Voges Yvonne, Michaelis Martin, Rothweiler Florian, Schaller Torsten, Schneider Constanze, Politt Katharina, Mernberger Marco, Nist Andrea, Stiewe Thorsten, Wass Mark N, Rödel Franz, Cinatl Jindrich
Institut für Medizinische Virologie, Klinikum der Goethe-Universität, Paul Ehrlich-Str. 40, Frankfurt am Main 60596, Germany.
Centre for Molecular Processing and School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK.
Cell Death Dis. 2016 Oct 13;7(10):e2410. doi: 10.1038/cddis.2016.257.
Resistance formation after initial therapy response (acquired resistance) is common in high-risk neuroblastoma patients. YM155 is a drug candidate that was introduced as a survivin suppressant. This mechanism was later challenged, and DNA damage induction and Mcl-1 depletion were suggested instead. Here we investigated the efficacy and mechanism of action of YM155 in neuroblastoma cells with acquired drug resistance. The efficacy of YM155 was determined in neuroblastoma cell lines and their sublines with acquired resistance to clinically relevant drugs. Survivin levels, Mcl-1 levels, and DNA damage formation were determined in response to YM155. RNAi-mediated depletion of survivin, Mcl-1, and p53 was performed to investigate their roles during YM155 treatment. Clinical YM155 concentrations affected the viability of drug-resistant neuroblastoma cells through survivin depletion and p53 activation. MDM2 inhibitor-induced p53 activation further enhanced YM155 activity. Loss of p53 function generally affected anti-neuroblastoma approaches targeting survivin. Upregulation of ABCB1 (causes YM155 efflux) and downregulation of SLC35F2 (causes YM155 uptake) mediated YM155-specific resistance. YM155-adapted cells displayed increased ABCB1 levels, decreased SLC35F2 levels, and a p53 mutation. YM155-adapted neuroblastoma cells were also characterized by decreased sensitivity to RNAi-mediated survivin depletion, further confirming survivin as a critical YM155 target in neuroblastoma. In conclusion, YM155 targets survivin in neuroblastoma. Furthermore, survivin is a promising therapeutic target for p53 wild-type neuroblastomas after resistance acquisition (neuroblastomas are rarely p53-mutated), potentially in combination with p53 activators. In addition, we show that the adaptation of cancer cells to molecular-targeted anticancer drugs is an effective strategy to elucidate a drug's mechanism of action.
在初始治疗反应后出现耐药性（获得性耐药）在高危神经母细胞瘤患者中很常见。YM155是一种作为生存素抑制剂引入的候选药物。该机制后来受到质疑，取而代之的是DNA损伤诱导和Mcl-1耗竭的观点。在此，我们研究了YM155在具有获得性耐药的神经母细胞瘤细胞中的疗效和作用机制。在对临床相关药物具有获得性耐药的神经母细胞瘤细胞系及其亚系中测定了YM155的疗效。测定了对YM155反应后的生存素水平、Mcl-1水平和DNA损伤形成情况。进行RNAi介导的生存素、Mcl-1和p53耗竭，以研究它们在YM155治疗过程中的作用。临床YM155浓度通过生存素耗竭和p53激活影响耐药神经母细胞瘤细胞的活力。MDM2抑制剂诱导的p53激活进一步增强了YM155的活性。p53功能丧失通常会影响针对生存素的抗神经母细胞瘤方法。ABCB1上调（导致YM155外排）和SLC35F2下调（导致YM155摄取）介导了YM155特异性耐药。适应YM155的细胞显示ABCB1水平升高、SLC35F2水平降低以及p53突变。适应YM155的神经母细胞瘤细胞还表现出对RNAi介导的生存素耗竭敏感性降低，进一步证实生存素是神经母细胞瘤中关键的YM155靶点。总之，YM155在神经母细胞瘤中靶向生存素。此外，对于获得性耐药后的p53野生型神经母细胞瘤（神经母细胞瘤很少发生p53突变），生存素可能是一个有前景的治疗靶点，可能与p53激活剂联合使用。此外，我们表明癌细胞对分子靶向抗癌药物产生适应性是阐明药物作用机制的有效策略。
