The Role Of Ang ? Receptor In Adriamycin Induced Cardiomyocyte Toxicity And Its Antitumor Activity

Chemotherapy is one of the malignant tumor treatment in addition to surgery,radiotherapy is the most effective treatment,doxorubicin(DOX)is one of the anthracycline-based drugs,effective and widely used in patients with leukemia,ovarian cancer,endometrial cancer and breast cancer,but its cardiac toxicity is the most important and inevitable due to side effects,the combination in patients with heart disease especially when using anthracycline-based chemotherapy drugs.Therefore,it is an important problem to be solved urgently in the early warning and detection of the cardiotoxicity caused by anthracycline and the timely use of effective measures to protect the myocardium.Renin angiotensin system renin-angiotensin system(RAS)in cardiovascular system play an important role in the process of physical adjustment,it mainly by angiotensin ? instead of the main two Receptor subtypes,angiotensin ? Type1 Receptor(AT1R)and angiotensin ? Type 2 Receptor(AT2R)a combination of mediated.AT1 R and AT2 R play an important role in myocardial cell injury and repair,and are proved to be highly expressed in many malignant tumors,and are closely related to tumor proliferation and apoptosis.Valsartan(VAT)is angiotensin ? receptor antagonist(ARB),as one of the RAS blockers,it have aprotective effect on the myocardial cells,ARB can selectively AT1 receptor on the heart,the walls of blood vessels and the reversal of ventricular reconstruction,improve the functional recovery of the heart.More and more clinical trials have shown that ARB has anti-inflammatory and decreased apoptosis of myocardial cells,and has become a new target for anti-tumor drugs.By building the myocardial cell damage model,this study screened the best doxorubicin concentration and time,to study by valsartan AT1 R and AT2 R in the role of the myocardial cell injury induced by adriamycin,and adriamycin and combination of valsartan in endometrial cancer cells,observe AT1 R and AT2 R gene by RAS/RAF/ERK/BAX/BCL-2 signaling pathways effects on tumor cell proliferation and apoptosis.Part1.Establishment of myocardial cell damage model Objective To study the effect of DOX on myocardial cell injury.Methods DOX was applied to establish the DOX myocardial injury model of H9C2 myocardial cells,CCK-8 method was used to detect the cell survival,Cell apoptosis rate was detected by flow cytometry,the gene of AT1 R and AT2 R m RNA in the cells of H9C2 myocardial cells were detected by RT-PCR.Result The toxicity reaction of the DOX with the increased.concentration of(0.25-16)?mol/L treated H9C2 cells 12 h and 24 h was the dose and time to be lazy.Among them,the 1?mol/L DOX can obviously cause myocardial cell injury in 24 h,and the survival rate of the cells decreased to(75.5 + 5.6)%,and the apoptosis rate of cells reached(11.94 +2.07)%,The expression of AT1 R and AT2 R m RNA in cardiomyocytes increased with DOX dose.Conclusion DOX induced cardiomyocyte injury may be associated with cardiac toxicity.Part2.The protective effect of valsartan on adriamycin induced cardiomyocyte injuryObjective To explore the role of valsartan in inducing myocardial cytotoxicity induced by adriamycin.Methods According to the damage model of H9C2 myocardial cells induced by DOX,The cell viability was detected by CCK-8,and the optimum saturation concentration of valsartan was selected for the experimental group: Control group ? DOX group ? DOX+VAT group ? VAT group,Cell cycle and cell apoptosis rate detected by FCM,The expression of AT1 R,AT2R m RNA and protein in the cells before and after the drug stimulation detected by RT-PCR and WB.Result The effect of H9C2 cell 24 h on the growth of myocardial cells was not significant in the treatment of H9C2 cells with a gradient of(1-20)?mol/L.The survival rate of the cells was increased after the DOX and the different concentrations of VAT at different concentrations,Including 10 ?mol/L VAT preprocessing myocardial cells after 24 h can obviously inhibit 1 ?mol/L DOX cardiac muscle toxicity caused by function,compared with the control performance of elevated cell survival,cell apoptosis rate,cell block in G2 / M phase is given priority to,at the same time,The expression of AT1 R m RNA and AT1 R protein in cells was down-regulated,AT2 R m RNA and AT2 R protein expression were up-regulated.Conclusion VAT can suppress the myocardial cell injury induced by DOX,protection may be related to its regulation of angiotensin ? receptor system.Part3.The antitumor activity of Ang? receptorObjective Investigate valsartan through AT1R/AT2R/RAS/RAF/ERK/BAX/BCL-2 signal path effects on tumor cell proliferation and apoptosis.Methods The cell inhibition rate was determined by CCK-8 colorimetry,and the optimal concentration of adriamycin and valsartan was screened in four groups: Control group?DOX group?DOX+VAT group?VAT group,Cell cycle and apoptosis rate detected by FCM,High performance liquid chromatography(HPLC)detected the drug concentration of DOX in cells,WB method was used to detect the protein expression of AT1 R,AT2R,RAS,RAF,ERK,BAX and bcl-2 in the cells before and after the stimulation.Result At times than increasing concentration of DOX(0.5-40)?mol/L and VAT(1-500)?mol/L,respectively dealing with endometrial cancer cells(HEC-1 A,ISHIKAWA)24 h effect on tumor cell growth assumes the dosage according to the lazy,with the increase of drug concentration,the inhibition rate increased.After the DOX and VAT of the same IC15,IC30 and IC50 were applied to endometrial cancer cells,the cell survival rate was significantly lower than that of the DOX group and the VAT group alone.5 ?mol/L DOX and 10?mol/L VAT and pretreatment endometrial cancer cells can obviously inhibit the growth of tumor cells,compared with the control performance for the cell survival rate drop,cell apoptosis rate increased,cell block in G0 / G1 phase is given priority to,The expression of AT1 R,RAS,RAF,ERK and BCL--2 in cells was down-regulated,and AT2 R and BAX protein expression were up-regulated.Conclusion VAT can promote tumor cell apoptosis caused by DOX,promoting effect may be related to its regulation of angiotensin ? receptor system.