miR-375靶向SHOX2调控人食管鳞癌细胞侵袭迁移的初步研究

目的 探讨miR-375/SHOX2轴对食管鳞癌细胞侵袭迁移能力的影响,为食管鳞癌的靶向治疗寻找潜在新靶点。方法 选取对数生长期的人食管鳞癌细胞（kyse-70、kyse-30）,分别过表达以及干扰miR-375和SHOX2基因,采用克隆形成、MTT、划痕、Transwell等体外细胞功能学实验检测miR-375、SHOX2对食管鳞癌细胞增殖、迁移和侵袭能力的影响,通过拯救实验验证miR-375对SHOX2的靶向调控作用。结果 与对照组的kyse-70、kyse-30细胞相比,过表达miR-375或干扰SHOX2基因后的细胞增殖率、克隆形成率和Transwell细胞穿透数均降低,差异均有统计学意义（P＜0.01）;与对照组的kyse-70、kyse-30细胞相比,干扰miR-375或过表达SHOX2后的细胞增殖率、克隆形成率和Transwell细胞穿透数均升高,差异均有统计学意义（P＜0.01）;miR-375过表达后的食管鳞癌细胞SHOX2基因表达减少,而抑制miR-375后SHOX2基因表达增强。拯救实验结果显示,共转染miR-375和SHOX2后细胞增殖和侵袭能力较对照组又有所增强。结论 miR-375抑制食管鳞癌细胞增殖和侵袭;SHOX2促进食管鳞癌细胞增殖和侵袭。miR-375靶向负调控SHOX2表达,对食管鳞癌细胞的增殖和侵袭起调控作用。     

微小RNA miR-155在肿瘤中的研究

微小RNA miR-155在多种人体肿瘤中异常表达,与肿瘤的发生、发展及预后密切相关,被认为是癌性微小RNA(oncomiR).研究发现miR-155可通过抑制其靶基因如SHIP1、C/EBPβ、SOCS1、TP53INP1等促进肿瘤的增殖、侵袭及转移.检测miR-155的表达可对早期诊断恶性肿瘤提供重要依据,抑制其表达将成为肿瘤治疗的新方向.     

miR-375调控PDGFC基因表达抑制肝癌血管生成

  目的  miR-375已被证明能够抑制肝癌细胞增殖、迁移和侵袭,促进肝癌细胞凋亡,本研究旨在探索miR-375对肝癌新生血管生成的影响及其分子机制。  方法  利用血管生成相关的功能实验探索miR-375对肝癌新生血管生成的影响;使用生物信息学方法预测miR-375潜在的与血管生成相关的功能靶基因;在肝癌细胞系中过表达和下调表达miR-375,验证miR-375对靶基因的调控作用,并利用双荧光素酶报告实验明确其分子机制;靶基因功能挽救实验明确miR-375通过调控靶基因的表达发挥抑制肝癌新生血管生成的作用。  结果  miR-375能够抑制肝癌新生血管生成;血小板源性生长因子C（PDGFC）是miR-375的潜在功能靶基因;miR-375能够直接作用于PDGFC基因mRNA 3'-非编码端（3'-UTR）而抑制PDGFC基因表达;miR-375能够通过抑制PDGFC基因表达抑制肝癌新生血管生成。  结论  miR-375能够调控PDGFC基因表达抑制肝癌新生血管生成。      

微小RNA-203与肿瘤

微小RNA (miR)-203具有细胞干性抑制潜能,可通过抑制细胞干性相关转录因子的表达来调节细胞上皮样分化.研究表明miR-203在多种肿瘤组织中表达异常,包括膀胱癌、乳腺癌、结肠癌和胰腺癌等.miR-203通过调节细胞增殖、分化和凋亡在肿瘤的发生发展中发挥重要作用.     

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-486在非小细胞肺癌血液中表达及意义

目的:对比分析非小细胞肺癌患者肿瘤组织、瘤旁组织和外周血清中miR-486的表达情况,探讨miR-486是否有可能成为新的非小细胞肺癌标记物。方法:选取20例临床上确诊并进行外科治疗的非小细胞肺癌病例,每个病例取3块肿瘤组织,3块正常肺组织以及3×10ml外周血液样本。另选取20例健康志愿者抽取3×10ml外周血液作为对照。提取总RNA进行qRT-PCR实验。分析外周血清和肿瘤组织中miR-486的表达情况。结果:miR-486在非小细胞肺癌肿瘤组织中呈低表达状态（P＜0.05）,其在瘤组织内的表达与外周血清中的表达呈正相关性（P＜0.05）。结论:miR-486在人体外周血清中的表达与非小细胞肺癌存在正相关性,提示外周血清中miR-486可以成为非小细胞肺癌的预警因子。     

非小细胞肺癌组织中miR-371-5p、miR-452、miR-5100、LZTS1表达水平及临床意义

目的 探讨非小细胞肺癌组织中微小RNA-371-5p(miR-371-5p)、微小RNA-452(miR-452)、微小RNA-5100(miR-5100)、亮氨酸拉链肿瘤抑制基因1(LZTS1)表达水平及临床意义.方法 选择非小细胞肺癌患者100例为研究对象,并收集患者的癌旁正常组织及肺癌组织.检测肺癌组织与癌旁正常...     

miR-21对骨肉瘤细胞增殖的影响

背景与目的:微小RNA(microRNA,miRNA)是一类内源性的非编码小分子RNA,其主要通过与靶mRNA作用抑制转录后的翻译.miR-21是唯一一个在9种人类肿瘤细胞中高表达的小RNA分子.本研究旨在观察anti-miR-21反义寡核苷酸(ASO)对骨肉瘤MG-63细胞增殖的影响.方法:通过转染miR-21 ASO和对照组ASO,采用实时荧光定量RT-PCR检测MG-63细胞中miR-21的表达变化,并运用多种细胞增殖检测方法观察miR-21 ASO对MG-63细胞调控产生的系列效应.结果:与对照相比,miR-21 ASO显著减少miR-21的表达(P=0.003);克隆形成实验结果显示miR-21 ASO导致克隆形成率较对照组低(P=0.012);MTT实验结果显示转染miR-21 ASO后,MG-63细胞存活数明显低于对照组(P=0.023);在体实验结果发现miR-21 ASO抑制肿瘤细胞增殖,导致肿瘤质量较对照轻(P=0.013),形成的体积较对照小(P=0.028);流式细胞仪检测显示转染mi R-21 ASO后,MG-63细胞凋亡明显增加(P=0.022).结论:miR-21 ASO对骨肉瘤细胞miR-21水平降低有靶向特异性,转染miR-21 ASO可有效抑制miR-21的促癌作用,利用反义核酸技术可为骨肉瘤的基因治疗开辟新的径路.     

miR-125a增强多西他赛对乳腺癌生长的抑制作用

背景与目的:研究表明miR-125a通过下调Her-2或者Her-3的表达抑制乳腺癌细胞生长,可能是指导乳腺癌治疗的靶点.本研究旨在观察miR-125a是否具有增强多西他赛对乳腺癌细胞株和裸鼠荷瘤模型的生长抑制作用.方法:转染miR-125a联合不同浓度多西他赛处理MCF-7和MDA-MB-231乳腺癌细胞株和MDA-MB-231乳腺癌裸鼠模型,观察细胞株和裸鼠接种肿瘤的生长情况.结果:miR-125a与多西他赛可协同抑制MDA-MB-231及MCF-7乳腺癌细胞株、MDA-MB-231乳腺癌裸鼠模型肿瘤的增殖,单纯转染miR-125a也可抑制MDA-MB-231及MCF-7乳腺癌细胞株的增殖.结论:miR-125a与多西他赛有协同抗乳腺癌作用,可成为乳腺癌靶向治疗的潜在靶点.     

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.     

miR-375靶向YAP1调控上皮-间质转化参与乳腺癌细胞曲妥珠单抗的耐药

背景与目的:曲妥珠单抗作为人表皮生长因子受体2(human epidermal growth factor receptor 2,HER2)常用靶向抗体药物,其耐药问题日益凸显.探讨miR-375靶向Yes相关蛋白1(Yes-associated protein 1,YAP1)介导上皮-间质转化(epithelial-...     

Tumor suppressive microRNA-375 regulates lactate dehydrogenase B in maxillary sinus squamous cell carcinoma

The expression of microRNA-375 (miR-375) is significantly reduced in cancer tissues of maxillary sinus squamous cell carcinoma (MSSCC). The aim of this study was to investigate the functional significance of miR-375 and a possible regulatory role in the MSSCC networks. Restoration of miR-375 significantly inhibited cancer cell proliferation and invasion in IMC-3 cells, suggesting that miR-375 functions as a tumor suppressor in MSSCC. Genome-wide gene expression data and luciferase reporter assays indicated that lactate dehydro-genase?B (LDHB) was directly regulated by miR-375. Cancer cell proliferation and invasion were significantly inhibited by transfection of si-LDHB into IMC-3 cells, suggesting that LDHB may play a role in MSSCC oncogenic function. In clinical MSSCC specimens, LDHB mRNA levels were up-regulated in cancer tissues, which were inversely correlated with the expression of miR-375. In addition, Kaplan-Meier curves and log-rank tests revealed that the high mRNA expression levels of LDHB had a significant adverse effect on survival rate. The identification of a cancer network regulated by the miR-375 tumor suppressor could provide new insights into the molecular mechanisms of MSSCC oncogenesis.     

miR-375 is upregulated in acquired paclitaxel resistance in cervical cancer

Background:

Chemo-resistance is one of the key causal factors in cancer death and emerging evidences suggest that microRNAs (miRNAs) have critical roles in the regulation of chemo-sensitivity in cancers. Cervical cancer is one of the most common malignancies in women and insensitive to chemotherapy clinically.

Methods:

The differentially expressed miRNAs in cervical squamous cell carcinoma tissues were screened by using a microarray platform (μParaflo Sanger miRBase release 13.0). The expression of miR-375 was determined by stem-loop RT–PCR using 23 clinical cervical cancer samples and 2 cervical cancer cell lines. We exogenously upregulated miR-375 expression in SiHa and Caski cells using a pre-miRNA lentiviral vector transfection and observed its impact on paclitaxel sensitivity using MTS. The cells that stably overexpressed miR-375 were subcutaneously injected into mice to determine tumour growth and chemo-sensitivity in vivo.

Results:

Twenty-one differentially expressed miRNAs were found by miRNA microarray between pro- and post-paclitaxel cervical cancer tissues. Of those, miR-375 showed consistent high expression levels across paclitaxel-treated cervical cells and tissues. Paclitaxel induced upregulated miR-375 expression in a clear dose-dependent manner. Forced overexpression of miR-375 in cervical cancer cells decreased paclitaxel sensitivity in vitro and in vivo.

Conclusion:

Collectively, our results suggest that miR-375 might be a therapeutic target in paclitaxel-resistant cervical cancer.     

Claudin-1 is a novel target of miR-375 in non-small-cell lung cancer

Objectives

We previously reported low expression of miR-375 in squamous-cell carcinoma (SCC) and high expression in adenocarcinoma (AC) of the lung. miR-375's target genes and its function in non-small-cell lung cancer (NSCLC) have not been elucidated. Therefore, the present study was designed to identify the targets of miR-375 and to characterize its function in NSCLC.

Materials and methods

Candidate targets of miR-375 were determined using a prediction database and previous data on differential gene expression between SCC and AC. We evaluated miR-375 and target-gene expression levels in 12 NSCLC cell lines. The effect of miR-375 overexpression and knockdown was evaluated in NSCLC cell lines by transfecting them with an miR-375 precursor or inhibitor. A luciferase-reporter assay was performed to confirm a direct interaction between miR-375 and its target gene. Further, a wound-healing assay was performed to evaluate the effect of miR-375 overexpression on the migration of SK-MES-1 cells. Finally, to assess the clinical relevance, 63 clinical NSCLC samples were analyzed.

Results

Claudin-1 (CLDN1) has 4 putative miR-375 target sites in its 3′-untranslated region, and this gene was determined to be a target of miR-375. CLDN1 messenger RNA and protein expression were attenuated by overexpression of miR-375 and increased by knockdown of miR-375 in NSCLC cell lines. In a luciferase-reporter assay, miR-375 overexpression resulted in a 3-fold repression of luciferase activity (P < 0.001). Cell migration was promoted by miR-375 overexpression, suggesting a high potential for invasion and metastasis in NSCLC expressing high levels of miR-375. In clinical NSCLC samples, there was a negative correlation between miR-375 and CLDN1 expression (r = −0.35, P = 0.005). In addition, high miR-375 expression was correlated with a shorter survival time among the clinical samples (P = 0.043).

Conclusion

CLDN1 is a novel target of miR-375, and high miR-375 expression shortens survival in NSCLC.