Nutlin-3 up-regulates the expression of Notch1 in both myeloid and lymphoid leukemic cells, as part of a negative feedback antiapoptotic mechanism
Nutlin-3 up-regulates the expression of Notch1 in both myeloid and lymphoid leukemic cells, as part of a negative feedback antiapoptotic mechanism
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DOI：
10.1182/blood-2008-11-187708
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发表时间：
2009-04-30
期刊：
影响因子：
20.3
通讯作者：
Zauli, Giorgio
中科院分区：
文献类型：
--
作者：
Secchiero, Paola;Melloni, Elisabetta;Zauli, Giorgio
MDM 2/p53相互作用的小分子抑制剂Nutlin-3显著上调TP 53（野生型）（OCI，SKW6.4）中Notch 1的稳态mRNA和蛋白水平，但在TP 53（缺失型）（HL-60）或TP 53（突变型）（BJAB）白血病细胞系中不上调。在用针对p53的siRNA进行的实验中，获得了NOTCH 1是白血病细胞中p53的转录靶标的直接证明。此外，使用Notch 1特异性siRNA抑制Notch 1表达显著增加了TP 53（野生型）白血病细胞的细胞毒性。值得注意的是，Nutlin-3也在原代TP 53（野生型）B-慢性淋巴细胞白血病（B-CLL）细胞中上调Notch 1表达，并且Nutlin-3加上Notch信号传导的药理学γ-分泌酶抑制剂的组合使用在TP 53（野生型）白血病细胞系和原代B-CLL细胞中显示协同细胞毒性。γ-分泌酶抑制剂的一个潜在缺点是它们能够增强RANKL + M-CSF诱导的正常循环前破骨细胞的骨细胞成熟。尽管如此，Nutlin-3完全抑制破骨细胞生成，而不管是否存在γ-分泌酶抑制剂。总之，这些数据表明Notch 1响应Nutlin-3的p53依赖性上调代表了能够抑制Nutlin-3在血液恶性肿瘤中的潜在治疗功效的抗凋亡反馈机制。因此，Nutlin-3 + γ-分泌酶抑制剂的治疗组合可能增强Nutlin-3在p53（野生型）白血病细胞中的细胞毒性。（血。2009; 113：4300-4308）
The small molecule inhibitor of the MDM2/p53 interaction Nutlin-3 significantly upregulated the steady-state mRNAand protein levels of Notch1 in TP53(wild-type) (OCI, SKW6.4) but not in TP53(deleted) (HL-60) or TP53(mutated) (BJAB) leukemic cell lines. A direct demonstration that NOTCH1 was a transcriptional target of p53 in leukemic cells was obtained in experiments carried out with siRNA for p53. Moreover, inhibition of Notch1 expression using Notch1-specific siRNA significantly increased cytotoxicity in TP53(wild-type) leukemic cells. Of note, Nutlin-3 up-regulated Notch1 expression also in primary TP53(wild-type) B-chronic lymphocytic leukemia (B-CLL) cells and the combined use of Nutlin-3 plus pharmacological gamma-secretase inhibitors of the Notch signaling showed a synergistic cytotoxicity in both TP53(wild-type) leukemic cell lines and primary B-CLL cells. A potential drawback of gamma-secretase inhibitors was their ability to enhance osteoclastic maturation of normal circulating preosteoclasts induced by RANKL + M-CSF. Notwithstanding, Nutlin-3 completely suppressed osteoclastogenesis irrespective of the presence of gamma-secretase inhibitors. Taken together, these data indicate that the p53-dependent up-regulation of Notch1 in response to Nutlin-3 represents an antiapoptotic feedback mechanism able to restrain the potential therapeutic efficacy of Nutlin-3 in hematologic malignancies. Therefore, therapeutic combinations of Nutlin-3 + gamma-secretase inhibitors might potentiate the cytotoxicity of Nutlin-3 in p53(wild-type) leukemic cells. (Blood. 2009; 113: 4300-4308)