FRUCTOSE EXACERBATES ANTHRACYCLINE AND HER–2 BLOCKING AGENT MEDIATED CARDIOTOXICITY THROUGH NLRP3 AND MYD88 MEDIATED PATHWAYS: NEW ROLES OF SWEETENERS IN CARDIO–ONCOLOGY

Abstract

Abstract Background Combinatorial therapy based on anthracyclines and HER–2 blocking agents increases the risk of cardiomyopathy in women with breast cancer. Fructose is a monosaccharide associated with high risk of diabetes, non–alcoholic fatty liver disease, atherosclerosis and visceral obesity. A high fructose diet is a potential cardiometabolic risk factor and may increase cardiac risk in women with breast cancer treated with cardiotoxic drugs. Purpose In this study, we highlighted the role of sweeteners fructose in the worsening of cardiotoxicity induced by combinatorial therapy anthracycline–HER2–blocking agents. Methods Human cardiomyocytes were pre–exposed with doxorubicin combined to trastuzumab (at 300 and 1000 nM) for 48 and 72h alone or combined to fructose at 0.25, 1 and 2.5 mM. After the incubation period, we performed the following tests: determination of cell viability, through mitochondrial dehydrogenase activity, study of lipid peroxidation (quantifying cellular Malondialdehyde and 4–hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro–inflammatory studied were also performed (activation of NLRP3 inflammasome; expression of peroxisome proliferator–activated receptor–α; transcriptional activation of p65/NF–κB and secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6, CXCL–12). Results High fructose increases significantly cell mortality of cardiomyocytes exposed to doxorubicin and trastuzumab thorugh the activation of NLRP–3 and Myd–88 expression. Intracellular Ca++ levels were also increased of 4 times compared to non–fructose exposed cardiomyocytes; MDA and 4–HNA levels were increased of 48,3 and 51,2 % compared to non–fructose exposed cells (p<0.001). Fructose increases IL–1, IL–6 and CXCL–12 expression in cardiomyocytes in a concentration dependent manner, compard to doxorubicin–trastuzumab group (p<0.05). Conclusion Data of the present study indicate that fructose induces a pro–inflammatory phenotype in human cardiac cells exposed to anticancer cardiotoxic drugs, providing even more data on the harmful role of fructose as a key player of cardiotoxic phenomena.