Loss of Wilms tumor 1 protein is a marker for apoptosis in response to replicative stress in leukemic cells
Loss of Wilms tumor 1 protein is a marker for apoptosis in response to replicative stress in leukemic cells
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DOI：
10.1007/s00204-018-2202-3
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发表时间：
2018-03
影响因子：
6.1
通讯作者：
Miriam Pons;Claudia M. Reichardt;D. Hennig;Abinaya Nathan;N. Kiweler;C. Stocking;C. Wichmann;M. Christmann;F. Butter;Sigrid Reichardt;G. Schneider;T. Heinzel;C. Englert;J. Hartkamp;O. Krämer;Nisintha Mahendrarajah
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作者：
Miriam Pons;Claudia M. Reichardt;D. Hennig;Abinaya Nathan;N. Kiweler;C. Stocking;C. Wichmann;M. Christmann;F. Butter;Sigrid Reichardt;G. Schneider;T. Heinzel;C. Englert;J. Hartkamp;O. Krämer;Nisintha Mahendrarajah
细胞毒性化疗后转录因子Wilms tumor 1 （WT1）的剩余表达表明患者中仍存在白血病克隆。我们确定了WT1在暴露于复制应激和DNA损伤的白血病细胞中的调控和相关性。为了诱导这些条件，我们使用了临床相关的化疗药物羟基脲和阿霉素。我们另外用促凋亡激酶抑制剂staurosporine处理细胞。我们的数据显示，这些药物在12个白血病细胞系的小组中以不同程度促进细胞凋亡，并且在细胞凋亡过程中caspase切割WT1。在羟基脲敏感的急性早幼粒细胞白血病细胞中，caspase的化学抑制以及线粒体抗凋亡BCL2家族蛋白的过表达可显著降低WT1的加工和细胞死亡。虽然WT1的降低与化疗药物在各种白血病细胞中的药理效果有关，但通过不同的RNA干扰（RNAi）策略消除WT1并不会导致慢性髓系白血病K562细胞的细胞周期发生变化。抗WT1的RNAi也不会增加羟基脲暴露的K562细胞的凋亡程度和γ - h2ax的积累。同样，原代输卵管细胞中WT1的靶向基因缺失不会增加γ - h2ax的水平。我们的研究结果将WT1定位为细胞凋亡过程的下游靶点，该过程发生在对复制应激和DNA损伤的细胞毒性形式的反应中。
A remaining expression of the transcription factor Wilms tumor 1 (WT1) after cytotoxic chemotherapy indicates remaining leukemic clones in patients. We determined the regulation and relevance of WT1 in leukemic cells exposed to replicative stress and DNA damage. To induce these conditions, we used the clinically relevant chemotherapeutics hydroxyurea and doxorubicin. We additionally treated cells with the pro-apoptotic kinase inhibitor staurosporine. Our data show that these agents promote apoptosis to a variable extent in a panel of 12 leukemic cell lines and that caspases cleave WT1 during apoptosis. A chemical inhibition of caspases as well as an overexpression of mitochondrial, anti-apoptotic BCL2 family proteins significantly reduces the processing of WT1 and cell death in hydroxyurea-sensitive acute promyelocytic leukemia cells. Although the reduction of WT1 correlates with the pharmacological efficiency of chemotherapeutics in various leukemic cells, the elimination of WT1 by different strategies of RNA interference (RNAi) does not lead to changes in the cell cycle of chronic myeloid leukemia K562 cells. RNAi against WT1 does also not increase the extent of apoptosis and the accumulation of γH2AX in K562 cells exposed to hydroxyurea. Likewise, a targeted genetic depletion of WT1 in primary oviduct cells does not increase the levels of γH2AX. Our findings position WT1 as a downstream target of the apoptotic process that occurs in response to cytotoxic forms of replicative stress and DNA damage.