Prolactin upregulates sphingosine kinase-1 expression and activity in the human breast cancer cell line MCF7 and triggers enhanced proliferation and migration

Döll, Frauke; Pfeilschifter, Josef; Huwiler, Andrea (2007). Prolactin upregulates sphingosine kinase-1 expression and activity in the human breast cancer cell line MCF7 and triggers enhanced proliferation and migration. Endocrine-related cancer, 14(2), pp. 325-35. Bristol: BioScientifica Ltd. 10.1677/ERC-06-0050

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Sphingosine kinases (SK) catalyze the formation of sphingosine-1-phosphate (S1P) which plays a crucial role in cell growth and survival. Here, we show that prolactin (PRL) biphasically activates the SK-1, but not the SK-2 subtype, in the breast adenocarcinoma cell-line MCF7. A first peak occurs after minutes of stimulation and is followed by a second delayed activation after hours of stimulation. A similar biphasic effect on SK-1 activity is seen for 17beta-estradiol (E(2)). The delayed activation of SK-1 derives from an upregulated mRNA and protein expression and is due to increased SK-1 promoter activity and mechanistically involves STAT5 activation as well as protein kinase C and the classical mitogen-activated protein kinases. Furthermore, glucocorticoids also block both hormone-induced SK-1 expression and activity. Functionally, long-term stimulation of MCF7 cells with PRL or E(2) is well known to trigger increased cell proliferation and migration. Both hormone-induced cell responses critically involve SK-1 activation since the depletion of SK-1, but not SK-2, by siRNA transfection abolishes the hormone-induced cell proliferation and migration. In summary, our data show that PRL and E(2) cause a pronounced delayed SK-1 activation which is due to increased gene transcription, and critically determines the capability of cells to grow and move. Thus, the SK-1 may represent a novel attractive target for anti-tumor therapy.

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Pharmacology
UniBE Contributor:	Döll, Frauke, Huwiler, Andrea
ISSN:	1351-0088
ISBN:	17639048
Publisher:	BioScientifica Ltd.
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:54
Last Modified:	05 Dec 2022 14:16
Publisher DOI:	10.1677/ERC-06-0050
PubMed ID:	17639048
Web of Science ID:	000248720300013
URI:	https://boris.unibe.ch/id/eprint/23003 (FactScience: 38531)