Curcumin Regulates Drug Resistance Of Esophageal Carcinoma Eca-109/VCR Cells By Regulating P38MAPK Signaling Pathway

With the increase of the incidence of esophageal carcinoma,the multidurg resistance(MDR)phenomenon in chemotherapy is one of the main factors affecting the clinical efficacy of esophageal carcinoma.At present,the mechanism of MDR has not been fully elucidated.Curcumin(Cur)is a natural dietary polyphenol extracted from turmeric and has various pharmacological effects such as anti-oxidation,anti-cancer,anti-inflammatory and anti-microbial activities.Curcumin has been proven to be an effective multidrug resistance reversal agent in recent years.The p38 mitogen-activated protein kinase(p38MAPK)signal transduction pathway regulates the balance between cell survival and cell death and has a direct impact on the development of various cancers.SB203580,a specific inhibitor of p38 MAPK,can effectively reduce the expression of P-glycoprotein(P-gp)in tumor cells and is an effective multidrug resistance reversal agent.However,whether Cur can improve the sensitivity of esophageal carcinoma to chemotherapy drugs and reverse the MDR mechanism of esophageal carcinoma through p38 MAPK signaling pathway remains to be explored.In this study,esophageal carcinoma-resistant Eca-109/VCR cells were used as the research object,and the possible mechanism of curcumin reversing drug resistance was studied by the combination of curcumin and VCR.MTT assay was used to detect the effects of different concentrations of oxaliplatin(OXA),taxol(TAX)and 5-fluorouracil(5-FU)on the proliferation of Eca-109 and Eca-109/VCR in drug-resistant esophageal carcinoma cells.MTT assay was used to detect the effect of different concentrations of VCR on the proliferation of drug-resistant esophageal carcinoma cells Eca-109/VCR,and the reversal effect of Cur(20 μmol/L)on multidrug resistance in Eca-109/VCR cells.Cur group(20 μmol/L),VCR group(2.0 μg/mL),combination group(Cur 20 μmol/L,VCR 2.0 μg/mL)and inhibitor group(p38MAPK signaling pathway inhibitor SB203580: 10,20,40 μmol/mL),after 24 hours of Eca-109/VCR cells:(1)FCM assay for apoptosis rate;(2)RT-PCR analysis of excision repair cross-complementation group 1(ERCC1)mRNA1,p38 MAPK mRNA and multidrug Expression of multidrug resistance-1(MDR1)mRNA;(3)Western blot detection of p38 mitogen-activated protein kinase(p38MAPK)protein and pathway activation of p38 MAPK signal transduction pathway phospho-p38 mitogen-activated protein kinase(p-p38MAPK)protein and its downstream resistance-related target molecule excision repair cross-complementation group 1(ERCC1),the expression of P-gp.The inhibition rate of Cur on Eca-109/VCR cells was dose-dependent,and the inhibition rate of cell proliferation at Cur 20 μmol/L was(8.33±0.12)%.The cell proliferation inhibition rate of VCR combined with Cur was significantly increased,and the reversal resistance multiplicity was 3.57.Cur 20μmol/L,combined with VCR 2.0μg/mL for Eca-109/VCR cells for 24h:(1)Apoptosis rate was(39.53±6.02)%,which was significantly higher than that of VCR alone(P<0.05);(2)Expressions of p38 MAPK mRNA,ERCC1 mRNA and MDR 1 mRNA were lower than those in the VCR group alone(P<0.05).(3)Expression rates of p38 MAPK,p-p38 MAPK,ERCC1 and P-gp protein were significantly lower than those in the VCR group alone(P<0.05).After p48 MAPK signaling pathway inhibitor SB203580(10,20,40 μmol/mL)for 24 h,the expression of p38,p-p38,ERCC1,P-gp protein and the levels of p38,ERCC1 and MDR1 mRNA in Eca-109/VCR cells decreased(P<0.05).These results suggest that Cur reversal of multidrug resistance in esophageal carcinoma cells may be related to down-regulation of p38 MAPK pathway-related ERCC1 mRNA,MDR1 mRNA expression and pathway-related p-p38 MAPK,ERCC1,and P-gp protein expression.