5-Azacytidine, a DNA methyltransferase inhibitor, induces ATR-mediated DNA double-strand break responses, apoptosis, and synergistic cytotoxicity with doxorubicin and bortezomib against multiple myeloma cells
5-Azacytidine, a DNA methyltransferase inhibitor, induces ATR-mediated DNA double-strand break responses, apoptosis, and synergistic cytotoxicity with doxorubicin and bortezomib against multiple myeloma cells
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DOI：
10.1158/1535-7163.mct-07-0010
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发表时间：
2007-06-01
影响因子：
5.7
通讯作者：
Anderson, Kenneth C.
中科院分区：
文献类型：
--
作者：
Kiziltepe, Tanyel;Hideshima, Teru;Anderson, Kenneth C.
在这项研究中，我们研究了5-氮杂胞苷，DNA甲基转移酶抑制剂，对多发性骨髓瘤（MM）细胞的细胞毒性，并表征了DNA损伤相关的细胞死亡机制。5-氮杂胞苷对传统治疗敏感和治疗耐药的MM细胞系以及多药耐药患者来源的MM细胞均显示出显著的细胞毒性，IC 50值为0.8-3 μ mol/L。相反，在这些剂量下，5-氮杂胞苷对外周血单核细胞或患者来源的骨髓基质细胞（BMSC）无细胞毒性。重要的是，5-氮杂胞苷克服了外源性白细胞介素-6（IL-6）、胰岛素样生长因子-I（IGF-I）或MM细胞与BMSC粘附所带来的存活和生长优势。5-氮杂胞苷处理诱导DNA双链断裂（DSB）反应，如MM细胞的H2 AX、Chk 2和p53磷酸化和凋亡所证明。5-氮杂胞苷诱导的细胞凋亡既依赖于caspase，又不依赖于caspase，具有caspase 8和caspase 9切割; Mcl-1切割; Bax、Puma和Noxa上调;以及线粒体释放AIF和EndoG。最后，我们表明，5-氮杂胞苷诱导的DNA DSB反应主要由ATR介导，并且多柔比星以及硼替佐米协同增强5-氮杂胞苷诱导的MM细胞死亡。综上所述，这些数据为5-氮杂胞苷单药治疗和与多柔比星和硼替佐米联合治疗改善MM患者结局的临床评价提供了临床前依据。
In this study, we investigated the cytotoxicity of 5-azacytidine, a DNA methyltransferase inhibitor, against multiple myeloma (MM) cells, and characterized DNA damage-related mechanisms of cell death. 5-Azacytidine showed significant cytotoxicity against both conventional therapy-sensitive and therapy-resistant MM cell lines, as well as multidrug-resistant patient-derived MM cells, with IC50 of similar to 0.8-3 mu mol/L. Conversely, 5-azacytidine was not cytotoxic to peripheral blood mononuclear cells or patient-derived bone marrow stromal cells (BMSC) at these doses. Importantly, 5-azacytidine overcame the survival and growth advantages conferred by exogenous interleukin-6 (IL-6), insulin-like growth factor-I (IGF-I), or by adherence of MM cells to BMSCs. 5-Azacytidine treatment induced DNA double-strand break (DSB) responses, as evidenced by H2AX, Chk2, and p53 phosphorylations, and apoptosis of MM cells. 5-Azacytidine-induced apoptosis was both caspase dependent and independent, with caspase 8 and caspase 9 cleavage; Mcl-1 cleavage; Bax, Puma, and Noxa up-regulation; as well as release of AIF and EndoG from the mitochondria. Finally, we show that 5-azacytidine-induced DNA DSB responses were mediated predominantly by ATR, and that doxorubicin, as well as bortezomib, synergistically enhanced 5-azacytidine-induced MM cell death. Taken together, these data provide the preclinical rationale for the clinical evaluation of 5-azacytidine, alone and in combination with doxorubicin and bortezomib, to improve patient outcome in MM.