微RNA与肿瘤

微RNA（miRNA）是一类非编码的小RNA分子,通过直接抑制基因转录或蛋白质的表达而在器官发育,细胞增殖、分化和凋亡等多种生理过程中发挥关键作用.miRNA异常表达往往导致包括肿瘤在内的多种疾病.研究发现,miRNA在肿瘤发生发展、侵袭转移及肿瘤的诊治中起着重要作用.     

微RNA与肿瘤

微RNA(miRNA)是一类非编码的小RNA分子,通过直接抑制基因转录或蛋白质的表达而在器官发育,细胞增殖、分化和凋亡等多种生理过程中发挥关键作用.miRNA异常表达往往导致包括肿瘤在内的多种疾病.研究发现,miRNA在肿瘤发生发展、侵袭转移及肿瘤的诊治中起着重要作用.     

微小RNA与肿瘤浸润转移

微小RNA(miRNA)在多数肿瘤中存在异常表达,能在转录后水平调控靶基因的表达,发挥促进或抑制肿瘤浸润转移的作用,其自身的表达也受表观遗传学静息等多种机制的调节.miRNA作为一种理想的标记物,有望成为临床肿瘤治疗的新靶点.     

MicroRNA与膀胱癌的研究进展

微小RNA(MicroRNA,miRNA)是一类小分子RNA,在转录后水平对基因的表达进行调控.目前研究证明,miRNA可通过不同信号通路直接参与人类多种肿瘤的形成与发展.本文就miRNA的形成、作用机制及其与肿瘤的关系等方面予以综述,并着重介绍了miRNA在膀胱癌中的研究进展.     

微小RNA与肿瘤诊断

微小RNA (miRNA)能在转录后水平调节mRNA表达。miRNA与胃肠癌、肺癌、乳腺癌、卵巢癌、前列腺癌、胰腺癌和肝癌等多种肿瘤的发生、发展密切相关,而且很多miRNA在肿瘤中表达水平明显异常。miRNA可作为一种标志物用于多种肿瘤的诊断。     

微小RNA与肿瘤诊断

微小RNA（miRNA）能在转录后水平调节mRNA表达。miRNA与胃肠癌、肺癌、乳腺癌、卵巢癌、前列腺癌、胰腺癌和肝癌等多种肿瘤的发生、发展密切相关,而且很多miRNA在肿瘤中表达水平明显异常。miRNA可作为一种标志物用于多种肿瘤的诊断。     

微RNA与头颈鳞癌的研究进展

微RNA(miRNA)在转录后水平调控靶基因的表达.头颈肿瘤中存在多种miRNA的差异表达,其参与细胞发育、增殖、分化、凋亡等一系列重要生物学进程,有望成为诊断治疗头颈肿瘤的有效手段.     

微小RNA与肿瘤

微小RNA(miRNA)是一类小分子的非编码调控的单链RNA,它参与有机体的生长、发育等多种生理过程.近年来研究表明肿瘤组织具有不同的miRNA表达,异常表达的miRNA影响了肿瘤细胞的发生、进展、分化、转移和复发.miRNA的不同表达不仅有助于肿瘤组织的诊断,而且可以指导预后.针对miRNA为靶点的动物学研究也发现,干扰某种miRNA表达可以减小肿瘤体积,抑制腹膜转移而发挥治疗作用.     

微小RNA与人类肿瘤

微小RNA(microRNA,miRNA)是一类对基因具有调控功能的内源性非编码小分子RNA.目前认为miRNA在多种生物学过程中起着至关重要的作用,包括细胞增殖、分化、凋亡等.近年研究表明miRNA表达异常能导致疾病甚至肿瘤的发生,有类似于抑癌基因或癌基因的功能.因此,对miRNA的进一步研究为肿瘤的诊断和治疗开辟了...     

微小RNA与肿瘤

近年来微小RNA(miRNA)逐渐成为肿瘤研究的热点.越来越多的研究表明,miRNA已涉及到肿瘤的发生和发展,miRNA的表达与肿瘤的病理进程具有相关性,大约有数百个miRNA在肿瘤中异常表达,miRNA在不同肿瘤中具有时空特异性的表达谱.     

微小RNA研究进展

微小RNA(miRNA)是参与基因转录后水平调控的非编码小分子RNA.人类基因中大约有3%编码miRNAs,而编码蛋白的基因中30%受到miRNAs的调控.miRNAs在多种生物进程中起到关键作用,包括调节发育、细胞增殖、分化和凋亡,相应的miRNAs的表达变化与包括肿瘤在内的多种疾病有关.本文综述miRNAs的生物学及其与肿瘤的联系,并讨论了miRNAs的研究方法.     

let‐7 and miR‐17‐92: Small‐sized major players in lung cancer development

MicroRNA (miRNA)‐encoding small non‐coding RNA have been recognized as important regulators of a number of biological processes that inhibit the expression of hundreds of genes. Accumulating evidence also indicates the involvement of miRNA alterations in various types of human cancer, including lung cancer, which has long been the leading cause of cancer death in economically well‐developed countries, including Japan. We previously found that downregulation of members of the tumor‐suppressive let‐7 miRNA family and overexpression of the oncogenic miR‐17‐92 miRNA cluster frequently occur in lung cancers, and molecular insight into how these miRNA alterations may contribute to tumor development has been rapidly accumulating. The present review summarizes recent advances in elucidation of the molecular functions of these miRNA in relation to their roles in the pathogenesis of lung cancer. Given the crucial roles of miRNA alterations, additional studies are expected to provide a better understanding of the underlying molecular mechanisms of disease development, as well as a foundation for novel strategies for cancer diagnosis and treatment of this devastating disease. (Cancer Sci 2011; 102: 9–17)     

微小RNA相关调控通路与肿瘤发生发展

 研究表明,微小RNA（miRNA）在多数肿瘤中存在异常表达。miRNA相关调控通路,包括miRNA与蛋白编码基因及miRNA与长链非编码RNA（lncRNA）间的相互调控,与肿瘤的发生发展密切相关。miRNA有望成为临床肿瘤治疗的新靶点。     

Micro-RNA and oncogenesis

MicroRNA are endogenous molecules which negatively regulate the expression of a variety of genes. These tiny non coding RNA molecules--18 to 25 nucleotides in length--repress, with efficiency and specificity- translation of target mRNA into protein, according to a process akin to RNA interference. MiRNA are critical in the development of plants and mammals since they play a key role on proteins which regulate the strict spatiotemporal control of each tissue. Very recent reports published during 2005 summer show miRNA as also involved in oncogenesis. Specific miRNA elicit oncogenic and antiapoptotic properties in lymphoma models and glioblastoma, respectively. The expression profile of the two hundred miARN, so far identified, reflects the tumor tissue lineage, leading to a potential tool for diagnosis. The occurrence of miRNA in solid tumors and haematological neoplasia opens new avenues for understanding of oncogenesis and, likely, for management of cancer diseases.     

DNA methylation of microRNA genes in gastric mucosae of gastric cancer patients: Its possible involvement in the formation of epigenetic field defect

Accumulation of aberrant DNA methylation in normal‐appearing gastric mucosae, mostly induced by H. pylori infection, is now known to be deeply involved in predisposition to gastric cancers (epigenetic field defect), and silencing of protein‐coding genes has been analyzed so far. In this study, we aimed to clarify the involvement of microRNA (miRNA) gene silencing in the field defect. First, we selected three miRNA genes as methylation‐silenced after analysis of six candidate “methylation‐silenced” tumor‐suppressor miRNA genes. Methylation levels of the three genes (miR‐124a‐1, miR‐124a‐2 and miR‐124a‐3) were quantified in 56 normal gastric mucosae of healthy volunteers (28 volunteers with H. pylori and 28 without), 45 noncancerous gastric mucosae of gastric cancer patients (29 patients with H. pylori and 16 without), and 28 gastric cancer tissues (13 intestinal and 15 diffuse types). Among the healthy volunteers, individuals with H. pylori had 7.8–13.1‐fold higher methylation levels than those without (p < 0.001). Among individuals without H. pylori, noncancerous gastric mucosae of gastric cancer patients had 7.2–15.5‐fold higher methylation levels than gastric mucosae of healthy volunteers (p < 0.005). Different from protein‐coding genes, individuals with past H. pylori infection retained similar methylation levels to those with current infection. In cancer tissues, methylation levels were highly variable, and no difference was observed between intestinal and diffuse histological types. This strongly indicated that methylation‐silencing of miRNA genes, in addition to that of protein‐coding genes, contributed to the formation of a field defect for gastric cancers. © 2008 Wiley‐Liss, Inc.     

Proliferation and tumorigenesis of a murine sarcoma cell line in the absence of DICER1

MicroRNAs are a class of short ~22 nucleotide RNAs predicted to regulate nearly half of all protein coding genes, including many involved in basal cellular processes and organismal development. Although a global reduction in miRNAs is commonly observed in various human tumors, complete loss has not been documented, suggesting an essential function for miRNAs in tumorigenesis. Here we present the finding that transformed or immortalized Dicer1 null somatic cells can be isolated readily in vitro, maintain the characteristics of DICER1-expressing controls and remain stably proliferative. Furthermore, Dicer1 null cells from a sarcoma cell line, though depleted of miRNAs, are competent for tumor formation. Hence, miRNA levels in cancer may be maintained in vivo by a complex stabilizing selection in the intratumoral environment.     

微小RNA与肿瘤转移

微小RNA（miRNA）是一种内源性非编码小RNA,可在转录水平负调节靶基因的表达。在肿瘤中miRNA可起到癌基因和抑癌基因的作用,其在肿瘤中的功能失调可能是肿瘤发生、发展的重要原因,研究表明miRNA可望成为肿瘤转移治疗的新靶点。