Proteomic profile of early subclinical anthracycline cardiotoxicity: the ANT study

Background In clinical trials, neurohormonal inhibitors and sacubitril/valsartan did not consistently prevent asymptomatic cardiac dysfunction caused by anthracycline-containing chemotherapy. Purpose We explored the baseline profile and the early changes of the plasma proteome in patients with vs without biochemical and/or echocardiographic evidence of anthracycline cardiotoxicity. Methods We quantified 460 proteins in plasma samples collected before (T0) and 3 months (T3) after starting anthracycline chemotherapy by using the proximity extension assay technology (Olink). Cancer treatment-related cardiac dysfunction (CTRCD) was defined as a new rise in cardiac biomarkers (hs-TnI >18 ng/l and/or NT-proBNP ≥125 ng/l) and/or a new relative decline in global longitudinal strain (GLS) ≥15% from baseline with left ventricular ejection fraction remaining ≥50%. Plasma protein profile at T0 and its changes at T3 were filtered/normalized and compared between patients with or without CTRCD by means of the 'DaMiRseq' and 'LIMMA' R packages, respectively. Over-representation analysis (ORA) was performed with WebGestalt in order to identify the most informative enriched Reactome pathways. Results 48 patients were included in the study: 27 (56%) had breast cancer and 21 (44%) lymphoma. At T3, 15 subjects (31%, 9 with breast cancer and 6 with lymphoma) had CTRCD. None met the definitions of more severe forms of CTRCD. Compared to patients without CTRCD, those with CTRCD had higher creatinine concentrations and a trend for lower systolic blood pressure, greater GLS, and lower E/A ratio (Fig. 1A). At T0, 49 nominally significant (-log10(P) >2) plasma proteins were downregulated in CTRCD vs no-CTRCD (Fig. 1B). Some were previously linked to anthracycline effects on the heart, such as DECR1 and tenascin (TNC). At T3, 12 proteins were differentially changed from T0 with nominal significance in patients with vs without CTRCD. Most were implicated in inflammation/immunity, including IFN-γ, CXCL9, CXCL10, LAG-3, IL-6, CHI3L1, and KLRD1 (Fig. 1C). Transferrin receptor protein 1 (TFRC), which is necessary for iron import into cells, was downregulated at T0 and upregulated at T3 in patients with CTRCD. ORA revealed that processes related to extracellular matrix organization and vascular injury were downregulated at T0, while pathways related to cell motility, adhesion, and inflammation were upregulated at T3 (Fig. 1D). Moreover, 9 pathways related to immunity and inflammation were downregulated at T0, but upregulated at T3 (Fig. 1D, green frame). Conclusions Although with the limitation of a small sample, we highlight a proteomic signature of early subclinical anthracycline cardiotoxicity indicative of perturbations in inflammation/immunity and, secondarily, iron handling. These processes may be target of new pharmacological approaches to tackle anthracycline-induced CD.