title: Autoantibodies against stress-induced phosphoprotein-1 as a novel biomarker candidate for ovarian cancer.
abstract: Detection of autoantibodies against tumor-associated antigens (TAA) has recently been shown to be a powerful tool for early detection of various cancers. The aim of this study was to investigate the possibility of using autoantibodies against TAA as novel biomarkers by a proteomics-based approach in patients with ovarian cancer. We used two-dimensional differential gel electrophoresis analysis of immuno-precipitated tumor antigens (2D-DITA) to compare the levels of autoantibodies in pretreatment and posttreatment sera of patients with ovarian cancers. The identified autoantibodies were validated by SYBR Green real-time polymerase chain reaction (PCR) and immunohistochemistry (IHC). We further evaluated the level of autoantibody in sera of 68 ovarian cancer patients by an enzyme-linked immunosorbent assay (ELISA). The autoantibody directed against stress-induced phosphoprotein-1 (STIP-1) emerged as a novel biomarker candidate for ovarian cancer. SYBR Green PCR and IHC confirmed that the STIP-1 mRNA and protein expression levels were significantly up-regulated in ovarian cancers compared with normal and benign tumors (P = 0.003 and P < 0.001, respectively). A preliminary ELISA study showed that the serum levels of anti-STIP-1 autoantibodies were significantly elevated in ovarian cancer patients compared with healthy controls (P = 0.03). The results suggest that 2D-DITA is a useful tool to detect autoantibodies and that STIP-1 is a potential biomarker candidate for ovarian cancers.
authors.affiliation: Department of Obstetrics and Gynecology, Yonsei University College of Medicine, Gangnam-Gu, Seoul, Republic of Korea.
authors.forename: Sunghoon
authors.initials: S
authors.lastname: Kim
authors.forename: Hanbyoul
authors.initials: H
authors.lastname: Cho
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Nam
authors.forename: Sang Wun
authors.initials: SW
authors.lastname: Kim
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Yong Won
authors.initials: YW
authors.lastname: Park
authors.forename: Bo Wook
authors.initials: BW
authors.lastname: Kim
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000951:Antigens, Neoplasm / Q000235:genetics / Q000276:immunology; D001323:Autoantibodies / Q000097:blood* / Q000235:genetics / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006360:Heat-Shock Proteins / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D009369:Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000276:immunology; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000276:immunology* / Q000473:pathology; D010750:Phosphoproteins / Q000235:genetics / Q000276:immunology; D040901:Proteomics; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D001323:Autoantibodies; D015415:Biomarkers; D006360:Heat-Shock Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; C079373:STIP1 protein, human