Abstract
BACKGROUND: Prior research has identified ANGPTL4 as a key player in the control of the body's lipid and glucose metabolism and a contributor to the onset of numerous cardiovascular conditions. Recently, it has been shown that ANGPTL4 also plays a critical role in tumor growth and progression. Nowadays, the number of EGFR-TKI resistant patients is increasing, and it is important to investigate the role of ANGPTL4 in regulating gefitinib resistance in PC9/GR non-small-cell lung cancer (NSCLC). METHODS: The expression of ANGPTL4 in A549, PC9, H1975, BEAS-2B and PC9/GR cells was verified by Western blot and qRT-PCR assays, and the effect of gefitinib on the proliferative ability of each cell was probed by CCK-8 assay. By using shRNA to inhibit ANGPTL4 expression in cells, the effect of ANGPTL4 on cell migratory ability was examined and the effect of ANGPTL4 on cellular gefitinib sensitivity was confirmed using the CCK-8 assay and the edu proliferation test. Mouse transplantation tumors were constructed, and the effect of ANGPTL4 on cellular gefitinib sensitivity was investigated in vivo by flow cytometry, Tunel staining assay, immunohistochemical staining, and ROS fluorescence staining assay. ANGPTL4 expression in homoRNA overexpression cells was constructed, and the changes in the expression levels of ASC\NLRP3\Caspase 8 pathway and focal and apoptotic proteins were investigated in vitro, in vivo, afterknockdown and overexpression of ANGPTL4 expression by Westen blot assay. RESULTS: ANGPTL4 was highly expressed in PC9/GR cells. Interfering with ANGPTL4 expression resulted in decreased proliferation and migration ability, decreased resistance to gefitinib, and increased scorching and apoptosis in PC9/GR cells. Interfering with ANGPTL4 expression in PC9/GR cells was shown to promote sensitivity to gefitinib and to mediate the NLRP3/ASC/Caspase 8 pathway to induce cell scorching and apoptosis. CONCLUSIONS: ANGPTL4 promotes gefitinib resistance in PC9/GR cells by regulating the NLRP3/ASC/Caspase 8 pathway to inhibit scorch death. ANGPTL4 may be an effective new target for inhibiting EGFR-TKI resistance in lung adenocarcinoma cells.