Hematology Branch, NHLBI, NIH, Bld 10, CRC 3-5140, 10 Center Drive, 20892-1202 Bethesda, MD, USA.
Clin Cancer Res. 2012 Apr 1;18(7):1979-91. doi: 10.1158/1078-0432.CCR-11-2113. Epub 2012 Feb 20.
Chronic lymphocytic leukemia (CLL), a malignancy of mature B cells, is incurable with chemotherapy. Signals from the microenvironment support leukemic cell survival and proliferation and may confer chemotherapy resistance. ON 01910.Na (Rigosertib), a multikinase phosphoinositide 3-kinase (PI3K) inhibitor, is entering phase III trials for myelodysplastic syndrome. Our aim was to analyze the efficacy of ON 01910.Na against CLL cells in vitro and investigate the molecular effects of this drug on tumor biology.
Cytotoxicity of ON 01910.Na against CLL cells from 34 patients was determined in vitro with flow cytometry of cells stained with Annexin V and CD19. Global gene expression profiling on Affymetrix microarrays, flow cytometry, Western blotting, and cocultures with stroma cells were used to delineate ON 01910.Na mechanism of action.
ON 01910.Na induced apoptosis in CLL B cells without significant toxicity against T cells or normal B cells. ON 01910.Na was equally active against leukemic cells associated with a more aggressive disease course [immunoglobulin heavy-chain variable region unmutated, adverse cytogenetics] than against cells without these features. Gene expression profiling revealed two main mechanisms of action: PI3K/AKT inhibition and induction of ROS that resulted in an oxidative stress response through activating protein 1 (AP-1), c-jun-NH(2)-terminal kinase, and ATF3 culminating in the upregulation of NOXA. ROS scavengers and shRNA mediated knockdown of ATF3- and NOXA-protected cells from drug-induced apoptosis. ON 01910.Na also abrogated the prosurvival effect of follicular dendritic cells on CLL cells and reduced SDF-1-induced migration of leukemic cells.
These data support the clinical development of ON 01910.Na in CLL.
慢性淋巴细胞白血病（CLL）是一种成熟 B 细胞恶性肿瘤，用化疗无法治愈。微环境中的信号支持白血病细胞的存活和增殖，并可能导致化疗耐药。ON 01910.Na（Rigosertib）是一种多激酶磷酸肌醇 3-激酶（PI3K）抑制剂，目前正在进行骨髓增生异常综合征的 III 期临床试验。我们的目的是分析 ON 01910.Na 对体外 CLL 细胞的疗效，并研究该药物对肿瘤生物学的分子影响。
用 Annexin V 和 CD19 染色的流式细胞术测定来自 34 例患者的 ON 01910.Na 对 CLL 细胞的体外细胞毒性。利用 Affymetrix 微阵列进行全基因组表达谱分析、流式细胞术、Western blot 和与基质细胞共培养来描绘 ON 01910.Na 的作用机制。
ON 01910.Na 诱导 CLL B 细胞凋亡，而对 T 细胞或正常 B 细胞无明显毒性。ON 01910.Na 对伴有侵袭性疾病过程的白血病细胞（免疫球蛋白重链可变区未突变、不良细胞遗传学）与无这些特征的细胞同样有效。基因表达谱分析揭示了两种主要的作用机制：PI3K/AKT 抑制和 ROS 诱导，导致通过激活蛋白 1（AP-1）、c-jun-NH2-末端激酶和 ATF3 引起氧化应激反应，最终导致 NOXA 的上调。ROS 清除剂和 shRNA 介导的 ATF3 和 NOXA 敲低可保护细胞免受药物诱导的凋亡。ON 01910.Na 还消除了滤泡树突状细胞对 CLL 细胞的促生存作用，并减少了 SDF-1 诱导的白血病细胞迁移。
这些数据支持 ON 01910.Na 在 CLL 中的临床开发。
