Oestrogen receptors alpha and beta differ in normal human breast and breast carcinomas.
The identification of a second oestrogen receptor, oestrogen receptor (ER) beta, has led to a need to assess the relative importance of the classical ERalpha and ERbeta in human breast and breast carcinomas. ERalpha and ERbeta mRNA was assessed in 61 carcinomas, 8 benign breast lesions, and 30 samples of normal breast using reverse transcriptase (RT)-nested polymerase chain reaction (PCR). Immunohistochemical analysis of ERalpha and ERbeta was performed in 62 carcinomas, the 38 non-malignant breast tissues, and 32 normal breast samples with menstrual cycle data. ERalpha mRNA was detected in 92% of breast cancers, with ERbeta mRNA (wild-type and/or variant form) in 85%; 72% had ERalpha protein, 62% progesterone receptor (PgR), and 32% ERbeta. ERalpha protein had a strong correlation with grade; ERbeta did not, although it was present in three of four grade I carcinomas and in special types. There was no correlation between the presence of ERalpha and ERbeta protein. In non-malignant breast, similar expression of ERalpha and beta was observed, apart from expression of ERbeta in stromal cells and myoepithelium, the latter being confirmed by RT-PCR and western blotting. There were differences in ERalpha in relation to the menstrual cycle but not PgR or ERbeta. The findings indicate a need to understand the role and regulation of ERbeta in normal breast and the reason for its down-regulation in mammary carcinogenesis.
Shaw
Jacqueline A
JA
Breast Cancer Research Unit, Department of Pathology, University of Leicester, Clinical Sciences, Glenfield Hospital, Groby Road, Leicester LE3 9QP, UK.
Udokang
Kufre
K
Mosquera
Juan-Miguel
JM
Chauhan
Hina
H
Jones
J Louise
JL
Walker
Rosemary A
RA
D000328:Adult; D001940:Breast / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005260:Female; D015870:Gene Expression; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone