Entervention On Polβ Of Ec9706/cDDP Cells By AE

Esophageal cancer is a malignant tumor originated in the esophageal epithelium, squamous cell carcinoma is more common in clinical. In recent years, adenocarcinoma, undifferentiated carcinoma, and other types of cancer are increasing. This disease is common in many regions all over the world. In some provinces of China led by Henan, Hebei,and some local areas in Jiangsu, Shanxi, Shaanxi and other provinces, the number of new cases and deaths in various typesof malignant tumors, the esophagus have been living high and threated people’s health living greatly, and became a major psychological and economic burden of illness and their family members. Based on the nontypical early symptomsof esophageal cancer, it is often obtained clinical intervention at the disease progression period, treatment becomes a single, which makes the chemotherapy intreating this disease is increasingly prominent. However, resistance to chemotherapy drugs is gradually gaining people’s attention in recent years.It also becamethe main factors that influence the sustainable and effective treatment.The cause of tumor cells’ low reactivity to the drug is diverse and complicated, in recent years, the researchers gradually discovered and focused on the abnormal expression of DNA polymerase β (polβ) in drug-resistant tumor cells.It also providesa new direction of overcoming drug resistance besides the development of newdrugs, to find resistance reversal agents. The researchers at home and abroad has conducted extensive research to western medicine reversal agents, but the difficulty to overcome the normal tissue toxicity and new drug development technical difficulty and high cost, serious limits its development. Based on a wide range of anti-tumor applications, and multi-target effects of low toxicity and other characteristics, people has gradually poisoned their research direction on naturalChinese herbal medicine, astragalus is one of them.Objective: Astragalus is one of the most common traditional Chinese medic ine, with many kinds of ways of anti-tumor mechanism, much attention has been paid to its antitumor pharmacology research and reverse experiment. This project adopts the technology of modern experimental medicine study of Ec9706/cDDP cell line and quantify the specific experimental indexes to observe the changes of polβ gene expression level in the experimental group and discuss the relationship between the effectively improvement of the sensitivity to chemotherapy in esophageal cancer chemotherapy drug resistance cells and the changes of polβ expression after the intervention of Astragalus extract (AE), in order to expand the research methods of traditional Chinese medicine to reverse drug resistance, and provide some experimental evidence of pharmacological for the reversal of tumor resistance by traditional Chinese medicine.Methods:①Ec9706/cDDP cell lines were cultured in RPMI-1640medium withDDP; With a determined by MTT method to detect the cell toxicity intensity of AE toparticipate in the experimental, make sure no cytotoxicity of reversing drug resistancetest required concentration;detecting cell viability with and without AE after48hculturing by MTT, two sets of experimental data for linear regression to determinethe half inhibitory concentration (IC50) of each group to further experimental datacalculate the control group and test group, namely, relation between multiple of reversemultiples.②The cells were divided into two groups, the experimental group cell lineswere intervened with AE, by RT-PCR method to detect the expression level of eachpolβ.③statistical data were processed using the statistical software SPSS17.0, data±S said, IC50calculated by linear regression method, using t test to compare thestatistical difference between the data of the two groups.Results:①Astragalus extract up to a certain concentration showed certaincytotoxic effect in Ec9706/cDDP, and the intensity of the role is positively relatedwith the concentration of AE.Under10μg/mL and the concentration of inhibition ratelow dose group compared with control group to show no significant difference (P>0.05), AE100μg/mL group and higher concentration of inhibition rate reached18.8%and30.9%, compared with control group to carry on the t test, statistically significantdifference.(P＜0.05). So choose10μg/mL reversed as the best non-toxicconcentrations AE experimental concentration.②The IC50is42.49μg/mL onEc9706/cDDP of DDP alone, AE acellular toxic dose of10μg/mL application jointlywith DDP, half inhibitory concentration decreased to25.17μg/mL, the difference is1.69times.③By RT-PCR method to detect the expression level of polβ in the two groups of cells, the control group9out of10samples for high level expression, a lowlevel expression;Experimental group2out of10samples for high level expression, theremaining eight for low level expression.Statistical comparison analysis of two groupsof experimental data, polβ expression level significant difference, statisticallysignificant (P <0.05).Conclusion:①AE has cell cytotoxicity in the Ec9706/cDDP lines and its toxicityassociated with the AE concentration.②With separate application of DDP, IC50ofdrug-resistant cell lines is42.49μg/mL,10μg/mL cytotoxic doses of AE and DDPcombination, IC50dropped to25.17μg/mL, reversing a multiple of1.69. Show AEcan partially reverse the resistant to DDP of the Ec9706/cDDP.③RT-PCR was used todetect the expression levels of two groups of cells polβ, gene expression levels in theexperimental group were significantly decreased, indicating that AE within a certainrange of concentrations can reduce the gene expression levels of Ec9706/cDDP polβ,This is perhaps the related targets for AE to improve the chemotherapy sensitivity ofthe experimental cell lines.