miRNA在肿瘤及肿瘤干细胞中作用的研究进展

microRNAs(miRNAs)是一类含量丰富的非蛋白编码小分子RNA,miRNAs主要是与靶mRNA的3′UTR区域结合,抑制mRNA的翻译或直接使mRNA降解,能调节多种生物功能。一些miRNAs,如miR-17-92,可能作为致癌基因;而另一些miRNAs,如miR-15,可作为抑癌基因,它们在肿瘤的发生、发展过程中起着重要作用。同时它们在肿瘤干细胞中也发挥着重要的作用。因此miRNAs正成为肿瘤的诊断和治疗的新靶点。     

MicroRNA检测与膀胱癌的诊断及治疗

MicroRNA（miRNAs）是一类长约22-25个核苷酸序列组成的非蛋白编码的内源性RNA。它通过调控相关靶基因的表达,起到原癌基因或抑癌基因作用,参与真核生物的多种生理和病理过程,如个体发育、细胞分化、肿瘤增殖与凋亡等。经过大量研究发现,miRNAs与肿瘤的发生发展有明显相关性,其作用机制的研究是当前热点之一．这些研究已取得进展。现就当前miRNAs在膀胱癌中的研究进展作一综述。     

靶向miRNA在胃癌中的研究进展

微小RNA(microRNA,miRNA)是一类长度约22个核苷酸(nt)的内源性非编码小分子单链RNA。双体RNA(miRNAs)几乎参与了所有的细胞生物学过程,包括细胞分化、增殖、凋亡、侵袭和迁移等。miRNAs通过对多种靶基因表达的负性调控,在肿瘤发生、演变、转移中起重要作用。miRNAs在包括胃癌在内的不同肿瘤中的异常调节被频繁报道,表明与肿瘤相关的miRNA有希望作为     

MicroRNAs与糖代谢的研究进展

【摘要】 <正>MicroRNAs(miRNAs)是一组长约19～25个核苷酸(nucleotides,nt)的小分子非编码RNA,广泛存在于动植物中,在进化过程中高度保守,在阶段性发育、器官发育、细胞分化、信号传导、代谢和肿瘤的发生过程中都发挥了至关重要的作用,近年来发现miRNAs也参与葡萄糖的代谢调节。本文将miRNAs对糖尿病的调节作用综述如下。1MiRNA的产生和作用机制MiRNAs绝大部分位于基因间隔区,本身不具有开放阅读框架。多数动物miRNAs位于前体mRNA的内含子中,这     

miRNAs 以非细胞自主机制参与肿瘤微环境调节的研究进展

肿瘤微环境是肿瘤发生发展过程中所处的内环境 , 由多种细胞及细胞外基质组成, 是肿瘤形成、 转移以及耐药的关键因素。对肿瘤微环境的调控将成为治疗肿瘤的靶点之一。MicroRNAs（miRNAs） 是一类 21~25 个核苷酸的非编码单链 RNA, 主要参与基因的表达调控。近年来, 随着非细胞自主抑癌机制的提出, 使 miRNAs 对肿瘤微环境的调控受到了极大关注。本文主要阐述 miRNAs 通过非细胞自主机制对肿瘤微环境的影响, 为对肿瘤微环境的深入研究以及肿瘤治疗提供参考。     

miR-155在消化道肿瘤中的研究进展

microRNAs（miRNAs）是一种非编码的小分子RNA,调控转录后的基因表达水平。microRNA-155（miR-155）是典型的多功能miRNA,参与了多种生物学过程,包括造血、炎症、免疫和肿瘤等。消化道肿瘤是严重威胁人类生命健康的疾病,近年来研究表明miR-155与消化道肿瘤的发生发展关系密切,在肿瘤的发病机制、诊断、治疗及预后等方面有重要作用。本文就miR-155在消化道肿瘤的研究现状做一综述。     

miR-155在消化道肿瘤中的研究进展

microRNAs(miRNAs)是一种非编码的小分子RNA,调控转录后的基因表达水平。microRNA-155(miR-155)是典型的多功能miRNA,参与了多种生物学过程,包括造血、炎症、免疫和肿瘤等。消化道肿瘤是严重威胁人类生命健康的疾病,近年来研究表明miR-155与消化道肿瘤的发生发展关系密切,在肿瘤的发病机制、诊断、治疗及预后等方面有重要作用。本文就miR-155在消化道肿瘤的研究现状做一综述。     

MicroRNAs:过敏性疾病的潜在新靶点

过敏性疾病包括过敏性哮喘、过敏性皮炎、过敏性鼻炎等,是一种多基因病,涉及环境、基因及免疫之间的相互作用,在过去几十年中发病率明显上升,严重影响人们的生活质量。寻求防治过敏性疾病的新靶点及不良反应少的药物成为研究者关注的热点。MicroRNAs(miRNAs)是一类单链非编码小分子RNA,通过在转录后水平降解靶位基因或抑制蛋白的翻译来调控靶位基因的表达,广泛参与细胞的增殖、分化、免疫反应及肿瘤的发生等多种生物学过程。研究发现miRNAs可调控过敏性疾病的发生发展。深入探讨miRNAs在过敏性疾病中的作用,对进一步揭示其病理机制及发现新的药物治疗靶点具有重要意义。     

miRNAs与肝细胞癌的相关性研究进展

原发性肝细胞癌是全球最常见的恶性肿瘤之一。肝细胞癌起病隐匿,早期临床症状多不明显,造成早期发现及诊断的难度较大,确诊时多属中晚期,且由于肝细胞癌的高侵袭转移和高复发率,导致肝细胞癌的死亡率极高。MicroRNAs(miRNAs)是长约22个核苷酸的高度保守的内源性非编码单链小RNA。肝脏内存在大量miRNAs,miRNAs不仅可以调节肝脏的生长发育,还与肝细胞癌的形成密切相关。在肝细胞癌形成的过程中,miRNAs可作为致癌基因或抑癌基因调节肿瘤细胞的分化、增殖、肿瘤形成、血管生成及侵袭和转移等。近十年来,随着对miRNAs在肝细胞癌形成过程中的分子机制研究的深入,越来越多研究表明,miRNAs可成为早期诊断肝细胞癌的灵敏的生物指标和有效的治疗靶点。     

MicroRNA-145与肿瘤的关系及研究进展

随着人们对生命科学的认识不断加深,作为非编码RNA的重要代表microRNA受到越来越多的青睐。人类多种肿瘤的发生发展及侵袭转移与microRNAs（miRNAs）存在着密切关系,miRNAs可能成为一类新的致癌基因或抑癌基因,通过抑制靶mRNA翻译或诱导靶mRNA降解在转录后水平调控基因表达,参与肿瘤的发生、发展及侵袭转移。 MiR-145是microRNA家族中的成员之一,被认为是一种肿瘤抑制基因,可以靶向多个肿瘤相关基因,从而影响肿瘤的生长、侵袭转移以及肿瘤血管的生成。并且miR-145可以调控细胞重新编程基因 SOX2、OCT4、KLF4和C-MYC 的表达,由于这些基因也具有癌基因的特性,因此miR-145在肿瘤干细胞中的作用也受到关注。     

肿瘤干细胞miRNA及miRNA作为肿瘤标志物的研究和临床应用进展

肿瘤干细胞(CSCs)理论为肿瘤的研究开辟了一个新的方向,CSCs学说认为肿瘤细胞具有异质性,肿瘤中存在干细胞样细胞,该群细胞是一种增殖失控、可形成肿瘤的细胞,只占肿瘤细胞很少部分,具有干细胞特性,是形成不同分化程度肿瘤细胞和肿瘤增长、复发及转移的根源。微小核糖核酸(miRNA)是广泛存在的非编码小RNA,调节着人类1/3的基因,越来越多的证据显示miRNA在肿瘤的发生发展中起着重要的作用,作为重要的转录后调控因子,广泛参与肿瘤相关基因调控的生物程序,使不同类型的肿瘤表现出特异的miRNA表达谱。近年来,CSCs的miRNA研究日益成为热点,已经发现多种CSCs中存在特异性表达的miRNA,对CSCs的生物学行为有了更进一步的认识。有研究发现肿瘤患者血浆中表达某些特异的miRNA,这些miRNA可以作为肿瘤的标志物对患者的病情及预后进行预测和判断。本文就近来CSCs中miRNA研究进展及miRNA作为肿瘤标志物研究进展进行综述。     

let-7 microRNA functions as a potential growth suppressor in human colon cancer cells

MicroRNAs (miRNAs) are endogenously expressed RNAs, 18-25 nucleotides in length, that repress protein translation through binding to target mRNAs. miRNAs have been implicated in many cellular processes including cell proliferation, differentiation, and death. Recently, let-7 miRNAs were found to regulate human RAS oncogene expression and to be often down-regulated in human lung tumors. In this study, we examined the expression of let-7 miRNAs in human colon cancer tumors and cell lines, with the result that 2 of 6 cases and 1 of 3 cell lines showed reduced expression of let-7. When let-7 low-expressing DLD-1 human colon cancer cells were transfected with let-7a-1 precursor miRNA, which is located at chromosome 9q22.3, the cells underwent significant growth suppression. At that time, the levels of RAS and c-myc proteins were lowered after the transfection, whereas the levels of both of their mRNAs remained almost unchanged. These findings suggest the involvement of let-7 miRNA in the growth of colon cancer cells. Thus, miRNAs might provide a basis for novel RNA anti-cancer agents.     

miR-27a在妇科肿瘤中的研究进展 #br#

微小 RNA（miRNA）是一类内源性的非编码小 RNA,通常可通过特异性降解 mRNA或抑制蛋白质的翻译, 在转录后水平调控靶基因的表达,参与机体的多个生理或病理过程。miRNA可通过调节癌基因和抑癌基因的表达 来参与肿瘤的发生发展,在不同类型的肿瘤中及肿瘤的不同发展阶段,miRNA分子的表达谱呈现不同的特征。其 中,miR-27a定位于人类 19号染色体,在子宫内膜癌、宫颈癌、卵巢癌等多种妇科肿瘤中异常表达。本文对 miR-27a 在子宫内膜癌、宫颈癌和卵巢癌中的作用及其临床应用进展进行综述,为开发新型的肿瘤分子标志物或靶向药物提 供理论依据。     

Regulation of microRNAs by Natural Agents: An Emerging Field in Chemoprevention and Chemotherapy Research

In recent years, microRNAs have received greater attention in cancer research. These small, non-coding RNAs could inhibit target gene expression by binding to the 3′ untranslated region of target mRNA, resulting in either mRNA degradation or inhibition of translation. miRNAs play important roles in many normal biological processes; however, studies have also shown that aberrant miRNA expression is correlated with the development and progression of cancers. The miRNAs could have oncogenic or tumor suppressor activities. Moreover, some miRNAs could regulate formation of cancer stem cells and epithelial-mesenchymal transition phenotype of cancer cells which are typically drug resistant. Furthermore, miRNAs could be used as biomarkers for diagnosis and prognosis, and thus miRNAs are becoming emerging targets for cancer therapy. Recent studies have shown that natural agents including curcumin, isoflavone, indole-3-carbinol, 3,3′-diindolylmethane, (-)-epigallocatechin-3-gallate, resveratrol, etc. could alter miRNA expression profiles, leading to the inhibition of cancer cell growth, induction of apoptosis, reversal of epithelial-mesenchymal transition, or enhancement of efficacy of conventional cancer therapeutics. These emerging results clearly suggest that specific targeting of miRNAs by natural agents could open newer avenues for complete eradication of tumors by killing the drug-resistant cells to improve survival outcome in patients diagnosed with malignancies.     

Role of microRNAs in gliomagenesis: targeting miRNAs in glioblastoma multiforme therapy

Introduction: Gliomas consist of a very heterogeneous group of malignant tumors, accounting for 50 - 60% of primary brain tumors. Despite all the efforts of cytoreductive surgery in combination with intense chemoradiotherapy, glioblastoma multiforme (GBM, glioma grade IV) still has a dismal prognosis. Current research is focused on molecular targeting to overcome resistance to conventional therapy. MicroRNAs (miRNAs), small non-coding RNAs, represent endogenous agents of RNA interference, dramatically changing expression of target proteins. Their role in brain physiology as well as GBM development has attracted intense research efforts pointing toward therapeutic potential and immediate targeting for sensitization of glioma cells to chemo and/or radiotherapy. Areas covered: This review is focused on the variable role of miRNAs in gliomagenesis and their possible clinical relevance in patient's survival and prognosis. It further addresses the potential application of selected miRNAs as therapeutic targets or agents in GMB, including data from clinical studies in other central nervous system tumors. Expert opinion: Although miRNA-targeted therapy is still in its initial stage and clinical trials with glioma/brain tumor patients are under recruitment or currently running, several miRNAs have been selected as promising tumor biomarkers, with increased potential to reduce disease progression in combination to conventional first-line therapy for gliomas.     

Small RNAs as Potential Platelet Therapeutics

MicroRNAs (miRNAs) are 21-23 nucleotide RNAs that regulate more than 60% of mammalian protein coding genes. miRNAs play critical roles in hematopoiesis and megakaryocyte function and development. Platelets, in addition to possessing functional miRNA processing machinery, have miRNA levels that have been correlated with platelet reactivity, and these miRNAs have been shown to target mRNAs that encode proteins that alter platelet function. There are potential uses of platelet miRNA as biomarkers and therapeutic agents. Due to the ability of platelets to release miRNA-containing microparticles at sites of activation, including angiogenic regions, tumors, and atherosclerotic plaques, there is the possibility of engineering platelets to deliver miRNA-based therapies to these sites. Cellpreferential expression of miRNAs could be exploited to restrict transgene expression in hematopoietic stem cell gene therapy to the desired lineage, including megakaryocytes and platelets. Finally, manipulation of gene expression in stored platelets may allow more effective platelet storage. Although much work remains to be done, there is great potential in miRNA-based platelet therapies.