Effect of the long non-coding RNA CAF on Doxorubicin-induced cardiotoxicity and its possible mechanisms

CHEN Chao; ZHANG Yanhui; WANG Minghui; XU Sheng; LIU Cuiyun; LI Peifeng; WANG Kun

doi:10.3969/j.issn.2095-3097.2018.02.002

Abstract：Objective Doxorubicin (DOX) as a chemotherapeutic drug is widely used to treat a variety of human tumors. However,a major factor limiting its clinical use is its cardiotoxicity. The molecular components and detailed mechanisms regulating DOX-induced cardiotoxicity remain largely unidentified. Thus, we explores the effect of the long non-coding RNA (lncRNA) on DOX-induced cardiotoxicity and its possible mechanisms. Meth-ods LncRNAs expression profles in 2 μmol/L DOX-induced cell samples compared with control group samples were studied by high-throughput microarray. The significantly differentially expressed lncRNAs were verifed by real-time quantitative PCR. Six healthy male 8-week old mice,produced the model of cardiotoxicity in mice by DOX (model group);six healthy C57BL/6J mice were fed with basal diet as control group. Neonatal mouse cardiomyo-cytes were divided in negative control,pcDNA3.1(-)-lncRNA group and si-LnRNA group by their different trans-fection. Cardiotoxicity model and control mice were used to determine the MIEF1 expression using fluorescence quantitative PCR method. Results ①According to the microarray analysis,results of RT-qPCR revealed that one lnc-RNA,we named cardiac apoptosis factor (CAF) was up-regulated significantly in the DOX group (n=4; t=7.79,P<0.01). ②DOX-induced mouse cardiotoxicity model was successfully built. The fluorescence quantitative PCR results showed that compared with the control group,the expression of MIEF1 mRNA in model group was de-creased signifcantly (n=3;t=14.978,P<0.01). The higher the concentration of DOX,the expression of MIEF1 mRNA was signifcantly decreased (n=4; t2 μmol/L=33.423, P<0.01; t4 μmol/L=36.120, P<0.01; t6 μmol/L=40.205,P<0.01). MIEF1 was down-regulated in the CAF-siRNA group (n=4;t=12.909,P<0.01) and up-regulated in the CAF group (n=4;t=33.634,P<0.01). ③Western Blot results showed a significant down regu-lation of expression of MIEF1(n=4;P<0.01) in CAF group and a significant upregulation of expression of MIEF1 (n=4;t=4.892, P<0.01) in CAF-siRNA group compared with negative control group. Conclusion LncRNA CAF is down regulated in the cardiomyocyte and mouse heart in response to DOX treatment. The expression level of MIEF1 was significantly decreased after treatment with DOX. LncRNA CAF directly targets mitochondrial dynamics protein of 51kDa(MIEF1) and suppresses its expression at transcriptional level. Our study identified a novel path-way composed of lncRNA CAF and MIEF1 that mediates DOX cardiotoxicity. This discovery provides a promising therapeutic strategy for cardioprotection.