长链非编码RNA在肝细胞肝癌发病中的作用及其机制研究进展

肝细胞肝癌(HCC)是肝癌中最常见的病理类型,患者病死率高。对HCC发生发展机制的认知局限是其不良预后的重要原因。长链非编码RNA(LncRNA)是基因调控的重要组成部分,可通过表观遗传、转录调节和转录后调节等方式调控肝癌细胞的发生发展。近年来,LncRNA在肝癌发生发展中作用的研究逐渐深入,这为HCC早期诊断、病情控制和预后评估提供了新的方法和思路。本文就LncRNA在HCC中的研究进展作一综述。     

RNA interference: an emerging generation of biologicals

RNA interference (RNAi) is a mechanism displayed by most eukaryotic cells to rid themselves of foreign double-stranded RNA molecules. RNAi has now been demonstrated to function in mammalian cells to alter gene expression, and has been used as a means for genetic discovery as well as a possible strategy for genetic correction. RNAi was first described in animal cells by Fire and colleagues in the nematode, Caenorhabditis elegans. Knowledge of RNAi mechanism in mammalian cell in 2001 brought a storm in the field of drug discovery. During the past few years scientists all over the world are focusing on exploiting the therapeutic potential of RNAi for identifying a new class of therapeutics. The applications of RNAi in medicine are unlimited because all cells possess RNAi machinery and hence all genes can be potential targets for therapy. RNAi can be developed as an endogenous host defense mechanism against many infections and diseases. Several studies have demonstrated therapeutic benefits of small interfering RNAs and micro RNAs in animal models. This has led to the rapid advancement of the technique from research discovery to clinical trials.     

Identification of a universal 6-lncRNA prognostic signature for three pathologic subtypes of renal cell carcinoma

Renal cell carcinoma (RCC) is the most common adult renal epithelial cancer susceptible to metastasis and patients with irresectable RCC always have a poor prognosis. Long noncoding RNAs (lncRNAs) have recently been documented as having critical roles in the etiology of RCC. Nevertheless, the prognostic significance of lncRNA-based signature for outcome prediction in patients with RCC has not been well investigated. Therefore, it is essential to identify a lncRNA-based signature for predicting RCC prognosis. In the current study, we comprehensively analyzed the RNA sequencing data of the three main pathological subtypes of RCC (kidney renal clear cell carcinoma [KIRC], kidney renal papillary cell carcinoma [KIRP], and kidney chromophobe carcinoma [KICH]) from The Cancer Genome Atlas (TCGA) database, and identified a 6-lncRNA prognostic signature with the help of a step-wise multivariate Cox regression model. The 6-lncRNA signature stratified the patients into low- and high-risk groups with significantly different prognosis. Multivariate Cox regression analysis showed that predictive value of the 6-lncRNA signature was independent of other clinical or pathological factors in the entire cohort and in each cohort of RCC subtypes. In addition, the three independent prognostic clinical factors (including age, pathologic stage III, and stage IV) was also stratified into low- and high-risk groups basis on the risk score, and the stratification analyses demonstrated that the high-risk score was a poor prognostic factor. In conclusion, these findings indicate that the 6-lncRNA signature is a novel prognostic biomarker for all three subtypes of RCC, and can increase the accuracy of predicting overall survival.     

Identification and characterization of small RNAs involved in RNA silencing

Double-stranded RNA (dsRNA) is a potent trigger of sequence-specific gene silencing mechanisms known as RNA silencing or RNA interference. The recognition of the target sequences is mediated by ribonucleoprotein complexes that contain 21- to 28-nucleotide (nt) guide RNAs derived from processing of the trigger dsRNA. Here, we review the experimental and bioinformatic approaches that were used to identify and characterize these small RNAs isolated from cells and tissues. The identification and characterization of small RNAs and their expression patterns is important for elucidating gene regulatory networks.     

Knockdown of Ki-67 by small interfering RNA leads to inhibition of proliferation and induction of apoptosis in human renal carcinoma cells

To investigate the effect of small-interfering RNA (siRNA) targeted against Ki-67, which is an attractive molecular target for cancer therapy, on inhibiting Ki-67 expression and cell proliferation in human renal carcinoma cells (HRCCs), siRNAs were used to inhibit the expression of Ki-67 in HRCCs. Ki-67 mRNA levels were detected by RT-PCR and in situ hybridization analysis. Ki-67 protein levels were detected by Western blot and immunocytochemistry analysis. TUNEL assay was used to measure the apoptosis of carcinoma cells. Results of RT-PCR and in situ hybridization demonstrated reduction of Ki-67 mRNA expression in Ki-67 siRNAs treated 786-0 cells. Similar reduction in Ki-67 protein measured by Western blot and immunocytochemistry was observed in cells transfected with Ki-67 siRNA. Ki-67-siRNA treatment of HRCCs resulted in specific inhibition of proliferation and increased apoptotic cell death. From these findings we conclude that inhibition of Ki-67 expression by siRNA may be a reasonable approach in renal cancer therapy.     

microRNA在口腔鳞癌中的研究进展

口腔鳞状细胞癌(OSCC)是口腔颌面部恶性肿瘤中最主要的一类,约占80%以上,好发于男性,但近年来女性的发病率也呈现逐年增加的趋势;microRNA,是一类稳定的短序列非编码RNA,其主要功能是在转录后水平参与靶基因的调控,近来研究已发现在OSCC患者中存在许多异常表达的microRNAs,而这些分子在OSAS的发生发展中扮演着重要的角色,异常的microRNA同样对OSCC的临床诊断、治疗以及判断预后都有着重要的作用;本文对当前microRNA在OSCC中的的异常表达、作用机制以及作为诊断标记物、治疗靶点的潜能进行了综述。     

Candidate biomarkers in renal cell carcinoma

Although the human genome has been decoded, the knowledge about the pathogenesis of diseases including cancer is still limited. By focusing on renal cell carcinoma (RCC) we here summarize the data of various research groups analyzing the protein/peptide expression profiles of tumor lesions/cell lines or serum obtained from patients and respective controls. Different powerful approaches such as 2-DE, PROTEOMEX/SERPA/SPEARS, and T cell epitope discovery upon elution of MHC class I-bound peptides in combination with MS/LC-MS/MS revealed 500 differentially expressed proteins. The overlap in target recognition limits the pool to 299 unique protein identities, but only few thereof (12%) have been validated. The management, analysis, and interpretation of the distinct data sets derived from 27 publications required bioinformatic restructuring of the results. However, the comprehensive analysis of the results expands the knowledge about the pathophysiology of RCC in particular of the most prominent clear cell subtype by providing information on the differentially expressed proteins, their regulation status in RCC compared to normal kidney epithelium next to additional information on MHC-presented T cell epitopes and on serological targets. Despite the low number of validated differentially expressed proteins some of them might serve as candidate biomarkers for the diagnosis and/or as therapeutic targets.     

The circulatory small non-coding RNA landscape in community-acquired pneumonia on intensive care unit admission

Community-acquired pneumonia (CAP) is a major cause of sepsis. Despite several clinical trials targeting components of the inflammatory response, no specific treatment other than antimicrobial therapy has been approved. This argued for a deeper understanding of sepsis immunopathology, in particular factors that can modulate the host response. Small non-coding RNA, for example, micro (mi)RNA, have been established as important modifiers of cellular phenotypes. Notably, miRNAs are not exclusive to the intracellular milieu but have also been detected extracellular in the circulation with functional consequences. Here, we sought to determine shifts in circulatory small RNA levels of critically ill patients with CAP-associated sepsis and to determine the influence of clinical severity and causal pathogens on small RNA levels. Blood plasma was collected from 13 critically ill patients with sepsis caused by CAP on intensive care unit admission and from 5 non-infectious control participants. Plasma small RNA-sequencing identified significantly altered levels of primarily mature miRNAs in CAP relative to controls. Pathways analysis of high or low abundance miRNA identified various over-represented cellular biological pathways. Analysis of small RNA levels against common clinical severity and inflammatory parameters indices showed direct and indirect correlations. Additionally, variance of plasma small RNA levels in CAP patients may be explained, at least in part, by differences in causal pathogens. Small nuclear RNA levels were specifically altered in CAP due to Influenza infection in contrast to Streptococcus pneumoniae infection. Pathway analysis of plasma miRNA signatures unique to Influenza or Streptococcus pneumoniae infections showed enrichment for specific proteoglycan, cell cycle, and immunometabolic pathways.     

非编码RNA在胞内病原菌免疫逃逸与致病中的作用

非编码RNA(non-coding RNAs,ncRNAs)在细胞增殖、发育、分化、代谢、信号转导以及免疫调控中发挥重要调节作用。越来越多的研究证明,ncRNA在胞内病原菌的致病性和免疫逃逸中发挥重要调控作用。一方面ncRNA是细菌代谢、群体感应和毒力因子表达的调控因子,与胞内病原菌的致病性密切相关;另一方面ncRNA在调节宿主抗胞内病原菌免疫应答中发挥重要作用,深入研究ncRNA如何调节宿主免疫应答将有助于胞内菌免疫逃逸机制的研究。就非编码RNA在胞内病原菌免疫逃逸和致病中的作用作一综述。     

Photoperiod- and thermo-sensitive genic male sterility in rice are caused by a point mutation in a novel noncoding RNA that produces a small RNA

Photoperiod- and thermo-sensitive genic male sterility (PGMS and TGMS) are the core components for hybrid breeding in crops. Hybrid rice based on the two-line system using PGMS and TGMS lines has been successfully developed and applied widely in agriculture. However, the molecular mechanism underlying the control of PGMS and TGMS remains obscure. In this study, we mapped and cloned a major locus, p/tms12-1 (photo- or thermo-sensitive genic male sterility locus on chromosome 12), which confers PGMS in the japonica rice line Nongken 58S (NK58S) and TGMS in the indica rice line Peiai 64S (PA64S, derived from NK58S). A 2.4-kb DNA fragment containing the wild-type allele P/TMS12-1 was able to restore the pollen fertility of NK58S and PA64S plants in genetic complementation. P/TMS12-1 encodes a unique noncoding RNA, which produces a 21-nucleotide small RNA that we named osa-smR5864w. A substitution of C-to-G in p/tms12-1, the only polymorphism relative to P/TMS12-1, is present in the mutant small RNA, namely osa-smR5864m. Furthermore, overexpression of a 375-bp sequence of P/TMS12-1 in transgenic NK58S and PA64S plants also produced osa-smR5864w and restored pollen fertility. The small RNA was expressed preferentially in young panicles, but its expression was not markedly affected by different day lengths or temperatures. Our results reveal that the point mutation in p/tms12-1, which probably leads to a loss-of-function for osa-smR5864m, constitutes a common cause for PGMS and TGMS in the japonica and indica lines, respectively. Our findings thus suggest that this noncoding small RNA gene is an important regulator of male development controlled by cross-talk between the genetic networks and environmental conditions.     

植物小RNA的研究进展

在植物中发现大量内源性的小RNA,它们与真核生物中的内源性的微RNA和外源性的干扰小RNA有类似的性质和功能。本对植物中小RNA分子的分布、作用机制、功能以及信号传导等方面作一概述。     

羊布鲁氏菌非编码小RNA分子BSR-2的预测与鉴定

利用RT-PCR和RACE等方法对生物信息学预测的羊布鲁氏菌非编码小RNA(smallnon-codingRNA,sRNA)BSR-2进行了实验鉴定,并通过分析BSR-2在胞内生存缺陷株中的转录情况以及预测BSR-2的靶标基因对BSR-2的功能进行初步探讨.RT-PCR结果表明,BSR-2在羊布鲁氏菌的总RNA中存在转录本,而且在不同的应激条件下转录水平不同.RACE结果表明,BSR-2长224nt,位于Ⅱ号染色体的BMEII0742和BMEII0743之间的基因间区.进一步的实验结果表明,BSR-2可能与布鲁氏菌的胞内生存能力相关.     

Long noncoding RNA DLX6-AS1 promotes renal cell carcinoma progression via miR-26a/PTEN axis

Recently, long non-coding RNAs (lncRNAs) have emerged as new gene regulators and prognostic markers in several types of cancer, including renal cell carcinoma (RCC). In this study, we identified an upregulated lncRNA, DLX6-AS1, in RCC tumor tissues compared with normal kidney tissues. Our data suggested that DLX6-AS1 promoted RCC cell growth and tumorigenesis via targeting miR-26a. In addition, we observed that PTEN overexpression restored the renal cancer cell growth and also rescued the RCC tumorigenesis. In summary, we conclude that DLX6-AS1 promotes renal cell carcinoma development via regulation of miR-26a/PTEN axis.