Studies on oestrogen receptor-alpha and -beta mRNA in breast cancer.
The oestrogen receptor (ER) is widely used to predict response to tamoxifen in patients with breast cancer. Recently a new form of ER known as ER-beta was discovered, the original ER is now designated ER-alpha. In this investigation, ER-alpha and ER-beta were measured in 107 breast carcinomas and 22 fibroadenomas. Using reverse transcriptase-polymerase chain reaction (RT-PCR), ER-beta mRNA, but not ER-alpha mRNA was expressed more frequently in fibroadenomas than carcinomas. In the carcinomas, ER-beta mRNA was present in a greater proportion of samples positive for ER-alpha mRNA than in those lacking this form of the receptor. ER-alpha, but not ER-beta mRNA, was significantly associated with ER protein-positivity in the cancers. ER-alpha mRNA was also positively related to progesterone receptors (PR), but ER-beta mRNA showed an inverse relationship with PR. We conclude that the presently used enzyme-linked immunosorbent assay (ELISA) for ER appears to be mostly measuring ER-alpha and is unlikely to be detecting ER-beta.
Cullen
R
R
Department of Nuclear Medicine, St. Vincent's University Hospital, 4, Dublin, Ireland.
Maguire
T M
TM
McDermott
E W
EW
Hill
A D
AD
O'Higgins
N J
NJ
Duffy
M J
MJ
D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000175:diagnosis*; D002352:Carrier Proteins / Q000378:metabolism; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005260:Female; D018226:Fibroadenoma / Q000175:diagnosis*; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C010140:estrophilin