The Anti-Lung Squamous Cell Carcinoma Effects And Mechanism Of Ginsenoside Rk1

In recent years,ginsenosides have been widely used in the treatment of malignant tumors as a natural product.Ginsenoside is an active ingredient of Panax species and has various pharmacological effects such as anti-oxidation,anti-tumor and neuroprotection.Ginsenosides were divided into two categories:common ginsenosides and rare ginsenosides.Rare ginsenosides can be obtained by degrading a partial glycosyl group of common ginsenosides or changing its side chain structure,and the pharmacological activity is stronger than that of common ginsenosides.Ginsenoside Rk1 is a rare ginseng saponin obtained by high temperature cooking of Panax notoginseng and?-glucosidase conversion.At present,the method for obtaining ginsenoside Rk1 is relatively complicated,and there are relatively few studies on anti-tumor related thereto,especially lung squamous cell carcinoma.Therefore,this study is the first to study the anti-lung squamous cell carcinoma of ginsenoside Rk1,and further explore the mechanism of apoptosis.1.The inhibitory effect of ginsenoside Rk1 on lung squamous cell carcinoma cells SK-MES-1 and H226 and normal lung epithelial cell Bease-2b was studied by MTT cytotoxicity assay.The effect of ginsenoside Rk1 on the cloning ability of SK-MES-1and H226 cells was observed by cell colony assay.The results showed that ginsenoside Rk1 can effectively inhibited the proliferation of lung squamous carcinoma cells,but has little effect on Bease-2b cells.At the same time,it was found that ginsenoside Rk1significantly inhibited the formation of cloned colonies of SK-MES-1 and H226 cells.2.A xenograft model of lung squamous cell carcinoma SK-MES-1 cells was established and treated by gastric infusion.The correlation between the inhibition of tumor models and ginsenoside Rk1 was measured by the two indicators of body weight and tumor volume of nude mice and histopathology of major organs?kidney,liver,heart,spleen,lung?.Through the analysis of experimental data,the growth of nude mice tumors was significantly inhibited by ginsenoside Rk1,which had no significant effect on the body weight of mice,and had low toxic side effects.3.The effects of ginsenoside Rk1 on the cycle and apoptosis of SK-MES-1 and H226lung squamous cell carcinoma cells were studied by cell cycle analysis,Hoechst 33342staining,Annexin V/PI staining,JC-10 staining,western blot and IHC.The results showed that ginsenoside Rk1 could blocked the cell cycle of SK-MES-1 and H226 in G1phase and induced apoptosis of lung squamous carcinoma cells through Caspase endogenous apoptosis pathway.4.The effects of ginsenoside Rk1 on the endoplasmic reticulum and Ca²⁺signaling pathway were investigated by Fluo-3/AM staining,Rhod-2/AM staining and western blot analysis.The results showed that ginsenoside Rk1 induced endoplasmic reticulum stress,which leaded to the released of calcium ions and the increased of intracellular Ca²⁺,which in turn stimulated the Ca²⁺-related apoptosis pathway.Further studies have found that ginsenoside Rk1-induced apoptosis was attenuated by IP3R channel inhibitors,calcium ion chelators and Calpain inhibitors.In summary,the related research on anti-lung squamous cell carcinoma indicated that ginsenoside Rk1 induced endoplasmic reticulum stress in lung squamous cell carcinoma,leaded to calcium ion outflow in the endoplasmic reticulum,caused intracellular calcium ion overload,and then activated calcium-mediated apoptotic pathways.