title: Discovery of SLC3A2 cell membrane protein as a potential gastric cancer biomarker: implications in molecular imaging.
abstract: Despite decreasing incidence and mortality, gastric cancer remains the second leading cause of cancer-related deaths in the world. Successful management of gastric cancer is hampered by lack of highly sensitive and specific biomarkers especially for early cancer detection. Cell surface proteins that are aberrantly expressed between normal and cancer cells are potentially useful for cancer imaging and therapy due to easy accessibility of these targets. Combining two-phase partition and isobaric tags for relative and absolute quantification methods, we compared the relative expression levels of membrane proteins between noncancer and gastric cancer cells. About 33% of the data set was found to be plasma membrane and associated proteins using this approach (compared to only 11% in whole cell analysis), several of which have never been previously implicated in gastric cancer. Upregulation of SLC3A2 in gastric cancer cells was validated by immunoblotting of a panel of 13 gastric cancer cell lines and immunohistochemistry on tissue microarrays comprising 85 matched pairs of normal and tumor tissues. Immunofluorescence and immunohistochemistry both confirmed the plasma membrane localization of SLC3A2 in gastric cancer cells. The data supported the notion that SLC3A2 is a potential biomarker that could be exploited for molecular imaging-based detection of gastric cancer.
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599.
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Yang
authors.forename: Weiyi
authors.initials: W
authors.lastname: Toy
authors.forename: Lee Yee
authors.initials: LY
authors.lastname: Choong
authors.forename: Peiling
authors.initials: P
authors.lastname: Hou
authors.forename: Hassan
authors.initials: H
authors.lastname: Ashktorab
authors.forename: Duane T
authors.initials: DT
authors.lastname: Smoot
authors.forename: Khay Guan
authors.initials: KG
authors.lastname: Yeoh
authors.forename: Yoon Pin
authors.initials: YP
authors.lastname: Lim
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis* / Q000378:metabolism; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D027282:Fusion Regulatory Protein 1, Heavy Chain / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007525:Isoelectric Focusing; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D057054:Molecular Imaging / Q000379:methods*; D009363:Neoplasm Proteins / Q000032:analysis / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D027282:Fusion Regulatory Protein 1, Heavy Chain; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C545989:SLC3A2 protein, human