Ranolazine Attenuates Trastuzumab-Induced Heart Dysfunction by Modulating ROS Production

Abstract

The ErbB2 blocker trastuzumab improves survival in oncologic patients, but can cause cardiotoxicity. The late Na+ current inhibitor ranolazine has been shown to counter experimental HF, including doxorubicin cardiotoxicity (a condition characterized by derangements in redox balance), by lowering the levels of reactive oxygen species (ROS). Since ErbB2 can modulate ROS signaling, we tested whether trastuzumab cardiotoxicity could be blunted by ranolazine via redox-mediated mechanisms. Trastuzumab decreased fractional shortening and ejection fraction in mice, but ranolazine prevented heart dysfunction when co-administered with trastuzumab. Trastuzumab cardiotoxicity was accompanied by elevations in natriuretic peptides and matrix metalloproteinase 2 (MMP2) mRNAs, which were not elevated with co-treatment with ranolazine. Trastuzumab also increased cleavage of caspase-3, indicating activation of the proapoptotic machinery. Again, ranolazine prevented this activation. Interestingly, Neonatal Rat Ventricular Myocytes (NRVMs), labeled with MitoTracker Red and treated with trastuzumab, showed only a small increase in ROS compared to baseline conditions. We then stressed trastuzumab-treated cells with the beta-agonist isoproterenol to increase workload, and we observed a significant increase of probe fluorescence, compared with cells treated with isoproterenol alone, reflecting induction of oxidative stress. These effects were blunted by ranolazine, supporting a role for INa inhibition in the regulation of redox balance also in trastuzumab cardiotoxicity.

Keywords: heart failure; heart function; oxidative stress; ranolazine; trastuzumab cardiotoxicity.

Figure 1

Ranolazine protects from trastuzumab-related cardiac dysfunction. Ranolazine blunts reductions in fractional shortening (FS) and ejection fraction (EF) induced by trastuzumab (^**p < 0.01 vs TRA; ^***p < 0.001 vs TRA).

Figure 2

Effects of ranolazine on cardiac fetal gene reprogramming. ANP, BNP, and MMP2 mRNA expressions induced by trastuzumab were reduced in mice pretreated with ranolazine (^*p < 0.05 vs. TRA; ^**p < 0.005; ^***p < 0.0005).

Figure 3

Apoptotic pathway analysis in hearts of treated mice. Caspase 3 activation triggered by trastuzumab, was reduced by ranolazine treatment (^*p < 0.05 vs. TRA; ^**p < 0.005 vs. TRA; ^***p < 0.0005 vs. TRA).

Figure 4

Ranolazine (RAN) reduces Reactive Oxygen Species (ROS) formation induced by Trastuzumab (TRA) and isoproterenol (ISO). Neonatal Rat Ventricular Myocytes (NRVMs) untreated or treated for 24 h with 2 μM TRA, with 10 μM Ran or with 2 μM TRA and 10 μM Ran, were incubated for 1 h with 4 μM Iso. Microscopy analysis of cells labeled with the fluorescent probe Mitotracker Red CM-H2XRos was performed to detect the degree of mitochondrial oxidative stress. Data are normalized to the control after 24 h + 1 h of treatment with isoproterenol. n ISO: 24; n TRA+ISO: 22; n RAN+ISO: 19; n RAN+TRA+ISO: 20. ^*p < 0.05 vs. TRA; ^**p < 0.01 vs. TRA.