title: CAXII Is a sero-diagnostic marker for lung cancer.
abstract: To develop sero-diagnostic markers for lung cancer, we generated monoclonal antibodies using pulmonary adenocarcinoma (AD)-derived A549 cells as antigens by employing the random immunization method. Hybridoma supernatants were immunohistochemically screened for antibodies with AMeX-fixed and paraffin-embedded A549 cell preparations. Positive clones were monocloned twice through limiting dilutions. From the obtained monoclonal antibodies, we selected an antibody designated as KU-Lu-5 which showed intense membrane staining of A549 cells. Based on immunoprecipitation and MADLI TOF/TOF-MS analysis, this antibody was recognized as carbonic anhydrase XII (CAXII). To evaluate the utility of this antibody as a sero-diagnostic marker for lung cancer, we performed dot blot analysis with a training set consisting of sera from 70 lung cancer patients and 30 healthy controls. The CAXII expression levels were significantly higher in lung cancer patients than in healthy controls in the training set (P<0.0001), and the area under the curve of ROC was 0.794, with 70.0% specificity and 82.9% sensitivity. In lung cancers, expression levels of CAXII were significantly higher in patients with squamous cell carcinoma (SCC) than with AD (P = 0.035). Furthermore, CAXII was significantly higher in well- and moderately differentiated SCCs than in poorly differentiated ones (P = 0.027). To further confirm the utility of serum CAXII levels as a sero-diagnostic marker, an additional set consisting of sera from 26 lung cancer patients and 30 healthy controls was also investigated by dot blot analysis as a validation study. Serum CAXII levels were also significantly higher in lung cancer patients than in healthy controls in the validation set (P = 0.030). Thus, the serum CAXII levels should be applicable markers discriminating lung cancer patients from healthy controls. To our knowledge, this is the first report providing evidence that CAXII may be a novel sero-diagnostic marker for lung cancer.
authors.affiliation: Department of Applied Tumor Pathology, Graduate School of Medical Sciences, Kitasato University, Kanagawa, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Toshihide
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Ryuge
authors.forename: Kengo
authors.initials: K
authors.lastname: Yanagita
authors.forename: Ryo
authors.initials: R
authors.lastname: Nagashio
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Naoki
authors.initials: N
authors.lastname: Goshima
authors.forename: Shi-Xu
authors.initials: SX
authors.lastname: Jiang
authors.forename: Makoto
authors.initials: M
authors.lastname: Saegusa
authors.forename: Akira
authors.initials: A
authors.lastname: Iyoda
authors.forename: Yukitoshi
authors.initials: Y
authors.lastname: Satoh
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Masuda
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sato
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000201:enzymology; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived; D000918:Antibody Specificity; D014408:Biomarkers, Tumor / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D002256:Carbonic Anhydrases / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D018287:Carcinoma, Large Cell / Q000175:diagnosis / Q000201:enzymology; D018278:Carcinoma, Neuroendocrine / Q000175:diagnosis / Q000201:enzymology; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000201:enzymology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000201:enzymology; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000201:enzymology*; D008297:Male; D012698:Serologic Tests
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D014408:Biomarkers, Tumor; D002256:Carbonic Anhydrases; C477378:carbonic anhydrase XII