Using human adipose stromal cells in monolayer culture as a model system for study of the regulation of aromatase activity, as well as polyclonal antibodies raised in this laboratory against aromatase cytochrome P-450 (cytochrome P-450(AROM)), it was found that the rate of synthesis of cytochrome P-450(AROM) was stimulated by dibutyryl cyclic AMP. This stimulation was attenuated by epidermal growth factor and was potentiated by phorbol esters. These changes in cytochrome P-450(AROM) synthesis were associated with comparable changes in the levels of translatable cytochrome P-450(AROM) mRNA, as well as with changes in the activity or aromatase of these cells. By contrast, there was little change in the synthesis of the reductase component of the aromatase enzyme complex in response to these factors. The increase in mRNA was blocked by cycloheximide, indicative of a requirement for protein synthesis in mediating this inductive response. It is concluded that aromatase activity is regulated primarily by changes in the level of mRNA encoding cytochrome P-450(AROM), and that such changes are likely to a reflection of changes in the rate of transcription of the gene encoding this enzyme. Increases in the levels of cytochrome P-450(AROM) mRNA are apparently mediated by a regulatory protein(s), similar to that found for other steroidogenic forms of cytochrome P-450.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Biological Chemistry|
|State||Published - 1987|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology