The relationship between mouse lung adenocarcinoma at different stages and the expression level of exosomes in serum

Objective: The purpose of this study is to investigate the relationship between N-methylN'-nitro-N-nitrosoguanidine (MNNG)-induced lung adenocarcinoma mouse of different stages and the level of exosomes in serum. Methods: Fifty KM mice (4 weeks old, weighing 18-22 g, female) were selected for experiment. MNNG was applied to induce lung adenocarcinoma in mice for model establishment. HE staining method was used to observe pathological changes of lung tissues. Exosomes in serum were extracted, and observed under a Transmission Electron Microscopy (TEM). Western blot was employed to examine the protein levels of exosome markers TSG101 and CD63. Results: HE staining results suggested MNNG-induced lung adenocarcinoma model mice were successfully constructed. The morphology of exosomes in serum of mouse model was observed under an Electron Microscopy, showing clear membrane structures presenting as saucer or concave hemisphere. In addition, the protein level of exosome marker CD63 in advanced mouse model was significantly up-regulated relative to that in the control group. Meanwhile, the expression of exosome marker protein TSG101 was found to be markedly increased in mouse models by comparison with that in control cases. Conclusion: In lung adenocarcinoma model mice, the occurrence and development of lung adenocarcinoma are greatly correlated with the expression level of exosomes in serum, which provides theoretical basis for the diagnosis of pathological staging of lung adenocarcinoma by exosomes.