血清LncRNA XIST与miR-33a在膀胱癌中的表达及临床意义

目的:探究血清长链非编码RNA X染色体失活特异转录本(Lnc RNA XIST)与微小RNA-33a(mi R-33a)在膀胱癌中的表达及临床意义。方法:选择2017年4月至2019年8月青岛大学附属医院诊治的95例膀胱癌患者作为膀胱癌组,选择同期体检的95例健康者作为健康组。采用荧光定量PCR检测两组的血清LncRNA XIST与mi R-33a表达水平,分析患者的临床病理参数与血清LncRNA XIST、mi R-33a表达水平的关系,采用受试者工作特征曲线(ROC)分析血清LncRNA XIST与mi R-33a对膀胱癌的预测价值。结果:与健康组相比,膀胱癌组的血清LncRNA XIST表达水平明显升高(P0.05),而血清mi R-33a表达水平明显下降(P0.05)。血清LncRNA XIST与mi R-33a表达均与膀胱癌患者的TNM分期和淋巴结转移情况相关(P0.05)。血清LncRNA XIST联合mi R-33a(AUC=0.830,敏感性=90.47%,特异性=89.85%)预测膀胱癌的临床价值明显高于血清LncRNA XIST(AUC=0.716,敏感性=81.36%,特异性=80.74%)及血清mi R-33a(AUC=0.736,敏感性=82.19%,特异性=81.09%)单独检测。结论:血清LncRNA XIST表达异常升高、血清mi R-33a表达降低与膀胱癌发生密切相关,联合检测有助于预测膀胱癌发生的风险,从而为临床制定针对性干预和治疗方案提供参考。     

10Sa RNA, a small stable RNA of Escherichia coli, is functional

Summary The ssrA gene, coding for the metabolically stable 10Sa RNA, affects cell growth. A mutant in which the chromosomal 10Sa RNA gene is interrupted by a cat insert does not produce detectable levels of 10Sa RNA, and it grows more slowly than the parental strain.     

Cloning of a protein arginine methyltransferase PRMT1 homologue from Schistosoma mansoni: evidence for roles in nuclear receptor signaling and RNA metabolism

The most studied arginine methyltransferase is the type I enzyme, which catalyzes the transfer of an S-adenosyl-L-methionine to a broad spectrum of substrates, including histones, RNA-transporting proteins, and nuclear hormone receptor coactivators. We cloned a cDNA encoding a protein arginine methyltransferase in Schistosoma mansoni (SmPRMT1). SmPRMT1 is highly homologous to the vertebrate PRMT1 enzyme. In vitro methylation assays showed that SmPRMT1 recombinant protein was able to specifically methylate histone H4. Two schistosome proteins likely to be involved in RNA metabolism, SMYB1 and SmSmD3, that display a number of RGG motifs, were strongly methylated by SmPRMT1. In vitro GST pull-down assays showed that SMYB1 and SmSmD3 physically interacted with SmPRMT1. Additional GST pull-down assay suggested the occurrence of a ternary complex including SmPRMT1, SmRXR1 nuclear receptor, and the p160 (SRC-1) nuclear receptor coactivator. Together, these data suggest a mechanism by which SmPRMT1 plays a role in nuclear receptor-mediated chromatin remodeling and RNA transactions.     

Characterization of a novel small RNA encoded by Dictyostelium discoideum mitochondrial DNA

In this study, we analyzed a mitochondrial small (ms) RNA in Dictyostelium discoideum, which is 129 nucleotides long and has a GC content of only 22.5%. In the mitochondrial DNA, a single-copy gene (msr) for the ms RNA was located downstream of the gene for large-subunit rRNA. The location of msr was similar to that of the 5S rRNA gene in prokaryotes and chloroplasts, but clearly different from that in mitochondria of plants, liverwort and the chlorophycean alga Prototheca wikerhamii, in which small-subunit rRNA and 5S rRNA genes are closely linked. The primary sequence of ms RNA showed low homology with mitochondrial 5S rRNA from plants, liverwort and the chlorophycean alga, but the proposed secondary structure of ms RNA was similar to that of cytoplasmic 5S rRNA. In addition, ms RNA showed a highly conserved GAAC sequence in the same loop as in common 5S rRNA. However, ms RNA was detected mainly in the mitochondrial 25 000 × g supernatant fraction which was devoid of ribosomes. It is possible that ms RNA is an evolutionary derivative of mitochondrial 5S rRNA. Received: 17 May 1997 / Accepted: 26 August 1997     

Analysis of messenger RNA expression by in situ hybridization using RNA probes synthesized via in vitro transcription

The analysis of the spatial patterning of mRNA expression is critically important for assigning functional and physiological significance to a given gene product. Given the tens of thousands of mRNAs in the mammalian genome, a full assessment of individual gene functions would ideally be overlaid upon knowledge of the specific cell types expressing each mRNA. In situ hybridization approaches represent a molecular biological/histological method that can reveal cellular patterns of mRNA expression. Here, we present detailed procedures for the detection of specific mRNAs using radioactive RNA probes in tissue sections followed by autoradiographic detection. These methods allow for the specific and sensitive detection of spatial patterns of mRNA expression, thereby linking mRNA expression with cell type and function. Radioactive detection methods also facilitate semi-quantitative analyses of changes in mRNA gene expression.     

The RNA components of Schizosaccharomyces pombe RNase P are essential for cell viability

The fission yeast Schizosaccharomyces pombe contains in the haploid genome one copy of the gene (designated rrkl) for the RNA components of RNase P. Gene disruption in diploid cells of one copy of rrkl resulted in a moderate reduction of the level of cellular RNase P activity. Haploidization by meiosis demonstrated that rrkl is required for cell growth. Thus, the RNA components of S. pombe RNase P are essential in vivo. This is similar to the situation in Escherichia coli.     

RNA在生物学的重要地位及其作为常规治疗药物的研究进展

20多年来的研究发现,RNA除了具有如tRNA、rRNA参与蛋白质生物合成的基本功能外,细胞内还存在许多种类的RNA,它们执行着不同的功能,在细胞内生物化学反应及机体发育调控过程中发挥着重要作用。正因为RNA功能多样性,在体内、体外开展的众多实验表明,RNA或其修饰形式可以抑制基因的表达。该文将探讨RNA在常规基因治疗中的研究。     

Crystal structure of the single-stranded RNA binding protein HutP from Geobacillus thermodenitrificans

RNA binding proteins control gene expression by the attenuation/antitermination mechanism. HutP is an RNA binding antitermination protein. It regulates the expression of hut operon when it binds with RNA by modulating the secondary structure of single-stranded hut mRNA. HutP necessitates the presence of l-histidine and divalent metal ion to bind with RNA. Herein, we report the crystal structures of ternary complex (HutP–l-histidine–Mg²⁺) and EDTA (0.5 M) treated ternary complex (HutP–l-histidine–Mg²⁺), solved at 1.9 Å and 2.5 Å resolutions, respectively, from Geobacillus thermodenitrificans. The addition of 0.5 M EDTA does not affect the overall metal-ion mediated ternary complex structure and however, the metal ions at the non-specific binding sites are chelated, as evidenced from the results of structural features.     

The cell biology of ion pumps: sorting and regulation

The physiologic function of an ion pump is determined, in part, by its subcellular localization and by the cellular mechanisms that modulate its activity. The Na,K-ATPase and the gastric H,K-ATPase are two closely related members of the P-type family of ion transporting ATPases. Despite their homology, these pumps are sorted to different domains in polarized epithelial cells and their enzymatic activities are subject to distinct regulatory pathways. The molecular signals responsible for these properties have begun to be elucidated. It appears that a complex array of inter- and intra-molecular interactions govern these proteins' trafficking, distribution and catalytic capacity.     

竞争性内源RNA:一种全新的基因表达调控模式

竞争性内源RNA(ceRNA)假说是一种全新的基因表达调控模式:mRNA、假基因转录物和长链非编码RNA等转录物通过microRNA应答元件竞争结合相同的microRNA来调控各自的表达水平,从而影响细胞的功能.迄今为止,多家实验室已从生物信息学、细胞生物学和动物实验等层面验证了该假说.本文追溯了ceRNA假说提出的历程,讨论了ceRNA调控网络的影响因素,并提出了一些有待进一步完善的内容.ceRNA假说大大拓展了人类基因组中功能遗传信息的范畴,也为解析一些人类疾病发生的机制提供了新线索.