In epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC), acquired resistance to EGFR tyrosine kinase inhibitors (TKI) leads to disease progression. Strategies to overcome the resistance are required in treatment for advanced lung cancer. In this study, we investigated the therapeutic effect of afatinib and HangAmDan-B1 (HAD-B1) co-administration in gefitinib-resistant NSCLC using HCC827-GR, NSCLC cell line with gefitinib resistance, and the HCC827-GR cell implanted mouse model. HAD-B1 consists of 4 herbs, Panax notoginseng Radix, Cordyceps militaris, Panax ginseng C. A. Mey, and Boswellia carteri Birdwood, and has been reported to be effective in patients with advanced lung cancer in clinical practice. Our findings demonstrated that HAD-B1 combined with afatinib markedly inhibited cell proliferation and induced apoptosis compared to afatinib monotherapy and HAD-B1 monotherapy. Inhibition of HCC827-GR cell proliferation by HAD-B1 occurred through MET amplification and reduced phosphorylation, and the synergistic effect of afatinib and HAD-B1 induced cell cycle arrest and apoptosis in HCC827-GR cells via the downregulation of ERK and mTOR signaling pathways. In hematology and biochemistry tests, HAD-B1 alleviated the toxicity of tumor. In conclusion, HAD-B1 combined with afatinib would be a promising therapeutic strategy for NSCLC with EGFR-TKI resistance.
Keywords: EGFR-TKI; ERK; HCC827-GR; HangAmDan-B1; afatinib; mTOR.