Establishment of Animal Model of A Human Lung Adenocarcinoma Drug-resistant Cell Line Anip973/NVB and Investigation on Mechanism of Drug Resistance

Background and objective Multidrug resistance (MDR) is the main cause of chemotherapeutic failure in lung cancer, and vinorelbine (NVB) is one of the most efficient drugs that threaten non-small cell lung cancer (NSCLC). The current study aims to establish tumor xenografts and investigate the molecular mechanisms involved in the resistance of NVB in lung adenocarcinoma. Methods Nude mice were implanted with Anip973 and Anip973/NVB, and tumor-bearing mice were divided into the Anip973 treatment, Anip973 control, Anip973/NVB treatment, and Anip973/NVB control groups, respectively. The current study observes tumor growth, draws growth curves, and calculates inhibitory rates. The morphological changes in cell tumor were observed through the immunohistochemical method using an electron microscope to detect the expressions of MRP3 and Bcl-2 and to investigate the molecular mechanisms of Anip973/NVB cells. Results The tumor inhibitory rates of the Anip973 and Anip973/NVB cells treated with NVB were 60.00% and 4.65%, respectively, compared with the control group. The growth inhibition in the Anip973/NVB cell transplantation tumor had no significant difference. Apoptosis was observed using TEM when the Anip973 transplantation tumor was treated with NVB. On the other hand, no apoptosis was found in the Anip973/NVB transplantation tumor using TEM. Immunohistochemical staining (SP) shows the positive expressions of Bcl-2 and MRP3 proteins in Anip973/NVB transplantation tumor, which were observed to be higher than those in the Anip973 transplantation tumor. Conclusion The overexpression of Bcl-2 and MRP3 might be one of the major mechanisms of the MDR of Anip973/NVB.