微小RNA132在突触可塑性以及药物成瘾中的作用

复吸是药物成瘾防治的一个难题,它被认为是由于脑内正常的奖赏相关学习记忆环路被篡夺或改变而导致的病理行为。研究成瘾记忆形成和提取后突触可塑性的机制,对于寻找能够消除成瘾记忆的靶分子极为重要。已有研究显示,成瘾性药物（如可卡因）能诱导成瘾相关脑区中多种非编码微小RNA(microRNA,miRNA)表达水平的变化,而部分miRNAs也被证明可通过调控靶基因的表达参与调控突触结构可塑性。其中,非编码微小RNA 132(microRNA-132,miR-132)不仅与树突棘的形态发生、学习记忆等功能相关,也可能参与药物成瘾过程。因此,本文对miR-132调控突触可塑性的作用作一综述,以期为miR-132在药物成瘾病理性记忆方面的深入研究提供思路。     

抗肿瘤药物与miRNA靶点相互作用研究进展

miRNA是一大类非编码的小分子RNA,在肿瘤等许多疾病的发生过程中起重要作用。该文综述了miRNA的生物合成过程以及有关的酶与辅助因子,抗肿瘤药物对miRNA表达的改变以及药物与miRNA靶点的相互作用和机制。同时提出了有关miRNA的功能研究,以miRNA为靶点的药物筛选以及药物对miRNA表达的调控机制是未来研究的重点。     

中枢神经系统mTOR信号通路与药物成瘾关系的研究进展

药物成瘾属于一种慢性复发性脑疾病。反复的药物暴露会导致脑环路产生神经适应性变化,进而出现强迫性觅药行为。在生物体内,信号通路转导级联的放大会介导中枢神经系统奖赏环路的重塑。研究发现,哺乳动物雷帕霉素靶点(mTOR)信号通路与药物成瘾引起的神经适应性和奖赏效应直接相关。本文就mTOR信号通路及其与药物成瘾关系的研究进展作一综述,为深入探索药物成瘾的分子调控机制提供理论依据。     

MiRNAs在苯丙胺类兴奋剂成瘾中作用的研究进展

苯丙胺类兴奋剂(amphetamine-type stimulants,ATS)是一组以精神依赖为主的新型合成毒品,近年来流行,滥用趋势愈发严峻。MicroRNAs(MiRNAs)作为一类非编码小分子RNAs,通过与靶基因mRNA的互补配对,在转录后水平上对基因的表达进行负调控,从而导致靶基因mRNA的降解或翻译抑制。ATS能诱导miRNAs表达水平的变化,而成瘾相关脑区miRNAs表达的改变直接参与了对ATS成瘾行为的调节。因此,研究miRNAs在ATS成瘾中的调控作用,对进一步揭示新型毒品的成瘾机制及发现新的药物作用靶点具有重要意义。     

中枢神经系统ERK信号通路在药物成瘾中的作用机制研究进展

药物成瘾是一种慢性复发性脑病。反复的药物暴露可引起脑环路产生神经适应性变化,导致强迫性觅药行为以及复吸。有许多研究发现,生物体内细胞间的信号转导级联放大通路介导的中枢神经系统奖赏环路的重塑,以及成瘾相关的学习和记忆的神经可塑性改变是药物成瘾的重要分子机制。研究表明细胞外调节激酶(extracellular signal-regulatedkinase,ERK)与药物成瘾引起的神经适应性、奖赏效应和觅药行为的复吸直接相关。因此,该文就ERK在药物成瘾中的作用机制做系统的综述。药物成瘾中ERK信号通路作用机制的研究将为深入理解药物成瘾的分子调控机制提供重要的理论基础,并为临床药物成瘾和复吸的治疗提供新的分子靶标和新的策略。     

miRNAs在甲基苯丙胺成瘾中的作用研究进展

甲基苯丙胺(methamphetamine,METH)成瘾是机体长期接触METH后,中枢神经系统在分子、细胞、神经环路功能和脑结构等层次发生的代偿性适应,该过程有多种途径和多种机制共同参与。miRNAs作为一种新型基因转录后调控分子和突触的调节因子,大量存在于中枢神经系统,对中枢神经系统具有重要的调控作用。研究表明,miRNAs在METH成瘾中发挥着重要的调控作用。该文对miRNAs在METH成瘾机制中的表达特征及调控作用进行综述,并将与METH成瘾相关的miRNAs分子以及各miRNAs分子在不同组织器官中的差异性表达部位进行归纳整理,为进一步研究miRNAs分子在METH成瘾中的作用及发现新的药物作用靶点提供参考。     

药物成瘾的强迫觅药模型

药物成瘾患者缺乏对觅药冲动的自我控制能力,并伴有以认知功能损伤为主要特征的认知功能障碍;表现为不顾严重负性后果的强迫性觅药和用药行为(compulsive drug-seeking and drug-taking behavior)。这些强迫症状往往出现在长期使用成瘾药物的患者中,即使在身体戒断症状消退后依然持久地存在,且与成瘾药物的复吸密切相关。因此,理想的药物成瘾模型不仅应造成动物的自主觅药行为及复吸,而且可再现长期使用成瘾药物后出现的强迫觅药冲动及认知功能损伤等核心症状。本文回顾近年有关药物成瘾强迫觅药模型建立及相关神经机制的研究进展;这些研究提示不可抑制的觅药冲动、以及对惩罚的认知缺陷能够较好体现强迫性觅药伴随的认知功能的损伤,并且与大脑前额叶皮质功能紊乱关联密切。强迫觅药行为神经生物学机制的阐明将为理解人类成瘾行为的生物学本质、开发有效治疗成瘾的新药提供策略依据。     

miRNA调控乳腺癌多药耐药机制的研究进展

乳腺癌是女性发病率最高的恶性肿瘤之一。化学治疗是乳腺癌临床治疗的主要手段之一,然而乳腺癌细胞对化疗药物产生的MDR成为乳腺癌治疗的瓶颈。miRNA是一种存在于真核生物中的内源性非编码短链RNA,广泛参与到增殖、凋亡等多种生理过程。近年来,有关miRNA在乳腺癌MDR中的作用及机制研究取得了诸多进展,因此就miRNA调控乳腺癌MDR分子机制的研究进展做一综述。     

microRNAs在甲基苯丙胺滥用诱导神经退行性疾病中的研究进展

微小RNA(microRNA)是一种仅有21-25个核苷酸序列的非编码RNA,可以通过靶向目标mRNA来调控目标蛋白的表达水平。研究表明,microRNA在神经退行性疾病中发挥着重要的调控作用,对甲基苯丙胺成瘾也存在潜在的作用。目前,越来越多的研究者聚焦于microRNA对药物成瘾的研究中。本文就microRNA在甲基苯丙胺滥用诱导神经退行性疾病中的作用研究进展进行综述。     

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。     

MicroRNAs in Opioid Pharmacology

MicroRNAs (miRNA), a class of ~22-nucleotide RNA molecules, are important gene regulators that bind to the target sites of mRNAs to inhibit the gene expressions either through translational inhibition or mRNA destabilization. There are growing evidences that miRNAs have played several regulatory roles in opioid pharmacology. Like other research fields such as cancer biology, the area where numerous miRNAs are found to be involved in gene regulation, we assume that in opioid studies including research fields of drug additions and opioid receptor regulation, there may be more miRNAs waiting to be discovered. This review will summarize our current knowledge of miRNA functions on opioids biology and briefly describe future research directions of miRNAs related to opioids.     

MicroRNAs as therapeutic targets and their potential applications in cancer therapy

INTRODUCTION: The results of cancer-associated miRNA research have yielded surprising insights into the pathogenesis of a range of different cancers. Many of the dysregulated miRNAs are involved in the regulation of genes that are essential for carcinogenesis. AREAS COVERED: This review discusses the latest discovery of miRNAs acting as oncogenes and tumor suppressor genes, as well as the potential applications of miRNA regulations in cancer therapy. Several translational studies have demonstrated the feasibility of targeting oncogenic miRNAs and restoring tumor-suppressive miRNAs for cancer therapy using in vivo model systems. EXPERT OPINION: miRNAs are extensive regulators of cancer progression. With increasing understanding of the miRNA target genes and the cellular behaviors influenced by them, modulating the miRNA activities may provide exciting opportunities for cancer therapy. Despite the hurdles incurred in acquiring effective systemic drug delivery systems, in vivo delivery of miRNAs for therapeutic purposes in preclinical animal models is rapidly developing. Accumulating evidences indicate that using miRNA expression alterations to influence molecular pathways has the potential of being translated into clinical applications.     

Implication of microRNAs in drug resistance for designing novel cancer therapy

Recently, microRNAs (miRNAs) have received increasing attention in the field of cancer research. miRNAs play important roles in many normal biological processes; however, the aberrant miRNA expression and its correlation with the development and progression of cancers is an emerging field. Therefore, miRNAs could be used as biomarkers for diagnosis of cancer and prediction of prognosis. Importantly, some miRNAs could regulate the formation of cancer stem cells and the acquisition of epithelial–mesenchymal transition, which are critically associated with drug resistance. Moreover, some miRNAs could target genes related to drug sensitivity, resulting in the altered sensitivity of cancer cells to anti-cancer drugs. Emerging evidences have also shown that knock-down or re-expression of specific miRNAs by synthetic anti-sense oligonucleotides or pre-miRNAs could induce drug sensitivity, leading to increased inhibition of cancer cell growth, invasion, and metastasis. More importantly, recent studies have shown that natural agents including isoflavone, 3,3′-diindolylmethane, and (?)-epigallocatechin-3-gallate altered miRNA expression profiles, leading to an increased sensitivity of cancer cells to conventional therapeutics. These emerging results suggest that specific targeting of miRNAs by different approaches could open new avenues for cancer treatment through overcoming drug resistance and thereby improve the outcome of cancer therapy.     

Reversing epigenetic mechanisms of drug resistance in solid tumors using targeted microRNA delivery

ABSTRACT

Introduction: Tumor cells utilize many different mechanisms to desensitize themselves to the cytotoxic effects of drugs, but it has recently been recognized that alterations in epigenetic control of gene expression underly many of them. As master regulators of gene expression, microRNAs (miRNAs) present a promising therapeutic strategy for the reversal of epigenetic changes that lead to drug resistance phenotypes in tumor cells.

Areas covered: Effects of epigenetic changes on drug resistance in a variety of solid tumors are discussed. Specific miRNAs that are involved with the regulation of epigenetic machinery are highlighted. Further, we consider how delivery of miRNA or antagomirs may be utilized to resensitize drug-resistant tumor cells.

Expert opinion: Reversal of epigenetically controlled tumor drug resistance mechanisms via miRNA delivery presents a novel strategy for enhancing the efficacy of chemotherapeutics. Further, the ability to target delivery of miRNAs may provide the opportunity to go beyond reversal of resistance to hyper-sensitization of tumor cells to the cytotoxic effects of drugs. However, understanding of the role of miRNA in epigenetic regulation is still in its early stages and further research is critical for potential utility in improving therapeutic efficacy in cancer patients.     

MicroRNAs as therapeutic targets and their potential applications in cancer therapy

Introduction: The results of cancer-associated miRNA research have yielded surprising insights into the pathogenesis of a range of different cancers. Many of the dysregulated miRNAs are involved in the regulation of genes that are essential for carcinogenesis.

Areas covered: This review discusses the latest discovery of miRNAs acting as oncogenes and tumor suppressor genes, as well as the potential applications of miRNA regulations in cancer therapy. Several translational studies have demonstrated the feasibility of targeting oncogenic miRNAs and restoring tumor-suppressive miRNAs for cancer therapy using in vivo model systems.

Expert opinion: miRNAs are extensive regulators of cancer progression. With increasing understanding of the miRNA target genes and the cellular behaviors influenced by them, modulating the miRNA activities may provide exciting opportunities for cancer therapy. Despite the hurdles incurred in acquiring effective systemic drug delivery systems, in vivo delivery of miRNAs for therapeutic purposes in preclinical animal models is rapidly developing. Accumulating evidences indicate that using miRNA expression alterations to influence molecular pathways has the potential of being translated into clinical applications.     

The role of microRNAs in cancer: diagnostic and prognostic biomarkers and targets of therapies

INTRODUCTION: miRNAs are noncoding RNAs that target specific mRNA with subsequent regulation of particular genes, implicated in various biological processes. In cancer, miRNAs could show a different expression from normal tissues. miRNAs have a role as oncogenes when they target tumor suppressor genes and similarly they are tumor suppressors when they target oncogenes. AREAS COVERED: In this review, areas covered include the role of miRNAs in cancer diagnosis, prognosis and research for achievement of therapeutic strategies implicating miRNAs in oncology. As biogenesis of miRNAs is fundamental to understand their usefulness, this has also been discussed. Both miRNA expression profiles in cancer tissues and miRNA levels in peripheral blood were studied for improvement in the management of cancer patients. EXPERT OPINION: miRNAs have the potential for better understanding of tumor biology, but could also provide clinical advancement in management and therapy of various malignancies. The possibility of miRNA detection in peripheral blood would allow an eager expansion of their application in various clinical settings for cancer. The applicability of miRNA expression profiles still needs to be defined.