title: Identification of potential breast cancer markers in nipple discharge by protein profile analysis using two-dimensional nano-liquid chromatography/nanoelectrospray ionization-mass spectrometry.
abstract: This research aimed to establish a diagnostic technique for breast cancer using nipple discharge (ND), with the objective of preventive diagnosis. ND has been proposed as a source of secreted proteomes that reflect early pathological changes in the ductal-lobular epithelial microenvironment, and could thus provide breast-specific cancer biomarkers that could be accessed noninvasively as a new clinical diagnostic technique.
  
  
  
  Minute amounts of ND from patients with and without breast cancer (n = 19 and 12, respectively) were collected at the hospital and kept frozen until just before use. They were analyzed using high-pH RP peptide fractionations/low-pH RP 2D nano-LC/ESI-MS/MS. Biomarker candidates were also investigated using Western blot analysis and sandwich ELISA on ND and/or sera.
  
  
  
  We found distinct tendencies in protein expression and three candidate breast cancer biomarkers (carbonic anhydrase 2, catalase, and peroxiredoxin-2) whose levels differed significantly between ND specimens from patients with and without breast cancer.
  
  
  
  These tendencies in protein expression and markers provide new ways to identify breast cancer patients. Therefore, RP/RP 2D LC/MS/MS analyses of ND and the above three markers are supported as a new breast cancer diagnostic technique.
authors.affiliation: Laboratory of Molecular Signature Analysis, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.|Laboratory Chemicals Division, Wako Pure Chemical Industries, Ltd, Osaka, Japan.
authors.forename: Sadamu
authors.initials: S
authors.lastname: Kurono
authors.affiliation: Laboratory of Molecular Signature Analysis, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.|Laboratory Chemicals Division, Wako Pure Chemical Industries, Ltd, Osaka, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Department of Molecular Pathology, Osaka University Graduate School of Medicine and Health Science, Suita, Osaka, Japan.|Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Nariaki
authors.initials: N
authors.lastname: Matsuura
authors.affiliation: Laboratory of Molecular Signature Analysis, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Haruki
authors.initials: H
authors.lastname: Oishi
authors.affiliation: Department of Breast and Endocrine Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Shinzaburo
authors.initials: S
authors.lastname: Noguchi
authors.affiliation: Department of Breast and Endocrine Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Seung Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Breast Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tamaki
authors.affiliation: Osaka Center for Cancer and Cardiovascular Diseases Prevention, Osaka, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Aikawa
authors.affiliation: Kotsuma Clinic, Osaka, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kotsuma
authors.affiliation: Department of Breast Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Inaji
authors.affiliation: Laboratory of Molecular Signature Analysis, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Matsuura
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D024402:Carbonic Anhydrase II / Q000235:genetics* / Q000378:metabolism; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D016022:Case-Control Studies; D002374:Catalase / Q000235:genetics* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D042241:Early Diagnosis; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D000071936:Nipple Discharge / Q000737:chemistry; D054464:Peroxiredoxins / Q000235:genetics* / Q000378:metabolism; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D020543:Proteome; C086065:PRDX2 protein, human; D054464:Peroxiredoxins; D002374:Catalase; D024402:Carbonic Anhydrase II
keywords: 2D LC/MS; Biomarkers; Breast cancer; Nipple discharge; Proteomics