title: Comprehensive characterization of glioblastoma tumor tissues for biomarker identification using mass spectrometry-based label-free quantitative proteomics.
abstract: Cancer is a complex disease; glioblastoma (GBM) is no exception. Short survival, poor prognosis, and very limited treatment options make it imperative to unravel the disease pathophysiology. The critically important identification of proteins that mediate various cellular events during disease is made possible with advancements in mass spectrometry (MS)-based proteomics. The objective of our study is to identify and characterize proteins that are differentially expressed in GBM to better understand their interactions and functions that lead to the disease condition. Further identification of upstream regulators will provide new potential therapeutic targets. We analyzed GBM tumors by SDS-PAGE fractionation with internal DNA markers followed by liquid chromatography-tandem mass spectrometry (MS). Brain tissue specimens obtained for clinical purposes during epilepsy surgeries were used as controls, and the quantification of MS data was performed by label-free spectral counting. The differentially expressed proteins were further characterized by Ingenuity Pathway Analysis (IPA) to identify protein interactions, functions, and upstream regulators. Our study identified several important proteins that are involved in GBM progression. The IPA revealed glioma activation with z score 2.236 during unbiased core analysis. Upstream regulators STAT3 and SP1 were activated and CTNNα was inhibited. We verified overexpression of several proteins by immunoblot to complement the MS data. This work represents an important step towards the identification of GBM biomarkers, which could open avenues to identify therapeutic targets for better treatment of GBM patients. The workflow developed represents a powerful and efficient method to identify biomarkers in GBM.
authors.affiliation: Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin;
authors.forename: Maxime S
authors.initials: MS
authors.lastname: Heroux
authors.affiliation: Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin;
authors.forename: Marla A
authors.initials: MA
authors.lastname: Chesnik
authors.affiliation: Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, Wisconsin;
authors.forename: Brian D
authors.initials: BD
authors.lastname: Halligan
authors.affiliation: Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin;
authors.forename: Mona
authors.initials: M
authors.lastname: Al-Gizawiy
authors.affiliation: Department of Neurology, Medical College of Wisconsin, Milwaukee, Wisconsin;
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Connelly
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin;
authors.forename: Wade M
authors.initials: WM
authors.lastname: Mueller
authors.affiliation: Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin;
authors.forename: Scott D
authors.initials: SD
authors.lastname: Rand
authors.affiliation: Department of Pathology, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Cochran
authors.affiliation: Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Peter S
authors.initials: PS
authors.lastname: LaViolette
authors.affiliation: Department of Neurology, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Malkin
authors.affiliation: Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Schmainda
authors.affiliation: Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin; smirza@mcw.edu spmirza@gmail.com.
authors.forename: Shama P
authors.initials: SP
authors.lastname: Mirza
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000378:metabolism*; D001932:Brain Neoplasms / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D005909:Glioblastoma / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008875:Middle Aged; D040901:Proteomics / Q000379:methods*; D013194:Staining and Labeling; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor
keywords: glioblastoma; label-free quantification; mass spectrometry-based proteomics; tumor tissue biomarkers