title: Expression of phosphorylated raf kinase inhibitor protein (pRKIP) is a predictor of lung cancer survival.
abstract: BACKGROUND
  Raf-1 kinase inhibitor protein (RKIP) has been reported to negatively regulate signal kinases of major survival pathways. RKIP activity is modulated in part by phosphorylation on Serine 153 by protein kinase C, which leads to dissociation of RKIP from Raf-1. RKIP expression is low in many human cancers and represents an indicator of poor prognosis and/or induction of metastasis. The prognostic power has typically been based on total RKIP expression and has not considered the significance of phospho-RKIP.
  
  
  METHODS
  The present study examined the expression levels of both RKIP and phospho-RKIP in human lung cancer tissue microarray proteomics technology.
  
  
  RESULTS
  Total RKIP and phospho-RKIP expression levels were similar in normal and cancerous tissues. phospho-RKIP levels slightly decreased in metastatic lesions. However, the expression levels of phospho-RKIP, in contrast to total RKIP, displayed significant predictive power for outcome with normal expression of phospho-RKIP predicting a more favorable survival compared to lower levels (P = 0.0118); this was even more pronounced in more senior individuals and in those with early stage lung cancer.
  
  
  CONCLUSIONS
  This study examines for the first time, the expression profile of RKIP and phospho-RKIP in lung cancer. Significantly, we found that phospho-RKIP was a predictive indicator of survival.
authors.affiliation: Unidad de Investigacion en Enferemedades Oncologicas, Hospital Infantil de Mexico, Federico Gomez, SSa, Mexico.
authors.forename: Sara
authors.initials: S
authors.lastname: Huerta-Yepez
authors.forename: Nam K
authors.initials: NK
authors.lastname: Yoon
authors.forename: Angeles
authors.initials: A
authors.lastname: Hernandez-Cueto
authors.forename: Vei
authors.initials: V
authors.lastname: Mah
authors.forename: Clara M
authors.initials: CM
authors.lastname: Rivera-Pazos
authors.forename: Devasis
authors.initials: D
authors.lastname: Chatterjee
authors.forename: Mario I
authors.initials: MI
authors.lastname: Vega
authors.forename: Erin L
authors.initials: EL
authors.lastname: Maresh
authors.forename: Steve
authors.initials: S
authors.lastname: Horvath
authors.forename: David
authors.initials: D
authors.lastname: Chia
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bonavida
authors.forename: Lee
authors.initials: L
authors.lastname: Goodglick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D045744:Cell Line, Tumor; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000401:mortality* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049488:Phosphatidylethanolamine Binding Protein / Q000378:metabolism*; D010766:Phosphorylation; D011379:Prognosis; D016019:Survival Analysis
chemical_list: D049488:Phosphatidylethanolamine Binding Protein