title: Secretory protein enrichment and analysis: an optimized approach applied on cancer cell lines using 2D LC-MS/MS.
abstract: Reliable methods for profiling secretory proteins are highly desirable for the identification of biomarkers of disease progression. Secreted proteins are often masked by high amounts of protein supplements in the culture medium. We have developed an efficient method for the enrichment and analysis of the secretome of different cancer cell lines, free of essential contaminants. The method is based on the optimization of cell incubation conditions in protein-free medium. Secreted proteins are concentrated and fractionated using a reversed-phase tC2 Sorbent, followed by peptide mass fingerprinting for protein identification. An average of 88 proteins were identified in each cancer cell line, of which more than 76% are known to be secreted, possess a signal peptide or a transmembrane domain. Given the importance of secreted proteins as a source for early detection and diagnosis of disease, this approach may help to discover novel candidate biomarkers with potential clinical significance.
authors.affiliation: Cancer Research Institute, University of South Alabama, Mobile, 36688, USA. fmbeunkui@usouthal.edu
authors.forename: Flaubert
authors.initials: F
authors.lastname: Mbeunkui
authors.forename: Oystein
authors.initials: O
authors.lastname: Fodstad
authors.forename: Lewis K
authors.initials: LK
authors.lastname: Pannell
mesh_terms: D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D005591:Chemical Fractionation; D017077:Culture Media, Conditioned / Q000737:chemistry; D016895:Culture Media, Serum-Free; D016208:Databases, Factual; D019075:Electrophoresis, Capillary; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical; D008970:Molecular Weight; D010449:Peptide Mapping; D021382:Protein Sorting Signals; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D040901:Proteomics
chemical_list: D017077:Culture Media, Conditioned; D016895:Culture Media, Serum-Free; D021382:Protein Sorting Signals; D011506:Proteins