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ABSTRACT: Background
The ATLANTIC trial reported that higher PD-L1 expression in tumors was involved in a higher objective response in patients with EGFR+/ALK+ non-small cell lung cancer (NSCLC), indicating the possibility of anti-PD-1/PD-L1 therapy as a third-line (or later) treatment for advanced NSCLC. Therefore, the determination of status and regulatory mechanisms of PD-L1 in EGFR mutant NSCLC before and after acquired EGFR-TKIs resistance are meaningful.Methods
The correlation among PD-L1, c-MET, and HGF was analyzed based on TCGA datasheets and paired NSCLC specimens before and after acquired EGFR-TKI resistance. EGFR-TKI resistant NSCLC cells with three well-known mechanisms, c-MET amplification, hepatocyte growth factor (HGF), and EGFR-T790M, were investigated to determinate PD-L1 expression status and immune escape ability. PD-L1-deleted EGFR-TKIs sensitive and resistant cells were used to evaluate the immune escape ability of tumors in mice xenograft models.Results
Positive correlations were found among PD-L1, c-MET, and HGF, based on TCGA datasheets and paired NSCLC specimens. Moreover, the above three resistant mechanisms increased PD-L1 expression and attenuated activation and cytotoxicity of lymphocytes in vitro and in vivo, and downregulation of PD-L1 partially restored the cytotoxicity of lymphocytes. Both MAPK and PI3K pathways were involved in the three types of resistance mechanism-induced PD-L1 overexpression, whereas the NF-kappa B pathway was only involved in T790M-induced PD-L1 expression.Conclusions
HGF, MET-amplification, and EGFR-T790M upregulate PD-L1 expression in NSCLC and promote the immune escape of tumor cells through different mechanisms.
SUBMITTER: Peng S
PROVIDER: S-EPMC6864970 | biostudies-literature | 2019 Nov
REPOSITORIES: biostudies-literature
Peng Shunli S Wang Rong R Zhang Xiaojuan X Ma Yueyun Y Zhong Longhui L Li Ke K Nishiyama Akihiro A Arai Sachiko S Yano Seiji S Wang Wei W
Molecular cancer 20191120 1
<h4>Background</h4>The ATLANTIC trial reported that higher PD-L1 expression in tumors was involved in a higher objective response in patients with EGFR<sup>+</sup>/ALK<sup>+</sup> non-small cell lung cancer (NSCLC), indicating the possibility of anti-PD-1/PD-L1 therapy as a third-line (or later) treatment for advanced NSCLC. Therefore, the determination of status and regulatory mechanisms of PD-L1 in EGFR mutant NSCLC before and after acquired EGFR-TKIs resistance are meaningful.<h4>Methods</h4> ...[more]