Medical Research Council (MRC) Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Cambridge CB2 0XZ, United Kingdom.
Department of Oncology, Addenbrooke's Hospital, Cambridge, CB2 0QQ, United Kingdom.
Genes Dev. 2017 Jul 1;31(13):1339-1353. doi: 10.1101/gad.298463.117. Epub 2017 Aug 8.
Lung adenocarcinoma accounts for ∼40% of lung cancers, the leading cause of cancer-related death worldwide, and current therapies provide only limited survival benefit. Approximately half of lung adenocarcinomas harbor mutations in (p53), making these mutants appealing targets for lung cancer therapy. As mutant p53 remains untargetable, mutant p53-dependent phenotypes represent alternative targeting opportunities, but the prevalence and therapeutic relevance of such effects (gain of function and dominant-negative activity) in lung adenocarcinoma are unclear. Through transcriptional and functional analysis of murine - , - (conformational), and - (contact) mutant lung tumors, we identified genotype-independent and genotype-dependent therapeutic sensitivities. Unexpectedly, we found that wild-type p53 exerts a dominant tumor-suppressive effect on mutant tumors, as all genotypes were similarly sensitive to its restoration in vivo. These data show that the potential of p53 targeted therapies is comparable across all p53-deficient genotypes and may explain the high incidence of p53 loss of heterozygosity in mutant tumors. In contrast, mutant p53 gain of function and their associated vulnerabilities can vary according to mutation type. Notably, we identified a -specific sensitivity to simvastatin in lung tumors, and the transcriptional signature that underlies this sensitivity was also present in human lung tumors, indicating that this therapeutic approach may be clinically relevant.
肺腺癌约占肺癌的 40%,是全球癌症相关死亡的主要原因,目前的治疗方法仅提供有限的生存获益。大约一半的肺腺癌存在 (p53) 突变,这使得这些突变体成为肺癌治疗的有吸引力的靶标。由于突变型 p53 仍然无法靶向,因此突变型 p53 依赖性表型代表了替代的靶向机会,但这些效应(获得功能和显性负性活性)在肺腺癌中的普遍性和治疗相关性尚不清楚。通过对小鼠 - 、- (构象)和- (接触)突变肺肿瘤的转录和功能分析,我们确定了基因型独立和基因型依赖的治疗敏感性。出乎意料的是,我们发现野生型 p53 对突变型肿瘤具有显性肿瘤抑制作用,因为所有基因型在体内恢复其功能时都具有相似的敏感性。这些数据表明,p53 靶向治疗的潜力在所有 p53 缺陷基因型中是相当的,这可能解释了突变型肿瘤中 p53 杂合性丢失的高发生率。相比之下,突变型 p53 的获得功能及其相关的脆弱性可能因突变类型而异。值得注意的是,我们在肺肿瘤中发现了一种针对辛伐他汀的 - 特异性敏感性,而这种敏感性所依赖的转录特征也存在于人类肺肿瘤中,表明这种治疗方法可能具有临床相关性。