title: Discovery and identification of Serum Amyloid A protein elevated in lung cancer serum.
abstract: Two hundred and eighteen serum samples from 175 lung cancer patients and 43 healthy individuals were analyzed by using Surface Enhaced Laser Desorption/Ionization Time of Flight Mass Spectrome-try (SELDI-TOF-MS). The data analyzed by both Biomarker Wizardtrade mark and Biomarker Patternstrade mark software showed that a protein peak with the molecular weight of 11.6 kDa significantly increased in lung cancer. Meanwhile, the level of this biomarker was progressively increased with the clinical stages of lung cancer. The candidate biomarker was then obtained from tricine one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis by matching the molecular weight with peaks on WCX2 chips and was identified as Serum Amyloid A protein (SAA) by MALDI/MS-MS and database searching. It was further validated in the same serum samples by immunoprecipitation with commercial SAA antibody. To confirm the SAA differential expression in lung cancer patients, the same set of serum samples was measured by ELISA assay. The result showed that at the cutoff point 0.446 (OD value) on the Receiver Operating Characteristic (ROC) curve, SAA could better discriminate lung cancer from healthy individuals with sensitivity of 84.1% and specificity of 80%. These findings demonstrated that SAA could be characterized as a biomarker related to pathological stages of lung cancer.
authors.affiliation: Key Laboratory of Cell Proliferation and Regulation of Ministry of Education, Beijing Normal University, Beijing, 100875, China.
authors.forename: SongWei
authors.initials: S
authors.lastname: Dai
authors.forename: XiaoMin
authors.initials: X
authors.lastname: Wang
authors.forename: LiYun
authors.initials: L
authors.lastname: Liu
authors.forename: JiFu
authors.initials: J
authors.lastname: Liu
authors.forename: ShanShan
authors.initials: S
authors.lastname: Wu
authors.forename: LingYun
authors.initials: L
authors.lastname: Huang
authors.forename: XueYuan
authors.initials: X
authors.lastname: Xiao
authors.forename: DaCheng
authors.initials: D
authors.lastname: He
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000473:pathology; D008970:Molecular Weight; D009367:Neoplasm Staging; D012016:Reference Values; D012680:Sensitivity and Specificity; D000685:Serum Amyloid A Protein / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D000685:Serum Amyloid A Protein