Department of Oncology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Department of Oncology, the Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, China.
Clin Transl Med. 2022 Jun;12(6):e882. doi: 10.1002/ctm2.882.
Targeted drugs have greatly improved the therapeutic outcome of non-small cell lung cancer (NSCLC) patients compared with conventional chemotherapy, whereas about one-third of patients are so far not suitable for targeted therapy due to lack of known driver oncogenes such as a mutated receptor tyrosine kinase (RTK) genes. In this study, we aimed to identify therapeutic targets for this subgroup of NSCLC patients.
We performed genome-wide CRISPR/Cas9 screens in two NSCLC cell lines carrying wild-type TP53 and receptor tyrosine kinase (wtTP53-RTK) genes using a GeCKO v2.0 lentiviral library (containing 123411 sgRNAs and targeting 19050 genes). MAGeCKFlute was used to analyse and identify candidate genes. Genetic perturbation and pharmacological inhibition were used to validate the result in vitro and in vivo.
The Genome-wide CRISPR/Cas9 screening identified MDM2 as a potential therapeutic target for wtTP53-RTK NSCLC. Genetic and pharmacological inhibition of MDM2 reduced cell proliferation and impaired tumour growth in the xenograft model, thus confirming the finding of the CRISPR/Cas9 screening. Moreover, treatment by a selective MDM2 inhibitor RG7388 triggered both cell cycle arrest and apoptosis in several NSCLC cell lines. Additionally, RG7388 and pemetrexed synergistically blocked the cell proliferation and growth of wtTP53-RTK tumours but had limited effects for other genotypes.
We identified MDM2 as an essential gene and a potential therapeutic target in wtTP53-RTK NSCLC via a genome-wide CRISPR/Cas9 screening. For this subgroup, treatment by RG7388 alone or by its combination with pemetrexed resulted in significant tumour inhibition.
与传统化疗相比，靶向药物极大地改善了非小细胞肺癌（NSCLC）患者的治疗效果，然而，由于缺乏已知的驱动癌基因，如突变的受体酪氨酸激酶（RTK）基因，目前约有三分之一的患者不适合进行靶向治疗。在这项研究中，我们旨在为这组 NSCLC 患者确定治疗靶点。
我们使用 GeCKO v2.0 慢病毒文库（包含 123411 个 sgRNA，靶向 19050 个基因），在携带野生型 TP53 和受体酪氨酸激酶（wtTP53-RTK）基因的两种 NSCLC 细胞系中进行了全基因组 CRISPR/Cas9 筛选。使用 MAGeCKFlute 进行分析和鉴定候选基因。在体外和体内进行遗传干扰和药理学抑制实验来验证结果。
全基因组 CRISPR/Cas9 筛选鉴定出 MDM2 是 wtTP53-RTK NSCLC 的潜在治疗靶点。MDM2 的遗传和药理学抑制可减少异种移植模型中的细胞增殖并损害肿瘤生长，从而证实了 CRISPR/Cas9 筛选的结果。此外，选择性 MDM2 抑制剂 RG7388 可在几种 NSCLC 细胞系中引发细胞周期停滞和凋亡。此外，RG7388 和培美曲塞联合使用可协同阻断 wtTP53-RTK 肿瘤的细胞增殖和生长，但对其他基因型的影响有限。
我们通过全基因组 CRISPR/Cas9 筛选鉴定出 MDM2 是 wtTP53-RTK NSCLC 中的必需基因和潜在治疗靶点。对于这一组患者，单独使用 RG7388 或与培美曲塞联合使用可显著抑制肿瘤。
