Raman-Encoded Molecular Imaging and Lipidomics as Predictors of Pancreatic Cancer Microenvironment Changes During Treatment with 3-Bromopyruvate
E Sheikh1*, K Agrawal2, S Roy3, M Gartia4, H Shukla5, N Biswal6, (1) Department Of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA,(2) Department Of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA,(3) University Of Maryland School Of Medicine, Baltimore, MD,(4) Department Of Mechanical And Industrial Engineering, Louisiana State University, Baton Rouge, LA,(5) University Of Maryland School Of Medicine, Baltimore, MD,(6) University of Maryland, School of Medicine, Baltimore, MD
Presentations
TU-J430-BReP-F1-3 (Tuesday, 7/12/2022) 4:30 PM - 5:30 PM [Eastern Time (GMT-4)]
Exhibit Hall | Forum 1
Purpose: 3-bromopyruvate (3BP) is a promising anticancer drug that inhibits glycolysis in cancer cells. The 2 major mechanisms of cell killing are by: (1) blocking energy metabolism in cancer cells; and (2) overexpressing caspase-3 and activating apoptotic cancer cell death. The objective of this study was to use Raman-encoded molecular imaging to characterize lipidomics and other biochemical changes in the tumor microenvironment after 3BP treatment.
Methods: After IACUC approval, we developed a syngeneic subcutaneous mouse model of pancreatic cancer. Mouse Panc-2 cancer cells were injected in the right flank of six 8-wk-old C57BL/6 female mice. Animals were then randomized into 2 groups that received: (1) 5.0 mg/Kg 3BP, 3 d/wk (every other day) for 30 d; and (2) saline-only injection on the same schedule. Animals were under observation for another 2 wk without injection before tumor harvesting. Confocal microscopy was used to collect fluorescence lifetime imaging microscopy (FLIM) data. Raman spectra of tissues were recorded using a Renishaw inVia Reflex Raman spectrometer.
Results: H&E images showed morphologic changes in tumor texture after 3BP treatment. Picrosirius red staining showed that fibrotic collagen fibers were reduced after treatment. FLIM data showed shifts from glycolysis to oxidative phosphorylation after 3BP treatment. The FLIM mainly showed decay functions for nicotinamide adenine dinucleotide phosphate and flavin adenine dinucleotide in treated tissue. To further analyze relevant protein distributions (TGFB1, HK2, CASP3), antibodies were conjugated to gold nanoparticles (60 nm) with Raman reporter molecules. To understand profile changes after treatment, liquid chromatography–mass spectrometry analysis of the saline- and 3BP-treated tissue samples was performed, and 301 lipid species were identified.
Conclusion: Raman molecular imaging combined with lipidomics may elucidate changes in molecular signatures during 3BP treatment of pancreatic cancer and could be used as a prognostic biomarker.
Keywords
Quantitative Imaging, Optical Imaging, Tissue Characterization
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