| Globally,more than one million people die from malignancies every year.Lung cancer is at the forefront of all types of malignancies in terms of morbidity and mortality.Therefore,the current biological and medical circles have done a lot of related research on lung cancer Although there is a certain degree of achievements,no revolutionary progress has been made to break the research bottleneck.It still needs a lot of research and energy to explore its mechanism In recent years,with the many medicinal effects of traditional Chinese medicine extracts being further revealed,the role of traditional Chinese medicine extracts in cancer treatment has received increasing attention.After consulting a large number of references,we observed that cytisine has strong anti-cancer activity due to its unique tetracyclic quinolidine structure,but its effect on lung cancer and its mechanism are not clear.Therefore,this experiment uses a variety of lung cancer cells as the basis for in vitro research,and nude mice and mice as the research object in vivo to explore whether cytisine has anticancer activity on lung cancer and its molecular mechanism.This study hopes to provide a theoretical basis for the application of cytisine and even quinolidine structure alkaloids in anticancer,and to better promote the medical research and development of lung cancerIn this experiment,the CCK-8 test was first used to test whether cytisine has anticancer activity on lung cancer at the cellular level,and the survival rate of lung cancer cells treated with cytisine at different concentrations was tested.Used double staining microscopy and flow cytometry to verify whether cytisine can induce apoptosis in lung cancer cells.Flow cytometry was used to detect cell cycle changes after cytisine treatment at different times.Flow cytometry was used to detect changes in reactive oxygen species in cells after cytisine treatment at different times.Western blot was used to detect the change of cytisine on lung cancer cell apoptosis,cycle and the expression of signal pathway-related proteins.Finally,a nude mouse xenograft model was constructed to detect the inhibition of cytisine on tumors in vivo.Cytisine produces anti-cancer effects on lung cancer cells grown in vitro,and the effect of inhibition of proliferation is proportional to the concentration of treatment,Cytisine inhibited the proliferation of lung cancer cells better than the positive control 5-FU and cisplatin at the same concentration,and there was a significant difference.In addition,from the perspective of toxic and side effects,cytisine has fewer side effects and the difference is statistically significant with 5-FU and cisplatin;Under the condition that the cytisine has an IC50 value,A549 cells undergo mitochondrial-dependent apoptosis,Pro-apoptotic proteins Bad,Cyt-c,and cleaved-Caspase-3 are highly expressed,and Bcl-2 is low-expressed;Under the condition that the cytisine has an IC50 value,Up-regulates the level of reactive oxygen species in A549 cells and inhibits the excessive activation of the AKT signaling pathway,The expression of CyclinBl and CDK1/2 was blocked,and p27 and p21 showed high expression.This causes the A548 cell cycle stagnate in the G2/M phase;Under the condition that the cytisine has an IC50 value,it can increase the level of reactive oxygen species in A549 cells,regulate the expression of MAPK/STAT3/NF-?B pathway proteins,and then activate downstream apoptotic proteins,leading to mitochondrial-dependent apoptosis in cells.Cytisine can inhibit tumor growth in nude mice transplanted with tumors,and its anti-cancer effect in vivo is better than that of the positive control drug 5-FU.Treatment of lung cancer cells with cytisine can increase the level of intracellular reactive oxygen species.On the one hand,it directly induces apoptosis by regulating the MAPK/STAT3/NF-?B pathway;On the other hand,by regulating the AKT signal pathway to regulate the cell cycle,and then play an anti-cancer effect. |
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