miR-126调控前列腺癌机制研究

miR-126通过靶向作用于表皮生长因子域7（EGFL7）、同源框A9（HOXA9）、胰岛素受体底物-1（11LS-1）、p85-B基因等,在转录后水平调控靶基因表达,在肿瘤形成中起重要作用。前列腺癌细胞中高表达miR,126,能明显下调VEGF—A、EGLF7、HOXA9、VCAM—1等与肿瘤生长、转移密切相关的蛋白分子。miR-126作为抑癌因子,在多种肿瘤中均下调。其抑癌作用及机制在肺癌、白血病、乳腺癌、宫颈癌等中均已得到证实。本课题拟对miR-126调控前列腺癌机制做一综述。     

MiR-26b是前列腺癌中的抑癌微RNA（英文）

微RNAs(又称miRNAs或miRs)是一类长度为19~24个核苷酸的单链非编码RNA分子.miRNA通过与其靶向的mRNA分子序列特异性互补配对,调节mRNA表达水平,抑制转录后的蛋白质翻译.miRNA在肿瘤中既可作为致癌因子也可作为抑癌因子.本研究前期已报道miR-26b在前列腺癌细胞系中低表达,并且抑制细胞自噬.本研究进一步全面揭示miR-26b对前列腺肿瘤细胞的作用.我们发现过表达miR-26b能够在体外抑制前列腺癌细胞的增殖和侵袭,并抑制裸鼠体内原位异种前列腺肿瘤的生长.为了探究miR-26b对前列腺癌细胞增殖和侵袭的潜在调控机制,我们进行了表达谱芯片鉴定miR-26b调控基因.表达谱芯片分析表明,在前列腺癌细胞系PC-3中过表达miR-26b后,显著上调的基因57个,显著下调的基因55个(变化倍数均大于2,且P值小于0.05).差异基因的功能多与细胞增殖、凋亡调控、蛋白质磷酸化和泛素化修饰调控过程相关,并且富集在多种信号通路中,例如TNF和TGF-β信号通路.在这些筛选出的基因中,CEACAM6表达水平下调2.17倍;序列分析及实验验证表明,CEACAM6的3′UTR区存在miR-26b的互补序列,是miR-26b的直接靶标.本研究证明了miR-26b能够靶向结合抑制CEACAM6的表达,从而抑制前列腺癌细胞在体外和体内的细胞增殖和侵袭活性,miR-26b是前列腺癌中的抑癌microRNA.     

miR-30a与其靶基因在肝癌中的作用研究进展

miRNA-30a(miR-30a)在肝癌组织中表达水平显著下调,可能是肝癌发展过程中的肿瘤抑制因子.miR-30a通过调控靶基因的表达参与肝癌细胞的增殖、凋亡、侵袭、转移以及自噬反应等一系列生理病理过程,从而发挥抑癌作用.本文就近年来miR-30a在肝癌中的靶基因及其调控分子机制做一综述.     

MiR-26b是前列腺癌中的抑癌微RNA

microRNAs（又称miRNAs或miRs）是一类长度为19-24个核苷酸的单链非编码RNA分子。miRNA通过与其靶向的mRNA分子序列特异性互补配对,调节mRNA表达水平,抑制转录后的蛋白翻译。miRNA在肿瘤中既可作为致癌因子也可作为抑癌因。本研究前期已报道miR-26b在前列腺癌细胞系中低表达,并且抑制细胞自噬。本研究进一步全面揭示miR-26b对前列腺肿瘤细胞的作用。我们发现过表达miR-26b能够在体外抑制前列腺癌细胞的增殖和侵袭,并抑制裸鼠体内原位异种前列腺肿瘤的生长。为了探究miR-26b对前列腺癌细胞增殖和侵袭的潜在调控机制,我们进行了表达谱芯片鉴定miR-26b调控基因。表达谱芯片分析表明,在前列腺癌细胞系PC-3中过表达miR-26b后,显著上调的基因57个,显著下调的基因55个（变化倍数均大于2,且P值小于0.05）。差异基因的功能多与细胞增殖、凋亡调控、蛋白磷酸化和泛素化修饰调控过程相关,并且富集在多种信号通路中,例如TNF和TGF-β信号通路。在这些筛选出的基因中,CEACAM6表达水平下调2.17倍;序列分析及实验验证表明,CEACAM6的3’UTR区存在miR-26b的互补序列,是miR-26b的直接靶标。本研究证明了miR-26b能够靶向结合抑制CEACAM6的表达,从而抑制前列腺癌细胞在体外和体内的细胞增殖和侵袭活性,miR-26b是前列腺癌中的抑癌microRNA。     

miR-182在前列腺癌组织中的表达及其对前列腺癌细胞增殖和凋亡的影响

目的:观察前列腺癌组织及不同前列腺癌细胞系中miR-182的表达,并探讨下调其表达对前列腺癌细胞增殖和凋亡的影响及机制。方法:采用实时荧光定量PCR(q RT-PCR)检测30例前列腺癌组织和30例相应的癌旁组织以及前列腺正常上皮RWPE-1细胞、前列腺癌PC-3、LNCa P和DU145细胞中miR-182的表达,进一步采用Lipfectamine 2000脂质体转染miRNA-182 inhibitor和阴性对照miRNA于PC-3细胞后,通过噻唑蓝(MTT)比色法检测细胞增殖情况,流式细胞术检测细胞凋亡率,免疫印迹(Western blot)法检测转录因子FOXO1、血管内皮生长因子(VEGF)和抑癌基因p53蛋白的表达。结果:miR-182在前列腺癌组织中的表达明显高于癌旁组织(P0.05);miR-182在前列腺癌细胞系PC-3、LNCa P和DU145中的表达均高于前列腺正常上皮细胞RWPE-1(P0.05),其中PC-3细胞中miR-182表达水平最高。转染miRNA-182 inhibitor至PC-3细胞成功下调miR-182表达后,细胞的增殖能力明显受到抑制,细胞凋亡能力明显增强,FOXO1表达水平显著升高,VEGF和p53的表达明显降低,差异均具有统计学意义(P0.05)。结论:miR-182在前列腺癌组织及细胞中呈高表达,下调miR-182的表达可能通过增加FOXO1的表达并减少VEGF和p53的表达,抑制前列腺癌细胞增殖并诱导细胞凋亡。     

miR-429与肿瘤

miR-429是miR-200家族成员之一。研究表明,miR-429异常表达与肿瘤的发生、发展、转移、凋亡和耐药等密切相关。但miR-429在肿瘤中所起的作用一直有争议,可作为肿瘤抑制剂或促进剂,具肿瘤细胞/组织特异性。其在骨肉瘤、肾癌、卵巢癌、乳腺癌、宫颈癌、胶质瘤、口腔鳞状细胞癌、胃癌、食管癌、胰腺癌中起抑癌作用,而在肺癌、前列腺癌和子宫内膜癌中起促癌作用,但在结肠癌、肝癌、膀胱癌中的作用尚不明确。本文综述了近年来miR-429在肿瘤发生、发展中的作用及潜在的调控机制,为其作为肿瘤诊断、治疗及预后的潜在生物标记分子提供新的启示和参考。     

miR-126增加非小细胞肺癌细胞A549对顺铂的敏感性

miR-126在多种恶性肿瘤中存在表达下调并显示抑癌基因的功能,然而其在肿瘤敏感性中的作用仍不明确.为了探讨miR-126在非小细胞肺癌细胞A549对顺式铂氨(cis-diammine dichloroplatoum, cisplatin, CDDP)敏感性中的作用及可能机制,本研究用MTS法检测非小细胞肺癌细胞A549及其衍生的CDDP耐受细胞A549/DDP对CDDP的敏感性.结果表明,A549/DDP细胞对CDDP的耐受性是A549细胞的4.05倍(P=0.0078)|用qRT-PCR检测发现,相比于A549细胞,A549/DDP细胞中miR-126的表达下调了8.45倍(P=0.0063),而survivin和Bcl-2的表达明显上调|通过MTS、qRT-PCR及Western印迹实验发现,miR-126 mimics使A549/DDP细胞中miR-126的表达上调了12.63倍(P=0.0013),并明显增加A549/DDP细胞对CDDP的敏感性及下调survivin和Bcl-2的表达;相反,miR-126 inhibitor能明显增加A549细胞对CDDP的耐受性及增加survivin和Bcl-2的表达.本研究结果提示,miR-126在非小细胞肺癌CDDP耐受细胞中的表达下调,上调miR-126的表达能增加耐药细胞对CDDP的敏感性. miR-126是逆转肺癌CDDP耐受的可能潜在靶标.     

MiR-126增加非小细胞肺癌细胞A549对顺式铂氨的敏感性

miR-126在多种恶性肿瘤中存在表达下调并显示抑癌基因的功能,然而其在肿瘤敏感性中的作用仍不明确.为了探讨miR-126在非小细胞肺癌细胞A549对顺式铂氨(cis-diammine dichloroplatoum,cisplatin,CDDP)敏感性中的作用及可能机制,本研究用MTS法检测非小细胞肺癌细胞A549及其衍生的CDDP耐受细胞A549/DDP对CDDP的敏感性.结果表明,A549/DDP细胞对CDDP的耐受性是A549细胞的4.05倍(P=0.0078);用qRT-PCR检测发现,相比于A549细胞,A549/DDP细胞中miR-126的表达下调了8.45倍(P=0.0063),而survivin和Bcl-2的表达明显上调;通过MTS、qRT-PCR及Western印迹实验发现,miR-126 mimics使A549/DDP细胞中miR-126的表达上调了12.63倍(P=0.0013),并明显增加A549/DDP细胞对CDDP的敏感性及下调survivin和Bcl-2的表达;相反,miR-126 inhibitor能明显增加A549细胞对CDDP的耐受性及增加survivin和Bcl-2的表达.本研究结果提示,miR-126在非小细胞肺癌CDDP耐受细胞中的表达下调,上调miR-126的表达能增加耐药细胞对CDDP的敏感性.miR-126是逆转肺癌CDDP耐受的可能潜在靶标.     

微小RNA-29与恶性肿瘤

miR-29家族是人类重要的miRNA分子,在多数恶性肿瘤中扮演抑癌RNA分子的作用,因而呈现低表达水平,它通过上调抑癌基因表达及调控相关肿瘤信号通路等机制,抑制恶性肿瘤的增殖、分化、侵袭和转移。miR-29家族不仅能作为恶性肿瘤治疗的靶点,而且在肿瘤的诊断及预后评估方面具有重要价值。     

miR-145靶向调控DAB2对前列腺癌PC3细胞迁移和侵袭能力的影响

已有研究表明, miR-145在多种肿瘤中低表达, 并与细胞增殖和转移相关。文章通过生物信息学分析并结合体外实验鉴定, 发现DAB2(Disabled homolog 2)为miR-145在肿瘤转移过程中累及的新靶点。DAB2一直被认为是一个重要的抑癌基因, 在多种肿瘤标本中表达低下。然而, 研究发现, 在具高侵袭能力的前列腺癌细胞株PC3中DAB2基因却呈较高水平表达。另外, 外源表达miR-145能显著下调 DAB2表达水平, 并抑制PC3细胞的迁移和侵袭能力, 且这种miR-145诱导的PC3细胞功能缺陷能被DAB2过表达修复。上述结果表明, miR-145能通过靶向调控DAB2而影响高侵袭前列腺癌细胞的迁移和侵袭能力。     

MiR-126 suppresses colon cancer cell proliferation and invasion via inhibiting RhoA/ROCK signaling pathway

Recent data strongly suggests the profound role of miRNAs in cancer progression. Here, we showed miR-126 expression was much lower in HCT116, SW620 and HT-29 colon cancer cells with highly metastatic potential and miR-126 downregulation was more frequent in colorectal cancers with metastasis. Restored miR-126 expression inhibited HT-29 cell growth, cell-cycle progression and invasion. Mechanically, microarray results combined with bioinformatic and experimental analysis demonstrated miR-126 exerted cancer suppressor role via inhibiting RhoA/ROCK signaling pathway. These results suggest miR-126 function as a potential tumor suppressor in colon cancer progression and miR-126/RhoA/ROCK may be a novel candidate for developing rational therapeutic strategies.     

miR-126 inhibits non-small cell lung cancer cells proliferation by targeting EGFL7

MicroRNAs (miRNAs) represent an abundant group of small non-coding RNAs that regulate gene expression, and have been demonstrated to play roles as tumor suppressor genes (oncogenes), and affect homeostatic processes such as development, cell proliferation, and cell death. Subsequently, epidermal growth factor-like domain 7 (EGFL7), which is confirmed to be involved in cellular responses such as cell migration and blood vessel formation, is identified as a potential miR-126 target by bioinformatics. However, there is still no evidence showing EGFL7’s relationship with miR-126 and the proliferation of lung cancer cells. The aim of this work is to investigate whether miR-126, together with EGFL7, have an effect on non-small cell lung cancer (NSCLC) cells’ proliferation. Therefore, we constructed overexpressed miR-126 plasmid to target EGFL7 and transfected them into NSCLC cell line A549 cells. Then, we used methods like quantitative RT-PCR, Western blot, flow cytometry assay, and immunohistochemistry staining to confirm our findings. The result was that overexpression of miR-126 in A549 cells could increase EGFL7 expression. Furthermore, the most notable finding by cell proliferation related assays is that miR-126 can inhibit A549 cells proliferation in vitro and inhibit tumor growth in vivo by targeting EGFL7. As a result, our study demonstrates that miR-126 can inhibit proliferation of non-small cell lung cancer cells through one of its targets, EGFL7.     

let-7b and miR-126 Are Down-Regulated in Tumor Tissue and Correlate with Microvessel Density and Survival Outcomes in Non–Small–Cell Lung Cancer

Angiogenesis is a critical event in the development, progression, and spread of various human cancers, including lung cancer. Molecular mechanisms that underlie the complex regulation of angiogenic processes are poorly understood. However, an increasing body of evidence indicates miRNAs as important regulators of tumor angiogenesis. Forceps biopsies were collected from tumor tissue, surrounding tissue, and non-tumor tissue from 50 NSCLC patients. Lung tissue samples from individuals with no clinical evidence of a cancerous disease served as controls. Immunohistochemical staining for Factor VIII was used to evaluate microvessel density (MVD). TaqMan® primer-probe sets were used in quantitative real-time RT-PCR reactions to determine expression levels of let-7b, miR-126, miR-9, and miR-19a. We demonstrated significantly higher MVD and decreased expression levels of let-7b and miR-126 in tumor tissue and surrounding tissue in comparison to corresponding non-tumor tissue or lung tissue from the control group. In addition, no differences in MVD and expression levels of both miRNAs between tumor tissue and surrounding tissue from NSCLC patients were observed. Low expression of both miRNAs correlated with high MVD and worse progression-free survival and overall survival. These observations strongly suggest similar molecular alternations within tumor tissue and surrounding tissue that comprise a specific microenvironment. Low expression of let-7b and miR-126 seems to have a possible anti-angiogenic role in lung tumor tissue and significantly correlates with worse survival outcomes for lung cancer patients. Moreover, the regulation of let-7b and miR-126 expression could have therapeutic potential because it could reduce tumor angiogenesis and therefore suppress tumor growth in lung cancer patients.     

miR-126 在膀胱癌患者尿液中的表达及临床意义

目的:探讨miR-126在膀胱癌患者尿液中的表达与临床病理特征的关系,评估miR-126的肿瘤标志物诊断价值。方法:收集48例初发膀胱尿路上皮癌患者与32例健康对照者晨尿,提取尿液总RNA,通过实时荧光定量PCR技术检测各样本中的miR-126的表达水平,并经受试者工作曲线(ROC)分析其诊断价值。结果:膀胱癌患者尿液中的miR-126表达水平相对健康对照组明显上调(P0.01),其表达水平在不同病理级别之间存在显著差异(P均0.05),且低级别组表达水平略高于高级别组,与肿瘤大小、数目以及淋巴转移也有一定的相关性(P0.05),而与患者的年龄、性别、TNM分期等均无相关性(P0.05)。通过ROC曲线分析尿液中miR-126诊断膀胱肿瘤的曲线下面积(AUC)为0.861,当最佳切点定在7.475时,miR-126诊断膀胱肿瘤的敏感性和特异性分别为75.0%、81.2%。结论:膀胱癌患者尿液中miR-126的表达差异能够反映病情进展程度,其表达水平对膀胱肿瘤的早期诊断及病情评估具有一定的价值。     

miR-126&126* Restored Expressions Play a Tumor Suppressor Role by Directly Regulating ADAM9 and MMP7 in Melanoma

The abnormal expression of several microRNAs has a causal role in tumorigenesis with either antineoplastic or oncogenic functions. Here we demonstrated that miR-126 and miR-126* play a tumor suppressor role in human melanoma through the direct or indirect repression of several key oncogenic molecules. The expression levels of miR-126&126* were elevated in normal melanocytes and primary melanoma cell lines, whereas they markedly declined in metastatic cells. Indeed, the restored expression of miR-126&126* in two advanced melanoma cell lines was accompanied by a significant reduction of proliferation, invasion and chemotaxis in vitro as well as of growth and dissemination in vivo. In accordance, the reverse functional effects were obtained by knocking down miR-126&126* by transfecting antisense LNA oligonucleotides in melanoma cells. Looking for the effectors of these antineoplastic functions, we identified ADAM9 and MMP7, two metalloproteases playing a pivotal role in melanoma progression, as direct targets of miR-126&126*. In addition, as ADAM9 and MMP7 share a role in the proteolytic cleavage of the HB-EGF precursor, we looked for the effectiveness of this regulatory pathway in melanoma, confirming the decrease of HB-EGF activation as a consequence of miR-126&126*-dependent downmodulation of ADAM9 and MMP7. Finally, gene profile analyses showed that miR-126&126* reexpression was sufficient to inactivate other key signaling pathways involved in the oncogenic transformation, as PI3K/AKT and MAPK, and to restore melanogenesis, as indicated by KIT/MITF/TYR induction. In view of this miR-126&126* wide-ranging action, we believe that the replacement of these microRNAs might be considered a promising therapeutic approach.     

microRNA-802 inhibits cell proliferation and induces apoptosis in human cervical cancer by targeting serine/arginine-rich splicing factor 9

microRNAs (miRNAs) play crucial roles in cancer development and progression by targeting mRNAs for degradation and/or translational repression. microRNA-802 (miR-802) has been reported as a tumor suppressor and its deregulation is observed in various human cancers. However, the prognostic value of miR-802 and its underlying mechanisms involved in human cervical cancer are poorly investigated. The purposes of this study were to explore the role of miR-802 in cervical cancer and to clarify the regulation of serine/arginine-rich splicing factor 9 (SRSF9) by miR-802. Here, we found that miR-802 was downregulated in both cervical cancer tissues and cell lines. Transfection of a miR-802 mimic into cervical cancer cells inhibited their proliferation and colony formation, and promoted cell cycle arrest at the G0/G1 phase and cell apoptosis. In addition, we found that miR-802 could directly target the 3′-untranslated region of SRSF9 and suppress SRSF9 expression. Rescue experiments revealed that overexpression of SRSF9 partially reversed the inhibition effect of miR-802 in cervical cancer cells. Overall, these findings demonstrate that miR-802 functions as a tumor suppressor in cervical cancer by targeting SRSF9, suggesting that miR-802 might serve as a potential therapeutic target in cervical cancer.