目的:致癌因子ZNF217促进侵袭性雌激素受体(ER)+乳腺癌疾病,提示其抑制可能在临床上有用。不幸的是,没有直接的药物抑制剂可用。富马酸二甲酯(DMF)具有抗乳腺癌活性,体外和临床前体内模型。它的治疗益处源于细胞硫醇的共价修饰,如蛋白质半胱氨酸,但是介导其抗乳腺癌作用的分子靶标的全部特征仍有待确定。
方法:用DMF处理ER+乳腺癌细胞,然后进行半胱氨酸指导的蛋白质组学。使用具有调节的ZNF217水平的细胞来探测DMF的功效。
结果:通过使用DMF-化学探针证实通过蛋白质组学鉴定的DMF对ZNF217的共价修饰。DMF对ZNF217转录活性的抑制在报道的ZNF217靶基因上是明显的。ZNF217作为癌基因已被证明可以增强茎样特性,生存,扩散,和入侵。与ZNF217抑制一致,DMF在具有升高的ZNF217表达的细胞中更有效地阻断这些ZNF217驱动的表型。此外,部分敲除ZNF217导致DMF的疗效降低。在具有升高的ZNF217表达的MCF-7HER2细胞的异种移植模型中评估DMF的体内活性,并且DMF处理导致肿瘤生长的显著抑制。
结论:这些数据表明,DMF在ER+HER2+模型中的抗乳腺癌活性,至少在某种程度上,是由于ZNF217的抑制。DMF被鉴定为ZNF217的新共价抑制剂。
OBJECTIVE: The oncogenic factor ZNF217 promotes aggressive estrogen receptor (ER)+breast cancer disease suggesting that its inhibition may be useful in the clinic. Unfortunately, no direct pharmacological inhibitor is available. Dimethyl fumarate (DMF) exhibits anti-breast cancer activities, in vitro and in pre-clinical in vivo models. Its therapeutic benefits stem from covalent modification of cellular thiols such as protein cysteines, but the full profile of molecular targets mediating its anti-breast cancer effects remains to be determined.
METHODS: ER+breast cancer cells were treated with DMF followed by cysteine-directed proteomics. Cells with modulated ZNF217 levels were used to probe the efficacy of DMF.
RESULTS: Covalent modification of ZNF217 by DMF identified by proteomics was confirmed by using a DMF-chemical probe. Inhibition of ZNF217\'s transcriptional activity by DMF was evident on reported ZNF217-target genes. ZNF217 as an oncogene has been shown to enhance stem-like properties, survival, proliferation, and invasion. Consistent with ZNF217 inhibition, DMF was more effective at blocking these ZNF217-driven phenotypes in cells with elevated ZNF217 expression. Furthermore, partial knockdown of ZNF217 led to a reduction in DMF\'s efficacy. DMF\'s in vivo activity was evaluated in a xenograft model of MCF-7 HER2 cells that have elevated expression of ZNF217 and DMF treatment resulted in significant inhibition of tumor growth.
CONCLUSIONS: These data indicate that DMF\'s anti-breast cancer activities in the ER+HER2+models, at least in part, are due to inhibition of ZNF217. DMF is identified as a new covalent inhibitor of ZNF217.