title: ERK and AKT phosphorylation status in lung cancer and emphysema using nanocapillary isoelectric focusing.
abstract: BACKGROUND
  Emphysema is an independent risk factor for the development of lung cancer in smokers. Activation of oncogenic signalling proteins AKT and ERK by phosphorylation has an established role in the development of lung cancer and has also been implicated in the pathogenesis of emphysema. The aim of this study was to compare the protein level and phosphorylation status of AKT and ERK in paired lung cancer and emphysema tissue using a highly sensitive phosphoprotein analysis approach.
  
  
  METHODS
  An antibody-based, nanocapillary isoelectric focusing (cIEF) assay was used to determine the relative quantities and phosphorylation status of AKT and ERK in tumour and matched lung tissue from patients, with or without evidence of emphysema, undergoing curative resection for non-small cell lung cancer.
  
  
  RESULTS
  20 patients with adenocarcinoma (n=9) or squamous cell carcinoma (n=11) of the lung were included (mean age 67.3 years (SD 7.5, range 47-80 years)), 12 were men and all were current (n=10) or former smokers (n=10). Paired macroscopically normal lung tissue was either histologically normal (n=7) or showed emphysema (n=13). Total and phosphorylated AKT levels were fourfold (p=0.0001) and fivefold (p=0.001) higher in tumour compared with matched lung, respectively. There was no correlation with tumour histology, stage or differentiation; however, total AKT signal in tumour was significantly correlated with fluorodeoxyglucose avidity on positron emission tomography-CT scan (r=0.53, p=0.035). Total ERK was not differentially expressed, but doubly phosphorylated (activated) ERK was threefold higher in emphysema (23.5%, SD 9.2) than either matched tumour (8.8%, SD 8.6) or normal lung tissue (8.3%, SD 9.0) and correlated with the histological severity of emphysema (p=0.005).
  
  
  CONCLUSIONS
  cIEF offers opportunities for quantifying subtle shifts in the phosphorylation status of oncoproteins in nanogram amounts of lung tissue. ERK activation is a feature of emphysema.
authors.affiliation: North West Lung Centre, University Hospital of South Manchester, Manchester, UK; Stem Cell and Leukaemia Proteomics Laboratory, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.
authors.forename: Philip A J
authors.initials: PA
authors.lastname: Crosbie
authors.affiliation: Institute of Cancer Sciences, University of Manchester, St Mary's Hospital , Manchester , UK.
authors.forename: Emma J
authors.initials: EJ
authors.lastname: Crosbie
authors.affiliation: Stem Cell and Leukaemia Proteomics Laboratory , University of Manchester, Manchester Academic Health Science Centre , Manchester , UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Aspinall-O'Dea
authors.affiliation: Stem Cell and Leukaemia Proteomics Laboratory , University of Manchester, Manchester Academic Health Science Centre , Manchester , UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Walker
authors.affiliation: Manchester Medical School, University of Manchester , Manchester , UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Harrison
authors.affiliation: Department of Oncology and Pathology , Karolinska Institutet, SciLifeLab , Stockholm , Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Pernemalm
authors.affiliation: Department of Thoracic Surgery , University Hospital of South Manchester , Manchester , UK.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Shah
authors.affiliation: Department of Pathology , University Hospital of South Manchester , Manchester , UK.
authors.forename: Leena
authors.initials: L
authors.lastname: Joseph
authors.affiliation: North West Lung Centre, University Hospital of South Manchester , Manchester , UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Booton
authors.affiliation: Stem Cell and Leukaemia Proteomics Laboratory , University of Manchester, Manchester Academic Health Science Centre , Manchester , UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Pierce
authors.affiliation: Stem Cell and Leukaemia Proteomics Laboratory , University of Manchester, Manchester Academic Health Science Centre , Manchester , UK.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Whetton
keywords: Emphysema; Lung Cancer; Non-Small Cell Lung Cancer