title: Proteomics-based identification of autoantibody against heat shock protein 70 as a diagnostic marker in esophageal squamous cell carcinoma.
abstract: Detection of novel tumor-related antigens and autoantibodies in cancer patients is expected to facilitate the diagnosis of early-stage malignant tumor and establish effective new immunotherapies. The purpose of this study was to identify novel tumor antigens in an esophageal squamous cell carcinoma (ESCC) cell line (TE-2) and related autoantibodies in sera from patients with ESCC using a proteomics-based approach. TE-2 proteins were separated by two-dimensional polyacrylamide gel electrophoresis, followed by Western blot analysis in which sera from patients with ESCC, healthy controls and patients with other cancers were tested for primary antibodies. Positive spots were excised from silver-stained gels and analyzed by matrix-assisted laser disorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). Sera from patients with ESCC yielded multiple spots, one of which was identified as heat shock protein 70 (Hsp70) by MALDI-TOF/TOF-MS. Concentrations of serum Hsp70 autoantibody were significantly higher for patients with ESCC (mean, 0.412+/-0.096 mg/ml) than for patients with gastric (0.236+/-0.112 mg/ml, P<0.001) or colon cancer (0.231+/-0.120 mg/ml, P<0.001) or healthy individuals (0.207+/-0.055 mg/ml, P<0.001) by enzyme-linked immunosorbent assay. We have identified an autoantibody against Hsp70 in ESCC patients. The proteomic approach implemented herein offers a powerful tool for identifying novel serum markers that may display clinical utility against cancer.
authors.affiliation: Department of General and Gastroenterological Surgery, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki-city, Osaka 569-8686, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Fujita
authors.forename: Toyofumi
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Masako
authors.initials: M
authors.lastname: Hiramatsu
authors.forename: Hideaki
authors.initials: H
authors.lastname: Mabuchi
authors.forename: Akiko
authors.initials: A
authors.lastname: Miyamoto
authors.forename: Akira
authors.initials: A
authors.lastname: Shimizu
authors.forename: Takayuki
authors.initials: T
authors.lastname: Takubo
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Tanigawa
mesh_terms: D000328:Adult; D000368:Aged; D000912:Antibodies, Neoplasm / Q000032:analysis; D000951:Antigens, Neoplasm / Q000032:analysis; D001323:Autoantibodies / Q000302:isolation & purification*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis*; D045744:Cell Line, Tumor; D004938:Esophageal Neoplasms / Q000175:diagnosis*; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology*; D006801:Humans; D008875:Middle Aged; D040901:Proteomics
chemical_list: D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D001323:Autoantibodies; D014408:Biomarkers, Tumor; D018840:HSP70 Heat-Shock Proteins