1α,25-dihydroxyvitamin D3 stimulates steroid sulphatase activity in HL60 and NB4 acute myeloid leukaemia cell lines by different receptor-mediated mechanisms

✍ Scribed by Philip J. Hughes; Andreas Steinmeyer; Roshantha A.S. Chandraratna; Geoffrey Brown

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 230 KB
• Volume: 94
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.20377

✦ Synopsis

Abstract

Steroid sulphatase is a key enzyme in the biosynthesis of bioactive estrogens and androgens from highly abundant inactive circulating sulphated steroid precursors. Little is known about how the expression/activity of this enzyme is regulated. In this article, we show that of 1α,25(OH)~2~D~3~ stimulates an increase steroid sulphatase activity in the HL60 myeloid leukaemic cell line that is inhibited by a specific nuclear VDR (VDR~nuc~) antagonist and unaffected by plasma membrane‐associated vitamin D receptor (VDR~mem~) agonists and antagonists. 1α,25(OH)~2~D~3~‐mediated up‐regulation of steroid sulphatase activity in HL60 cells was augmented by RXR agonists, blocked by RXR‐specific antagonists, and RAR specific agonists and antagonists had no effect. In contrast, the 1α,25(OH)~2~D~3~‐mediated up‐regulation of steroid sulphatase activity in the NB4 myeloid leukaemic cell line was unaffected by the specific VDR~nuc~ and RXR antagonists, but was blocked by a VDR~mem~‐specific antagonist and was increased by VDR~mem~‐specific agonists. The findings reveal that VDR~nuc~‐RXR‐heterodimers play a key role in the 1α,25(OH)~2~D~3~‐mediated up‐regulation of steroid sulphatase activity in HL60 cells. However, in NB4 cells, VDR~nuc~‐derived signals do not play an obligatory role, and non‐genomic VDR~mem~‐derived signals are important. © 2005 Wiley‐Liss, Inc.