Raloxifene increases proliferation of human endothelial cells in association with increased gene expression of cyclins A and B1.
OBJECTIVE
To examine the proliferative effect of of raloxifene on human umbilical-vein endothelial cells (HUVECs), and to investigate whether there is an associated increased expression of some key regulators of the cell cycle.


METHODS
Cell culture for different incubation times.


METHODS
University research laboratory.


METHODS
Sources of HUVECs.


METHODS
Measurement of cell proliferation, of protein levels of cyclin A, cyclin B1, cyclin D1, cyclin-dependent protein kinase (CDK) 2, CDK4, and p27(Kip1), and of messenger RNA expression of cyclin A, cyclin B1, and p27(Kip1).


METHODS
Cell proliferation was measured by the 3-(4.5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the bromo-2'-deoxyuridine assay, and the sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis (4-methoxy-6-nitro) benzene sulfonic acid hydrate assay. Changes in protein expression were measured by immunoblotting, and modifications in gene expression were measured by quantitative real-time polymerase chain reaction.


RESULTS
Both 1 nM and 10 nM of either E(2) or raloxifene achieved a similar increase in cell proliferation. The pure antiestrogen ICI 182780 only blocked the E(2)-induced proliferative effect. Western blot experiments detected an increase in the expression of only cyclin A and B1, and a decreasing trend for p27(Kip1). Enhancements in gene expression were observed in response to E(2) and raloxifene for cyclin A and B1. No significant changes were found for p27(Kip1). The ICI 182780 effectively abrogated the increased gene expression associated with E(2) for cyclin B1, but not for cyclin A. In contrast, ICI 182780 was ineffective in the case of raloxifene.


CONCLUSIONS
Raloxifene increased the proliferation of HUVECs in association with enhanced gene expression of cyclins A and B1.
Oviedo
Pilar J
PJ
Department of Pediatrics, Obstetrics and Gynecology, Faculty of Medicine, University of Valencia, Valencia, Spain.
Hermenegildo
Carlos
C
Tarín
Juan J
JJ
Cano
Antonio
A
D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D019925:Cyclin A / Q000235:genetics* / Q000378:metabolism; D019926:Cyclin B / Q000235:genetics* / Q000378:metabolism; D056744:Cyclin B1; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D004958:Estradiol / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020849:Raloxifene Hydrochloride / Q000494:pharmacology*; D011960:Receptors, Estrogen / Q000235:genetics; D020845:Selective Estrogen Receptor Modulators / Q000494:pharmacology
C534699:CCNB1 protein, human; D019925:Cyclin A; D019926:Cyclin B; D056744:Cyclin B1; D011960:Receptors, Estrogen; D020845:Selective Estrogen Receptor Modulators; D050760:Cyclin-Dependent Kinase Inhibitor p27; D020849:Raloxifene Hydrochloride; D004958:Estradiol