Inhibin alpha-subunit and the inhibin coreceptor betaglycan are downregulated in endometrial carcinoma.
OBJECTIVE
In the present study we evaluated the protein distribution and mRNA levels of inhibin alpha-subunit and its coreceptor betaglycan in endometrial adenocarcinoma.


METHODS
Two groups of postmenopausal women were studied: the first group had recently diagnosed endometrial adenocarcinoma (n = 16; age range 61-79 years), and the second group (n = 12; age range 64-78 years) had undergone hysterectomy for uterine prolapse and served as control.


METHODS
Inhibin alpha-subunit and betaglycan gene expression and tissue distribution were evaluated by semiquantitative RT-PCR and immunohistochemistry respectively.


RESULTS
Inhibin alpha-subunit and betaglycan mRNAs were expressed by both healthy and tumoral endometria, but their expression was significantly lower in endometrial carcinoma (P < 0.001, based on Student's t test). Inhibin alpha-subunit expression was much weaker in the glands of tumours than in non-neoplastic specimens. Betaglycan protein was identified in the epithelial cells lining non-tumoral endometrium, and in endothelial cells of both normal and tumoral endometria. Well-differentiated neoplastic cells had a faint and scarce betaglycan staining, and poorly differentiated cells did not express betaglycan at all.


CONCLUSIONS
The lower inhibin alpha and betaglycan expression in endometrial adenocarcinoma suggests that the inhibin action may be disrupted. However, the expression of betaglycan in the endothelia of the tumour vasculature suggests that a selective vascular response to inhibin may be possible in these tumours.
Florio
Pasquale
P
Clinic of Obstetrics and Gynaecology, Department of Paediatrics, University of Siena, 53 100 Siena, Italy.
Ciarmela
Pasquapina
P
Reis
Fernando M
FM
Toti
Paolo
P
Galleri
Letizia
L
Santopietro
Rosa
R
Tiso
E
E
Tosi
Piero
P
Petraglia
Felice
F
D029404:Activin Receptors; D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D000368:Aged; D015536:Down-Regulation; D016889:Endometrial Neoplasms / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007265:Inhibins / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D017698:Postmenopause; D011509:Proteoglycans / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D018000:Receptors, Peptide / Q000235:genetics* / Q000378:metabolism; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism
D011509:Proteoglycans; D012333:RNA, Messenger; D018000:Receptors, Peptide; D018125:Receptors, Transforming Growth Factor beta; C094377:inhibin-alpha subunit; C071736:betaglycan; D007265:Inhibins; D029404:Activin Receptors