title: Expression of the tumor suppressor gene maspin and its significance in intraductal papillary mucinous neoplasms of the pancreas.
abstract: BACKGROUND
  Maspin is a member of the serpin family of protease inhibitors and is thought to inhibit carcinoma invasion, metastasis, and angiogenesis and induce apoptosis. We examined maspin expression immunohistochemically and assessed its significance in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.
  
  
  METHODS
  We examined 39 surgically resected specimens of IPMN that included 17 adenomas (IPMAs), 5 borderline tumors (IPMBs), 4 non-invasive carcinomas (non-invasive IPMCs), and 13 invasive carcinomas (invasive IPMCs). Immunostaining was performed according to the EnVision ChemMate method. The degree of maspin expression was scored and assessed according to the percentage and staining intensity of positive cells.
  
  
  RESULTS
  Maspin expression was minimal in normal pancreatic duct epithelium, whereas in IPMNs, maspin was expressed in neoplasms of all stages. Maspin expression increased with increasing grade from IPMAs, IPMBs, to non-invasive IPMCs but decreased significantly in invasive IPMCs. No specific association between maspin expression and mucin type was found. Analysis of maspin expression with respect to clinicopathologic factors in cases of invasive IPMC revealed a greater extent of invasion in cases of low maspin expression and significantly fewer apoptotic cells in the tumor.
  
  
  CONCLUSIONS
  Maspin was expressed at high levels in IPMNs at various stages from adenoma to invasive carcinoma, and our results suggest that maspin may be involved in the occurrence and progression of IPMN. In addition, our data suggest that the apoptosis-inducing action of maspin suppresses invasion and progression of IPMN.
authors.affiliation: First Department of Pathology, Showa University School of Medicine, Tokyo, Japan. kyoko119@med.showa-u.ac.jp
authors.forename: Kyoko
authors.initials: K
authors.lastname: Kashima
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ohike
authors.forename: Seishiro
authors.initials: S
authors.lastname: Mukai
authors.forename: Masashi
authors.initials: M
authors.lastname: Sato
authors.forename: Manabu
authors.initials: M
authors.lastname: Takahashi
authors.forename: Toshio
authors.initials: T
authors.lastname: Morohoshi
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000378:metabolism* / Q000473:pathology; D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D000368:Aged; D017209:Apoptosis; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D015843:Serpins / Q000378:metabolism*
chemical_list: C085344:SERPIN-B5; D015843:Serpins