cytometry. Results: The 50% inhibitory concentrations (IC50 values) for As2O3 against proliferation of HL-60 and HL-60-R2 cells were 12.2 and 7.2 μM, while those for arsenate were >200 and 62.1 μM, respectively. In contrast, organic methylarsinic acid, dimethylarsonic acid, trimethylarsine oxide, and tetramethylarsonium did not exert any inhibitory effects even at 200 μM. As2O3 and arsenate increased the proportion of apoptotic cells dose-dependently at a concentration range of 5-200 μM. As2O3 did not activate caspase 3/7 in HL-60 and HL-60-R2 cells. Conclusion: As2O3 and arsenate inhibit cell proliferation, affect cell-cycle distribution, and induce apoptosis of ATRA-resistant HL-60-R2 cells. The apoptosis-inducing mechanism appears not to be mediated through caspase3/7. ER -