Abstract A48: Novel dual mode fluorine MRI, NIR fluorescent probe for noninvasive detection of tumor-associated inflammation.

Abstract

Abstract Tumor-associated macrophage are active in both tumor progression and remission processes, affecting prognosis depending on the nature of their involvement. Imaging macrophage recruitment and persistence to gauge tumor from normal host tissue is an area of great interest. Herein we propose the use of a novel dual mode fluorine magnetic resonance imaging (MRI), near infrared (NIR) fluorescent probe for the non-invasive detection of tumor associated inflammation. The use of this technique allows for rapid optical assessment of tumor associated macrophage as well as the specificity and detailed resolution provided by pairing 19F and conventional 1H MRI. Upon administration of the 19F/NIR reagent, tumors were visible at 6h. Both the liver and spleen were also visible due to clearance through the reticuloendothelial system. Use of the dual mode reagent was also compatible with MRI visualization, where detection of inflammation was in the periphery of, and not integral to, the tumor itself, information that could not be detected by optical means. Upon resection of the tumor, liver, spleen and other regions of interest fluorescence detection within the organs/tissue correlated with fluorine content and agreed with macrophage infiltrates and regions of reagent clearance. Flow cytometric analysis of whole blood show the preferential labeling of the macrophage population and immunofluorescent analysis of labeled macrophage further confirms cellular labeling. Dual functioning contrast agents enable both quick monitoring and sensitive quantification when evaluating the tumor microenvironment and potential changes in macrophage infiltrates as a result of therapeutic intervention. Citation Format: Anthony Balducci, Yi Wen, Yang Zhang, Brooke M. Helfer, Kevin Hitchens, Wilson Meng, Jelena Janjic, Amy Wesa. Novel dual mode fluorine MRI, NIR fluorescent probe for noninvasive detection of tumor-associated inflammation. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A48.