title: Activation of P21-activated protein kinase 2 is an independent prognostic predictor for patients with gastric cancer.
abstract: OBJECTIVE
  p21-activated kinase (PAK) 2, as a member of the PAK family kinases, is involved in a number of hallmark processes including cell proliferation, survival, mitosis, apoptosis, motility and angiogenesis. However, the clinical significance of the activation of PAK2 in human gastric cancer has not been fully elucidated. The aim of this study was to investigate whether PAK2 expression and its phosphorylation status are correlated with tumor progression and prognosis in gastric cancer.
  
  
  METHODS
  Expression patterns and subcellular localizations of PAK2 and Ser20-phosphorylated PAK2 (pSer20PAK2) in 82 gastric cancer patients were detected by immunohistochemistry.
  
  
  RESULTS
  Both PAK2 and pSer20PAK2 immunostainings were localized in the cytoplasm of tumor cells of gastric cancer tissues. Compared with the normal gastric mucosa, the expression levels of PAK2 and pSer20PAK2 proteins were both significantly increased (both P < 0.001). Additionally, the patients displaying the over-expression of PAK2 and pSer20PAK2 proteins were dramatically associated with unfavorable clinicopathologic variables including higher tumor depth (P = 0.022 and 0.036, respectively), greater extent of lymph node metastasis ((P = 0.022 and 0.036, respectively), positive distant metastasis (P = 0.025 and 0.038, respectively) and advanced tumor stage (P = 0.018 and 0.031, respectively). Moreover, the patients overexpressing PAK2 and pSer20PAK2 proteins have poor overall survival rates relative to those without overexpression of these proteins. Furthermore, cox multi-factor analysis showed that PAK2 (p = 0.012) and pSer20PAK2 (p = 0.010) were independent prognosis factors for human gastric cancer.
  
  
  CONCLUSIONS
  Our data suggest for the first time that PAK2 activation may be associated with advanced tumor progression and poor prognosis of gastric cancer.
  The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1236344107120406.
authors.forename: Chengcheng
authors.initials: C
authors.lastname: Gao
authors.forename: Tianheng
authors.initials: T
authors.lastname: Ma
authors.forename: Liqun
authors.initials: L
authors.lastname: Pang
authors.affiliation: Department of Gastroenterology, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Road West, Huai'an, Jiangsu 223300, P, R, China. gao.jsha@gmail.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Xie
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D004789:Enzyme Activation / Q000502:physiology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010766:Phosphorylation; D011379:Prognosis; D016016:Proportional Hazards Models; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D054462:p21-Activated Kinases / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C515907:PAK2 protein, human; D054462:p21-Activated Kinases