leptin has been researched along with 4-hydroxyestradiol* in 2 studies
2 other study(ies) available for leptin and 4-hydroxyestradiol
| Article | Year |
|---|---|
Unique effect of 4-hydroxyestradiol and its methylation metabolites on lipid and cholesterol profiles in ovariectomized female rats.
Animal studies have shown that endogenous estrogens such as 17β-estradiol (E Topics: Adipose Tissue; Animals; Body Weight; Cholesterol; Cholesterol 7-alpha-Hydroxylase; Eating; Estrogens, Catechol; Female; Gene Expression Regulation, Enzymologic; Leptin; Liver; Liver X Receptors; Methylation; Ovariectomy; PPAR gamma; Rats; Rats, Sprague-Dawley | 2017 |
Leptin induces CYP1B1 expression in MCF-7 cells through ligand-independent activation of the ERα pathway.
Leptin, a hormone with multiple biological actions, is produced predominantly by adipose tissue. Among its functions, leptin can stimulate tumour cell growth. Oestrogen receptor α (ERα), which plays an essential role in breast cancer development, can be transcriptionally activated in a ligand-independent manner. In this study, we investigated the effect of leptin on CYP1B1 expression and its mechanism in breast cancer cells. Leptin induced CYP1B1 protein, messenger RNA expression and promoter activity in ERα-positive MCF-7 cells but not in ERα-negative MDA-MB-231 cells. Additionally, leptin increased 4-hydroxyoestradiol in MCF-7 cells. Also, ERα knockdown by siRNA significantly blocked the induction of CYP1B1 expression by leptin, indicating that leptin induced CYP1B1 expression via an ERα-dependent mechanism. Transient transfection with CYP1B1 deletion promoter constructs revealed that the oestrogen response element (ERE) plays important role in the up-regulation of CYP1B1 by leptin. Furthermore, leptin stimulated phosphorylation of ERα at serine residues 118 and 167 and increased ERE-luciferase activity, indicating that leptin induced CYP1B1 expression by ERα activation. Finally, we found that leptin activated ERK and Akt signalling pathways, which are upstream kinases related to ERα phosphorylation induced by leptin. Taken together, our results indicate that leptin-induced CYP1B1 expression is mediated by ligand-independent activation of the ERα pathway as a result of the activation of ERK and Akt in MCF-7 cells. Topics: Aryl Hydrocarbon Hydroxylases; Breast Neoplasms; Cell Line, Tumor; Cytochrome P-450 CYP1B1; Estrogen Receptor alpha; Estrogens, Catechol; Female; Humans; Leptin; MCF-7 Cells; Phosphorylation; Response Elements; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Transcriptional Activation; Transfection; Up-Regulation | 2014 |