Formation of Gefitinib-Resistant Lung Cancer Cell Lines and their Changes in Epidermal Growth Factor Receptor Signaling Pathway

Lung cancer is one of the top ten malignant tumors, seriously endangering people's lives and health, with morbidity and mortality ranking first. Molecular targeted therapy overcomes the shortcomings of traditional chemotherapy. In recent years, the application of tumor therapy has become wider and wider. Gefitinib is the most successful molecular targeted drug for the treatment of lung cancer in recent years. The purpose of this article is to explore the establishment method of gefitinib-resistant lung cancer cell lines and the mechanism of epidermal growth factor receptor signaling pathway change. The method of gradually increasing the concentration of gefitinib was used to successfully establish NC-H1985 gefitinib-resistant cells. The strains were also analyzed for epidermal growth factor receptor, messenger ribonucleic acid expression at different times. The results show that this cell line has a certain difference compared to the parental NC-H1985 cell. With the extension of the culture time, the ribonucleic acid concentration decreased by 51 % and the 18S ribosomal ribonucleic acid, cycle threshold value increased by 39 %. In addition, the higher the relative expression of messenger ribonucleic acid in gefitinib-resistant lung cancer cells, the epidermal growth factor receptor signaling pathway is likely to change. From 24 h to 72 h, the relative expression of messenger ribonucleic acid has increased by 37.5 %. After gefitinib resistance culture of NC-H1985 gefitinib-resistant cells were 44.1 % in resting phase, 36.9 % in growth 1 phase, 11.4 % in synthesis phase, 4.3 % in growth 2 phase and 3.3 % in mitotic phase.