CONGRESS ABSTRACT

Background: Combining anthracyclines and trastuzumab is highly effective in treating HER2-positive breast cancer but significantly increases the risk of cardiotoxicity. The sequential approach is often preferred, where anthracyclines are given first, followed by trastuzumab, with careful monitoring of heart function. Purpose: We report for the first time the cardioprotective effects of Dapagliflozin against anthracycline and HER-2 blocking agents cardiotoxicity in preclinical models. Methods:  C57Bl/6 mice were untreated (Sham, n = 6) or treated for 10 days with doxorubicin-HER-2 blocking agent (DOXO-TRA, n = 6), Dapagliflozin (DAPA, n = 6) or doxorubicin-trastuzumab combined to DAPA (DOXO-TRA-DAPA, n = 6). DOXO and TRA were injected intraperitoneally. Ferroptosis and xanthine oxidase were studied before and after treatments. Cardiac function studies, including EF, FS and radial/longitudinal strain were analysed through transthoracic echocardiography (Vevo 2100). Cardiac and renal fibrosis and apoptosis were histologically studied through Picrosirius red and TUNEL assay, respectively and quantified through pro-collagen-1α1, MMP-9 and Caspase-3 expression. Cardiac and renal expression of NLRP3, MyD88, IL1, IL-6 and pAMPK were analyzed through immunohistochemistry. Moreover, pro-inflammatory studied were also performed (activation of NLRP3; expression of TLR4/MyD88; mTORC1 Fox01/3a; transcriptional activation of p65/NF-κB and expression of cytokines involved in cardiotoxicity (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL17-α, IFN-γ, TNF-α, G-CSF, GM-CSF). Results: In preclinical study, DAPA increased EF and FS compared to DOXO-TRA groups (p < 0.001), prevented the reduction of radial and longitudinal strain. Significant reductions in ferroptosis, xanthine oxidase expression, cardiac fibrosis and apoptosis in DAPA associated to DOXO-TRA were also seen. Histological studies confirmed reduced staining of NLRP3, MyD88, IL1, IL-6 and increased in pAMPK in DOXO-TRA-DAPA group vs DOXO-TRA. A reduced expression of pro-inflammatory cytokines and NF-kB in heart  kidneys was also seen in DOXO-TRA-DAPA group compared to DOXO-TRA (p < 0.001). Conclusion:  The overall picture of the study warrent on the use of dapagliflozin in primary prevention of doxorubicin-trastuzumab induced cardiovascular events in cancer patients.