敌敌畏对肝脏细胞色素P450含量及活性水平的影响

目的 观察敌敌畏对小鼠肝脏组织的细胞色素P450（CYP450）含量和氨基比林-N-去甲基化酶活性水平影响，探讨CYP450在敌敌畏代谢中的作用。方法 雄性小鼠16只，随机分成诱导组和对照组，诱导组按10mg／kg腹腔注射敌敌畏，对照组注射生理盐水，每2d一次。14d后处死，分别测定肝脏组织的洲50含量、氨基比林-N-去甲基化酶活性水平，并测定血清丙氨酸氨基转移酶（ALT）活性。结果 小鼠经过14d的敌敌畏诱导后，两组肝脏洲50的含量无统计学意义（P〉0．05）；氨基比林-N-去甲基化酶的活性水平在敌敌畏诱导组明显高于对照组（P〈0．05），两组肝脏的ALT无显著统计学意义（P〉0．05）。结论 低剂量的敌敌畏不引起肝脏功能的损害，肝脏CYP450虽然没有直接参与敌敌畏的代谢且不影响CYP450含量，但氨基比林-N-去甲基化酶活性水平的增加提示部分CYP450参与敌敌畏的中间代谢产物代谢。     

冷冻保存时长对卵裂期胚胎组蛋白表观遗传修饰的影响

【目的】研究不同的冷冻保存时长对人类卵裂期胚胎的组蛋白表观遗传修饰的影响。【方法】采用经患者知情同意捐献用于科研的慢速冷冻的卵裂期胚胎,根据冷冻时长分为6、9和12年组,以新鲜胚胎为对照组,每组6枚捐献胚胎。采用细胞免疫荧光技术观察去乙酰化酶HDAC1、组蛋白（H3K9ac、H3K4me3、H3K9me3）的表达量在各组胚胎中的差异,并以单细胞RT-qPCR技术检测去乙酰化酶HDAC1、甲基化酶（SUV39H1、SET?DB1）、去甲基化酶KDM5A对应mRNA的表达量。【结果】4组胚胎的去乙酰化酶HDAC1、组蛋白（H3K9ac、H3K4me3和H3K9me3）的蛋白表达量无统计学意义的差异（P>0.05）。同时去乙酰化酶HDAC1、甲基化酶SUV39H1对应mRNA的表达量也无统计学意义的差异（P>0.05）。随着胚胎冷冻时长的增加,甲基化酶SETDB1对应mRNA的表达量有递增趋势,然而差异无统计学意义（P>0.05）。去甲基化酶KDM5A对应的mRNA的表达量也随冷冻时长的增加而增强,差异有统计学意义（P<0.05）。【结论】慢速冷冻保存时长对卵裂期胚胎的组蛋白（H3K9ac、H3K4me3和H3K9me3）的蛋白表达量无显著影响,甲基化酶（SUV39H1、SETDB1）对应的mRNA表达量没有明显影响;但随着冷冻保存时长增加,胚胎去甲基化酶KDM5A对应的mRNA表达量增加,有可能导致胚胎转录抑制程度增强。     

Biology and targeting of the Jumonji-domain histone demethylase family in childhood neoplasia: a preclinical overview

Introduction: Epigenetic mechanisms of gene regulatory control play fundamental roles in developmental morphogenesis, and, as more recently appreciated, are heavily implicated in the onset and progression of neoplastic disease, including cancer. Many epigenetic mechanisms are therapeutically targetable, providing additional incentive for understanding of their contribution to cancer and other types of neoplasia.

Areas covered: The Jumonji-domain histone demethylase (JHDM) family exemplifies many of the above traits. This review summarizes the current state of knowledge of the functions and pharmacologic targeting of JHDMs in cancer and other neoplastic processes, with an emphasis on diseases affecting the pediatric population.

Expert opinion: To date, the JHDM family has largely been studied in the context of normal development and adult cancers. In contrast, comparatively few studies have addressed JHDM biology in cancer and other neoplastic diseases of childhood, especially solid (non-hematopoietic) neoplasms. Encouragingly, the few available examples support important roles for JHDMs in pediatric neoplasia, as well as potential roles for JHDM pharmacologic inhibition in disease management. Further investigations of JHDMs in cancer and other types of neoplasia of childhood can be expected to both enlighten disease biology and inform new approaches to improve disease outcomes.     

The role of histone demethylases in cancer therapy

Reversible histone methylation has emerged in the last few years as an important mechanism of epigenetic regulation. Histone methyltransferases and demethylases have been identified as contributing factors in the development of several diseases, especially cancer. Therefore, they have been postulated to be new drug targets with high therapeutic potential. Here, we review histone demethylases with a special focus on their potential role in oncology drug discovery. We present an overview over the different classes of enzymes, their biochemistry, selected data on their role in physiology and already available inhibitors.     

The hinge region in androgen receptor control

The region between the DNA-binding domain and the ligand-binding domain of nuclear receptors is termed the hinge region. Although this flexible linker is poorly conserved, diverse functions have been ascribed to it. For the androgen receptor (AR), the hinge region and in particular the (629)RKLKKL(634) motif, plays a central role in controlling AR activity, not only because it acts as the main part of the nuclear translocation signal, but also because it regulates the transactivation potential and intranuclear mobility of the receptor. It is also a target site for acetylation, ubiquitylation and methylation. The interplay between these different modifications as well as the phosphorylation at serine 650 will be discussed here. The hinge also has an important function in AR binding to classical versus selective androgen response elements. In addition, the number of coactivators/corepressors that might act via interaction with the hinge region is still growing. The importance of the hinge region is further illustrated by the different somatic mutations described in patients with androgen insensitivity syndrome and prostate cancer. In conclusion, the hinge region serves as an integrator for signals coming from different pathways that provide feedback to the control of AR activity.     

组蛋白赖氨酸去甲基化酶家族在膀胱癌中的表达模式及其潜在作用：基于多组学分析

目的 探讨 19 个组蛋白赖氨酸去甲基化酶（KDMs）在膀胱癌多组学中的表达模式与潜在作用。方法 本研究使用UALCAN和GSCALite分析来自TCGA的膀胱癌样本的KDMs的转录表达和甲基化水平、体细胞变异多组学高通量测序数据。使用Kaplan Meier-Plotter和Assistant for clinical bioinformatics探讨KDMs的表达对BLCA样本的预后影响。利用Timer和GSCALite分析KDMs在膀胱癌中的免疫浸润和药物敏感性。结果 分析结果首先揭示了KDMs在膀胱癌多组学中的表达特征,并不是所有KDMs都具有一致的表达模式。转录组数据分析显示KDM1A/1B/2B/4A/4B/5B/5C的表达上调（P<0.05）,而KDM3B/6B/7C的表达下调。甲基化水平差异分析显示KDM1A/3B/4A/4B/4C/5A/5B/5C/7B的甲基化水平下调,而KDM7C甲基化水平上调（P<0.05）。相关性分析显示,14个KDMs家族成员的转录水平与甲基化水平呈负相关,其中KDM1A最显著。突变分析显示,KDM6A非同义突变频率最高,突变种类最多,且与其它KDMs 的非同义突变具有互补性。生存分析显示,KDM3A/4C/5D/6A/7B对BLCA患者总生存率具有保护性作用,而KDM3B/5B/5C对BLCA患者无复发生存率具有危险性影响。综合预后模型证实KDM4C/6A/7B具有膀胱癌预后生物标志物的潜在作用,其表达与BLCA患者免疫浸润呈正相关。药物敏感性分析显示,KDM2B/3B/4B/4C/5A与大多数抗癌药物呈负相关,而KDM2B/4B与6种抗癌药物呈正相关（P<0.05）。结论 本研究系统性地揭示了KDMs基因家族在膀胱癌中的高突变互补性、过表达与低甲基化负相关性的特征,并与膀胱癌预后、免疫浸润和药物敏感性密切相关。