Huang Shanshan, Long Yaling, Gao Yuan, Lin Wanling, Wang Lei, Jiang Jizong, Yuan Xun, Chen Yuan, Zhang Peng, Chu Qian
Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Exp Hematol Oncol. 2024 Oct 1;13(1):97. doi: 10.1186/s40164-024-00565-9.
Aberrant activation of mesenchymal epithelial transition (MET) has been considered to mediate primary and acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC). However, mechanisms underlying this process are not wholly clear and the effective therapeutic strategy remains to be determined.
The gefitinib-resistant NSCLC cell lines were induced by concentration increase method in vitro. Western blot and qPCR were used to investigate the relationship between MET and vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) signaling pathway. Double luciferase reporter gene and co-immunoprecipitation were used to further reveal the regulation mechanism between MET and VEGF/VEGFR2. The effect of combined inhibition of MET and VEGF/VEGFR2 signaling pathway on the therapeutic sensitivity of EGFR-TKI in gefitinib resistant cell lines with MET aberration was verified ex vivo and in vivo.
We successfully obtained two gefitinib-resistant NSCLC cell lines with EGFR mutation and abnormal activation of MET. We observed that MET formed a positive feedback loop with the VEGF/VEGFR2 signaling, leading to persistent downstream signaling activation. Specifically, MET up-regulated VEGFR2 expression in a MAPK/ERK/ETS1-dependent manner, while VEGF promoted physical interaction between VEGFR2 and MET, thereby facilitating MET phosphorylation. A MET inhibitor, crizotinib, combined with an anti-VEGF antibody, bevacizumab, enhanced the sensitivity of NSCLC cells to gefitinib and synergistically inhibited the activation of downstream signaling in vitro. Dual inhibition of MET and VEGF combined with EGFR TKIs markedly restrained tumor growth in both human NSCLC xenograft models and in an EGFR/MET co-altered case.
Our work reveals a positive feedback loop between MET and VEGF/VEGFR2, resulting in continuous downstream signal activation. Combined inhibition of MET and VEGF/VEGFR2 signaling pathway may be beneficial for reversing EGFR TKIs resistance.
间充质-上皮转化（MET）的异常激活被认为介导了表皮生长因子受体（EGFR）酪氨酸激酶抑制剂（TKIs）对EGFR突变的非小细胞肺癌（NSCLC）的原发性和获得性耐药。然而，这一过程的潜在机制尚不完全清楚，有效的治疗策略仍有待确定。
采用浓度递增法在体外诱导吉非替尼耐药的NSCLC细胞系。采用蛋白质免疫印迹法（Western blot）和实时荧光定量聚合酶链反应（qPCR）研究MET与血管内皮生长因子（VEGF）/VEGF受体2（VEGFR2）信号通路之间的关系。采用双荧光素酶报告基因实验和免疫共沉淀法进一步揭示MET与VEGF/VEGFR2之间的调控机制。在体外和体内验证联合抑制MET和VEGF/VEGFR2信号通路对MET异常的吉非替尼耐药细胞系中EGFR-TKI治疗敏感性的影响。
我们成功获得了两株具有EGFR突变且MET异常激活的吉非替尼耐药NSCLC细胞系。我们观察到MET与VEGF/VEGFR2信号形成正反馈环，导致下游信号持续激活。具体而言，MET以丝裂原活化蛋白激酶/细胞外信号调节激酶/ETS1依赖的方式上调VEGFR2表达，而VEGF促进VEGFR2与MET之间的物理相互作用，从而促进MET磷酸化。MET抑制剂克唑替尼与抗VEGF抗体贝伐单抗联合使用，可增强NSCLC细胞对吉非替尼的敏感性，并在体外协同抑制下游信号的激活。在人NSCLC异种移植模型和EGFR/MET共同改变的病例中，联合抑制MET和VEGF并联合EGFR TKIs可显著抑制肿瘤生长。
我们的研究揭示了MET与VEGF/VEGFR2之间的正反馈环，导致下游信号持续激活。联合抑制MET和VEGF/VEGFR2信号通路可能有助于逆转EGFR TKIs耐药。
