title: Characterisation of the Phosphatidylinositol 3-Kinase Pathway in Non-Small Cell Lung Cancer Cells Isolated from Pleural Effusions.
abstract: OBJECTIVE
  We hypothesised that it was possible to quantify phosphorylation of important nodes in the phosphatidylinositol 3-kinase (PI3K) pathway in cancer cells isolated from pleural effusions of patients with non-small cell lung cancer (NSCLC) and study their correlation to somatic mutations and clinical outcomes.
  
  
  METHODS
  Cells were immunomagnetically separated from samples of pleural effusion in patients with NSCLC. p-AKT, p-S6K and p-GSK3β levels were quantified by ELISA; targeted next-generation sequencing was used to characterise mutations in 26 genes.
  
  
  RESULTS
  It was possible to quantify phosphoproteins in cells isolated from 38/43 pleural effusions. There was a significant correlation between p-AKT and p-S6K levels [r = 0.85 (95% confidence interval 0.73-0.92), p < 0.0001], but not p-AKT and p-GSK3β levels [r = 0.19 (95% confidence interval -0.16 to 0.5), p = 0.3]. A wide range of mutations was described and p-S6K was higher in samples that harboured at least one mutation compared to those that did not (p = 0.03). On multivariate analysis, p-S6K levels were significantly associated with poor survival (p < 0.01).
  
  
  CONCLUSIONS
  Our study has shown a correlation between p-AKT levels and p-S6K, but not GSK3β, suggesting differences in regulation of the distal PI3K pathway by AKT. Higher p-S6K levels were associated with adverse survival, making it a critically important target in NSCLC.
authors.affiliation: The Institute of Cancer Research, London, UK.
authors.forename: Martina
authors.initials: M
authors.lastname: Puglisi
authors.forename: Adam
authors.initials: A
authors.lastname: Stewart
authors.forename: Parames
authors.initials: P
authors.lastname: Thavasu
authors.forename: Michael
authors.initials: M
authors.lastname: Frow
authors.forename: Suzanne
authors.initials: S
authors.lastname: Carreira
authors.forename: Anna
authors.initials: A
authors.lastname: Minchom
authors.forename: Ravi
authors.initials: R
authors.lastname: Punwani
authors.forename: Jaishree
authors.initials: J
authors.lastname: Bhosle
authors.forename: Sanjay
authors.initials: S
authors.lastname: Popat
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ratoff
authors.forename: Johann
authors.initials: J
authors.lastname: de Bono
authors.forename: Timothy Anthony
authors.initials: TA
authors.lastname: Yap
authors.forename: Mary
authors.initials: M
authors.lastname: O''Brien
authors.forename: Udai
authors.initials: U
authors.lastname: Banerji
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D005260:Female; D000071679:Glycogen Synthase Kinase 3 beta / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009360:Neoplastic Cells, Circulating / Q000378:metabolism; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism*; D016066:Pleural Effusion, Malignant / Q000473:pathology*; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D058539:Phosphatidylinositol 3-Kinase; D000071679:Glycogen Synthase Kinase 3 beta; D038762:Ribosomal Protein S6 Kinases, 70-kDa; C448959:ribosomal protein S6 kinase, 70kD, polypeptide 2