miR-215抑制骨肉瘤细胞生长及其分子机制

目的:研究miR-215对骨肉瘤细胞143B生长的影响及其分子机制。方法:通过转染miR-215 agomir稳定升高143B细胞内miR-215表达水平，CCK-8实验、平板克隆形成实验以及流式细胞术检测143B细胞的增殖状况以及周期分布。利用生物信息学分析miR-215潜在的靶基因，并通过双荧光素酶报告基因实验、qPCR实验、Western blot实验验证miR-215靶基因。结果:在143B细胞内将miR-215表达水平上调数倍。CCK-8实验、平板克隆形成实验表明miR-215能够抑制143B细胞生长，流式细胞术实验表明miR-215能够延缓143B细胞周期进程。生物信息学、qPCR实验和Western blot实验表明转化生长因子β受体1（transforming growth factor β receptor 1，TGFβR1）是miR-215潜在的靶基因。结论:miR-215能够抑制骨肉瘤细胞生长，并且该抑制作用可能通过miR-215靶向抑制TGFβR1实现，为骨肉瘤早期诊断和靶向治疗提供了理论依据。     

微小RNA-494在肿瘤发生发展中的作用

微小RNA-494 (miR-494)参与正常细胞的细胞周期调控、分化和凋亡等过程.近年来研究表明,miR-494的异常表达与肿瘤的发生密切相关,其参与肿瘤细胞的侵袭和转移等过程.miR-494是一种肿瘤抑制基因,也可作为癌基因,其通过多种靶基因、信号通路对肿瘤发生发展进行调控.     

miR-30a-5p通过靶向下调ATF1提高非小细胞肺癌A549细胞放射敏感性北大核心

目的:探索miR-30a-5p对非小细胞肺癌(non-small cell lung cancer,NSCLC)A549细胞的放射增敏效应及其相关机制,为提高NSCLC放射敏感性提供理论依据。方法:采用qRT-PCR检测人正常肺上皮细胞株BEAS-2B、人肺癌细胞株A549、H460中miR-30a-5p表达情况;应用miR-30a-5p agomir、antagomir及对照转染A549细胞株,联合放射,检测miR-30a-5p对A549细胞株的放射增敏效应;通过生物信息学预测并筛选miR-30a-5p的靶基因,采用双荧光素酶报告基因检测进行验证;siATF1、miR-30a-5p agomir及siATF1+miR-30a-5p agomir转染A549细胞,通过qRT-PCR、Western Blotting检测靶基因表达与miR-30a-5p的关系,并通过平板克隆形成实验检测其对A549细胞株的放射增敏效应。结果:miR-30a-5p在A549和H460细胞株中表达均低于BEAS-2B细胞株(P<0.001);miR-30a-5p agomir转染联合放射,A549细胞放射生物学参数D_(0)、D_(q)、N较agomir NC组降低(均为P<0.05)。靶基因预测及验证结果显示,miR-30a-5p可以与ATF1的3'UTR特异性结合,ATF1是miR-30a-5p的一个靶基因,过表达miR-30a-5p可下调ATF1表达。siATF1、miR-30a-5p agomir及siATF1+miR-30a-5p agomir转染A549细胞联合照射,A549细胞克隆形成率及放射生物学参数D_(0)、D_(q)、N均低于对照组(均为P<0.05)。结论:miR-30a-5p通过靶向下调ATF1表达,在A549细胞中发挥放射增敏效应。     

肺癌转移相关microRNA miR-29b的生物信息学分析*

目的: 应用生物信息学分析A549细胞中在CD133阳性低表达的miR-29b的靶基因及其功能,为以miR-29b为靶点的肿瘤研究提供线索。 方法: 利用miRNA PCR芯片筛选A549细胞中CD133阳性和CD133阴性差异表达的miRNA,选用miRecords预测miR-29b的靶基因,合并已证实的靶基因,利用GOEAST和DAVID数据库对所得靶基因进行功能富集分析和信号转导通路富集分析。 结果: A549细胞中与CD133阴性比较,miR-29b在CD133阳性中表达下调。miR-29b靶基因有106个,其靶基因功能富集于结合和细胞外基质形成等作用（P<0.01）;信号转导通路显著富集于JAK-STAT和TGF-β等信号转导通路（P<0.05）。 结论: miR-29b可能与肺癌转移相关,miR-29b的靶基因显著富集在与肿瘤相关的信号通路中。      

miR-138-5p靶向调控RAB22A表达抑制胶质瘤细胞的增殖、迁移和侵袭

目的:探讨miR-138-5p对胶质瘤细胞增殖、迁移与侵袭的影响以及其作用机制。方法:U251细胞分为miR-NC组(对照组)、miR-mimics组、miR-inhibitor组以及miR-mimics+RAB22A-pcDNA3.1组。qRT-PCR检测miR-138-5p在胶质瘤细胞中的表达量;CCK8实验检测U251细胞的增殖能力;Transwell实验检测U251细胞的迁移和侵袭能力;Targetscan数据库预测miR-138-5p的下游靶基因;运用双荧光素酶报告基因实验验证细胞周期蛋白RAB22A是miR-138-5p的靶基因;RNA结合蛋白免疫沉淀实验进一步验证miR-138-5p与RAB22A之间的相互作用;运用蛋白免疫印迹实验检测组织和细胞中RAB22A的蛋白表达水平。结果:与正常人星形胶质细胞相比较,miR-138-5p 在胶质瘤细胞中表达量降低(P<0.05);CCK8和Transwell实验结果表明,在U251细胞中,过表达miR-138-5p能显著抑制细胞的增殖、迁移和侵袭能力(P＜0.05);运用Targetscan数据库预测miR-138-5p下游靶基因为RAB22A,miR-138-5p作用于RAB22A的3' UTR区域,双荧光素酶报告基因实验与蛋白免疫沉淀实验结果证实miR-138-5p与RAB22A之间的相互作用;RAB22A在胶质瘤细胞中明显高表达(P＜0.05),在U251细胞中过表达miR-138-5p明显抑制RAB22A的表达(P＜0.05)。结论:miR-138-5p在胶质瘤细胞中表达降低,miR-138-5p通过下调RAB22A表达而抑制细胞增殖、迁移和侵袭。     

miR-455-5p在上皮性卵巢癌中表达研究及其靶基因功能分析

目的 研究miR-455-5p在上皮性卵巢癌中的表达情况,分析其表达对上皮性卵巢癌发生发展的影响。方法 从GEO数据库中下载正常卵巢上皮组织与上皮性卵巢癌组织miRNA表达数据GSE83693,通过差异表达分析获得上皮性卵巢癌中miRNA差异表达数据,分析miR-455-5p在正常卵巢上皮与上皮性卵巢癌组织中的表达是否存在差异,应用qRT-PCR验证差异表达预测结果;应用生物信息学软件对miR-455-5p靶基因进行KEGG通路富集分析及GO基因功能注释,探究miR-455-5p表达失调在上皮性卵巢癌发生发展过程中的作用。结果 筛选出明显差异表达miRNA 101例,34例表达上调,67例表达下调;其中miR-455-5p呈明显下调(P＜0.01),差异倍数为-2.9019;qRT-PCR验证结果显示,上皮性卵巢癌细胞(SKOV-3,OVCAR-3,A2780)中miR-455-5p表达量明显低于正常卵巢上皮细胞(IOSE-80),差异均有统计学意义(P＜0.05);KEGG通路富集分析结果显示,miR-455-5p调控的靶基因主要参与的通路共5个,包括有TGF-β信号通路,Hippo信号通路,ECM-受体相互作用,癌症中的转录失调通路,慢性粒细胞白血病,这些通路均与肿瘤相关。GO功能注释分析结果显示上述通路中miR-455-5p调控的靶基因主要参与蛋白质磷酸化,促进细胞增殖、迁移,抑制细胞凋亡,促进上皮-间充质转化,转录调节及调控细胞周期等与肿瘤发生相关的功能。结论 miR-455-5p在上皮性卵巢癌中表达下调,miR-455-5p靶基因参与上皮性卵巢癌肿瘤相关通路与功能,与上皮性卵巢癌发生发展相关。     

MicroRNA-143 functions as a tumor suppressor in human bladder cancer T24 cells

MicroRNA (miR)-143 and -145 were down-regulated in human bladder cancer T24 cells. The enforced expression of miR-143 induced growth-suppression in T24 cells through down-regulation of ERK5 and Akt expression at translational level, and chemically-modified synthetic miR-143 (miR-143/BP) exhibited a greater growth inhibitory effect than wild-type miR-143. In addition, the synthetic miR-143/BP induced apoptotic cell death in some of the transfected cells. Furthermore, co-treatment with the synthetic miR-143/BP and cisplatin showed the additive growth-suppressing effect on T24 cells. These findings suggest that the chemically-modified synthetic miR-143 functions as a tumor suppressor in T24 cells by targeting ERK5 and/or Akt.     

肿瘤细胞miR-145表达生物学意义的研究现状

目的:总结国内外研究miR-145与肿瘤关系的文献,评价miR-145在肿瘤发生、发展中的作用.方法:以“miR-NAs、miR-145、肿瘤”为关键词,检索1993-2011年PubMed及CNKI期刊全文数据库.纳入标准:1)miR-145基因结构及生物学特性的研究;2)miR-145与肿瘤发生发展关系的研究;3)miR-145与肿瘤诊断、治疗和预后关系的研究.根据纳入标准,纳入分析30篇文献.结果:miR-145定位于5号染色体肿瘤相关的脆性位点上,在多种组织的恶性肿瘤中miR-145表达明显下调.过表达miR-145可抑制肿瘤细胞增殖及诱导肿瘤细胞凋亡.检测血清中miR-145的含量,有助于肿瘤的早期诊断.肿瘤组织中miR-145的表达量与患者放化疗疗效及预后密切相关.结论:miR-145是一个潜在的肿瘤生物标志,有可能成为肿瘤治疗的新靶标.     

MicroRNA-3127 promotes cell proliferation and tumorigenicity in hepatocellular carcinoma by disrupting of PI3K/AKT negative regulation

Recent studies have shown that multiple phosphatases deactivate the PI3K/AKT signaling pathway. Here we demonstrated that, by suppressing multiple phosphatases, miR-3127 promotes growth of hepatocellular carcinoma (HCC). Our study also reveals clinical significance of miR-3127 expression in HCC patients. MiR-3127 expression was markedly upregulated in HCC tissues and cells. Furthermore, high miR-3127 expression was associated with an aggressive phenotype and poor prognosis. MiR-3127 overexpression promoted HCC cell proliferation in vitro and tumor growth in vivo. Also, miR-3127 accelerated G1-S transition by activating AKT/FOXO1 signaling, by directly targeting the 3′ untranslated regions (3`UTR) of pleckstrin homology domain leucine-rich repeat protein phosphatase 1/2 (PHLPP1/2), inositol polyphosphate phosphatase 4A (INPP4A), and inositol polyphosphate-5-phosphatase J (INPP5J) mRNA, repressing their expression. In agreement, the miRNA antagonist antagomir-3127 suppressed HCC cell proliferation and tumor growth by inhibiting the AKT/FOXO1 signaling. Taken together, these findings suggest that silencing miR-3127 might be a potential therapeutic strategy.     

MicroRNA-15a-5p suppresses cancer proliferation and division in human hepatocellular carcinoma by targeting BDNF

We examined the expression pattern and functional roles of microRNA 15a-5p (miR-15a-5p) in human hepatocellular carcinoma (HCC). Possible miR-15a-5p aberrant expression in HCC cell lines or clinical HCC specimens was examined by quantitative real-time PCR (qRT-PCR). In HCC HepG2 and SNU-182 cells, miR-15a-5p was ectopically overexpressed by lentiviral transduction. Its effect on HCC proliferation, cancer division, and in vivo tumor growth were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell cycle assay, and tumorigenicity assay, respectively. The targeting of miR-15a-5p on its downstream gene, brain-derived neurotrophic factor (BDNF), was examined by dual-luciferase assay, qRT-PCR, and Western blot, respectively. BDNF was then overexpressed in HepG2 and SNU-182 cells to evaluate its selective effect on miR-15a-5p in HCC modulation. MiR-15a-5p is aberrantly downregulated in in vitro HCC cell lines and in vivo HCC clinical specimens. Ectopic overexpression of miR-15a-5p suppressed cancer proliferation, induced cell cycle arrest in HepG2 or SNU-182 cells in vitro, and inhibited HCC tumor growth in vivo. MiR-15a-5p selectively and negatively regulated BDNF at both gene and protein levels in HCC cells. Forced overexpression of BDNF effectively reversed the tumor suppressive functions of miR-15a-5p on HCC proliferation and cell division in vitro. Our study demonstrated that miR-15a-5p is a tumor suppressor in HCC and its regulation is through BDNF in HCC.     

MicroRNA-19 and neoplasms

The miR-17-92 cluster, consisting of six individual microRNAs, including miR-17, miR-20a,miR-18a, miR-19a, miR-19b and miR-92a-1, is a kind of typical oncogenic polycistron microRNA. MiR-19 (containing miR-19a and miR-19b), as the key oncogenic component in miR-17-92 cluster, is overexpressed in human cancers including lymphomas, leukaemia, lung cancer, breast cancer and multiple myeloma, and has been one of research focus in recent years. It is found that miR-19 promotes tumor growth,invasion and metastasis through negative regulation of target genes such as PTEN, PP2A, Bim,SOCS1, and is correlated strongly with PI3K-AKT-mTOR pathway. MiR-19 plays an important role in tumor genesis and development.     

miR-133a-5p suppresses gastric cancer through TCF4 down-regulation

BackgroundThe effect of microRNAs (miRNA) on cancer regulations has received a considerable amount of attention recently. MiR-133a-5p has been identified as an anti-tumor miRNA in several types of cancers. However, the effect of miR-133a-5p on gastric cancer (GC) have not been uncovered. In this study, we sought to evaluate the regulation of TCF4 expression by miR-133-5p and the role of the miR-25-3p/TCF4 axis in the progression of GC, with the aim of identifying a potential therapeutic target for GC.MethodsTCGA (The Cancer Genome Atlas), GTEx (The Genotype-Tissue Expression) and GEO (Gene Expression Omnibus) database were used to analyze the expression and prognosis. We performed MTT and EdU assays to elucidate the effect on cell replication. Apoptotic cells were stained with annexin V-fluorescein isothiocyanate and propidium iodide to stain, and then analyzed by flow cytometry. The effect on cell metastasis was investigated in wound healing and transwell assays. A dual-luciferase reporter assay was used to check for the direct targeting of TCF4 by miR-133a-5p. Bioinformatic analysis of the relationship of TCF4 with tumor microenvironment and the signaling cascade of TCF4 was finally performed.ResultsWe found that the level of miR-133a-5p was decreased in both tumor tissues and GC cell lines. MiR-133a-5p inhibited cell growth and metastasis, but promoted cell apoptosis. MiR-133a-5p directly targeted TCF4 and downregulated its expression. TCF4 was highly expressed in tumor and higher level of TCF4 indicated poorer prognosis. Moreover, TCF4 overexpression reversed the aforementioned anti-tumor activity of miR-133a-5p. The expression level of TCF4 was significantly correlated with tumor-infiltrating immune cells.ConclusionsOur findings altogether reveal that miR-133a-5p can serve as a tumor suppressor in gastric cancer via the miR-133a-5p/TCF4 pathway.     

miR-19与肿瘤

 miR-17~92基因簇编码6种成熟的miRNA,包括miR-17、miR-20a、miR-18a、miR-19a、miR-19b和miR-92a-1,是一类典型的致癌多作用子miRNA。miR-19（包括miR-19a和miR-19b）是其中最重要的致癌miRNA,在淋巴瘤、白血病、肺癌、乳腺癌、多发性骨髓瘤等肿瘤中均表达上调,成为研究的热点之一。miR-19可通过抑制靶基因如PTEN、PP2A、Bim、SOCS1等促进肿瘤的增殖、侵袭和转移,与PI3K-AKT-mTOR信号转导通路关系密切,在肿瘤的发生发展中起着非常重要的作用。     

MicroRNA-143 replenishment re-sensitizes colorectal cancer cells harboring mutant,but not wild-type,KRAS to paclitaxel treatment

Colorectal cancer (CRC) global incidence is one of the highest among cancers. The KRAS gene has been shown as a robust biomarker for poor prognosis and drug resistance. MicroRNA-143 (miR-143) and let-7 are families of tumor suppressor microRNAs that are often downregulated in CRC, especially with coexistent KRAS mutations. In order to evaluate if miR-143 and/or let-7b replenishment would re-sensitize CRC cells to paclitaxel treatment, we investigated in effect of miR-143 and let-7b replenishments on sensitivity to paclitaxel treatment in KRAS mutant LoVo and wild-type SW48 CRC cell lines. Our results showed that miR-143, but not let-7b, increased sensitization of KRAS mutant tumor cells to paclitaxel. Furthermore, transfection of miR-143, but not let-7b, mimic negatively regulated the expression of mutant but not wild-type KRAS. Combination of miR-143 mimic and paclitaxel induced the onset of apoptosis, and reverted in vitro metastatic properties (migration and invasion) in KRAS mutant tumor cells. MiR-143 thus can be used as a chemosensitizer for the treatment of KRAS mutant tumors and warrants further investigations in in vitro and pre-clinical in vivo models.     

miR-143 and miR-145 inhibit stem cell characteristics of PC-3 prostate cancer cells

Emerging evidence demonstrates that cancer stem cells (CSCs) are the critical drivers of tumor progression and metastasis. The microRNAs (miRNAs) may play a crucial role in repressing/promoting metastasis of cancer by regulating CSCs. A previous study showed that miR-143 and miR-145 play an important role in regulating bone metastasis of prostate cancer (PCa), but the exact mechanism of regulation of bone metastasis of PCa is not fully understood. In this study, we found that overexpression of miR-143 and miR-145 inhibited the cell viability and colony formation of PC-3 cells from PCa bone metastasis. Furthermore, miR-143 and miR-145 suppressed tumor sphere formation and expression of CSC markers and 'stemness' factors including CD133, CD44, Oct4, c-Myc and Klf4 in PC-3 cells. The study further found that miR-143 and miR-145 inhibit bone invasion and tumorigenicity of PC-3 cells in vivo. Collectively, these findings demonstrate that miR-143 and miR-145 inhibit CSC properties of PC-3 cells and suggest that miR-143 and miR-145 may play a significant role in the bone metastasis progression of PCa by regulating CSC characteristics.