Corcoran Aoife, Nadkarni Sharmin, Yasuda Kaori, Sakaki Toshiyuki, Brown Geoffrey, Kutner Andrzej, Marcinkowska Ewa
Faculty of Biotechnology, University of Wroclaw, 14a Joliot-Curie, Wroclaw 50-383, Poland.
Pharmaceutical Research Institute, 8 Rydygiera, Warsaw 01-793, Poland.
Int J Mol Sci. 2016 Feb 1;17(2):91. doi: 10.3390/ijms17020091.
Structurally similar double-point modified analogues of 1,25-dihydroxyvitamin D₂ (1,25D₂) were screened in vitro for their pro-differentiating activity against the promyeloid cell line HL60. Their affinities towards human full length vitamin D receptor (VDR) and metabolic stability against human vitamin D 24-hydroxylase (CYP24A1) were also tested. The analogues (PRI-1730, PRI-1731, PRI-1732, PRI-1733 and PRI-1734) contained 5,6-trans modification of the A-ring and of the triene system, additional hydroxyl or unsaturation at C-22 in the side chain and reversed absolute configuration (24-epi) at C-24 of 1,25D₂. As presented in this paper, introduction of selected structural modifications simultaneously in two distinct parts of the vitamin D molecule resulted in a divergent group of analogues. Analogues showed lower VDR affinity in comparison to that of the parent hormones, 1,25D₂ and 1,25D₃, and they caused effective HL60 cell differentiation only at high concentrations of 100 nM and above. Unexpectedly, introducing of a 5,6-trans modification combined with C-22 hydroxyl and 24-epi configuration switched off entirely the cell differentiation activity of the analogue (PRI-1734). However, this analogue remained a moderate substrate for CYP24A1, as it was metabolized at 22%, compared to 35% for 1,25D₂. Other analogues from this series were either less (12% for PRI-1731 and PRI-1733) or more (52% for PRI-1732) resistant to the enzymatic deactivation. Although the inactive analogue PRI-1734 failed to show VDR antagonism, when tested in HL60 cells, its structure might be a good starting point for our design of a vitamin D antagonist.
对1,25 - 二羟基维生素D₂（1,25D₂）结构相似的双点修饰类似物进行了体外筛选，以研究其对早幼粒细胞系HL60的促分化活性。还测试了它们对人全长维生素D受体（VDR）的亲和力以及对人维生素D 24 - 羟化酶（CYP24A1）的代谢稳定性。这些类似物（PRI - 1730、PRI - 1731、PRI - 1732、PRI - 1733和PRI - 1734）在A环和三烯系统中含有5,6 - 反式修饰，侧链C - 22处有额外的羟基或不饱和键，且1,25D₂的C - 24处绝对构型反转（24 - 表位）。如本文所述，在维生素D分子的两个不同部分同时引入选定的结构修饰，产生了一组不同的类似物。与母体激素1,25D₂和1,25D₃相比，类似物显示出较低的VDR亲和力，并且它们仅在100 nM及以上的高浓度下才引起有效的HL60细胞分化。出乎意料的是，引入5,6 - 反式修饰并结合C - 22羟基和24 - 表位构型完全关闭了类似物（PRI - 1734）的细胞分化活性。然而，该类似物仍是CYP24A1的中度底物，因为它的代谢率为22%，而1,25D₂为35%。该系列中的其他类似物对酶失活的抗性要么较低（PRI - 1731和PRI - 1733为12%），要么较高（PRI - 1732为52%）。尽管无活性的类似物PRI - 1734在HL60细胞中测试时未显示VDR拮抗作用，但其结构可能是我们设计维生素D拮抗剂的良好起点。
