Regulation of protein kinase C delta by estrogen in the MCF-7 human breast cancer cell line.
Mol Cell Endocrinol
; 148(1-2): 109-18, 1999 Feb 25.
Article
em En
| MEDLINE
| ID: mdl-10221776
ABSTRACT
We have previously shown that estrogen up-regulates expression of protein kinase C (PKC) delta in the rat and rabbit corpus luteum as well as in luteinized rat granulosa primary cell cultures. To determine whether a similar regulation of the PKC delta isoform by estrogen occurred in another estrogen responsive system, we investigated the estrogen receptor positive MCF-7 human breast cancer cells. In a characterization of PKC isoforms in MCF-7 cells we determined that PKC delta was the predominant PKC isoform. However in contrast to the effect of estrogen on PKC delta expression in ovarian cells, estrogen treatment of MCF-7 cells resulted in a significant decrease in PKC delta protein and mRNA expression in a time and dose dependent manner. Treatment of MCF-7 cells with 10(-10)-10(-8) M estrogen for 7 days down-regulated specifically PKC delta mRNA and protein while expression of other PKC isoforms was unchanged. The opposite regulation of PKC delta expression in ovarian and breast cancer cells prompted us to evaluate the type of estrogen receptor present in both cell types. Results showed that luteinized rat granulosa cells expressed predominantly estrogen receptor beta while the MCF-7 cells expressed predominantly estrogen receptor alpha and barely detectable levels of estrogen receptor beta. These results suggest that the differential ability of estrogen to regulate PKC beta expression could potentially be a result of differential signaling through the two estrogen receptor subtypes.
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Base de dados:
MEDLINE
Assunto principal:
Proteína Quinase C
/
Regulação Enzimológica da Expressão Gênica
/
Regulação Neoplásica da Expressão Gênica
/
Estrogênios
/
Isoenzimas
Limite:
Animals
/
Female
/
Humans
Idioma:
En
Revista:
Mol Cell Endocrinol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Estados Unidos