title: Proteomic analysis of autoantibodies in patients with hepatocellular carcinoma.
abstract: To detect autoantibodies that could be diagnostic markers for hepatocellular carcinoma (HCC), we analyzed serum autoantibodies comprehensively that showed immunoreactivity to proteins in tumor tissue obtained from patients with HCC. Fifteen paired samples of HCC tissue and corresponding nontumorous liver tissue as well as five normal liver tissue samples were used in the study. A combination of proteomics and SEREX (serologic analysis of recombinant cDNA expression libraries) technique was used. Tissue proteins were separated by 2-DE, transferred onto PVDF membranes, and immunoblotted with autologous sera. By comparing each immunoblot pattern, we identified four immunoreactive spots with stronger staining intensity in tumorous tissues than in corresponding nontumorous tissues and in normal liver tissues. Matched proteins on 2-DE gels were identified by LC-MS/MS. These immunoreactive proteins were heat shock 70 kDa protein 1 (HSP70), glyceraldehyde 3-phosphate dehydrogenase, peroxiredoxin, and manganese superoxide dismutase (Mn-SOD). In HCC sera, occurrences of autoantibodies against these proteins were 7/15 (46.7%), 5/15 (33.3%), 5/15 (33.3%), and 6/15 (40.0%), respectively, whereas 2/20 (10.0%), 7/20 (35.0%), 0/20 (0.0%), and 2/20 (10.0%) were in control sera. Immunoblot analysis using commercially available purified proteins was performed to confirm the specificity of autoantibodies. By statistical analysis, autoantibodies against HSP70, peroxiredoxin, and Mn-SOD showed significantly high-frequency immunoreaction in HCC sera. The three antibodies were considered patient-specific antibodies in HCC and may be candidate diagnostic biomarkers for HCC.
authors.affiliation: Department of Surgery II, Yamaguchi University School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Motonari
authors.initials: M
authors.lastname: Takashima
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kuramitsu
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: Norio
authors.initials: N
authors.lastname: Iizuka
authors.forename: Toshio
authors.initials: T
authors.lastname: Harada
authors.forename: Masanori
authors.initials: M
authors.lastname: Fujimoto
authors.forename: Isao
authors.initials: I
authors.lastname: Sakaida
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Okita
authors.forename: Masaaki
authors.initials: M
authors.lastname: Oka
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000918:Antibody Specificity; D001323:Autoantibodies / Q000737:chemistry / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000276:immunology*; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020543:Proteome
chemical_list: D001323:Autoantibodies; D020543:Proteome