Multiscale and Translational Quantitative Systems Toxicology, Pharmacokinetic-Toxicodynamic Modeling Analysis for Assessment of Doxorubicin-Induced Cardiotoxicity

Mathematical modeling of cardio-oncology: Modeling the systemic effects of cancer therapeutics on the cardiovascular system

Cardiotoxicity is a common side-effect of many cancer therapeutics; however, to-date there has been very little push to understand the mechanisms underlying this group of pathologies. This has led to the emergence of cardio-oncology, a field of medicine focused on understanding the effects of cancer and its treatment on the human heart. Here, we describe how mechanistic modeling approaches have been applied to study open questions in the cardiovascular system and how these approaches are being increasingly applied to advance knowledge of the underlying effects of cancer treatments on the human heart. A variety of mechanistic, mathematical modeling techniques have been applied to explore the link between common cancer treatments, such as chemotherapy, radiation, targeted therapy, and immunotherapy, and cardiotoxicity, nevertheless there is limited coverage in the different types of cardiac dysfunction that may be associated with these treatments. Moreover, cardiac modeling has a rich heritage of mathematical modeling and is well suited for the further development of novel approaches for understanding the cardiotoxicities associated with cancer therapeutics. There are many opportunities to combine mechanistic, bottom-up approaches with data-driven, top-down approaches to improve personalized, precision oncology to better understand, and ultimately mitigate, cardiac dysfunction in cancer patients.

In vitro to clinical translation of combinatorial effects of doxorubicin and dexrazoxane in breast cancer: a mechanism-based pharmacokinetic/pharmacodynamic modeling approach

Dexrazoxane (DEX) is the only drug clinically approved to treat Doxorubicin-induced cardiotoxicity (DIC), however its impact on the anticancer efficacy of DOX is not extensively studied. In this manuscript, a proof-of-concept in vitro study is carried out to quantitatively characterize the anticancer effects of DOX and DEX and determine their nature of drug-drug interactions in cancer cells by combining experimental data with modeling approaches. First, we determined the static concentration-response of DOX and DEX in breast cancer cell lines, JIMT-1 and MDA-MB-468. With a three-dimensional (3D) response surface analysis using a competitive interaction model, we characterized their interaction to be modestly synergistic in MDA-MB-468 or modestly antagonistic in JIMT-1 cells. Second, a cellular-level, pharmacodynamic (PD) model was developed to capture the time-course effects of the two drugs which determined additive and antagonistic interactions for DOX and DEX in MDA-MB-468 and JIMT-1, respectively. Finally, we performed in vitro to in vivo translation by utilizing DOX and DEX clinical dosing regimen that was previously identified to be maximally cardioprotective, to drive tumor cell PD models. The resulting simulations showed that a 10:1 DEX:DOX dose ratio over three cycles of Q3W regimen of DOX results in comparable efficacy based on MDA-MB-468 (additive effect) estimates and lower efficacy based on JIMT-1 (antagonistic effect) estimates for DOX + DEX combination as compared to DOX alone. Thus, our developed cell-based PD models can be used to simulate different scenarios and better design preclinical in vivo studies to further optimize DOX and DEX combinations.

In vitro to clinical translational pharmacokinetic/pharmacodynamic modeling of doxorubicin (DOX) and dexrazoxane (DEX) interactions: Safety assessment and optimization

Despite high anticancer activity, doxorubicin (DOX)-induced cardiotoxicity (DIC) limits the extensive utility of DOX in a clinical setting. Amongst various strategies explored, dexrazoxane (DEX) remains the only cardioprotective agent to be approved for DIC. In addition, altering the dosing regimen of DOX has also proved to be somewhat beneficial in decreasing the risk of DIC. However, both approaches have limitations and further studies are required to better optimize them for maximal beneficial effects. In the present work, we quantitatively characterized DIC as well as the protective effects of DEX in an in vitro model of human cardiomyocytes, by means of experimental data and mathematical modeling and simulation (M&S) approaches. We developed a cellular-level, mathematical toxicodynamic (TD) model to capture the dynamic in vitro drug-drug interaction, and relevant parameters associated with DIC and DEX cardio-protection were estimated. Subsequently, we executed in vitro-in vivo translation by simulating clinical PK profiles for different dosing regimens of DOX alone and in combinations with DEX and using the simulated PK profiles to drive the cell-based TD models to evaluate the effects of long-term, clinical dosing regimens of these drugs on the relative cell viability of AC16 and to determine optimal drug combinations with minimal cellular toxicity. Here, we identified that the Q3W (once every three weeks) DOX regimen with 10:1 DEX:DOX dose ratio over three cycles (nine weeks) may offer maximal cardio-protection. Overall, the cell-based TD model can be effectively used to better design subsequent preclinical in vivo studies aimed for further optimizing safe and effective DOX and DEX combinations to mitigate DIC.

Huaier Polysaccharide Attenuates Doxorubicin-Induced Acute Cardiotoxicity by Regulating Ferroptosis

We studied the effects of Huaier polysaccharide (HP) in doxorubicin-induced myocardial injury in mice. The content of HP in Trametes robiniophila Murr medicinal fungus determined by the phenol-sulfuric acid method was 85.25%. In the in vitro model, the viability of H9c2 cells was significantly increased after HP treatment compared to the control, while doxorubicin (DOX) decreased this parameter. The inhibitory effect of DOX on cell viability was attenuated after HP treatment. In the in vivo model, the body weight of mice in DOX and DOX+HP groups was significantly decreased compared to the control group. ECG showed significantly elevated ST segment in the DOX group, while in the DOX+HP group, ECG was close to normal. The levels of cardiotoxicity markers cTnI and lactate dehydrogenase in the DOX+HP group were significantly lower than in the DOX group. In the DOX group, the myocardial tissue had obvious structural disorder and interfibrillar vacuoles. In the DOX+HP group, the cardiomyocytes were neatly arranged without interfibrillar vacuoles. The expression of the ferroptosis marker glutathione peroxidase 4 was increased in the DOX+HP group compared to the DOX group. Thus, our study reveals that HP attenuated DOX-induced myocardial injury in mice probably by regulating ferroptosis.