title: The beta form of the estrogen receptor is predominantly expressed in the papillary cystic neoplasm of the pancreas.
abstract: BACKGROUND
  Papillary cystic neoplasm (PCN) of the pancreas is a low-malignancy tumor affecting predominantly young females. Sex steroid hormones have been involved in its development and/or growth. Estrogen receptor (ER) has been scarcely found in this tumor, although there is some evidence suggesting expression of the beta-isoform. Unlike ER, progesterone receptor (PR) expression has been consistently observed. Immunohistochemical analysis of the two isoforms of ER has not been performed in this tumor.
  
  
  OBJECTIVE
  To characterize expression of ER isoforms with an immunohistochemical method.
  
  
  METHODS
  Expression of ER-alpha, ER-beta, and PR was analyzed by immunohistochemistry using isoform-specific ER and PR antibodies in paraffin-embedded tissue blocks from seven cases of PCN of the pancreas.
  
  
  RESULTS
  Most patients were young females. ER-alpha and ER-beta were present in two and six tumors, respectively. PR was identified in six tumors.
  
  
  CONCLUSIONS
  ER-beta expression predominates over the alpha-isoform in PCN of the pancreas. This finding supports the idea that previous negative results on ER expression were a consequence of the use of antibodies with no anti-beta activity. The role of ER-beta in the milieu of factors promoting the development and aggressiveness of PCN needs to be elucidated to address novel diagnostic and therapeutic approaches.
authors.affiliation: Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México City, México.
authors.forename: Angélica
authors.initials: A
authors.lastname: Morales
authors.forename: Andrés
authors.initials: A
authors.lastname: Duarte-Rojo
authors.forename: Arturo
authors.initials: A
authors.lastname: Angeles-Angeles
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Mery
authors.forename: Juan M
authors.initials: JM
authors.lastname: Ruíz-Molina
authors.forename: Vicente
authors.initials: V
authors.lastname: Díaz-Sánchez
authors.forename: Guillermo
authors.initials: G
authors.lastname: Robles-Díaz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000378:metabolism* / Q000473:pathology; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D011960:Receptors, Estrogen / Q000276:immunology / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000276:immunology / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone