(d) The bFGFmAb inhibits the proliferation of A549 and A549/DDP cells. Keywords:Non-small cell lung cancer, cisplatin-resistance, basic fibroblast growth factor monoclonal antibody, epithelial-mesenchymal transition, chemotherapy == Introduction == Lung cancer is the most prevalent cancer type and the leading cause 4′-Methoxychalcone of cancer-related deaths worldwide, responsible for 19.4% of total cancer deaths.1,2Among the different histological types of lung cancer, non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer.3,4Despite great advancement in cancer treatment, platinum-based chemotherapy, like cisplatin, remains the first-line therapy for advanced NSCLC patients that lack targetable mutations.5For patients with high expression of programmed death ligand 1 (PDL-1), 50% or greater, pembrolizumab, an immune checkpoint inhibitor (ICI), 4′-Methoxychalcone has recently replaced cytotoxic chemotherapy as the first-line treatment of choice. However, ICI treatment is not suitable for patients that lack PDL-1 expression,5therefore the cisplatin-based doublet regimen remains the foundation of treatment for the majority of patients with advanced NSCLC.6Intrinsic and acquired drug resistance remains problematic. To enhance the efficacy and to minimize the development of drug resistance, the chemotherapeutic management of NSCLC patients usually involves combining the use of platinum-derived salts (such as cisplatin) with a second or third generation drug such as gemcitabine, pemetrexed, or taxanes.7One of the most 4′-Methoxychalcone challenging issues in the treatment of advanced NSCLC patients is acquired drug resistance, leading to morbidity and mortality of NSCLC patients, despite advancement in chemotherapy and targeted therapy.79Thus, strategies to counter drug resistance and to increase therapeutic efficacy are urgently needed. The molecular mechanisms underlying cisplatin resistance in cancer treatment are not fully understood. The main mechanisms are believed to be associated with a number of factors including induction of anti-apoptotic signals, the active efflux of cisplatin from the cell, tolerance to DNA lesion, epigenetic regulation by microRNAs.10,11Epithelial-to-mesenchymal transition (EMT), a process involving in the transformation of static epithelial cells into mobile mesenchymal cells, is also considered to be a significant factor in chemoresistance CDK4 related to the use cisplatin.12In recent years, increasing studies have shown that EMT plays a key role in the drug resistance of lung cancer. EMT reduced the sensitivity of lung cancer cells to antitumor drugs 4′-Methoxychalcone and produced drug resistance through the regulation of multiple signal pathways. Report by Shintani et al. demonstrated that EMT resulted in increased malignant potential and reduced sensitivity to cisplatin and paclitaxel in NSCLC cells.13Resistance of NSCLC to EGFR TKIs is accompanied by the activation of EMT and downstream PI3K/Akt and MAPK/ERK signaling pathways, suggesting that reversing EMT is expected to reverse the acquired resistance of EGFR TKIs.14Fuchs et al. also demonstrated EMT mediate sensitivity to epidermal growth factor receptor inhibition in human hepatoma cells.15Since bFGF is one 4′-Methoxychalcone of the important factors inducing EMT,16and bFGF protein is highly expressed in patients with malignant tumors.17,18Therefore, targeting bFGF involving in EMT process may become a new strategy for tumor treatment. However, research examining EMT change following bFGF blocking in resistant lung cancer has not been conducted. The basic fibroblast growth factor (bFGF) belongs to the family of heparin-binding growth factors, which mediates a series of cellular responses in embryonic development, haematopoiesis, wound healing, tumor growth, and tumor angiogenesis.19It utilizes heparan sulfate proteoglycans (HSPGs) as binding partners to bind to specific tyrosine kinase transmembrane receptors,.