Attenuation of Sunitinib-induced cardiotoxicity through the A3 adenosine receptor activation.

Sunitinib is an anti-cancer tyrosine kinase inhibitor associated with severe cardiotoxic adverse effects. Using rat Langendorff heart model and human acute myeloid leukaemia 60 (HL60) cell line we detected the involvement of protein kinase C (PKC) α during Sunitinib-induced cardiotoxicity and the effect of Sunitinib on cancer progression. The cardioprotective and anti-cancer properties of the A3 adenosine receptor agonist 2-chloro-N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) were investigated. The cardiac effect of Sunitinib (1µM) and IB-MECA (1nM) treatment was measured through haemodynamic and infarct size assessment. The cytotoxic effect of Sunitinib (0.1 - 10μM) and IB-MECA (10nM - 10μM) on HL60 cells was assessed using the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay technique. Myocardial injury associated microRNAs (miR-1, miR-27a, miR-133a and miR-133b) and cancer associated microRNAs (miR-15a, miR-16-1 and miR-155) were profiled by qRT-PCR in the cardiac tissue and HL60 cells, while phosphorylated PKCα levels were measured by Western Blot analysis. Sunitinib treatment increased infarct size and decreased left ventricular developed pressure and heart rate. Co-treatment of IB-MECA reversed the myocardial injury produced by Sunitinib administration. IB-MECA did not jeopardize the anti-cancer effect of Sunitinib in HL60 cells. The expression signature of the specific microRNAs in cardiac tissue and HL60 cells showed an altered expression profile when treated with Sunitinib and IB-MECA. pPKCα levels were increased by Sunitinib treatment in cardiac tissue and HL60 cells and co-administration of IB-MECA attenuated this increase in the cardiac tissue. This study reveals that A3 adenosine receptor activation by IB-MECA attenuates Sunitinib-induced cardiotoxicity through the involvement of PKCα.