Estrogen receptor beta (ERbeta) is expressed in brain astrocytic tumors and declines with dedifferentiation of the neoplasm.
OBJECTIVE
Estrogen receptor beta (ERbeta) is the second identified receptor mediating the effects of estrogen on target tissues. The role of ERbeta in cancer pathobiology is largely unknown, because specific antibodies have not been available until recently. Initial studies have shown that ERbeta expression declines in breast, ovarian, prostatic, and colon carcinomas. Tamoxifen, a synthetic anti-estrogen compound that is a mixed agonist/antagonist of estrogen receptor alpha (ERalpha) and a pure antagonist of ERbeta, has moderate beneficial effects in human astrocytic neoplasms. However, most published studies agree that glial tumors do not express ERalpha. The purpose of this study was to explore the expression of ERbeta in astrocytic neoplasms.


METHODS
ERbeta expression was monitored immunohistochemically in 56 cases of astrocytomas of all grades (grade I-IV) and in adjacent non-neoplastic brain tissue.


RESULTS
Moderate or strong nuclear immunopositivity was obtained in non-neoplastic astrocytes and in low-grade astrocytomas, whereas the majority of high-grade tumors were immunonegative or displayed weak immunoreactivity. The progressive decline in ERbeta expression paralleled the increase in tumor grade.


CONCLUSIONS
In as much as ERbeta is possibly the only ER expressed in astrocytes, its decreased expression may play an important role in astrocytic tumor initiation and in the potential response of glial neoplasms to tamoxifen.
Batistatou
Anna
A
Department of Pathology, University Campus, P.O. Box 1186, 45110 Ioannina, Greece.
Stefanou
Dimitrios
D
Goussia
Anna
A
Arkoumani
Evdokia
E
Papavassiliou
Athanasios G
AG
Agnantis
Niki J
NJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000737:chemistry* / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001923:Brain Chemistry; D001932:Brain Neoplasms / Q000737:chemistry* / Q000473:pathology*; D002648:Child; D047629:Estrogen Receptor beta / Q000032:analysis*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests
D014408:Biomarkers, Tumor; D047629:Estrogen Receptor beta