A Comparative Study On Lewis Lung Cancer Cells And Its Derived Cells

ObjectiveBy comparing the biological characteristics among Lewis lung cancer cells (LLC), LLC orthotopic transplantation derivative cells (Round 1-series) and Roundl derivative cells orthotopic transplantation derivative cells (Round2-series), we evaluate their invasion and metastatic abilities in orthotopic and subcutaneous transplantation model.Methods1. Establishment an orthotopic implantation model with Lewis lung cancer.2. Establishment lewis lung carcinoma-derived cell lines.3. In vitro:we applied CCK8, Clonogenic assay, and transwell invasion assay to detect proliferation ability, invasion ability and morphologic structures of derivative cells respectively, meanwhile observing morphologic structures through transmission electron microscope.4. In vivo:we constructed LLC-P, R1- derivative cells and R2-derivative cells orthotopic transplantation models. Herein, we observed their tumor growth and metastasis. The tumor formation rate and tumor-forming time were recorded for statistic analysis. Drug inhibition experiments in C57BL/6 mouse.Results1. In vitro:All cells showed no significant difference in proliferation ability(p>0.05), but significant differences in invasion ability:Round2 derived cell line> Roundl derived cell line> LLC-P (p<0.05).2. In vivo:1) the same number of cells in orthotopic implantation model had a higher rate in metastasis than in subcutaneous implantation model.2) With the increasing cells transplant in situ, the rate of tumor formation was significantly grow higher.3) through multiple passages in vivo, the invasion ability shows:Round2 derived cell line> Roundl derived cell line> LLC-P.4)The effect of chemotherapy with combined cisplatin and paclitaxel was superior to the cisplatin and paclitaxel alone group.ConclusionThrough in vitro and in vivo experiments, we found that with increasing passages in vivo, invasion and metastasis ability of cells are greatly enhanced, and this part of cells, plays a important role in tumor promoting development process. By comparing subcutaneous and orthotopic implantation mouse model, orthotopic implantation model shows that a more accurate simulation of the invasion and metastasis pathways in clinical patients. For further study,the efficacy of drug treatment can be clearly observed in our orthotopic implantation mouse model.