Plasma miR-183 predicts recurrence and prognosis in patients with colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies worldwide. The prognosis for this cancer is poor, and the development of novel biomarkers, particularly non-invasive surrogate biomarkers, is urgently needed. Recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in the blood and can serve as useful biomarkers for various types of cancer. In this study, the miR-183 expression levels were found to be significantly overexpressed in plasma samples from CRC patients compared with controls, and the postoperative plasma miR-183 levels were significantly reduced compared with the preoperative levels. The value of the area under the receiver operating characteristic (ROC) curve obtained for miR-183 was 0.829, which was higher than those for carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9). High plasma miR-183 expression was significantly associated with lymph node metastasis, distant metastasis, higher pTNM stage (III-IV), and tumor recurrence. CRC patients with elevated miR-183 expression in plasma displayed shorter disease-free survival (DFS) and lower overall survival (OS). More importantly, plasma miR-183 was independently correlated with tumor recurrence and a lower OS. Collectively, our results suggested that the elevated miR-183 in the plasma could be a promising biomarker for predicting the risk of tumor recurrence and poor survival in CRC patients.     

MicroRNA‐135b regulates ERα, AR and HIF1AN and affects breast and prostate cancer cell growth

MicroRNAs (miRNAs) regulate a wide range of cellular signaling pathways and biological processes in both physiological and pathological states such as cancer. We have previously identified miR‐135b as a direct regulator of androgen receptor (AR) protein level in prostate cancer (PCa). We wanted to further explore the relationship of miR‐135b to hormonal receptors, particularly estrogen receptor α (ERα). Here we show that miR‐135b expression is lower in ERα‐positive breast tumors as compared to ERα‐negative samples in two independent breast cancer (BCa) patient cohorts (101 and 1302 samples). Additionally, the miR‐135b expression is higher in AR‐low PCa patient samples (47 samples). We identify ERα as a novel miR‐135b target by demonstrating miR‐135b binding to the 3′UTR of the ERα and decreased ERα protein and mRNA level upon miR‐135b overexpression in BCa cells. MiR‐135b reduces proliferation of ERα‐positive BCa cells MCF‐7 and BT‐474 as well as AR‐positive PCa cells LNCaP and 22Rv1 when grown in 2D. To identify other genes regulated by miR‐135b we performed gene expression studies and found a link to the hypoxia inducible factor 1α (HIF1α) pathway. We show that miR‐135b influences the protein level of the inhibitor for hypoxia inducible factor 1α (HIF1AN) and is able to bind to HIF1AN 3′UTR. Our study demonstrates that miR‐135b regulates ERα, AR and HIF1AN protein levels through interaction with their 3′UTR regions, and proliferation in ERα‐positive BCa and AR‐positive PCa cells.     

K14‐EGFP‐miR‐31 transgenic mice have high susceptibility to chemical‐induced squamous cell tumorigenesis that is associating with Ku80 repression

Squamous cell carcinoma (SCC) occurring in the head and neck region and the esophagus causes tremendous cancer mortality around the world. miR‐31 is among the most eminently upregulated MicroRNAs in SCC, when it occurs in the head and neck region and the esophagus. We established miR‐31 transgenic mouse lines, in which miR‐31 is under the control of the K14 promoter. 4‐nitroquinoline 1‐oxide (4NQO) is a mutagen that causes double strand breaks. The transgenic mice exhibited a higher potential for tumor induction than wild‐type (Wt) mice of the tongue and esophagus after 4NQO treatment. After 4NQO treatment or irradiation, p‐γH2AX expression in squamous epithelium of transgenic mice was increased more than in Wt mice. Exogenous expression of miR‐31 was also found to be associated with the higher p‐γH2AX expression induced by 4NQO in human oral SCC (OSCC) cell lines. The repair genes PARP1 and Ku80 were validated as new targets of miR‐31 in human OSCC cell lines, and were found to be downregulated in the squamous epithelium of the tongue in transgenic mice. However, only the downregulation of Ku80 was essential for maintaining the high level of p‐γH2AX induced by 4NQO in OSCC cells. Inverse expression profiles for miR‐31 and Ku80 were noted in human OSCC tissue. Our study identifies the high sensitivity of K14‐EGFP‐miR‐31 transgenic mice to chemical carcinogen‐induced squamous cell tumorigenesis and shows that this seems to be associated with the downregulation of Ku80 and an impairment of repair activity in squamous cells, which are mediated by miR‐31.     

微小RNA let-7c慢病毒载体的构建及过表达研究

目的 构建微小RNA let-7c重组慢病毒载体,验证转染该载体系统后对肝癌细胞增殖的影响 方法 构建表达含494bp let-7c基因的重组慢病毒载体,检测let-7c及对照组病毒滴度分别为5.01×10E8 TU/m1、5.15×10E8TU/ml;转染HepG2细胞,以荧光定量聚合酶链反应(PCR)对let-7e表达水平进行检测;细胞计数试剂盒(CCK-8)试验评价let-7c过表达后对HepG2细胞增殖的影响.结果 构建的let-7c慢病毒载体经质粒酶切和测序鉴定正确;转染HepG2细胞72 h后,let-7c表达上调312倍;CCK-8法检测显示HepG2细胞增殖受到明显抑制(P＜0.01).结论 成功构建Iet-7c重组慢病毒载体并感染HepG2细胞后高效表达成熟let-7c,抑制了HepG2肝癌细胞的增殖.     

心房颤动患者血清和组织miR-223及MMP-9的表达及临床价值

目的探索miRNA-223在房颤患者心房肌组织和血清的表达差异及miRNA-223与MMP-9在房颤患者的表达水平及在房颤结构重构的发生机制。方法患有风湿性心瓣膜病接受心脏瓣膜置换术的患者31例,其中窦性心律患者15例,慢性房颤患者16例。另选取15名健康人血清作为对照组。实时荧光定量PCR检测心房肌组织和血清miRNA-223的相对表达量。ELISA及免疫组织化学检测MMP-9蛋白的表达及分布水平;HE染色及Masson染色观察心肌组织病理结构及胶原纤维含量。结果与窦性心律组相比,房颤组心房肌组织miRNA-223和血清miRNA-223表达水平均显著升高（0.0603±0.0228 vs.0.0261±0.0035,P〈0.01;4.2281±0.9165 vs 2.7613±1.2166,P〈0.05）;房颤组血清MMP-9表达水平高于窦性心律组（4.2281±0.9165 vs 2.7613±1.2166,P〈0.05）;MiRNA-223表达水平与MMP-9蛋白表达呈正相关（r=0.901,P〈0.05）。结论 MiRNA-223表达增高及正向调控MMP-9的表达,共同影响心肌胶原的代谢,促进心肌纤维化,参与房颤发生与维持。miRNA-223有望成为一种新型风湿性心脏病合并房颤的诊断标志物。     

miRNA与食管癌

动植物中广泛存在着一大类小的非编码蛋白质的RNA,21-25个核苷酸长度,被命名为microRNA(miRNA). miRNA在物种进化中相当保守,其表达有组织特异性和时序特异性. 其功能为负调控基因表达,进而调节细胞的代谢,增殖,分化和凋亡等基本的生理过程. 因此,miRNA的改变必会导致一些严重的病理过程. 研究已证实miRNA在肿瘤的发生和发展起着癌基因或抑癌基因的作用,miRNA的表达谱可用于某些肿瘤的诊断、分期和判断预后,并且在肿瘤分类方面较mRNA有更大地优越性. 本文着重介绍miRNA的产生,作用机制,与肿瘤的关系,检测方法及其在食管癌的诊断、分期和生物治疗方面的潜在作用.     

The role of microRNA in periodontal tissue: A review of the literature

MicroRNAs (miRNAs) bind at the 3′UTR of their target mRNA to induce gene silencing. Through this mechanism, number of biological pathways implicated in developmental, physiological, and pathological processes, have been frequently found to involve miRNA functions. MiRNA functions in bone metabolism have also been reported, especially in association with receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastogenesis. Expression of RANKL has been related to several inflammatory mediators, and thus some miRNAs may be implicated in the regulatory mechanism of inflammatory-induced RANKL expression as shown in periodontal resident cells such as gingival fibroblasts or periodontal ligament cells. This review aims to review the current miRNA research relating periodontal tissue and its relevance in periodontal inflammation. In miRNA profiling studies of tissues isolated from individuals with periodontal disease, miR-223 has been consistently identified as a potential candidate miRNA to be further investigated in periodontitis-related processes. Although these studies point to an important role of miRNA-mediated epigenetic changes in tissue inflammation and alveolar bone loss, further investigation is still required to determine the function of miRNAs in the complex processes of periodontal tissue homeostasis and pathogenesis. Knowledge gained from future studies will be beneficial in developing alternative therapeutic approaches, especially ones that use miRNA delivery systems to treat periodontal disease.     

MicroRNA在代谢综合征疾病中的研究进展

MicroRNA(miRNA)是一个非编码RNA,能在转录后水平调控基因的表达,广泛地存在于真核细胞内。miRNA与胰岛素抵抗以及血糖调控过程密切相关,同时也与脂代谢、动脉粥样硬化的发生、发展紧密联系,而糖尿病、胰岛素抵抗、高血脂、动脉粥样硬化以及高血压是代谢综合征的主要表现。因此,研究miRNA与代谢综合征的关系可进一步阐明代谢综合征的发病机制,并为其预防和治疗提供新的方向。     

肝癌细胞株HepG2与正常肝细胞株7702差异微小RNA筛选

目的：初步探讨肝癌细胞株 HepG2与正常肝细胞株7702微小 RNA（miRNA）分子表达谱的差异。方法选取肝癌细胞株 HepG2与正常肝细胞株7702样本分别作为实验组和对照组,采用高通量的 miRNA微阵列芯片技术筛选两者间差异表达的 miRNA,并运用实时荧光定量聚合酶链反应（RT-qPCR）验证芯片结果的可靠性（样品间变化标准以上调或者下调2倍作为判定的阈值范围）。结果在肝癌细胞株 HepG2中,上调2倍的差异表达 miRNA分子有32个,其中上调超过8倍差异表达 miRNA有12个;下调2倍的差异表达miRNA有26个,其中下调超过8倍的miRNA分子有4个（P＜0．05）,miRNA上调与下调表达率差异有统计学意义。结论肝癌细胞株 HepG2与正常肝细胞株7702的差异表达 miRNA分子可能与肝细胞癌（hepatocellular carcinoma,HCC）的发生、转移以及侵袭能力相关,为进一步研究与肿瘤相关的 miRNA在肝细胞癌发病机制中的作用奠定基础。