title: Inhibin/activin subunits beta-A (-betaA) and beta-B (-betaB) are differentially localised in normal, hyperplastic and malignant human endometrial tissue.
abstract: Inhibins (INHs) are dimeric glycoproteins composed of an alpha (-alpha) subunit and one of two possible beta (beta-) subunits (betaA or betaB). The aims of this study were to determine the frequency and distribution of INH beta (betaA and betaB) subunits in normal, hyperplastic and malignant human endometrium. Endometrial tissue was obtained from normal, hyperplastic (simple, complex and atypical) and endometrioid adenocarcinoma (EC) and INH-alpha, -betaA and -betaB were labelled using immunohistochemistry and immunofluorescence. INH-betaA and -betaB labelling was increased significantly between the proliferative and secretory phase (p<0.05). The lowest labelling was demonstrated in EC, being significantly lower than in secretory phase (p<0.01) and in simple, complex and atypical hyperplastic tissue (p<0.05). For inhibin-betaB, the most intense labelling was noted in atypical hyperplasia compared to EC (p<0.05). A strong colocalisation of inhibin-alpha and -betaA could be demonstrated in malignant endometrial tissue, suggesting the production of inhibin A within the tumour. Additionally, only limited colocalisation of inhibin-betaB with -alpha subunit could be observed, suggesting the synthesis of activin B rather than inhibin B in malignant endometrium. In conclusion, INH-betaA and -betaB were labelled in normal, hyperplastic and malignant endometrium. Hyperplastic tissue labelled more intensely than EC for the presence of INH-betaA and -betaB, suggesting a substantial function in endometrial pathogenesis and an important role in endometrial carcinogenesis.
authors.affiliation: 1st Department of Obstetrics and Gynaecology, Ludwig-Maximilians-University Munich, Munich, Germany. ioannis.mylonas@med.uni-muenchen.de
authors.forename: Ioannis
authors.initials: I
authors.lastname: Mylonas
authors.forename: Josef
authors.initials: J
authors.lastname: Makovitzky
authors.forename: Anna
authors.initials: A
authors.lastname: Hoeing
authors.forename: Dagmar-Ulrike
authors.initials: DU
authors.lastname: Richter
authors.forename: Julia
authors.initials: J
authors.lastname: Vogl
authors.forename: Sandra
authors.initials: S
authors.lastname: Schulze
authors.forename: Udo
authors.initials: U
authors.lastname: Jeschke
authors.forename: Volker
authors.initials: V
authors.lastname: Briese
authors.forename: Klaus
authors.initials: K
authors.lastname: Friese
mesh_terms: D016889:Endometrial Neoplasms / Q000378:metabolism* / Q000473:pathology; D004717:Endometrium / Q000737:chemistry* / Q000473:pathology; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D028322:Inhibin-beta Subunits / Q000032:analysis*; D007265:Inhibins / Q000032:analysis; D008597:Menstrual Cycle; D020033:Protein Isoforms / Q000032:analysis
chemical_list: D020033:Protein Isoforms; C103008:inhibin beta A subunit; C094377:inhibin-alpha subunit; D007265:Inhibins; D028322:Inhibin-beta Subunits