title: Loss of PTEN expression is associated with poor prognosis in patients with intraductal papillary mucinous neoplasms of the pancreas.
abstract: OBJECTIVE
  Previously, we reported PIK3CA gene mutations in high-grade intraductal papillary mucinous neoplasms (IPMN). However, the contribution of phosphatidylinositol-3 kinase pathway (PI3K) dysregulation to pancreatic carcinogenesis is not fully understood and its prognostic value unknown. We investigated the dysregulation of the PI3K signaling pathway in IPMN and its clinical implication.
  
  
  METHODS
  Thirty-six IPMN specimens were examined by novel mutant-enriched sequencing methods for hot-spot mutations in the PIK3CA and AKT1 genes. PIK3CA and AKT1 gene amplifications and loss of heterozygosity at the PTEN locus were also evaluated. In addition, the expression levels of PDPK1/PDK1, PTEN, and Ki67 were analyzed by immunohistochemistry.
  
  
  RESULTS
  Three cases carrying the E17K mutation in the AKT1 gene and one case harboring the H1047R mutation in the PIK3CA gene were detected among the 36 cases. PDK1 was significantly overexpressed in the high-grade IPMN versus low-grade IPMN (P = 0.034) and in pancreatic and intestinal-type of IPMN versus gastric-type of IPMN (P = 0.020). Loss of PTEN expression was strongly associated with presence of invasive carcinoma and poor survival in these IPMN patients (P = 0.014).
  
  
  CONCLUSIONS
  This is the first report of AKT1 mutations in IPMN. Our data indicate that oncogenic activation of the PI3K pathway can contribute to the progression of IPMN, in particular loss of PTEN expression. This finding suggests the potential employment of PI3K pathway-targeted therapies for IPMN patients. The incorporation of PTEN expression status in making surgical decisions may also benefit IPMN patients and should warrant further investigation.
authors.affiliation: Authors' Affiliations: Herbert Irving Comprehensive Cancer Center; Departments of Pathology, Surgery, and Otolaryngology/Head and Neck Surgery; Institute for Cancer Genetics, Columbia University Medical Center; and The Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York.
authors.forename: Dario
authors.initials: D
authors.lastname: Garcia-Carracedo
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Turk
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Fine
authors.forename: Nathan
authors.initials: N
authors.lastname: Akhavan
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Tweel
authors.forename: Ramon
authors.initials: R
authors.lastname: Parsons
authors.forename: John A
authors.initials: JA
authors.lastname: Chabot
authors.forename: John D
authors.initials: JD
authors.lastname: Allendorf
authors.forename: Jeanine M
authors.initials: JM
authors.lastname: Genkinger
authors.forename: Helen E
authors.initials: HE
authors.lastname: Remotti
authors.forename: Gloria H
authors.initials: GH
authors.lastname: Su
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000235:genetics / Q000473:pathology*; D058534:Class I Phosphatidylinositol 3-Kinases; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009154:Mutation; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis* / Q000235:genetics; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology*; D019869:Phosphatidylinositol 3-Kinases / Q000096:biosynthesis; D011379:Prognosis; D015398:Signal Transduction / Q000235:genetics
chemical_list: D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human