Electrophysiological mechanisms of vandetanib-induced cardiotoxicity: Comparison of action potentials in rabbit Purkinje fibers and pluripotent stem cell-derived cardiomyocytes

Hyang-Ae Lee,Byungjin Byun,Jong-Hak Chae,Ki-Suk Kim,Sung-Ae Hyun,Shang-Zhong Xu

doi:10.1371/journal.pone.0195577

Abstract

Vandetanib, a multi-kinase inhibitor used for the treatment of various cancers, has been reported to induce several adverse cardiac effects. However, the underlying mechanisms of vandetanib-induced cardiotoxicity are unclear. This study aimed to investigate the mechanism of vandetanib-induced cardiotoxicity using intracellular electrophysiological recordings on human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), rabbit Purkinje fibers, and HEK293 cells transiently expressing human ether-a-go-go-related gene (hERG; the rapidly activating delayed rectifier K+ channel, IKr), KCNQ1/KCNE1 (the slowly activating delayed rectifier K+ current, IKs), KCNJ2 (the inwardly rectifying K+ current, IK1) or SCN5A (the inward Na+ current, INa). Purkinje fiber assays and ion channel studies showed that vandetanib at concentrations of 1 and 3 μM inhibited the hERG currents and prolonged the action potential duration. Alanine scanning and in silico hERG docking studies demonstrated that Y652 and F656 in the hERG S6 domain play critical roles in vandetanib binding. In hiPSC-CMs, vandetanib markedly reduced the maximum rate of depolarization during the AP upstroke. Ion channel studies revealed that hiPSC-CMs were more sensitive to inhibition of the INa by vandetanib than in a heterogeneously expressed HEK293 cell model, consistent with the changes in the AP parameters of hiPSC-CMs. The subclasses of Class I antiarrhythmic drugs inhibited INa currents in a dose-dependent manner in hiPSC-CMs and SCN5A-encoded HEK293 cells. The inhibitory potency of vandetanib for INa was much higher in hiPSC-CMs (IC50: 2.72 μM) than in HEK293 cells (IC50: 36.63 μM). These data suggest that AP and INa assays using hiPSC-CMs are useful electrophysiological models for prediction of drug-induced cardiotoxicity.

Highlights

Tyrosine kinase inhibitors (TKIs), small molecules that interfere with kinase activity [1], are used for cancer chemotherapy because they play an important role in the modulation of growth factor signaling [2]
We compared the respective values of two in vitro preclinical tests, the commonly used test employing SCN5A-encoded HEK293 cells and the new model based on hiPSC-CMs using Class I antiarrhythmic drugs, for the detection of cardiac conduction slowing
The Purkinje fiber assay demonstrated that vandetanib prolonged APD90 and APD50 repolarization in a dose-dependent manner without affecting the resting membrane potential (RMP), Vmax, or AP amplitude (APA) (Fig 1)

Summary

Introduction

Tyrosine kinase inhibitors (TKIs), small molecules that interfere with kinase activity [1], are used for cancer chemotherapy because they play an important role in the modulation of growth factor signaling [2]. The blockage of human ether-a-go-go related gene (hERG) channels by diverse groups of drugs is associated with QT prolongation and cardiac arrhythmia [10], and these side effects are common reasons for drug failure in preclinical safety trials. Human-induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CMs) are drawing attention because they can be used to overcome the limitations of currently used assays of the preclinical safety of pharmaceutical compounds. They provide a potentially unlimited source of human CMs without ethical hurdles. The proposed CiPA approach includes multiple ion channel effects of a drug ( hERG) in heterologous expression systems, the integration of ion channel/drug interaction data in in silico models of human ventricular electrophysiology to predict and evaluate changes in the human AP, and the in vitro evaluation

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