Effect of oestradiol-17 beta on the expression of oestrogen receptor mRNA in human tonsillar cells.
We have investigated the expression of oestrogen receptor (ER) mRNA in Ficoll-separated tonsillar cells and the changes that occur with the addition of oestradiol (OE2) both in the presence and the absence of the T cell mitogen phytohaemagglutinin (PHA). The amounts of ER mRNA and beta-actin mRNA in the samples were determined by slot blotting and hybridization and quantified by densitometry. The levels of ER mRNA were normalized against the beta-actin mRNA content. In the presence of OE2 (7 x 10(-8) M) after a 10-h culture there was a significant decrease (P < 0.05) to about 66% of the control (0-h culture) ER mRNA levels. Stimulating the cultures with PHA (1 microgram/ml), without the presence of OE2, had no effect on the expression of ER mRNA. However, when OE2 was present in a 10-h culture of PHA-stimulated cells, the ER mRNA level was significantly decreased (P < 0.05) to about 60% of control levels. In 24-h cultures, the presence of OE2 and/or PHA had no effect. When separated T cell preparations from the tonsils were used, no significant effects of OE2 were seen in either the 10-h or 24-h cultures. In conclusion, OE2 downregulates the ER mRNA content in a tonsillar mononuclear cell system in vitro as it does in many primary oestrogen target cells.
Evagelatou
M
M
MRC Clinical Research Centre, Immunodeficiency Diseases Research Group, Harrow, Middlesex, UK.
Farrant
J
J
D000199:Actins / Q000235:genetics; D004958:Estradiol / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D014066:Palatine Tonsil / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000235:genetics*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
D000199:Actins; D010835:Phytohemagglutinins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D004958:Estradiol