Long Non-Coding RNAs: Critical Players in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a complex disease with multiple underlying pathogenic mechanisms caused by a variety of etiologic factors. Emerging evidence showed that long non-coding RNAs (lncRNAs), with size larger than 200 nucleotides (nt), play important roles in various types of cancer development and progression. In recent years, some dysregulated lncRNAs in HCC have been revealed and roles for several of them in HCC have been characterized. All these findings point to the potential of lncRNAs as prospective novel therapeutic targets in HCC. In this review, we summarize known dysregulated lncRNAs in HCC, and review potential biological roles and underlying molecular mechanisms of lncRNAs in HCC. Additionally, we discussed prospects of lncRNAs as potential biomarker and therapeutic target for HCC. In conclusion, this paper will help us gain better understanding of molecular mechanisms by which lncRNAs perform their function in HCC and also provide general strategies and directions for future research.     

Cooperative enhancement of deoxyribozyme activity by chemical modification and added cationic copolymer

Deoxyribozymes (DNAzymes) having RNA-cleaving activity have widely been explored as tools for therapeutic and diagnostic purposes. Both the chemical cleaving step and the turnover step should be improved for enhancing overall activity of DNAzymes. We have shown that cationic copolymer enhanced DNAzyme activity by increasing turnover efficacy. In this paper, effectｓ of the copolymer on DNAzymes modified with locked nucleic acids (LNA) or 2′-O-methylated (2′-OMe) nucleic acids were studied. The copolymer increased activity of these chemically modified DNAzymes. More than 30-fold enhancement in multiple-turnover catalytic activity was observed with 2′-OMe-modified DNAzyme in the presence of the copolymer. DNAzyme catalytic activity was successfully enhanced by cooperation of the added copolymer and chemical modification of DNAzyme.     

Quorum-sensing Cascades Governing Bacterial Multicellular Communities

Quorum sensing (QS) is an efficient mode of intercellular communication between bacteria. This mode is regulated by self-produced small chemical signals, activating dedicated receptors once accumulated. Numerous architecturally complex QS cascades are cardinal for governing bacterial behaviors, such as pathogenicity, luminescence, and bacterial competence. Importantly, QS cascades are essential for the formation of bacterial multicellular communities. Once informed via QS cascades, motile cells often organize themselves into conspicuous multicellular structures that carry out specialized tasks. This review focuses on the major QS systems, playing an active role in the rise of complex bacterial communities in different bacterial models.     

多发性骨髓瘤骨髓单个核细胞缺氧诱导因子1α mRNA的表达及其临床意义

目的 探讨多发性骨髓瘤(MM)患者缺氧诱导因子1 α(HIF-1 α)基因mRNA表达和临床各指标的相关性,了解HIF-1 α基因在MM患者中的表达和意义.方法 应用实时荧光定量聚合酶链反应(RQ-PCR)28例检测MM患者和22例骨科外伤患者或非血液系统恶性肿瘤患者(对照组)骨髓单个核细胞中的HIF-1 α mRNA,以β-actin作为内参照,用SDS分析软件测定Ct值,用2-△△Ct表示目的 基因的量.结果 HIF-1 α mRNA在MM骨髓单个核细胞中表达为对照组的12.68倍,HIF-1 α mRNA水平(以-△Ct表示)与患者血清β2-微球蛋白(r=0.575,P=0.000)、红细胞沉降率(r=0.522,P=0.000)、乳酸脱氢酶(r=0.286,P=0.044)、C反应蛋白(r=0.356,P=0.011)水平呈正相关,与患者血红蛋白(Hb)水平呈负相关(r=-0.556,P=0.000).结论 HIF-1 α mRNA在MM组织中高表达,与临床多项指标有关,可作为临床监测指标之一,有可能成为肿瘤分子靶向治疗中新的靶点.     

siRNA转染肝癌HepG2细胞Survivin基因凋亡机制探讨

Objective: The aim of this study was to investigate the molecular mechanism of anti-apoptotic action of survivin to the hepatoma-cellular carcinoma cell line HepG2. Methods: Design and synthesize siRNA gene sequence specifically targeting at HepG2 cell. HepG2 cells cultures were divided into five groups: blank control group, negative control group, low dose group, medium dose group and high dose group. HepG2 cells were treated respectively by pshRNA-survivin-387 of different concentrations. The apoptosis index (AI) was determined by flow cytometry (FCM). Cells were stained with rhodomine-123 (Rh123) to detect changes of mitochondrial membrane potentials. The concentration of cytoplasmic cytochrome C (Cyt.C) was continuously determined by ELISA. Relative activities of caspase-9 and caspase-3 were assessed by colorimetric assay. Results: Compared with the control group, due to the function of short interference RNAs (SiRNAs) that suppresses the survivin gene expression, the apoptotic index of transfected groups were significantly higher than those of control groups (F = 13568.68, q = 110.47–327.16, P < 0.01), the apoptosis index of high concentration of transfected cells was higher than the low concentration transfected group (q = 39.63–168.22, P < 0.01). The apoptosis index of high concentrations transfected HepG2 cells was 25.54%, higher than that of blank control group, negative control group, low dose group and medium dose group (5.24%, 6.61%, 12.63% and 15.64%, respectively). HepG2 cells transfected with SiRNA exhibit gradually decreasing mitochondrial membrane potentials, which then lead to the releasing of Cyt C, following it were the activation of caspase-9 and caspase-3. Conclusion: Survivin performs the function of anti-apoptosis to the HepG2 cells via modulating the apoptosis of mitochondrial. HepG2 cells transfected with SiRNA survivin can significantly induce apoptosis.     

从RNA酶解液中分离5'-尿苷酸

采用2根强酸性阳离子交换柱、1根弱碱性阴离子交换柱和1根强碱性阴离子交换柱进行4柱串联,可以从RNA酶解液中分离得到5'-尿苷酸,而不混有其它核苷酸,并对离子交换树脂种类、树脂量、洗脱剂等作了进一步研究.结果表明,采用4柱串联分离5'-尿苷酸,其总收率达到92.1％、结晶纯度达到86％以上.     

RNA聚合酶Ⅱ转录的ALU序列对HEK293细胞凋亡的影响

目的探讨RNA聚合酶Ⅱ转录的ALU序列对人胚肾293(HEK293)细胞凋亡的影响以及干扰素(IFN)在此机制中的作用。方法取对数生长期的HEK293细胞,分为6组,ALU-293组(瞬时转染重组质粒pcDNA3.1-ALU)、pcDNA3.1-293组[瞬时转染空质粒pcDNA3.1(-),作为阴性对照]、Poly I∶C-293组[瞬时转染dsRNA的多聚肌苷胞苷酸(Poly I∶C),作为阳性对照]、IFNβ-293组(加入1.65×104 U IFNβ,作为阳性对照)、空白对照组(未经处理的HEK293细胞)和HBs-293组(瞬时转染重组质粒pcDNA3.1-HBs),转染后48 h,采用MTT法检测细胞的增殖活性;Cellular DNA Fragmentation ELISA和DNA Ladder法检测细胞的凋亡情况;Real-time PCR检测细胞中IFNβ基因mRNA的水平。结果瞬时转染重组质粒pcDNA3.1-ALU能够抑制HEK293细胞增殖,并促使其凋亡,且细胞中IFNβmRNA的水平显著上调。结论 RNA聚合酶Ⅱ转录的ALU序列能够通过激活干扰素系统来诱导细胞凋亡。     

A novel developed method based on single primer isothermal amplification for rapid detection of Alicyclobacillus acidoterrestris in apple juice

Alicyclobacillus acidoterrestris (A. acidoterrestris), as one of the most major spoilage-causing species within the Alicyclobacillus genus, can survive and multiply in the pasteurization process. Nowadays, A. acidoterrestris has become worldwide issue in the fruit juice industry due to its spore-forming and thermo-acidophilic features. A novel single primer isothermal amplification assay (SPIA) was developed for the rapid detection of A. acidoterrestris in apple juice. This assay was designed to target the 16S rRNA gene with a DNA/RNA chimeric primer. Detection of gene amplification was accomplished by amplification curve, turbidity and addition of single strand DNA binding dye SYBR Green II allowing visualization under ultra violet light. The specificity of the assay was confirmed using 7 strains of A. acidoterrestris and 30 strains of non-A. acidoterrestris. The SPIA was highly sensitive and the detection limit was as low as 4.8 CFU/mL. Furthermore, the apple juice inoculated with 61 CFU/mL of A. acidoterrestris could be detected as positive. The novel SPIA with visualization results was successfully applied for the detection of A. acidoterrestris and exhibited high specificity and sensitivity, making it a powerful tool for the detection of A. acidoterrestris in fruit juice industry and being conveniently applied in developing countries with limited resource.