Development of selective nuclear receptor modulators with a 2,25-modified seco-steroidal skeleton

已知1α，25-二羟基维生素D_3 （1α,25(OH)_2D_3）可抑制前列腺癌细胞的增殖和侵袭性。然而，1α,25(OH)_2D_3可引起高钙血症，不适合作为治疗剂。19 .去维生素D衍生物在系统使用时，已知钙化程度较低。为了开发更有效的抗肿瘤药物，我们利用^ 3h -胸苷结合作为细胞增殖的指标，在永生化PZ-HPV-7正常前列腺细胞株中检测了15种c -2取代的19-no -1α，25(OH)_2D_3类似物，包括14-epi类似物的抗增殖活性。在这15个类似物中，我们观察到用2α-或2β-羟丙基取代产生的两种类似物具有比天然的1α，25(OH)_2D_3高约500至1000倍的抗增殖能力。细胞经1α，25(OH)_2D_3、19-no -2α-（3-羟丙基）-1α,25(OH)_2D_3或19-no -2β-（3-羟丙基）-1α,25(OH)_2D_3处理7d后，细胞计数数据支持^ 3h -胸腺嘧啶掺入数据。19-no -2α-（3-羟丙基）-1α,25(OH)_2D_3和19-no -2β-（3-羟丙基）-1α,25(OH)_2D_3在前列腺癌细胞的细胞侵袭研究中也显示出比1α，25(OH)_2D_3高10倍的活性。我们还发现一种含2取代基的14-epi-19-nor-1α，25(OH)_2D_3类似物对OVX模型大鼠具有成骨作用，每天0.1 μg/kg， 1周后骨密度增加18%。这种类似物对该剂量的高钙血症没有效果。在日本有超过1100万的骨质疏松症患者，因此，开发有效的抗骨质疏松药物是非常重要的。综上所述，在19-no -1α，25(OH)_2D_3分子的C-2位置上用3-羟丙基取代可显著提高其抗增殖和抗侵袭能力。因此，这两种类似物可以开发为治疗早期和晚期前列腺癌的有效药物。我们还发现了14-epi-19-nor-1α，25(OH)_2D_3类似物，具有很强的骨形成活性，但没有钙化作用。少

1α,25-Dihydroxyvitamin D_3 (1α,25(OH)_2D_3) is known to inhibit the proliferation and invasiveness of prostate cancer cells. However, 1α,25(OH)_2D_3 can cause hypercalcemia and is not suitable as a therapeutic agent. 19-Norvitamin D derivatives are known to be less calcemic when administered systemically. In order to develop more potent anti-cancer agents with less calcemic side effect, we therefore utilized ^3H-thymidine incorporation as an index for cell proliferation and examined the antiproliferative activities of fifteen C-2-substituted 19-nor-1α,25(OH)_2D_3 analogs including 14-epi analogs in the immortalized PZ-HPV-7 normal prostate cell line. Among the fifteen analogs we observed that the substitution with the 2α- or 2β-hydroxypropyl group produced two analogs having antiproliferative potency that is approximately 500- to 1000-fold higher than the natural 1α,25(OH)_2D_3. The ^3H-thymidine incorporation data were supported by the cell counting data after cells were treated with … More 1α,25(OH)_2D_3, 19-nor-2α-(3-hydroxypropyl)-1α,25(OH)_2D_3 or 19-nor-2β-(3-hydroxypropyp-1α,25(OH)_2D_3 for 7days. 19-Nor-2α-(3-hydroxypropyl)-1α,25(OH)_2D_3 and 19-nor-2β-(3-hydroxypropy1)-1α,25(OH)_2D_3 were also shown to be about 10-fold more active than 1α,25(OH)_2D_3 in cell invasion studies using prostate cancer cells.We also found that one of the 14-epi-19-nor-1α,25(OH)_2D_3 analogs with a 2-substituent showed bone formation effect on the OVX model rats, which was 18% increase in bone density after 0.1 μg/kg treatment a day in one week. This analog has no effect for hypercalcemia with that dose. We have more than eleven million patients of osteoporosis in Japan, today, therefore, it is very important to develop effective anti-osteoporosis drugs.In conclusion, a substitution at the C-2 position of 19-nor-1α,25(OH)_2D_3 molecule with a 3-hydroxypropyl group greatly increased the antiproliferative and anti-invasion potencies. Thus, these two analogs could be developed to be effective therapeutic agents for treating early and late stages of prostate cancer. We also found the 14-epi-19-nor-1α,25(OH)_2D_3 analog which has strong bone formation activity without calcemic effect. Less