title: Proteomic profiling of N-linked glycoproteins identifies ConA-binding procathepsin D as a novel serum biomarker for hepatocellular carcinoma.
abstract: The aim of this study was to identify novel biomarkers for the diagnosis of, and potential therapeutic targets for, hepatocellular carcinoma (HCC). Multilectin affinity chromatography was used to enrich N-linked glycoproteins from nontumorous liver and HCC tissues followed by 2DE and protein identification by MS. Twenty-eight differentially expressed proteins were identified. Western blotting validated consistently lower concentrations of human liver carboxylesterase 1 and haptoglobin, and higher concentration of procathepsin D (pCD) in HCC tissues. Knockdown of cathepsin D (CD) expression mediated by siRNA significantly inhibited the in vitro invasion of two HCC cell lines, SNU449 and SNU473, which normally secrete high-levels of CD. Prefractionation using individual lectins demonstrated an elevation in ConA-binding glycoforms of proCD and CD in HCC tissues. In the serum of HCC patients, "ConA-binding proCD" (ConA-pCD) is significantly increased in concentration and this increase is comprised of several distinct upregulated acidic isoforms (pI 4.5-5.5). Receiver operating characteristic analysis showed that the sensitivity and specificity of serum ConA-pCD for HCC diagnosis were 85% and 80%, respectively. This is the first report that serum ConA-pCD is increased significantly in HCC and is potentially useful as a serological biomarker for diagnosis of HCC.
authors.affiliation: Key Laboratory of Cellular and Molecular Immunology, College of Medicine, Henan University, Kaifeng, P. R. China.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Qi
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Ward
authors.forename: Chun
authors.initials: C
authors.lastname: Pang
authors.forename: Qi-Ming
authors.initials: QM
authors.lastname: Wang
authors.forename: Wenbin
authors.initials: W
authors.lastname: Wei
authors.forename: Jin
authors.initials: J
authors.lastname: Ma
authors.forename: Juan
authors.initials: J
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lou
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Shimwell
authors.forename: Ashley
authors.initials: A
authors.lastname: Martin
authors.forename: Nathalie
authors.initials: N
authors.lastname: Wong
authors.forename: Wei-Xia
authors.initials: WX
authors.lastname: Chao
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Yuan-Fang
authors.initials: YF
authors.lastname: Ma
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002265:Carboxylic Ester Hydrolases / Q000032:analysis; D006528:Carcinoma, Hepatocellular / Q000097:blood* / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D002402:Cathepsin D / Q000032:analysis / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D003208:Concanavalin A / Q000378:metabolism; D004792:Enzyme Precursors / Q000032:analysis / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000032:analysis / Q000097:blood / Q000378:metabolism; D006242:Haptoglobins / Q000032:analysis; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D040901:Proteomics / Q000379:methods*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D004792:Enzyme Precursors; D006023:Glycoproteins; D006242:Haptoglobins; D034741:RNA, Small Interfering; D003208:Concanavalin A; D002265:Carboxylic Ester Hydrolases; C474609:CES1 protein, human; C058345:procathepsin D; D002402:Cathepsin D
keywords: Cathepsin D; Glycoproteins; Haptoglobin; Hepatocellular carcinoma; Human liver carboxylesterase 1