Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Switzerland.
Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
Mol Oncol. 2018 Jun;12(6):953-971. doi: 10.1002/1878-0261.12307. Epub 2018 May 1.
The absence of biomarkers to accurately predict anticancer therapy response remains a major obstacle in clinical oncology. We applied a genome-wide loss-of-function screening approach in human haploid cells to characterize genetic vulnerabilities to classical microtubule-targeting agents. Using docetaxel and vinorelbine, two well-established chemotherapeutic agents, we sought to identify genetic alterations sensitizing human HAP1 cells to these drugs. Despite the fact that both drugs act on microtubules, a set of distinct genes were identified whose disruption affects drug sensitivity. For docetaxel, this included a number of genes with a function in mitosis, while for vinorelbine we identified inactivation of FBXW7, RB1, and NF2, three frequently mutated tumor suppressor genes, as sensitizing factors. We validated these genes using independent knockout clones and confirmed FBXW7 as an important regulator of the mitotic spindle assembly. Upon FBXW7 depletion, vinorelbine treatment led to decreased survival of cells due to defective mitotic progression and subsequent mitotic catastrophe. We show that haploid insertional mutagenesis screens are a useful tool to study genetic vulnerabilities to classical chemotherapeutic drugs by identifying thus far unknown sensitivity factors. These results provide a rationale for investigating patient response to vinca alkaloid-based anticancer treatment in relation to the mutational status of these three tumor suppressor genes, and could in the future lead to the establishment of novel predictive biomarkers or suggest new drug combinations based on molecular mechanisms of drug sensitivity.
缺乏能够准确预测抗癌治疗反应的生物标志物仍然是临床肿瘤学的一个主要障碍。我们应用全基因组功能丧失筛选方法在人类单倍体细胞中对遗传易感性进行了特征描述，以鉴定对经典微管靶向药物的遗传易感性。我们使用多西紫杉醇和长春瑞滨这两种成熟的化疗药物，旨在确定使人类 HAP1 细胞对这些药物敏感的遗传改变。尽管这两种药物都作用于微管，但我们发现了一组不同的基因，其破坏会影响药物敏感性。对于多西紫杉醇，这包括许多在有丝分裂中具有功能的基因，而对于长春瑞滨，我们鉴定出 FBXW7、RB1 和 NF2 的失活，这三个是经常发生突变的肿瘤抑制基因，是敏感因素。我们使用独立的基因敲除克隆对这些基因进行了验证，并证实 FBXW7 是有丝分裂纺锤体组装的重要调节因子。在 FBXW7 耗尽后，长春瑞滨治疗会导致细胞存活率降低，原因是有丝分裂进展缺陷和随后的有丝分裂灾难。我们表明，单倍体插入诱变筛选是一种有用的工具，可通过鉴定迄今为止未知的敏感性因素来研究对经典化疗药物的遗传易感性。这些结果为研究与这三个肿瘤抑制基因的突变状态相关的长春碱类抗癌治疗患者反应提供了依据，并可能在未来导致建立新的预测性生物标志物，或基于药物敏感性的分子机制提出新的药物组合。
