Doxorubicin and Liposomal Doxorubicin Differentially Affect Expression of miR-208a and let-7g in Rat Ventricles and Atria

Anthracyclines use is limited by profound cardiotoxicity. Involvement of miRNAs in anthracycline-induced cardiotoxicity (AIC) is still not completely understood. Thus, the expression of AIC-related microRNAs was determined in rat atria and ventricles after doxorubicin (DOX) and liposomal doxorubicin (L-DOX) administration. Vehiculum, DOX or L-DOX were applied intraperitoneally in a single dose to male Wistar rats (3 groups: control, DOX and L-DOX, respectively). Rats were sacrificed after 24 h, and samples from left atrium (LA)/ventricle (LV) and right atrium (RA)/ventricle (RV) were obtained. Expressions of miR-208a, let-7g and snU6 were determined using qRT-PCR. In the control group, miR-208a was highly abundant in the atria compared to the ventricles and in the left-sided structures compared to the right-sided structures, while let-7g showed only atrio-ventricular gradient with predominant expression in the atria. Administration of both DOX and L-DOX resulted in 38.87 and 23.57% reduction in miR-208a expression in the LV (p = 0.028) and in 13.79 and 14.70% reduction in let-7g expression in the LA (p = 0.015), respectively. Acute administration of DOX/L-DOX alters expression of miR-208a in LV and of let-7g in LA. These changes may partly contribute to the development of AIC.