微小RNA在卵巢肿瘤中的研究进展

微小RNA(miRNA)是动植物基因组中广泛存在的一类非编码单链小分子RNA,在转录后水平以完全或非完全互补的方式与其靶mRNA相结合,调节相应mRNA表达,影响生物学性状.研究发现,miRNA参与生命过程中一系列重要进程,包括基因表达调控,细胞增殖、分化,脂肪代谢,早期胚胎发育等,与人类多种疾病密切相关.目前,miRNA在卵巢肿瘤的研究尚处于起步阶段.主要包括miRNA在卵巢肿瘤的表达检测;miRNA与卵巢肿瘤的发生、分化、预后的相关性及其机制的研究:以及miRNA在卵巢肿瘤的诊断、治疗等应用方面的探索.     

微小RNA在卵巢肿瘤中的研究进展

微小RNA（miRNA）是动植物基因组中广泛存在的一类非编码单链小分子RNA,在转录后水平以完全或非完全互补的方式与其靶mRNA相结合,调节相应mRNA表达,影响生物学性状。研究发现,miRNA参与生命过程中一系列重要进程,包括基因表达调控,细胞增殖、分化,脂肪代谢,早期胚胎发育等,与人类多种疾病密切相关。目前,miRNA在卵巢肿瘤的研究尚处于起步阶段。主要包括miRNA在卵巢肿瘤的表达检测;miRNA与卵巢肿瘤的发生、分化、预后的相关性及其机制的研究：以及miRNA在卵巢肿瘤的诊断、治疗等应用方面的探索。     

配子及早期胚胎发育过程中的DNA甲基化动态改变

<正>近年来，随着对染色质DNA、组蛋白、RNA化学修饰了解的深入，表观遗传学在胚胎发育、疾病发生发展中的生物学作用被逐步揭示。其中，DNA甲基化作为一种重要的表观遗传学修饰，在基因表达调控与染色质结构调节中具有重要作用。在哺乳动物细胞中，胞嘧啶-鸟嘌呤二核苷酸(CpG)中胞嘧啶第5位碳原子甲基化(5mC)占99%,是最主要的甲基化类型。因此，本文关于配子和胚胎发育过程中的甲基化变化讨论也以5mC为主。在人类体细胞中，     

微小RNA在宫颈癌中的研究进展

微小RNA(microRNA,miRNA)是一类小分子的非编码调控的单链RNA。研究发现,miRNA参与有机体的一系列生理过程,包括基因表达调控和细胞增殖、分化、凋亡等,与人类的多种疾病密切相关。目前,miRNA在宫颈癌的研究尚处于初级阶段,主要包括miRNA在宫颈癌的表达检测;miRNA与宫颈癌的发生、分化、转移、预后的相关性及其机制的研究;及miRNA在宫颈癌的诊断、治疗等应用方面的探索。     

miRNA在妇科恶性肿瘤发病机制中的研究进展

MicroRNAs(miRNAs)是一种新的内源性非编码RNA(non-coding RNAs,ncRNAs),可通过靶信使RNA(message RNA,mRNA)在转录后水平发挥基因调控作用。近年研究证实,在包括肿瘤在内的多种疾病表达谱中miRNA表达有所改变,提示miRNA可能在不同疾病的发生过程中发挥了某种调节作用。越来越多的研究表明,miRNA与肿瘤的发生、发展、诊断、治疗和预后密切相关。现将miRNA与妇科恶性肿瘤研究方面的进展作一简要综述。     

微小RNA在宫颈癌中的研究进展

微小RNA（microRNA,miRNA）是一类小分子的非编码调控的单链RNA。研究发现,miRNA参与有机体的一系列生理过程,包括基因表达调控和细胞增殖、分化、凋亡等,与人类的多种疾病密切相关。目前。miRNA在宫颈癌的研究尚处于初级阶段,主要包括miRNA在宫颈癌的表达检测;miRNA与宫颈癌的发生、分化、转移、预后的相关性及其机制的研究;及miRNA在宫颈癌的诊断、治疗等应用方面的探索。     

微小RNA(microRNA)与雄性生殖

作为非编码RNA家族的一类重要成员,目前越来越多的证据显示microRNA(miRNA)分子广泛参与细胞增殖、分化、凋亡、信号转导、器官形成、脂肪代谢、造血、胚胎发育、病毒复制,甚至肿瘤发生等多种细胞生命活动进程的调控。对人与鼠睾丸组织的小RNA克隆文库测序发现了大量表达的miRNA分子,研究显示这些睾丸高丰度或特异表达的miRNAs可能发挥极其重要的对生殖细胞性别决定、自我更新、精原细胞有丝分裂增殖、精母细胞减数分裂以及圆形精子细胞变态等过程的调控作用。     

微小RNA在女性生殖调节中的研究进展

微小RNA(miRNA)是含有19~22个核苷酸序列的短链非编码RNA,调控内源性基因的转录后表达。随着miRNA在生殖领域不断被发现,miRNA作为女性生殖系统的重要调控因子越来越受到关注。miRNA通过调节靶基因的转录后水平,调控卵巢颗粒细胞的增殖、分化和凋亡并参与控制类固醇激素的分泌。卵巢功能异常,如多囊卵巢综合征(PCOS)和卵巢早衰(POF)均会发生miRNA调控异常。除此之外,miRNA还通过调节目标基因的表达决定胚胎的整倍体性及胚胎发育的命运。miRNA对于维持子宫内膜容受性非常重要,miRNA的异常表达会导致子宫内膜种植窗的偏移,从而导致胚胎种植失败。对miRNA在生殖调节中作用的了解,有助于发现新的预测体外受精成功率的生物指标和靶向治疗的位点,进一步提高辅助生殖的有效性和安全性。     

微小RNA在宫颈癌中的研究进展

微小RNA（microRNA,miRNA）是一类由18～25个核苷酸小分子组成的非编码单链小RNA。大量研究表明,miRNA在细胞增殖、凋亡和肿瘤形成等方面发挥重要作用,与多种肿瘤的发生、发展、侵袭、转移密切相关,近年有关miRNA与宫颈癌关系的研究日益增多。在宫颈癌中miRNA表达谱存在明显异常,提示其可能在宫颈癌的发生和发展中扮演重要角色,但关于miRNA在宫颈癌中表达异常的调控机制目前研究较少,仍有待进一步研究。现就宫颈癌中miRNA的异常表达及其可能的调控机制进行综述。     

miRNA与卵巢癌的研究进展

microRNAs(miRNAs或miRs)是一类在转录后水平调控基因表达的单链非编码小分子RNA.miRNA能调控机体多种生理和病理过程,如细胞增殖、分化、发育、凋亡、激素分泌和肿瘤形成等.miRNA在卵巢癌中表达异常,与卵巢癌的发生、发展、转移和耐药密切相关,提示其有望成为卵巢癌的诊断标记物,并为预后评估、化疗耐药分析和个性化治疗提供临床思路.     

组蛋白甲基化修饰与哺乳动物生殖

组蛋白甲基化是表观遗传学研究的热点和难点,研究表明,组蛋白甲基化修饰在哺乳动物配子的发生、胚胎着床和发育以及胎盘的发育过程中有着特殊作用,这些修饰可影响基因的表达,从而动态调节哺乳动物生殖过程中许多生物学进程。但目前研究的组蛋白甲基化修饰相关基因位点多而杂,且多停留在广泛的探索和描述这一层面,这些甲基化修饰发生动态变化的机制,以及相互作用等一系列过程还有待深入研究。     

MicroRNAs and mammalian ovarian development

Mammalian ovarian development involves unique interactions between the germ-line and somatic genomes. Several regulators affect gene expression, including a class of small RNAs called microRNAs (miRNAs). miRNAs are small, noncoding, regulatory RNAs that are 19 to 25 nucleotides long. miRNAs regulate gene expression in part via translational control of messenger RNAs (mRNAs). miRNAs are expressed during different stages of mammalian ovarian development and are likely to play important roles during gonadal development and folliculogenesis. The role of individual miRNAs in mammalian ovarian development is currently unknown and will remain an important focus for future investigations.     

The Role of Apoptosis in Normal and Abnormal Embryonic Development

Programmed cell death or apoptosis is a widespread biological phenomenon. Apoptosis is characterized by typical cell features such as membrane blebbing, chromatin condensation, and DNA fragmentation. It involves a number of membrane receptors (e.g., Fas, TNFR) and a cascade of signal transduction steps resulting in the activation of a number of cysteine proteases known as caspases. Disordered apoptosis may lead to carcinogenesis and participates in the pathogenesis of Alzheimer disease, Parkinson disease, or AIDS. Programmed cell death plays an important role in the processes of gamete maturation as well as in embryo development, contributing to the appropriate formation of various organs and structures. Apoptosis is one of the mechanisms of action of various cytotoxic agents and teratogens. Teratogen-induced excessive death of embryonic cells is undoubtedly one of the most important events preceding the occurrence of structural abnormalities, regardless of their nature. Therefore understanding the mechanisms involved in physiological as well as in disturbed or dysregulated apoptosis may lead to the development of new methods of preventive treatment of various developmental abnormalities. The present review summarizes data on the mechanisms of programmed cell death and concentrates on apoptosis involved in normal or disturbed gametogenesis and in normal and abnormal embryonic development.     

Epigenetic consequences of assisted reproduction and infertility on the human preimplantation embryo

Epigenetic information, which is essential for normal mammalian development, is acquired during gametogenesis and further regulated during preimplantation development. The epigenetic consequences of assisted reproductive technologies (ARTs) and infertility on the health and quality of the human preimplantation embryo are considered in this review. In the zygote, the epigenetic information that is inherited from the sperm and the oocyte intersects and must be appropriately recognized, regulated and then propagated during preimplantation development so as to regulate gene expression in an appropriate manner. A growing body of evidence suggests that ARTs and/or infertility itself may affect these complex processes leading to epigenetic diseases that include disorders of genomic imprinting. The epigenetic safety of human gametes and embryos is of paramount importance. Unfortunately, morphological methods of assessing embryo quality are incapable of detecting epigenetic errors. Further research is therefore critical to resolve these issues.     

Ovarian differentiation and human embryo quality. 1. Molecular and morphogenetic homologies between oocytes and embryos in Drosophila,C. elegans,Xenopus and mammals

Knowledge on the formation of oocytes and follicles in Drosophila, C. elegans and Xenopus, and the genetic regulation of polarities and embryo growth, has been related to comparable data in mammalian oocytes and embryos. Initially, details of the nature of the regulatory processes in the non-mammals are described, with considerable attention being paid to the role of individual genes and their specific functions. The molecular genetic aspects of these developmental processes are discussed in detail. Attention then turns to mammals, to identify, describe and evaluate their homologies with the lower animals and flies. Several of these homologies are described, including genes regulating primary ovarian failure and various aspects of early embryonic growth. The polarized distribution of genes in mammalian oocytes and embyros is discussed, together with the implications in the form of differentiation in the early embryo. Morphogenetic systems operative during follicle maturation, fertilization and cleavage are described and related to similar processes in lower forms. These events include ooplasmic and pronuclear rotations, the form of ooplasmic inheritance in early blastomeres and the establishment of embryonic axes. Models of early mammalian development are considered.     

不同来源外泌体中微小RNA在子痫前期的研究进展

子痫前期（pre-eclampsia,PE）的发病机制至今尚未明确,而外泌体为PE发病机制的研究提供了新的方向。有研究表明外泌体在人体中广泛存在,红细胞、上皮细胞、间充质干细胞和胎盘细胞等细胞均可分泌外泌体。而这些不同来源外泌体中的微小RNA（microRNA,miRNA）被证明可以在PE的发生及预防、治疗中发挥一定的作用,例如胎盘来源外泌体中的miRNA可能与PE的发生息息相关,脐带血来源外泌体中的miRNA可能与胚胎发育有一定关系,而间充质干细胞来源外泌体中的miRNA则可能在PE的治疗中发挥重要作用。因此,探索这些miRNA及其外泌体来源对于明确PE的发病机制及靶向治疗具有重要意义。     

Embryo aneuploidy screening for repeated implantation failure and unexplained recurrent miscarriage

Among other factors, chromosomal abnormalities that originate from gametogenesis and preimplantation embryonic development are thought to be one of the major contributing factors for early embryonic death and failure of pregnancy. However, so far, no non-invasive technique exists that allows the detection of the chromosomal complement of an oocyte or a developing embryo as a whole. Rather, by removing polar bodies/blastomeres, recent developments on preimplantation genetic diagnosis for aneuploidy screening (PGD-AS) have paved the way to detect and possibly eliminate the majority of chromosomally abnormal embryos, thereby increasing the chance of a healthy pregnancy. This article summarizes the origin and impact of chromosomal abnormalities on human reproduction in cases with repeated implantation failure (RIF) and unexplained recurrent miscarriage. It also discusses recent advances regarding the possible benefits of PGD-AS in such cases.     

钙粘素与哺乳动物生殖

钙粘素(cadherin)是细胞表面的糖蛋白,为细胞粘附分子(cell adhesion molecules,CAMs)超家族中的一员。钙粘素通过连接蛋白影响生物学过程,充当细胞内信使,从质膜向细胞核内传导信号,由此影响基因的转录来执行其功能。在配子发生、月经周期的组织修复、早期胚胎发育、着床、细胞凋亡等生殖过程中起着重要的作用。本文主要对其在生殖中的作用以及其表达的调控作一综述。