目的探讨甲基转移酶5(methyltransferase-like 5,METTL5)在三阴乳腺癌(triple-negative breast cancer,TNBC)中的作用和潜在机制。方法采用免疫组织化学方法和Western blot检测TNBC肿瘤组织和细胞系中METTL5的表达情况。用靶向METTL5的s...目的探讨甲基转移酶5(methyltransferase-like 5,METTL5)在三阴乳腺癌(triple-negative breast cancer,TNBC)中的作用和潜在机制。方法采用免疫组织化学方法和Western blot检测TNBC肿瘤组织和细胞系中METTL5的表达情况。用靶向METTL5的shRNA(shRNA-METTL5)转染TNBC细胞后,用CCK-8、集落形成、伤口愈合以及Transwell实验分别检测细胞增殖活性、迁移与侵袭,Western blot检测Wnt/β-catenin信号关键蛋白的表达。构建异种移植瘤模型,验证敲降METTL5对TNBC细胞在体内生长以及Wnt/β-catenin信号活性的影响。结果METTL5在TNBC肿瘤组织和细胞系中表达上调(P<0.01)。敲降METTL5可抑制TNBC细胞的增殖、迁移和侵袭并降低了Wnt/β-catenin信号分子β-catenin、细胞周期蛋白(Cyclin)D1、基质金属蛋白酶(MMP)-2和MMP-7的表达(均P<0.01)。体内实验显示,敲降METTL5减缓了移植瘤生长和Wnt/β-catenin信号活性。结论敲降METTL5能抑制TNBC细胞的增殖、迁移与侵袭,其作用可能与抑制Wnt/β-catenin信号通路有关。展开更多
Use of free air as oxidant and copper(II)chloride as catalyst,3,3'-di-tert-butylbi-phenyl-2,5,2',5'-diquinone(BBDQ)was prepared via catalytic oxidation of 2,2'-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethoxy-bip...Use of free air as oxidant and copper(II)chloride as catalyst,3,3'-di-tert-butylbi-phenyl-2,5,2',5'-diquinone(BBDQ)was prepared via catalytic oxidation of 2,2'-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethoxy-biphenyl(di-BHA).The yield of reaction attained 95% and the selectivity for BBDQ was 100%.The single-crystal X-ray diffraction analysis reveals that the dihedral angle between two rings(benzene rings for di-BHA and quinone rings for BBDQ)changes from 89.8 to 45.3o,indicating the steric hindrance effects of methyl disappear in the oxidation process.The crystal structures of di-BHA and BBDQ are further confirmed by their spectral characterizations.The probable mechanism for this oxidation process is also discussed.展开更多
基金supported by the 973 Program (2005CB623607)the National Natural Science Foundation of China (No.20771061)the scientific program 2008BAE64B09
文摘Use of free air as oxidant and copper(II)chloride as catalyst,3,3'-di-tert-butylbi-phenyl-2,5,2',5'-diquinone(BBDQ)was prepared via catalytic oxidation of 2,2'-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethoxy-biphenyl(di-BHA).The yield of reaction attained 95% and the selectivity for BBDQ was 100%.The single-crystal X-ray diffraction analysis reveals that the dihedral angle between two rings(benzene rings for di-BHA and quinone rings for BBDQ)changes from 89.8 to 45.3o,indicating the steric hindrance effects of methyl disappear in the oxidation process.The crystal structures of di-BHA and BBDQ are further confirmed by their spectral characterizations.The probable mechanism for this oxidation process is also discussed.