胃癌细胞株AZ-P7a通过外泌体分泌let-7 microRNAs维持其高转移性

外泌体(exosomes)是细胞分泌的膜性小泡,参与细胞间通讯。靶细胞通过胞吞样作用摄取外泌体中的蛋白质、mRNAs和microRNAs(miRNAs)等。miRNAs调节着多种细胞生物学过程,包括致癌、通过降解靶标RNA或干扰其翻译介导靶基因沉默。肿瘤患者循环血浆或血清中的miRNAs可包裹于外泌体中而免遭降解,但外泌体内     

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.     

MicroRNA在肺癌耐药中的作用

摘 要：微小RNA（microRNA，miRNA) 是一类短链、非编码小分子RNA，不同癌症治疗中特异性miRNAs失调参与了肿瘤细胞耐药的过程，进而调节肿瘤细胞对治疗的敏感性。研究表明miRNAs参与肺癌化疗及靶向的耐药过程。miRNAs具有克服肺癌耐药的潜能，同时能够增加肺癌细胞对化疗及靶向治疗的敏感性。全文综述了现阶段肺癌治疗中miRNAs在化疗药物及靶向药物耐药机制中的作用。     

MicroRNA在乳腺癌转移中的作用

MicroRNAs（miRNAs）是一类内源性小分子RNA,在转录后水平抑制基因的表达。研究表明多种miRNAs在包括乳腺癌在内的多种肿瘤中扮演着癌基因或者抑癌基因的角色,并且在肿瘤发生发展的各个阶段都有特定的miRNAs参与。本文综述了乳腺癌侵袭和转移过程中相关的miRNAs的作用。     

MicroRNA在乳腺癌转移中的作用

MicroRNAs(miRNAs)是一类内源性小分子RNA,在转录后水平抑制基因的表达。研究表明多种miRNAs在包括乳腺癌在内的多种肿瘤中扮演着癌基因或者抑癌基因的角色,并且在肿瘤发生发展的各个阶段都有特定的miRNAs参与。本文综述了乳腺癌侵袭和转移过程中相关的miRNAs的作用。     

miRNAs与鼻咽癌研究进展

0 引言 微小RNA(miRNAs)是一类长度为21～30nt的高度保守的、内源性非编码蛋白质的单链小RNA分子~([1]).随着对miRNAs研究的深入,发现miRNAs调节人类1/3的基因,不仅参与个体发育、器官形成和物质代谢等生理过程,还与病毒复制和肿瘤发生等密切相关.     

微小RNAs对胸腺上皮细胞肿瘤的影响及研究进展

胸腺作为机体重要免疫器官,参与机体多种免疫功能。胸腺瘤和胸腺癌是来源于胸腺上皮细胞的肿瘤,在我国前纵隔肿瘤中较为常见。微小RNA（microRNAs,miRNAs）是一类内源性非编码小分子单链RNA,长度约为22个氨基酸,参与转录后基因表达调控过程。近年来miRNAs的研究已成为各学科的研究热点,针对miRNAs的新型诊断方法与治疗手段不断在国内外学术期刊上报道。胸腺上皮细胞肿瘤由于常伴有副肿瘤综合征,使其在临床症状表现及治疗方面复杂多样,通过miRNAs与胸腺上皮细胞肿瘤的研究,有望从根源上找出胸腺肿瘤多样性的原因并找到有效治疗手段。本文对近几年miRNAs与胸腺上皮细胞肿瘤的研究进行文献复习,探讨miRNAs对胸腺上皮细胞肿瘤的影响及研究进展,并作一综述。     

miRNAs及其基因启动子DNA甲基化在肿瘤研究中的进展

0 引言 miRNAs(microRNAs)是长度约21～25个核苷酸的非编码的小RNA分子.miRNAs是通过Drosha剪切路径产生的.成熟的miRNAs在细胞核由长约2kb非编码的原始miRNA转录本(primiRNAs)转录而来.在细胞核的RNA酶Drosha作用下,长的pri-miRNAs被剪切为小的、长约70nt的具有茎环结构的前体miRNAs(pre-miRNAs),pre-miRNAs被输送到细胞质中,在另一种高度保守的RNA酶Dicer的作用下剪切成长约22nt的成熟的miRNAs[1-2].成熟的miRNAs介导基因调节调控基因表达参与人体病理生理的多种过程,是肿瘤发生过程中重要的调节分子.     

MicroRNA在肿瘤干细胞中的调控作用研究进展

肿瘤干细胞(CSCs)是导致肿瘤复发、转移和耐药的根源之一。microRNA(miRNAs)是一类小分子非编码RNA,可与靶mRNA的3’UTR区域结合而导致该mRNA分子的翻译受到抑制,参与多种生物功能的调节。最近的研究发现,miRNAs参与CSCs的分化、自我更新等生物学特性的调控。miRNAs可以作为CSCs研究的一个新的切入点。本文就近年来该方面的研究进展做简要综述。     

外泌体microRNAs在卵巢癌诊断和治疗中作用的研究进展

外泌体microRNAs(miRNAs)在卵巢癌进展的各种过程中发挥重要作用，如卵巢癌细胞增殖、凋亡和侵袭。外泌体miRNAs通过各种途径参与基因表达、信使RNA合成、蛋白生成等，有助于对卵巢癌发病机制的理解。由于miRNAs在血浆外泌体中的有效性，miRNAs可作为新兴的癌症早期检测和治疗评估生物标志物。外泌体miRNAs作为一种信使，在肿瘤微环境中起着重要的作用，越来越多的研究也证实了miRNAs作为靶点治疗卵巢癌的可行性。     

MicroRNAs in endometrial cancer

MicroRNAs (miRNAs) are small non-coding ribonucleic acids (RNAs) of approximately 22 bp that induce RNA interference with a complementary messenger RNA (mRNA) and act in silencing of mRNA. miRNAs are strongly associated with cancer development and those involved in carcinogenesis are classified into oncogenic miRNAs and tumor suppressor miRNAs (tumor suppressor miRs). Specific miRNAs are expressed in various tissues and changes in regulation of gene expression are thought to cause carcinogenesis. Thus, tissue-specific miRNAs may be biomarkers for cancer diagnosis and prognosis. Approaches to application of miRNAs as cancer therapy are also ongoing, based on the involvement of miRNAs in carcinogenesis. In endometrial cancer, miRNAs are associated with regulation of gene expression, epigenetic dysfunction and carcinogenesis. Thus, miRNAs are likely to have key roles in diagnosis, prognostic prediction, and therapy in endometrial cancer.     

MicroRNA therapeutics: principles, expectations, and challenges

MicroRNAs(miRNAs) are a class of highly abundant non-coding RNA molecules that are involved in several biological processes.Many miRNAs are often deregulated in several diseases including cancer.There is substantial interest in exploiting miRNAs for therapeutic applications.In this editorial,we briefly review current advances in the use of miRNAs or antisense oligonucleotides(antagomirs) for such therapies.One of the key issues related to therapy using miRNAs is degradation of naked particles in vivo.To ove...     

Identification of senescence-inducing microRNAs in normal human keratinocytes

MicroRNAs (miRNAs) are epigenetic regulators of eukaryotic gene expression and play key roles in many cellular processes. However, the role of miRNAs for replicative senescence of normal human keratinocytes (NHKs) remains unknown. Thus, we examined the expression profiles of 847 miRNAs in exponentially replicating and senescent NHKs and identified 126 senescence-associated miRNAs (SA-miRs). Among SA-miRs, 117 miRNAs (93%) were upregulated and 9 miRNAs (7%) were downregulated in senescent NHKs compared to those of exponentially replicating cells. Among the above miRNAs, we selected two miRNAs, miR-137 and miR-668, for further investigation because they were consistently upregulated with replicative senescence of three independent NHK cultures. Ectopic overexpression of miR-137 or miR-668 induced senescence in rapidly proliferating NHKs; a notable increase in senescence-associated β-galactosidase activity, p16INK4A and p53 was observed, indicating that they are novel senescence-inducing miRNAs. In addition, these senescence-inducing miRNAs were gradually increased during organismal aging of normal human oral epithelia. We also detected downregulation of miR-137 and miR-668 in many tested human head and neck squamous cell carcinoma cell lines. Since senescence would be viewed as a potent tumor suppressive pathway, the newly identified senescence-inducing miRNAs deserve to be further investigated for their therapeutic application in cancer treatment.     

微小RNA在肺癌中的研究进展

微小RNA（miRNA）的生物学功能广泛而重要,参与发育、生长、死亡等整个生命过程。超过50 %的miRNA位于肿瘤相关区域或脆性区域,与肿瘤发生、发展、侵袭转移关系密切的miRNA的发现使人们对基因表达调节有了新认识,也为肺癌等恶性肿瘤侵袭转移机制的研究以及miRNA在诊断治疗中的应用开拓了新视野。文章综述了miRNA在肺癌发病机制中的作用,并探讨其作为肺癌诊断与预后标志物的可能性及作为潜在治疗性靶点的应用前景。     

The expression and functions of microRNAs in pancreatic adenocarcinoma and hepatocellular carcinoma

Pancreatic adenocarcinoma and hepatocellular carcinoma are devastating human malignancies that are characterized by poor prognosis, late onset, and a lack of known biomarkers. New diagnostic and therapeutic molecular targets are desperately needed to develop novel and effective treatment strategies. MicroRNAs (miRNAs) are an emerging class of molecules with roles in various cellular processes, including growth, survival, and apoptosis. Most importantly, aberrant expression of miRNAs has been implicated in cancer pathogenesis. miRNA expression profiles of pancreatic adenocarcinoma and hepatocellular carcinoma indicate selective overexpression of oncogenic miRNAs and down-regulation of tumor suppressive miRNAs in these cancers. This review summarizes results from key studies conducted to characterize the miRNA expression profiles of pancreatic adenocarcinoma and hepatocellular carcinoma and describes the potential mechanisms by which some oncogenic or tumor suppressive miRNAs act. Furthermore, this review outlines novel therapeutic strategies for targeting miRNAs.     

Metastamirs: a stepping stone towards improved cancer management

MicroRNAs (miRNAs) are non-coding RNAs that regulate protein expression. Aberrant miRNA expression in cancer has been well documented; miRNAs can act as oncogenes or tumor-suppressor genes, depending on the cellular context and target genes that they regulate, and are involved in tumor progression and metastasis. The potential mechanisms by which miRNAs are involved in tumor aggressiveness include migration, invasion, cell proliferation, epithelial-to-mesenchymal transition, angiogenesis and apoptosis. MiRNAs are involved in various cellular pathways and an miRNA can elicit more than one biological effect in a given cell. Existing data show the potential clinical utility of miRNAs as prognostic and predictive markers for aggressive and metastatic cancers. The stability of miRNAs in formalin-fixed, paraffin-embedded tissues and body fluids is advantageous for biomarker discovery and validation. In addition, miRNAs can be extracted from small biopsy specimens, which is a further advantage. Finally, miRNAs are potential therapeutic agents for personalized cancer management.     

大肠癌相关microRNA研究进展

microRNA（miRNA）是一种大小约22个核苷酸的非编码单链小RNA分子，参与细胞增殖、分化、凋亡等多种重要细胞活动的调控。近来研究发现miRNA具有癌基因或抑癌基因样作用，参与多种恶性肿瘤的演进。是肿瘤发生、发展过程中重要分子。目前已发现多种miRNAs在大肠癌组织及大肠癌细胞系中异常表达，一部分在癌细胞中较正常细胞表达明显下降如miR-143、miR-145、let-7、miR-34a等，一部分表达则升高如miR-3l、miR-21等。体外试验中将miR-143、miR-145的前体导入大肠癌细胞中，可观察到癌细胞生长受到抑制，且呈剂量依赖性。miRNA表达谱与大肠癌的生物学行为和临床分期相关，如Ⅳ期大肠癌miR-31的表达水平明显较Ⅱ期升高。而大肠癌细胞系中miRNA表达谱与癌组织差别较大，由细胞系中得到miRNA表达谱可能不适于用来推断临床样本的相应表达谱。目前研究比较多的miRNAs如miR-143、miR-145、miR-34a、let-7a等，均有抑制细胞生长增殖的作用，它们在癌细胞中表达下降导致细胞过度生长增殖，可能参与大肠癌的发生。一些化疗药物能明显影响大肠癌细胞中miRNA的表达水平，如阿霉素可明显上调miR-34的表达水平，人们推测miRNA可能是一些化疗药物发挥抗肿瘤作用的重要分子。综上，阐明大肠癌相关miRNA的作用机制将可能丰富大肠癌的病因学及分子病理学理论，为大肠癌诊断治疗提供新策略和思路。