High-throughput analysis of kinase inhibitor drugs on cardiac function using engineered heart tissue constructs

Abstract

Event Abstract Back to Event High-throughput analysis of kinase inhibitor drugs on cardiac function using engineered heart tissue constructs Genevieve Conant1, 2, Yimu Zhao2 and Milica Radisic1, 2 1 University of Toronto, Institute of Biomaterials and Biomedical Engineering, Canada 2 University of Toronto, Chemical Engineering and Applied Chemistry, Canada Introduction: A serious concern in health care today is the unintentional long-term effects of pharmaceuticals on the heart, which are not detected during clinical trials. These side effects are burden to health care and can potentially waste millions of dollars in research should the drug be recalled. Tyrosine kinase inhibitors (TKIs) are commonly used as highly specific cancer targeting agents for their ability to prevent tyrosine kinase molecules from activating signaling pathways that regulate cell growth, differentiation, metabolism, migration, and programmed cell death[1]. Due to the highly metabolic nature of cardiac tissue, cardiomyocytes are sensitive to perturbations in mitochondrial function. As such, TKIs have been found to have severe adverse effects on cardiac tissue, however they are poorly understood. Although the human genome has been mapped, and 500 different kinases have been identified, only 50 have been thoroughly studied [2]. High-throughput preclinical screening of over 300 tyrosine kinase-inhibiting molecules could offer much information as to their cardiovascular effects and prevent any further strain on the health care system. We hypothesized that a high-fidelity model for evaluating the physiological effects of TKIs on human myocardium could be established using high-content screening assays and engineered heart tissue constructs, termed BioWires. Methods and Materials: Over 300 TKIs were screened on human cardiomyocytes plated as a monolayer at various concentrations. High-content screening assays from Molecular Devices were used sequentially to assess cell viability and basic cardiac function. TKIs that did not cause detrimental effects to cardiac tissue and cell viability were examined using our 3D BioWire platform. These BioWires are micro-scale cardiac tissues mimicking physiological tissue that consist of human cardiomyocytes seeded onto polymer wires and electrically stimulated in order to promote tissue maturation[3]. Fluorescent image microscopy was used to examine tissue contraction and calcium transient profiles. Particle-tracking software was developed to measure the deflection of the polymer wire, which can be directly related to force of contraction through basic engineering statics. Results and Discussion: Preliminary testing using human embryonic stem cell-derived cardiomyocytes (hES-CM) and human induced pluripotent stem cell-derived cardiomyocytes (iPS-CM) demonstrated that the two assays from Molecular Devices could be used sequentially with no detrimental effect on cardiac function. As well, the effects of known chronotropic and inotropic drugs were examined, and their effect could be quantified on our platform. In the future, TKIs that showed the greatest effect on cardiac function could be further studied to determine their cellular mode of action. Conclusion: In conclusion, this system was capable of providing much needed information regarding the effects of tyrosine kinase inhibiting molecules on the heart, and could also be applied to high-throughput screening of other molecules.