| Background: Esophageal cancer,one of the most common malignancies in the world,has a high fatality rate and causes over 400,000 deaths each year.The distribution of population and age,gender,occupation,race,geography,living environment,eating habits,genetic susceptibility have a certain relationship with esophageal cancer occurs.eating habits are considered the most relevant factor in the pathogenesis of esophageal cancer,including: excessive fasting food,long-term dry and hard food stimulation or excessive moldy food intake.The current main treatment methods include surgery,radiotherapy,chemotherapy and targeted therapy.Surgical resection is still the main treatment,but 5-year overall survival rate is only about 30%,of which about 20%-50% due to squamous cell carcinoma.The main limitations of surgical treatment include local recurrence and metastasis,postoperative immune function decline.At the same time,due to the lack of typical clinical symptoms of early esophageal cancer,most patients are in advanced stages when determining the clinical diagnosis.It has been reported that about 40%-60% of patients can not be treated by surgery because of late or high-risk patients.Traditional chemotherapy drugs for the treatment of esophageal cancer is not ideal,in recent decades with appearance of cisplatin and fluorouracil derivatives,nedaplatin,Xeloda,irinotecan and other new drugs provided more options for the chemotherapy of esophageal cancer,they have played a positive role in clinical applications.Radiotherapy is one of the best treatment options for patients with locally advanced disease.Since RTOG8501,radiotherapy combined with chemotherapy has become the best treatment option for patients with non-surgical esophageal cancer.The study of new combination therapy and the search for new drugs for the treatment of esophageal cancer is still of great significance.Ginseng is a precious Chinese herbal medicine in China,and ginsenosides are the main components of its pharmacological effects.Ginsenoside Rg5 belongs to the original ginseng diol ginsenosides,has been shown to have significant antioxidant,neuroprotective effects,immune enhancement.At the same time,it has been provedthat it has significant anti-tumor activity to breast cancer and esophageal cancer,but there are few researches on the function and mechanism of esophageal cancer cells.Currently,cisplatin is the most widely used anti-cancer drug,about 70-80% of the chemotherapy regimens include cisplatin.The drug inhibits DNA synthesis by crosslinking the intra-chain chains with nuclear DNA,while protein and RNA synthesis are also inhibited.However,It showed significant nephrotoxicity,nausea and vomiting and bone marrow suppression and other adverse reactions in the clinical application which greatly limits the application of cisplatin.To improve the efficacy of drugs and reduce the side effects of treatment is important in clinical work.Objective: To study the mechanism of ginsenoside Rg5 on the apoptosis of human esophageal cancer cell line Eca-109 and to investigate the effect of cisplatin combined with ginsenoside Rg5 on the proliferation of Eca-109 cells and its mechanism of interaction.Methods: The effect of ginsenoside Rg5 and cisplatin on the proliferation of Eca-109 cells was detected by CCK8 assay.The apoptosis of Eca-109 cells treated with ginsenoside Rg5 and cisplatin was detected by flow cytometry.Eca-109 cells were treated with different concentrations of ginsenoside Rg5.The changes of mitochondrial membrane potential were detected by flow cytometry.The changes of free calcium in cytoplasm were observed by confocal microscopy with fluorescent probe.Western blot was used to detect the changes of caspase 3,caspase 8,caspase 9,Bcl-2,p-Akt and other apoptosis proteins.Results: 1.Within a certain range,Ginsenoside Rg5 and Cisplatin and inhibit the Growth of Eca-109 Cells in a dose-dependent manner.2.With the increase of ginsenoside Rg5 concentration,the mitochondrial membrane potential of Eca-109 cells decreased and the concentration of cytoplasmic free calcium increased(P <0.05).It indicates that the pro-apoptotic effect of ginsenoside Rg5 acts through the mitochondrial and death receptor pathways.3.The results of Western blot showed that the expression of c-caspase 3,c-caspase 8 and c-caspase 9 increased and the expression of Bcl-2 and p-Akt decreased after Ginsenoside Rg5 treatment(P<0.05).4.Inhibition of proliferation and promotion of apoptosis in cells treated withginsenoside Rg5 combined with cisplatin were greater than a single drug,and showed an additive effect(P<0.05).5.The expressions of c-caspase 3,c-caspase 8 and c-caspase 9 in cells treated with ginsenoside Rg5 combined with cisplatin were higher than those in the drug alone,and the expressions of Bcl-2 and p-Akt were lower than those in the drug alone.(P<0.05).Conclusion: 1.Ginsenoside Rg5 can promote the apoptosis of esophageal cancer cells by regulating the caspase family and Bcl-2 family proteins,and it is related to the downregulation of p-Akt expression in PI3K/Akt signaling pathway.2.Ginsenoside Rg5 combined with cisplatin can enhance inhibition of proliferation and promotion of apoptosis compared with individual treatment in esophageal cancer cells;3.The additive effect of ginsenoside Rg5 combined with cisplatin is related to decreases of p-Akt and Bcl-2 expression. |
