title: Axl Is a Potential Cancer Prognostic Marker for the Migration and Invasion of Nasopharyngeal Carcinoma.
abstract: BACKGROUND
  The Axl receptor tyrosine kinase has been demonstrated to be elevated and activated in many human cancers including liver, lung, breast, and pancreatic cancer. Its high expression has been considered as a cancer biomarker for predicting poor prognosis and increased invasiveness/metastasis.
  
  
  OBJECTIVE
  The aim of the study was to investigate the clinical significance of Axl in nasopharyngeal carcinoma (NPC) and its role in cell migration and invasion.
  
  
  METHODS
  We detected Axl expression in 86 collected NPC tissues and 20 collected normal nasopharyngeal epithelial tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemical staining. Axl was knocked down by a specific shRNA in NPC cell lines, 5-8F and 6-10B. Transwell assays were used to determine NPC cell migration and invasion.
  
  
  RESULTS
  The expressions of Axl mRNA and protein in NPC tissues were significantly higher than those in normal nasopharyngeal epithelial tissues (p < 0.05, respectively). The positive expression of Axl was significantly correlated with distant metastasis and high TNM stage in NPC (p < 0.05, respectively). Furthermore, Axl positive expression was correlated with a worse overall survival of NPC patients (p < 0.05). Multivariate Cox repression analysis indicated that Axl was an independent factor for predicting overall survival of NPC patients (p < 0.05). In vitro studies found that Axl knockdown significantly reduced the number of migrated and invaded 5-8F and 6-10B cells (p < 0.05, respectively).
  
  
  CONCLUSIONS
  The positive expression of Axl is correlated with the poor clinicopathological features in NPC. Furthermore, Axl is an independent prognostic marker for predicting overall survival of NPC patients. Functionally, Axl may facilitate tumour progression by promoting NPC cell migration and invasion.
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China.
authors.forename: Chengyi
authors.initials: C
authors.lastname: Jiang
authors.affiliation: Department of Pathology, Bengbu Medical College, Bengbu, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Immunology, Bengbu Medical College, Bengbu, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Laboratory, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China.
authors.forename: Yajia
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods / Q000706:statistics & numerical data; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods / Q000706:statistics & numerical data; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000706:statistics & numerical data; D000094963:Axl Receptor Tyrosine Kinase
chemical_list: D014408:Biomarkers, Tumor; D011518:Proto-Oncogene Proteins; D020794:Receptor Protein-Tyrosine Kinases; D000094963:Axl Receptor Tyrosine Kinase; C000722289:AXL protein, human
keywords: Axl; invasion; migration; nasopharyngeal carcinoma; prognosis