title: Evaluation of annexin II as a potential serum marker for hepatocellular carcinoma using a developed sandwich ELISA method.
abstract: Annexin II (Annexin A2, ANXA2) is a 36 kDa calcium-dependent phospholipid-binding protein that is located on the surface of most eukaryotic cells. ANXA2 is involved in several biological processes, including anti-inflammatory effects, Ca27+-dependent exocytosis, immune responses, Ca2+ transport and phospholipase A2 regulation. In our previous study, ANXA2 was identified as an up-regulated gene in hepatocellular carcinoma (HCC) tissue by cDNA microarray. In the present study, we have evaluated ANXA2 as a tumor-associated marker of HCC. We determined the ANXA2 levels in human liver tissues with HCC using real-time RT-PCR and Western blot analysis. For quantitative analysis of the ANXA2 protein in body fluids, we developed a sandwich ELISA system in which a polyclonal antibody and a monoclonal antibody specific to ANXA2 were employed as a capture antibody and a probe antibody, respectively. We detected the ANXA2 concentration in human serum using our newly developed system and evaluated its usefulness as a tumor marker. Overexpression of ANXA2 in human liver tissue was confirmed by real-time RT-PCR and Western blot analysis. The sandwich ELISA system for ANXA2 was developed for the detection of ANXA2 in human samples. The dose-response relationship between ANXA2 and optical density was linear in the range of 0-10 microg/ml and the sensitivity was 0.02 microg/ml. We determined the ANXA2 concentration in serum specimens using the newly developed sandwich ELISA. The serum ANXA2 concentrations of the patients with HCC (53.38+/-36.23 microg/ml) were significantly elevated when compared with those of normal individuals (28.81+/-24.94 microg/ml). These results suggest that expression of ANXA2 may be increased in HCC patients and may play an important role in liver cancer progression. This new ELISA method can be used as a tool for the detection of ANXA2 in human serum, particularly for cancer diagnostics.
authors.affiliation: Medical Genomics Research Center, KRIBB, Daejeon, Korea.
authors.forename: Na Young
authors.initials: NY
authors.lastname: Ji
authors.forename: Mi-Young
authors.initials: MY
authors.lastname: Park
authors.forename: Yun Hee
authors.initials: YH
authors.lastname: Kang
authors.forename: Chung Il
authors.initials: CI
authors.lastname: Lee
authors.forename: Dae Ghon
authors.initials: DG
authors.lastname: Kim
authors.forename: Young Il
authors.initials: YI
authors.lastname: Yeom
authors.forename: Ye Jin
authors.initials: YJ
authors.lastname: Jang
authors.forename: Pyung-Keun
authors.initials: PK
authors.lastname: Myung
authors.forename: Jong Wan
authors.initials: JW
authors.lastname: Kim
authors.forename: Hee Gu
authors.initials: HG
authors.lastname: Lee
authors.forename: Jae Wha
authors.initials: JW
authors.lastname: Kim
authors.forename: Kyeong
authors.initials: K
authors.lastname: Lee
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Song
mesh_terms: D017306:Annexin A2 / Q000097:blood* / Q000235:genetics; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000097:blood*; D006528:Carcinoma, Hepatocellular / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D016014:Linear Models; D008113:Liver Neoplasms / Q000097:blood*; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D012372:ROC Curve
chemical_list: D017306:Annexin A2; D014408:Biomarkers, Tumor