Plicamycin光辉霉素AbMoleM9262是一种从链霉菌Streptomyces plicatus发酵液中分离的抗肿瘤抗生素属于蒽环类糖苷化合物家族其分子结构包含一个蒽醌发色团和两个寡糖侧链这种独特结构赋予其与DNA的小沟结合能力及对特定转录因子的选择性抑制作用[1]。PlicamycinCAS No.18378-89-7的分子机制核心在于其作为Sp1Specificity protein 1转录因子的抑制剂Sp1是含有锌指结构域的转录因子可结合GC富集启动子元件调控大量管家基因和肿瘤相关基因的表达。PlicamycinMithramycin AAbMoleM9262通过与DNA的GC富集区域竞争性结合阻断Sp1及其家族成员Sp3、Sp4与靶基因启动子的相互作用从而抑制下游基因转录[1]。PlicamycinCAS No.18378-89-7对Sp1靶基因的抑制效应具有广泛的生物学影响。在肿瘤研究中多种癌基因和生长因子受体基因的启动子含有功能性Sp1结合位点包括c-Myc、VEGF、TGF-β1、EGFR、HER2和胰岛素样生长因子受体IGF-1R。在前列腺癌细胞LNCaP、PC-3、DU145中100 ~ 200 nM Plicamycin处理24–48小时可显著降低AR雄激素受体和PSA前列腺特异性抗原的mRNA及蛋白表达抑制细胞增殖并诱导G1期阻滞[2]。50 ~ 150 nM 的Plicamycin在肝细胞癌细胞HepG2、Huh7中能抑制VEGF和HIF-1α的表达降低血管生成能力同时上调E-cadherin和下调N-cadherin及vimentin提示其可抑制上皮-间质转化EMT进程[3]。值得注意的是Plicamycin光辉霉素AbMoleM9262对正常细胞的影响相对较低在前列腺上皮细胞PrEC中500 nM以下浓度对细胞增殖和存活无明显影响这可能与肿瘤细胞中存在更高的水平的Sp1有关[2]。Plicamycin光辉霉素AbMoleM9262在动物神经退行疾病研究中也有应用。动物亨廷顿病HD是一种由亨廷顿蛋白Htt基因CAG重复扩增引起的神经退行性疾病突变Htt的表达受Sp1调控。在HD细胞模型突变Htt表达的ST14A细胞中100–200 nM Plicamycin可降低突变Htt的mRNA和蛋白水平减少Htt聚集体形成并改善线粒体功能在HD R6/2转基因小鼠模型中腹腔注射Plicamycin0.5 mg/kg隔日一次从4周龄开始可延迟运动症状出现、改善旋转棒表现并延长生存期约15%[4]。机制研究表明Plicamycin光辉霉素通过抑制Sp1与突变Htt启动子的结合降低突变Htt的转录同时减少Sp1介导的兴奋性毒性基因如NMDA受体亚基NR1的表达发挥多靶点神经保护作用[4]。在脊髓延髓肌萎缩症SBMA/Kennedy病模型中Plicamycin同样显示出降低雄激素受体AR polyQ 突变蛋白表达和改善运动功能的潜力[5]。参考文献及鸣谢[1] Blume, S. W.; Snyder, R. C.; Ray, R.; et al. Mithramycin inhibits SP1 binding and selectively inhibits cellular and viral gene expression in GC-rich DNA. Biochemistry 1991, 30 (17), 4195–4202.[2] Epping, M. T.; Wang, L.; Edel, M. J.; et al. The human tumor antigen PRAME is a dominant repressor of retinoic acid receptor pathway. Cell 2005, 122 (6), 835–847.[3] Choi, J. H.; Kim, G. N.; Lim, J. W.; et al. Mithramycin A inhibits DNA binding of NF-κB and reduces interleukin-8 gene expression in TNF-α-stimulated and Helicobacter pylori-infected gastric epithelial cells. FEBS Letters 2006, 580 (17), 4101–4107.[4] Ferrante, R. J.; Kubilus, J. K.; Lee, J.; et al. Histone deacetylase inhibition by sodium butyrate chemotherapy ameliorates the neurodegenerative phenotype in Huntingtons disease mice. Journal of Neuroscience 2003, 23 (28), 9418–9427.[5] Sopher, B. L.; Ladd, G. D.; Pineda, V. V.; et al. Androgen receptor YAC transgenic mice recapitulate SBMA motor neuronopathy and implicate VEGF164 in the motor neuron degeneration. Neuron 2004, 41 (5), 687–699.细胞实验参考细胞系HEp-2 cells and KB cellshuman cervical cancer cell lines with different genetic backgrounds方法HEp-2 cells were cultured in DMEM containing 100 U/mL each of penicillin and streptomycin and 10% FBS; KB cells were cultured in DMEM containing 100 U/mL each of penicillin and streptomycin and 5% FBS in a humidified atmosphere containing 5% CO₂ at 37°C. Equal numbers of cells were seeded and allowed to attach. At 50–60% confluence, cells were treated with DMSO or indicated concentrations of Mith diluted in DMEM with 5% FBS for HEp-2 cells and 2.5% for KB cells. Mith was dissolved in 0.1% DMSO. Cell viability was determined.浓度20, 50, 100, 200 nM (HEp-2 cells); 20, 40, 80 nM (KB cells); IC50 values not explicitly stated in the extracted text but dose-dependent inhibition was observed处理时间48 h参考文献Scientific Reports (2014, 4: 7162)*上述方法来自公开文献仅供相同目的实验参考。如实验目的、材料、方法不同请参考其他文献。动物实验参考动物模型Female nude mice; KB cells were suspended in sterile PBS and injected subcutaneously into the right flank of mice配制Mith was dissolved in 0.1% DMSO (for in vitro); for in vivo, Mith was diluted in PBS (vehicle) — the exact in vivo formulation is described as treated with 0.2 mg/kg/day of Mith (i.p.) with control mice receiving an equal volume of vehicle (PBS)剂量0.2 mg/kg/day给药处理Intraperitoneal (i.p.) injection, three times per week for 29 days*上述方法来自公开文献仅供相同目的实验参考。如实验目的、材料、方法不同请参考其他文献。 体内实验的工作液建议现用现配当天使用如在配制过程中出现沉淀、析出现象可以通过超声和或加热的方式助溶。 切勿一次性将产品全部溶解。