中枢神经系统弥漫大B 细胞淋巴瘤相关microRNAs 的研究进展

中枢神经系统(central nervous system,CNS)复发是弥漫大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)的一种不常见的严重的并发症,新诊断的患者2年内易于发生,最常见于非霍奇金淋巴瘤弥漫大B细胞型(non-Hodgkin diffuse large B-cell lymphoma-,NHL-DLBCL),目前,对于初始治疗后出现中枢复发其发病机制并不清楚。microRNA(miRNA)是一类新发现的非编码小分子RNA,通过抑制靶基因翻译或降解靶miRNA调控基因表达,参与细胞分化、增殖、调亡等生命活动。miRNA在淋巴瘤的发生发展中有重要作用。近年来大量研究已证实miRNA与肿瘤的组织来源、进展、转移预后与耐药都密切相关,既可作为抑癌基因,也可作为癌基因。淋巴瘤是一种血液免疫系统肿瘤,与淋巴瘤相关的miRNA已成为当前研究热点之一。microRNAs的功能紊乱如何导致DLBCL发生的机制目前还没有得到很好的证明,但DLBCL患者中464种miRNAs显示microRNA(包括miRNA-17-92簇)预测淋巴瘤的准确率达95%,为淋巴瘤研究提供了新依据。     

MicroRNA与变应性鼻炎

在变应性鼻炎(allergic rhinitis,AR)发病的免疫细胞分化及免疫应答过程中,micro RNA(miRNA)发挥着非常重要的调控作用。本文旨在对AR中miRNA研究进行回顾,以期为AR的有效治疗提供新的视角。首先,变应性鼻炎患者鼻粘膜中miR-7和miRPlus-E1194等差异表达。其次,在T辅助细胞发育、分化与活化过程中,miR-181a、miR-155、miR-21、miR-1、miR-31、miR-223、miR-139-3p、miR-126、Let-7家族成员会发生显著上调或下降,而且某些miRNA的相关作用靶点也得到验证。再次,嗜酸粒细胞定向分化祖细胞向成熟嗜酸粒细胞的分化过程中,miR-21和miR-223都有所上调。最后,在肥大细胞激活和脱颗粒过程中,miR-221和miR-222以及其他miRNA显著上调。以上miRNA参与了T辅助细胞分化与活化、嗜酸粒细胞发育、肥大细胞脱颗粒等AR病理进程的各个环节,而且,miRNA还会参与前期的抗原提呈等环节。可见miRNA对AR调控呈现出复杂性和多重性。     

miR-202 suppresses cell proliferation in human hepatocellular carcinoma by downregulating LRP6 post-transcriptionally

MicroRNAs have emerged as important regulators of carcinogenesis. In the current study, we observed that microRNA-202 (miR-202) is downregulated in hepatocellular carcinoma (HCC) cells and tissues, indicating a significant correlation between miR-202 expression and HCC progression. Overexpression of miR-202 in HCC cells suppressed cell proliferation and tumorigenicity, while downregulation of miR-202 enhanced the cells’ proliferative capacity. Furthermore, we identified low-density lipoprotein receptor-related protein 6 (LRP6) as a direct target of miR-202. miR-202 suppresses the expression of LRP6 by binding to the 3′-untranslated region (UTR) of its mRNA. Finally, we found that silencing the expression of LRP6 is the essential biological function of miR-202 during HCC cell proliferation. Collectively, our findings reveal that miR-202 is a potential tumor suppressive miRNA that participates in carcinogenesis of human HCC by suppressing LRP6 expression.     

An efficient method to enhance gene silencing by using precursor microRNA designed small hairpin RNAs

Gene silencing can be mediated by small interfering RNA (siRNA) and microRNA (miRNA). To investigate the potential application of using a precursor microRNA (pre-miRNA) backbone for gene silencing, we studied the inhibition efficiency of exogenous GFP and endogenous GAPDH by conventional shRNA- and pre-miRNA-designed hairpins, respectively. In this study, the conventional shRNA-, pre-miRNA-30-, and pre-miRNA-155-designed hairpins targeting either GFP or GAPDH were transfected into the HEK293 cells that were mediated by the pSilencer-4.1-neo vector, which carries a modified RNA polymerase II-type CMV promoter. Comparisons with conventional GFP shRNA showed that GFP levels were reduced markedly by pre-miRNA-30- and pre-miRNA-155-designed GFP shRNAs by fluorescence microscopy. The consistent results from semi-quantitative RT-PCR and Western blot analysis revealed that pre-miRNA-30- and pre-miRNA-155-designed GFP shRNAs could suppress GFP expression significantly. As for endogenous GAPDH, the results from semi-quantitative RT-PCR and Western blot analysis showed that pre-miRNA-30- and pre-miRNA-155-designed GAPDH shRNAs could suppress GAPDH expression even more efficiently than conventional GAPDH shRNA. Together, this study confirmed the efficiency of gene silencing mediated by pre-miRNA-30- and pre-miRNA-155-designed shRNAs, demonstrating that pre-miRNA-designed hairpins are a good strategy for gene silencing.     

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.     

Sertoli cell Dicer is essential for spermatogenesis in mice

Spermatogenesis requires intact, fully competent Sertoli cells. Here, we investigate the functions of Dicer, an RNaseIII endonuclease required for microRNA and small interfering RNA biogenesis, in mouse Sertoli cell function. We show that selective ablation of Dicer in Sertoli cells leads to infertility due to complete absence of spermatozoa and progressive testicular degeneration. The first morphological alterations appear already at postnatal day 5 and correlate with a severe impairment of the prepubertal spermatogenic wave, due to defective Sertoli cell maturation and incapacity to properly support meiosis and spermiogenesis. Importantly, we find several key genes known to be essential for Sertoli cell function to be significantly down-regulated in neonatal testes lacking Dicer in Sertoli cells. Overall, our results reveal novel essential roles played by the Dicer-dependent pathway in mammalian reproductive function, and thus pave the way for new insights into human infertility.     

Current therapeutic options for gastric adenocarcinoma

Gastric cancer inflicts significant health issues globally despite its declining incidence. The disease is known to be diagnosed at its advanced stages also corresponding with a poor prognosis for patients. The integral therapeutic choices to cure advanced gastric cancer have progressed swiftly in modern days. The preface of molecularly targeted therapeutic techniques would potentiate the personalized approach depending on patient-specific and tumor-specific features, exasperating the advantages of chemotherapy. Here we have reviewed the modern therapeutics such as immune therapy, chemotherapy, m-RNA based therapeutics, alongside evaluating the influence of age, sex and comorbidities-like factors on the occurrence of gastric cancer. Gastric cancer therapy consolidated target agents comprising inhibitors of programmed death-1(PD-1), human epidermal growth factor receptor 2 (HER2), mRNA, and epidermal growth factor receptor (EPGF). A combination of trastuzumab to platinum-mediated chemotherapy evolved has a typical front-line therapy in advanced gastric cancer. An attempt has been made to epitomize the contemporary-modern research on targeted therapy for advanced gastric cancer.     

The Hsa-miR-27a rs895819 (A > G) polymorphism and cancer susceptibility

Published data on the association between the rs895819 (A > G) polymorphism in the terminal loop of pre-miR-27a and cancer risk is inconclusive. Therefore, we conducted a meta-analysis to estimate the association between this polymorphism and cancer. The PubMed, Web of science, and Embase databases were searched for articles on the hsa-miR-27a rs895819 polymorphism and cancer risk published up to November 24, 2012. The genotype data obtained in the searches were pooled in our meta-analysis, and pooled odds ratio (OR) with 95% confidence interval (CI) was used to assess the association. Seven studies with a total of 3849 cases and 4781 controls were eligible for analysis. Overall, we found no significant associations between the hsa-miR-27a rs895819 (A > G) polymorphism and cancer susceptibility (homozygote model: OR = 0.88, 95% CI: 0.68–1.14; heterozygote model: OR = 0.96, 95% CI: 0.79–1.17; dominant model: OR = 0.94, 95% CI: 0.79–1.12; recessive model: OR = 0.88, 95% CI: 0.69–1.12). In the subgroup analysis by ethnicity, we found that the rs895819 AG genotype was associated with a decreased risk of cancer in white individuals (dominant model: OR = 0.85, 95% CI: 0.76–0.94; heterozygote model: OR = 0.84, 95% CI: 0.75–0.94). This meta-analysis indicated that the hsa-miR-27a rs895819 polymorphism did not correlate with overall cancer risk in the general population. However, the rs895819 AG genotype may protect against the development of cancer in white individuals. Larger, better studies of homogeneous cancer patients are needed to further assess the correlation between this polymorphism and cancer risk.