Abstract:Objective: To explore the effect of Ray cartilage glycosaminoglycans(RCG) on the expression of MMP-9 in Lewis lung carcinoma of mice.Method: The model of mice with Lewis lung carcinoma was induced.The experimental mice were randomly divided into normal saline group,RCG groups at varied concentrations and CTX group.Tumor growth state was observed,and tumor inhibitory rate of primary tumor and number of lung metastasis focus were measured.The expression of MMP-9 mRNA and protein in Lewis lung carcinoma was determined with RT-PCR and Western blot.Result: As compared with normal saline group,tumor growth curves in RCG groups were smooth,there were significant differences of inhibitory rates of primary tumor and number of lung metastasis focus between RCG groups and normal saline group,and MMP-9 mRNA and protein expression levels in RCG groups were reduced significantly.Conclusion: RCG can inhibit effectively the growth and metastasis of implanted Lewis lung carcinoma in C57BL/6 mice,which is probably attributed to reducing the expression of MMP-9 mRNA and protein.