title: Quantification and molecular analysis of cathepsin D in breast cyst fluids.
abstract: Cyst fluids from 55 premenopausal women with gross cystic breast disease were classified by K+/Na+ ratio: 19 with ratio over 1 (type I) and 36 with ratio less than 1 (type II). Immunoradiometric assay of cathepsin D in both types of cyst fluids revealed the presence of large amounts of this proteinase. The average concentration of cathepsin D in type I cyst fluids was 63.3 nmol/l, which was significantly higher than that corresponding to type II cyst fluids (35.1 nmol/l). Immunoprecipitation analysis of intracystic cathepsin D demonstrated that this protein was present as the 52 kD non-processed precursor form of the molecule. Since procathepsin D is a useful prognostic marker in breast carcinoma, we suggest that cyst fluid quantification of cathepsin D could aid to detect patients affecting of gross cystic disease with higher risk for developing breast cancer.
authors.affiliation: Departamento de Biología Funcional, Facultad de Medicina, Universidad de Oviedo, Spain.
authors.forename: L M
authors.initials: LM
authors.lastname: Sánchez
authors.forename: F
authors.initials: F
authors.lastname: Vizoso
authors.forename: M T
authors.initials: MT
authors.lastname: Allende
authors.forename: A
authors.initials: A
authors.lastname: Ruibal
authors.forename: C
authors.initials: C
authors.lastname: López-Otín
mesh_terms: D000328:Adult; D002402:Cathepsin D / Q000032:analysis*; D005122:Exudates and Transudates / Q000737:chemistry / Q000201:enzymology*; D005260:Female; D005348:Fibrocystic Breast Disease / Q000201:enzymology* / Q000209:etiology; D006801:Humans; D007527:Isoenzymes / Q000032:analysis*; D008875:Middle Aged; D011188:Potassium / Q000032:analysis; D012964:Sodium / Q000032:analysis
chemical_list: D007527:Isoenzymes; D012964:Sodium; D002402:Cathepsin D; D011188:Potassium