LAUSR

Doxorubicin (DOX)‐induced cardiotoxicity impedes its clinical application, but the mechanisms have not been thoroughly elucidated. Based on circRNA and mRNA expression profiles, we illustrated RNA expression signature changes during DOX‐induced cardiotoxicity; mechanism exploration and biomarkers screening were also conducted. Twelve mice were randomly divided into two groups, induction group was treated with doxorubicin, and the control group was given an equal quantity of saline. After the confirmation of myocardial injury in induction group, the heart tissues from both groups were isolated for RNA high‐throughput sequencing. The expression profiles were compared between the two groups; a total of 295 mRNAs and 11 circRNAs were shown as biased expression in DOX‐induced cardiotoxicity mouse hearts. The dysregulation of three circRNAs were validated by quantitative real‐time PCR: mmu_circ_0015773, mmu_circ_0002106, and mmu_circ_001606. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the differentially expressed RNAs were performed; the results implied that DOX might cause cardiotoxicity by interfering hemoglobin‐based oxygen delivery and DNA‐associated signal pathways. We integrated the differential expressed mRNA and validated circRNAs by constructing a competing endogenous RNA (ceRNA) network, which indicated that the alteration of the three circRNAs could activate apoptosis process of myocardial cells. This study provided novel insight into the mechanisms of DOX induced cardiotoxicity, and potential biomarkers or therapeutic targets were also proposed.