Expression of estrogen receptors-alpha and -beta in primary breast neoplasms and tumors exposed to neoadjuvant hormonal therapy.
We studied the content and expression of mRNA for estrogen receptors-alpha and -beta in breast tumors before and after 3-month neoadjuvant hormone therapy with antiestrogen tamoxifen and/or aromatase inhibitors. Expression of estrogen receptors-alpha and -beta was most often detected in ER+PR+ tumors and most significantly decreased in these neoplasms after exemestane therapy. Immunocytochemical and radioligand assays showed that tamoxifen and anastrozole have little effect on the number of estrogen receptors-alpha. The number of progesterone receptors in tumors decreased by the end of anastrozole therapy. Estrogen receptors-beta were immunocytochemically revealed in 50% primary breast tumors. Anastrozole slightly decreased, while tamoxifen increased the incidence of these receptors. Interruption of signaling through estrogen receptors and suppression of estrogen biosynthesis had different effects on the receptor status of neoplasms and distribution of estrogen receptors-alpha and -beta.
Bershtein
L M
LM
N. N. Petrov Institute of Oncology, Russian Ministry of Health, St. Petersburg, Russia.
Poroshina
T E
TE
Zimarina
T S
TS
Tsyrlina
E V
EV
Zhil'tsova
E K
EK
Kovalevskii
A Yu
AY
Semiglazov
V F
VF
D000077384:Anastrozole; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D020847:Estrogen Receptor Modulators / Q000627:therapeutic use; D047628:Estrogen Receptor alpha / Q000187:drug effects / Q000235:genetics*; D047629:Estrogen Receptor beta / Q000187:drug effects / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D009570:Nitriles / Q000008:administration & dosage / Q000627:therapeutic use; D012333:RNA, Messenger / Q000235:genetics; D011980:Receptors, Progesterone / Q000187:drug effects / Q000235:genetics; D013629:Tamoxifen / Q000008:administration & dosage / Q000627:therapeutic use; D014230:Triazoles / Q000008:administration & dosage / Q000627:therapeutic use
D020847:Estrogen Receptor Modulators; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D009570:Nitriles; D012333:RNA, Messenger; D011980:Receptors, Progesterone; D014230:Triazoles; D013629:Tamoxifen; D000077384:Anastrozole