title: Expression of RACK1 is a novel biomarker in pulmonary adenocarcinomas.
abstract: To develop useful early and/or differential diagnostic markers for pulmonary adenocarcinomas, we generated monoclonal antibodies using A549 cells derived from pulmonary adenocarcinomas as an immunogen. Hybridoma supernatants were immunohistochemically screened for antibody production by AMeX-fixed and paraffin-embedded A549 cell preparations. Positive clones were monocloned twice by limiting dilutions. From a group of obtained antibodies, an antibody designated as KU-Lu-3 showed cytoplasmic staining. The antigen recognized by KU-Lu-3 was detected by modified two-dimensional immunoblotting, and was determined to be the receptor of activated C kinase 1 (RACK1). To evaluate the utility of KU-Lu-3, we immunohistochemically studied 184 cases of pulmonary carcinoma and paired normal lung tissues, using formalin-fixed and paraffin-embedded tissue microarray sections. The expression was significantly high and frequent in adenocarcinomas but was barely detected in a few squamous cell carcinomas and large cell carcinomas (p<0.0001). Moreover, RACK1 expression was also significantly associated with the pathological stage, tumor size and lymph node status of adenocarcinoma patients, but not with tumor differentiation, or patient age and gender. These results suggest that RACK1 may be a novel differential diagnostic marker for pulmonary adenocarcinomas.
authors.affiliation: Division of Pathology, National Cancer Center Research Institute, Tokyo, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Nagashio
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sato
authors.forename: Toshihide
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Taihei
authors.initials: T
authors.lastname: Kageyama
authors.forename: Yukitoshi
authors.initials: Y
authors.lastname: Satoh
authors.forename: Ryuge
authors.initials: R
authors.lastname: Shinichiro
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Masuda
authors.forename: Naoki
authors.initials: N
authors.lastname: Goshima
authors.forename: Shi-Xu
authors.initials: SX
authors.lastname: Jiang
authors.forename: Isao
authors.initials: I
authors.lastname: Okayasu
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor / Q000276:immunology / Q000378:metabolism*; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D019204:GTP-Binding Proteins / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D006825:Hybridomas; D007150:Immunohistochemistry; D008168:Lung / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000276:immunology / Q000378:metabolism*; D009367:Neoplasm Staging; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000276:immunology / Q000378:metabolism*; D047368:Tumor Burden
chemical_list: D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; C419368:RACK1 protein, human; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D019204:GTP-Binding Proteins