TEI-9648, a Vitamin D3 Lactone analogue, is a potent and specific vitamin D receptor (VDR) antagonist. TEI-9648 inhibits VDR/VDRE-mediated genomic actions of 1α,25(OH)2D3. TEI-9648 also inhibits HL-60 cell differentiation induced by of 1α,25(OH)2D3. TEI-9648 has the potential for bone metabolism research[1][2].
TEI-9648 (10-1000 nM) dose-dependently blocks the reciprocal changes of CD11b and CD71 expression associated with HL-60 cell differentiation induced by 1α,25(OH)2D3[1]. TEI-9648 has consistently weaker suppressive effect than TEI-9647[1]. TEI-9648 can not induce cell differentiation even after treatment at 1 μM in HL-60 cell[1]. TEI-9648 alone can not induce activation of NBT-reducing activity or α-NB esterase activity. In contrast, TEI-9648 markedly suppresses the up-regulation induced by 1α,25(OH)2D3 (0.1 nM) in HL-60 cells[1].
[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]. 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.