Pathology

Biography

Biography: Lihong Weng

Abstract

Glioblastoma (GBM) is the most common and fatal type of brain tumor. GBM tumors are highly heterogenous, containing genetic and molecularly distinct clones that confer an evolutionary advantage under the selective pressure imposed by therapies. This heterogeneity is one of the leading causes of treatment failure and tumor relapse for targeted therapies. Identification and quantification of the multiple tumor specific antigens in the context of GBM tissue is therefore essential to provide targets for combination treatments. Matrix–Assisted Laser Desorption/Ionization Imaging Mass Spectrometry (MALDI-IMS) is a novel technology that enables identification of specific molecules, such as proteins, glycans, lipids and other endogenous molecules directly on tissue sections. We tested human GBM tissues, tumor edges and normal brain controls to identify novel GBM specific antigens using MALDI-IMS. By mounting tissue sections with different type of matrices, we identified the profiles of peptides and lipids (<1200 Da), as well as the expression patterns of proteins (2000-25000 Da) in GBM tumor and tumor edges. Two candidates of interest (10094,92 m/z and 13785,47 m/z) were found highly expressed in GBM dense tumor regions, but not tumor edges. Interestingly, these two candidates were differentially distributed in the regions within the tumor tissue, and thus may mark different tumor cell sub-populations. Our results demonstrate the potential for MALDI-IMS for identifying tumor specific molecules that could be useful in the development of novel combinatorial GBM therapies. This MALDI-IMS extracted information also yields important insights into special and regional tumor heterogeneity within the context of the tumor tissue.