Abstract 2376: Diagnostic and predictive biomarkers of radiation pneumonitis

Abstract

Increased rates of treatment failure in lung cancer patients necessitate treatment with high doses of radiation, which often cause toxicities. However, normal tissue injury in lung may manifest as acute toxicities or as delayed radiation pneumonitis. Identification of early indicators of delayed toxicities will allow timely management and mitigation. In present study, using mouse model, we identified a set of circulating microRNAs as biomarkers that potentially allow early detection of radiation induced lung injury such as inflammation and pneumonitis. Longitudinal analysis of serum samples collected from mice exposed to whole thorax lung irradiation (WTLI) allowed discovery of a panel of evolutionary conserved miRNAs that are potential predictors of radiation pneumonitis. Among these, miR21 and miR29a, miR130a, and miR19a were found peaked between 2-4 weeks after radiation, while miR146a exhibited a peculiar biphasic expression. Some of these changes were found to be associated with concomitant changes in anti- and pro-inflammatory serum cytokines. Several of the biomarkers identified in WTLI model, showed overlapping response in a bleomycin mouse model of acute lung injury. We further tested the translational utility of these biomarkers in single drop blood collected from mice using a validated internal normalizer, miR23a (Yadav et al., Science Translational Medicine, 2020, PMID: 32669422). The response noted for several of the candidate biomarkers identified in mouse model are conserved in specimens collected from human patients who received radiation therapy. In conclusion, our study has identified a panel of microRNA biomarkers with potential to develop as early predictor of pulmonary toxicities in patients receiving therapeutic radiation, and in victims of radiation accidents for timely mitigation. Citation Format: Marshleen Yadav, Joseph Liu, Zahida Qamri, Naduparambil K. Jacob. Diagnostic and predictive biomarkers of radiation pneumonitis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2376.