A case of dysmyelopoietic syndrome with hypotetraploid karyotype

We present a patient with dysmyelopoietic syndrome and with a complex, hypotetraploid karyotype with numerous structural aberrations.     

靶向miR-221 siRNA表达载体的构建及有效靶序列的筛选和表达

目的 构建靶向miR-221的siRNA表达载体,同时筛选出一条抑制效率最好的靶序列,为研究RNAi在哺乳动物细胞内抑制靶基因表达奠定基础.方法 根据siRNA靶点设计的原则运用相关软件设计靶序列并合成其表达框,连接入siRNA表达质粒pGCSIL-GFP,同时构建miR-221表达载体pEGFP-miR-221,共同转染293T细胞,Western blot检测转染后293T细胞中Flag蛋白表达,间接反映各靶序列抑制效率,最后将筛选出的抑制效率最好的质粒转染U87胶质瘤细胞,应用细胞增殖曲线及流式细胞仪检测其对U87细胞生长的影响.结果 重组质粒经测序鉴定证明各转录模板完整、正确插入到相应质粒中,并筛选出1号靶序列对miR-221抑制率最高,该组Flag蛋白的表达量仅为对照组的34.3%,同时该序列能有效抑制U87胶质瘤细胞的生长并诱导细胞凋亡,凋亡率达21.89%.结论 成功构建了靶向miR-221的siRNA 表达载体,并筛选出一个抑制效率最好的序列,在体外实验中该序列能有效抑制U87细胞的生长.     

miR-221与miR-222通过靶基因TIMP3调控胶质瘤细胞侵袭能力

目的 探讨miR-221和miR-222在胶质瘤细胞侵袭过程中的作用及其机制.方法 采用反义寡核苷酸下调miR-221和miR-222表达,Transwell、Western blot、荧光素酶实验及体内实验分别检测细胞侵袭能力、体内肿瘤生长、相关基因蛋白表达变化及靶基因鉴定.结果 下调miR-221和miR-222表达能明显抑制胶质瘤细胞侵袭能力,同时相关侵袭蛋白MMP2和MMP9表达下降.miRNA靶基因预测软件分析、Western blot、荧光素酶实验证实TIMP3是miR-221和miR-222的靶基因.裸鼠皮下肿瘤模型显示下调miR-221和miR-222表达抑制体内肿瘤生长.免疫组化发现TIMP3表达上调,MMP2和MMP9表达下调.结论 在胶质瘤细胞中,侵袭相关蛋白TIMP3是miR-221和miR-222的一个新靶基因.

Abstract：

Objective To investigate the role and mechanism of miR -221 and miR -222 in glioma cell invasion. Method After reduction of miR -221 and miR -222 by antisense oligonucleotides, cell invasion,invasion related - gene expression and target identification were determined by Transwell assay, Western blot analysis and luciferase reporter assay,respectively. Moreover,the effects of miR -221 and miR -222 on xenograft tumors in nude mice were also observed. Results Down - regulation of miR - 221 and miR - 222 decreased glioma cell invasion in vitro, and inhibited glioma growth in a subcutaneous mouse model. Furthermore,down -regulation of miR -221 and miR - 222 resulted in obvious inactivation of MMP2 and MMP9. Western blot analysis and luciferase reporter assay showed that the reduction of miR - 221 and miR -222 repressed TIMP3 protein expression and TIMP3 mRNA 3'UTR existed the biding sites of miR -221 and 222. Conclusions TIMP3 is a novel target of miR -221 and miR -222 in glioma cell invasion.     

微小RNA-221作用蓬乱蛋白2影响前列腺癌细胞系的侵袭功能研究

目的:探讨微小RNA-221(microRNA-221,miR-221)在前列腺癌细胞系中的表达,对神经内分泌样(NE)转化及其侵袭功能的影响.方法:以Northern blot检测雄激素依赖性前列腺癌(LNCaP) 细胞系,雄激素非依赖性前列腺癌(LNCaP-AI) 细胞系中miRNA的表达;细胞转染法检测在雄激素剥夺环境中LNCaP和LNCaP-AI细胞系中miR-221的作用;细胞增殖检测法检测细胞在不同阶段的生长增殖水平;Transwell法检测转染细胞的侵袭能力;定量逆转录聚合酶链反应和Western blot检测转染细胞中神经元特异性烯醇化酶及蓬乱蛋白2 (DVL2)表达的变化.结果:与LNCaP相比,miR-221在 LNCaP-AI中明显高表达.通过转染使miR-221在LNCaP中高表达可促进细胞的神经元特异性烯醇酶的表达,加速NE转化.而在LNCaP-AI中下调miR-221水平可增强靶基因DVL2的表达,并增强LNCaP-AI的迁移和侵袭能力(P<0.01).结论:LNCaP和LNCaP-AI中miR-221表达有差异.miR-221可促进前列腺癌细胞的NE转化,可能是导致前列腺癌雄激素非依赖转化的重要原因.MiR-221可通过作用DVL2调节前列腺癌细胞的转移和侵袭.     

microRNA-125b在孕期酒精暴露所致新生小鼠脑神经元凋亡中的作用

目的 探讨microRNA-125b（miR125b）调控孕期酒精暴露致胚胎神经元细胞凋亡的可能机制。方法给予孕期小鼠持续连续酒精暴露［50%酒精,5 μL/（g·d）］,对照组予以0.9%NaCl暴露;检测出生小鼠脑/体重比;Tunnel法检测新生小鼠脑组织中神经元细胞凋亡情况;利用定量PCR检测miR125b、p53、凋亡基因Bax mRNA表达水平,利用Western blot检测p53及Bax蛋白表达;体外情况下给予鼠PC-12细胞酒精暴露,然后进行miR125b mimic转染以上调miR125b表达;再次检测miR125b、p53及Bax表达水平。结果与对照组相比,酒精暴露组小鼠出生脑/体重比显著降低（P<0.05）,脑组织中神经元细胞凋亡增加。酒精暴露组新生小鼠脑组织中miR125b表达明显降低,而p53及Bax在mRNA和蛋白水平均显著升高（P<0.05）;PC-12细胞转染miR125b-mimic使其过表达后,miR125b表达显著升高,与酒精暴露组相比p53及Bax表达明显下降（P<0.05）。结论miR125b通过影响p53通路进而参与影响孕期酒精暴露致小鼠脑神经元凋亡。     

Clinical significance and correlation of miR-200c and P-gp expression in gastric cancer and the effects on multidrug resistance

BackgroundPoor prognosis is common in gastric cancer patients due to multidrug resistance (MDR)-induced recurrence and metastasis. In the present study, we investigated the expression of microRNA (miR)-200c in gastric cancer tissues and cell lines and its relationship with the expression of the drug resistant gene ABCB1, which encodes P-glycoprotein (P-gp).MethodsThe basic characteristics of 102 patients with gastric cancer were reviewed. Real time-polymerase chain reaction (PCR), immunohistochemistry, and Western blot were employed to detect the expression levels of miR-200c and P-gp in gastric carcinoma tissues and cell lines. The correlation of miR-200c messenger RNA (mRNA) level with clinicopathological characteristics and P-gp protein expression were analyzed. SGC7901/vincristine (VCR) cells were transfected with miR-200c mimics or a specific small interfering RNA (siRNA) targeting the ABCB1 gene. The methyl thiazolyl tetrazolium (MTT) assay and flow cytometry were used to determine the role of miR-200c and ABCB1 on the viability and apoptosis of gastric carcinoma cell lines.ResultsThe level of miR-200c in carcinoma tissues was significantly lower than that in adjacent tissues, and the expression level of P-gp in carcinoma tissues was obviously higher than that in adjacent tissues (P<0.01, P=0.029). The expression levels of miR-200c and P-gp were associated with the malignant characteristics of gastric cancer, and patients with high expression of miR-200c or negative expression of P-gp had a better prognosis (P=0.006, P=0.022). MiR-200c negatively regulated the ABCB1 gene in gastric cancer cell lines. MiR-200c overexpression and ABCB1 down-regulation increased the sensitivity of SGC7901/VCR cells to VCR and reversed MDR by promoting cell apoptosis.ConclusionsThe expression level of miR-200c decreases in gastric carcinoma tissues and drug-resistant gastric cancer SGC7901/VCR cells. Overexpression of miR-200c may enhance the sensitivity of SGC7901/VCR cells to VCR by regulating the expression of P-gp.     

MicroRNA in radiotherapy: miRage or miRador?

At least half of all cancer patients will receive radiation therapy. Tumour radioresistance, or the failure to control certain tumours with this treatment, can result in locoregional recurrence; thus there is great interest in understanding the underlying biology and developing strategies to overcome this problem. The expanding investigation of microRNA in cancer suggests that these regulatory factors can influence the DNA damage response, the microenvironment and survival pathways, among other processes, and thereby may affect tumour radioresistance. As microRNA are readily detectable in tumours and biofluids, they hold promise as predictive biomarkers for therapy response and prognosis. This review highlights the current insights on the major ways that microRNA may contribute to tumour radiation response and whether their levels reflect treatment success. We conclude by applying the potential framework of future roles of miR in personalised radiotherapy using prostate cancer clinical management as an example.     

Overlooked aspects concerning development and spread of antimicrobial resistance

miRNAs are short, nonprotein coding RNAs that regulate target gene expression principally by causing translational repression and/or mRNA degradation. miRNAs are involved in most mammalian biological processes and have pivotal roles in controlling the expression of factors involved in basal and stimulus-induced signaling pathways. Considering their central role in the regulation of gene expression, miRNAs represent therapeutic drug targets. Here we describe how miRNAs are involved in the regulation of aspects of innate immunity and inflammation, what happens when this goes awry, such as in the chronic inflammatory lung diseases cystic fibrosis and asthma, and discuss the current state-of-the-art miRNA-targeted therapeutics.