Deep sequencing identifies deregulation of microRNAs involved with vincristine drug-resistance of colon cancer cells

Background: Vincristine (VCR) is a chemical that is widely used in tumor therapy. While long-term use can make tumor cells resistant to VCR, the underlying mechanisms of this resistance are still unclear. Objective: This study aimed at investigating the role of microRNA (miRNA) in colon cancer drug resistance. Methods: HCT-8 colon carcinoma cells were cultured and treated with different VCR concentrations to establish an HCT-8/VCR resistant cell line. Whole-genome screens, HiSeq 2500 sequencing, and bioinformatics methods were used to detect and analyze differences in miRNA expression between the drug-resistant HCT-8/VCR cells and non-resistant HCT-8 cells. Differential expression profiles of miRNAs were constructed based on sequencing result. Results: The HCT-8/VCR resistant colon carcinoma cell line was established. With regard to the difference in drug resistance between HCT-8/VCR and HCT-8 cells, 24 miRNAs showed statistically significant differences in their expression (fold change > 4), of which 17 were up-regulated. Seven miRNAs were down-regulated. Conclusion: As abnormal expression of miRNAs was associated with VCR resistance of colon carcinoma cells, differences in miRNA expression may play a key role in VCR resistance of colon cancer cells.     

miR-17-5p在口腔鳞状细胞癌中的表达特点及其临床意义

目的:探讨口腔鳞状细胞癌(OSCC)患者肿瘤组织和血浆中miR-17-5p的表达特点及临床意义.方法:选取2009年6月-2013年6月经手术切除的OSCC组织标本和外周血标本各42例,使用qRT-PCR测定miR-17-5p的表达;采用Mann-Whitney U检验分析miR-17表达及预后的相关性. 结果:OSCC组织和血浆中miR-17-5p表达显著上调(P<0.05),与患者性别、年龄、肿瘤分化程度无明显相关(P>0.05),但与肿瘤的TNM分期、淋巴结转移密切相关(P<0.05);术前血浆中miR-17-5p高表达者术后1年的复发率高于低表达者(P <0.05);治愈患者术后血浆中miR-17-5p表达明显低于术前血浆中miR-17-5p含量(P<0.05),而OSCC术后复发患者无明显变化. 结论:miR-17-5p可以作为临床评估OSCC侵袭、转移和术后复发进行评价的重要指标.     

用实时荧光定量PCR选择急性呼吸窘迫综合征患者血清microRNA内参照基因

目的探讨用实时荧光定量PCR检测急性呼吸窘迫综合征(ARDS)患者血清微小RNA(microRNA,miRNA)的表达并选择最优内参照基因。方法用实时荧光定量PCR检测40例ARDS患者及20例体检健康者血清中5个miRNA候选内参照基因miR-16-5p、miR-93-5p、miR-101-3p、miR-191-5p和U6,并用ge Norm法、Norm Finder法、bestkeeper法和相对△Ct法4种算法分析内参照基因稳定性,通过对4种算法稳定值进行排序并计算几何均数的方法分析综合稳定值。结果比较5个候选内参照基因在ARDS患者和体检健康者的表达水平,差异均无统计学意义(P均0.05)。4种算法综合分析显示,miR-16-5p以最小的稳定值1.32成为综合稳定性最高的内参照基因,其次是miR-101-3p、U6、miR-93-5p和miR-191-5p。结论实时荧光定量PCR法确定ARDS患者血清miRNA最优的内参照基因为miR-16-5p。     

microRNA与心血管疾病发病机制的相关性

在胚胎发育时期,哺乳动物体内最先形成的器官即为心脏,由高保守性转录因子构成的调控体系控制着其信号通路的正确表达,并对心血管系统的正常发育及功能的维持发挥着重要作用。在心脏发育过程中,该调控体系受到任何微小的干扰,都可能会造成先天性心脏病、心律失常等各类心血管疾病的发生。 microRNAs作为一类小分子非编码RNA,其参与心血管系统的发育及疾病的发生过程,已经引起了各界研究人员的广泛关注。在大部分生物组织中, microRNAs主要通过抑制靶基因的翻译,从而在转录后抑制靶基因的表达。最新研究表明,在心脏等靶器官中,维持和恢复相应microRNA的稳定表达可能成为心血管等疾病治疗的一个新靶点。文章就microRNA在各类心血管疾病发病机制中扮演的重要角色进行了深入概括,这将有利于促进心血管疾病的预防和治疗。     

Nasopharyngeal cancer-derived microRNA-21 promotes immune suppressive B cells

The prevalence of nasopharyngeal cancer (NPC) is high in the southern area of China and some other districts in the world. The pathogenesis of NPC is unclear. It is reported that some microRNAs (miR) are involved in the progression of NPC. This study aims to investigate the role of miR-21 in the induction of immune tolerance of NPC. In this study, NPC tissue was collected from patients with NPC. Assessment of miR was performed with real time quantitative RT-PCR. Western blotting was used to assess proteins of interleukin 10 and nuclear factor I-A (NFI-A). Immune cells were analyzed by flow cytometry. The results showed that NPC cell line C666-1 and surgically removed NPC tissue expressed miR-21, which was upregulated by the presence of the Toll-like receptor 3 ligand, Poly I: C. Exposure to miR-21 increased the expression of NFI-A and interleukin (IL)-10 in naive B cells. High frequency of IL-10⁺ B cells was detected in the NPC tissue. The NPC- or miR-21-primed B cells suppressed cytotoxic CD8⁺ T cell activities. We conclude that NPC-derived miR-21 induces IL-10⁺ B cells; the latter is capable of suppressing CD8⁺ T-cell activities. miR-21 may be a potential target in the treatment of NPC.     

微小RNA与重症肌无力研究进展

微小RNA(miRNA)是一类进化上保守的内源性单链非编码小RNA分子,长度约为19 ～24个核苷酸,通过靶基因特异性结合从而导致mRNA降解或翻译抑制,在转录后水平调控基因表达.大量研究表明miRNA与多种人类自身免疫性疾病密切相关.重症肌无力(MG)是神经-肌肉接头处传递功能障碍的自身免疫性疾病.探究miRNA在MG发生发展中的分子机制有助于阐明MG的致病机制,为MG的分子诊断和个性化治疗提供重要依据.本文主要对miRNA与MG相关性的研究进展进行综述.     

miR-212 在乳腺浸润性导管癌 组织中的表达及效应分析

目的：分析miR-212在乳腺浸润性导管癌组织中的表达及与乳腺癌临床病理特征之间的相关性,并分析其效应。方法采用茎环RT- qPCR方法检测38例乳腺癌及癌旁正常乳腺组织标本中miR-212的表达,统计分析其表达水平与乳腺癌常用临床病理指标间的关系。不同浓度miR-212 inhibitor转染MCF7乳腺癌细胞,通过MTT法分析细胞活性,通过Tran- swel 实验检测细胞的侵袭能力。结果与癌旁正常乳腺组织比较,乳腺癌组织中miR-212的表达明显升高（P＜0.05）;分析miR-212表达水平与乳腺癌常用临床病理指标间的关系发现,miR-212表达水平与乳腺癌细胞与淋巴结转移、TNM分期相关及增殖指数（ki67）相关（P＜0.05）,与月经状况、肿块大小、雌激素和孕激素受体状态、Her-2表达未见显著相关性（P＞0.05）。细胞干预实验显示,与空白对照组、阴性对照组比较,miR-212 inhibitor可明显抑制MCF7细胞增殖活性（P＜0.05）和细胞迁移（P＜0.01）。结论乳腺癌组织高表达的miR-212在乳腺癌发展过程中发挥重要作用,有望成为乳腺癌防治的一个新靶点。     

Epigenetics and pancreatic cancer:Pathophysiology and novel treatment aspects

An improvement in pancreatic cancer treatment represents an urgent medical goal.Late diagnosis and high intrinsic resistance to conventional chemotherapy has led to a dismal overall prognosis that has remained unchanged during the past decades.Increasing knowledge about the molecular pathogenesis of the disease has shown that genetic alterations,such as mutations of K-ras,and especially epigenetic dysregulation of tumor-associated genes,such as silencing of the tumor suppressor p16ink4a,are hallmarks of pancreatic cancer.Here,we describe genes that are commonly affected by epigenetic dysregulation in pancreatic cancer via DNA methylation,histone acetylation or miRNA(microRNA)expression,and review the implications on pancreatic cancer biology such as epithelial-mesenchymal transition,morphological pattern formation,or cancer stem cell regulation during carcinogenesis from PanIN(pancreatic intraepithelial lesions)to invasive cancer and resistance development.Epigenetic drugs,such as DNA methyltransferases or histone deactylase inhibitors,have shown promising preclinical results in pancreatic cancer and are currently in early phases of clinical development.Combinations of epigenetic drugs with established cytotoxic drugs or targeted therapies are promising approaches to improve the poor response and survival rate of pancreatic cancer patients.