TEI-9647

TEI-9647, a Vitamin D3 Lactone analogue, is a potent and specific vitamin D receptor (VDR) antagonist. TEI-9647 inhibits VDR/VDRE-mediated genomic actions of 1α,25(OH)2D3. TEI-9647 inhibits bone resorption and HL-60 cell differentiation induced by of 1α,25(OH)2D3. TEI-9647 has the potential for suppressing the excessive bone resorption and osteoclast formation in Paget’s disease[1][2][3].

TEI-9647 (100 nM; 24 hours) treatment clearly suppresses p21WAF1,CIP1 gene expression induced by 1α,25(OH)2D3[1].TEI-9647 (10-1000 nM; 96 hours) dose-dependently blocks the reciprocal changes of CD11b and CD71 expression associated with HL-60 cell differentiation induced by 1α,25(OH)2D3. TEI-9647 completely blocks the increase in CD11b and the decrease in CD71 expression at 100 nM[1]. TEI-9647 blocks both 1α,25(OH)2D3-mediated HL-60 cell differentiation and also activation of the luciferase reporter in COS-7 cells that has been transfected with the cDNA containing the DRE of the rat 25(OH)D3-24-hydroxylase gene and cDNA of the human vitamin D nuclear receptor[1].TEI-9647 can not induce cell differentiation even after treatment at 1 μM in HL-60 cell. TEI-9647 alone can not induce activation of NBT-reducing activity or α-NB esterase activity. In contrast, TEI-9647 markedly suppresses the up-regulation induced by 1α,25(OH)2D3 (0.1 nM) in HL-60 cells[1]. TEI-9647 (0.001-1 μM; for 10 days) dose-dependently inhibits bone resorption induced by of 1α,25(OH)2D3 (1 nM). TEI-9647 alone never induces bone resorption even at 1 μM[2]. TEI-9647 (10 nM; 12 h) markedly inhibits TAFII-17 and 25-OH-D3-24-hydroxylase gene expression induced by 1α,25(OH)2D3 (0.1 nM) in bone marrow cells[2]. RT-PCR[1] Cell Line: HL-60 cells

[1]. Miura D, et al. Antagonistic action of novel 1α,25-dihydroxyvitamin D3-26, 23-lactone analogs on differentiation of human leukemia cells (HL-60) induced by 1α,25-dihydroxyvitamin D3. J Biol Chem. 1999 Jun 4;274(23):16392-9. [2]. Seiichi Ishizuka, et al. Vitamin D antagonist, TEI-9647, inhibits osteoclast formation induced by 1α,25-dihydroxyvitamin D3 from pagetic bone marrow cells. J Steroid Biochem Mol Biol. 2004 May;89-90(1-5):331-4. [3]. Kazuya Takenouchi, et al. Synthesis and structure-activity relationships of TEI-9647 derivatives as Vitamin D3 antagonists. J Steroid Biochem Mol Biol. 2004 May;89-90(1-5):31-4.