Identification of a novel microRNA profile in pediatric patients with cancer treated with anthracycline chemotherapy.

Anthracycline chemotherapy (AC) is associated with decline in left ventricular ejection fraction (LVEF), yet the mechanisms remain unclear. Although changes in microRNAs (miRs) have been identified in adult cardiovascular disease, miR profiles in pediatric patients with AC have not been well studied. The goal of this study was to examine miR profiles (unbiased array) in pediatric patients with AC compared with age-matched referent normal patients. We hypothesize that pediatric patients with AC will express a unique miR profile at the initiation and completion of therapy and will be related to LVEF. Serum was collected in pediatric patients (10-22 yr, n = 12) with newly diagnosed malignancy requiring AC within 24-48 h after the initiation of therapy (30-60 mg/m2) and ~1 yr after completing therapy. A custom microarray of 84 miRs associated with cardiovascular disease was used (quantitative RT-PCR) and indexed to referent normal profiles (13-17 yr, n = 17). LVEF was computed by cardiac MRI. LVEF fell from AC initiation at ~1 yr after AC completion (64.28 ± 1.78% vs. 57.53 ± 0.95%, respectively, P = 0.004). Of the 84 miRs profiled, significant shifts in 17 miRs occurred relative to referent normal ( P ≤ 0.05). Moreover, the functional domain of miRs associated with myocardial differentiation and development fell over threefold at the completion of AC ( P ≤ 0.05). Moreover, eight miRs were significantly downregulated after AC completion in those patients with the greatest decline in LVEF (≥10%, P < 0.05). This study demonstrates, for the first time, that changes in miR expression occur in pediatric patients with AC. These findings suggest that miRs are a potential strategy for the early identification of patients with AC susceptible to left ventricular dysfunction. NEW & NOTEWORTHY Although anthracycline chemotherapy (AC) is effective for a number of pediatric cancers, an all too often consequence of AC is the development of left ventricular failure. The present study identified that specific shifts in the pattern of microRNAs, which regulate myocardial growth, function, and viability, occurred during and after AC in pediatric patients, whereby the magnitude of this shift was associated with the degree of left ventricular failure.

Use of integrated imaging and serum biomarker profiles to identify subclinical dysfunction in pediatric cancer patients treated with anthracyclines.

BACKGROUND: Anthracycline induced cardiomyopathy is a major cause of mortality and morbidity among pediatric cancer survivors. It has been postulated that oxidative stress induction and inflammation may play a role in the pathogenesis of this process. Accordingly, the present study performed an assessment of biomarker profiles and functional imaging parameters focused upon potential early determinants of anthracycline induced cardiomyopathy. METHODS: Patients (10-22 years) were prospectively enrolled between January 2013 and November 2014. Thirteen subjects completed the study and underwent serial cardiac magnetic resonance imaging and plasma biomarker profiling performed 24-48 h after the first anthracycline dose and at set dose intervals. In addition, we collected plasma samples from 62 healthy controls to examine normal plasma biomarker profiles. RESULTS: Left ventricular ejection fraction (LVEF) decreased from 64.3 ± 6.2 at the first visit to 57.5 ± 3.3 (p = 0.004) 1 year after chemotherapy. A decline in longitudinal strain magnitude occurred at lower cumulative doses. A differential inflammatory/matrix signature emerged in anthracycline induced cardiomyopathy patients compared to normal including increased interleukin-8 and MMP levels. With longer periods of anthracycline dosing, MMP-7, a marker of macrophage proteolytic activation, increased by 165 ± 54% whereas interleukin-10 an anti-inflammatory marker decreased by 75 ± 13% (both p < 0.05). MMP7 correlated with time dependent changes in EF. CONCLUSIONS: Asymptomatic pediatric patients exposed to anthracycline therapy develop abnormal strain parameters at lower cumulative doses when compared to changes in EF. A differential biomarker signature containing both inflammatory and matrix domains occur early in anthracycline treatment. Dynamic changes in these domains occur with increased anthracycline doses and progression to anthracycline induced cardiomyopathy. These findings provide potential prognostic and mechanistic insights into the natural history of anthracycline induced cardiomyopathy. TRIAL REGISTRATION NUMBER: NCT03211520 Date of Registration February 13, 2017, retrospectively registered.