Radiation-induced heart disease (RIHD) is a potentially severe side effect of radiotherapy of thoracic and chest wall tumors. Despite advances in radiation delivery and treatment planning technology, cardiac radiation toxicity remains a key consideration in thoracic radiotherapy. Hence, research is urgently needed to elucidate biological mechanisms and identify potential targets for intervention. Our previous pre-clinical studies in a mast cell-deficient rat model have shown that, contrary to what had been the prevailing assumption, mast cells play a predominantly protective role in RIHD. The overall goal of this project is to uncover the role of three mast cell targets in RIHD. For this purpose, genetic animal models and pharmacological interventions will be used to define the involvement of 1) Proteinase-Activated Receptor (PAR)-2, the receptor that mediates cellular effects of mast cell proteinases;2) bradykinin, a cardioprotective hormone that is formed by mast cell proteinases;and 3) the cardioprotective sensory neuropeptide calcitonin gene-related peptide (CGRP), as part of the neuroimmune interactions that are known to alter cardiac function and disease. Functional, structural, cellular and molecular manifestations of RIHD will be measured after local heart irradiation. These in vivo experiments will be the first to provide mechanistic insight into the protective effects of mast cells in RIHD, providing critical pre-clinical data as a basis for future development of intervention strategies, thereby enhancing the efficacy and safety of thoracic radiotherapy.

Public Health Relevance

Radiation-induced heart disease (RIHD) is a severe side effect of radiotherapy of thoracic and chest wall tumors. This project will investigate underlying mechanisms of RIHD and will provide critical pre-clinical data as a basis for future development of strategies aimed at reducing RIHD, thereby enhancing the efficacy and safety of thoracic radiotherapy.

Agency
National Institute of Health (NIH)
Type
Research Project (R01)
Project #
5R01CA148679-05
Application #
8657868
Study Section
Radiation Therapeutics and Biology Study Section (RTB)
Program Officer
Prasanna, Pat G
Project Start
Project End
Budget Start
Budget End
Support Year
5
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Arkansas for Medical Sciences
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
City
Little Rock
State
AR
Country
United States
Zip Code
72205
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