title: Kinase activity of protein kinase cα in serum as a diagnostic biomarker of human lung cancer.
abstract: BACKGROUND
  Recently, we reported on the existence of activated protein kinase Cα (PKCα) in blood and the possibility for its use in cancer diagnosis.
  
  
  METHODS
  In the present study, serum samples collected from patients with different lung cancer types (small-cell cancer, adenocarcinoma, and anaplastic cancer) were phosphorylated with a PKCα-specific peptide substrate and the phosphorylation ratio was detected by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry.
  
  
  RESULTS
  When 13 patient serum samples were phosphorylated with peptide substrates, phosphorylated peaks were obtained in eight samples. However, no peak associated with the phosphorylated peptide was observed using serum samples obtained from 10 healthy persons. Moreover, broadly used cancer biomarkers (progastrin-releasing peptide, carcinoembryonic antigen, and cytokeratin-19 fragment) were identified in eight samples among the 13 samples studied.
  
  
  CONCLUSIONS
  These results suggest that serum activated PKCα is a reliable biomarker, applicable to lung cancer diagnosis.
authors: Professor, Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors: Jeong-Hun
authors: JH
authors: Kang
authors: Takeshi
authors: T
authors: Mori
authors: Hirotaro
authors: H
authors: Kitazaki
authors: Takuro
authors: T
authors: Niidome
authors: Koichi
authors: K
authors: Takayama
authors: Yoichi
authors: Y
authors: Nakanishi
authors: Yoshiki
authors: Y
authors: Katayama
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000201:enzymology*; D008875:Middle Aged; D051571:Protein Kinase C-alpha / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D051571:Protein Kinase C-alpha