Down-regulation of microRNA-126 and microRNA-133b acts as novel predictor biomarkers in progression and metastasis of non small cell lung cancer

Objective: MiRNAs play crucial roles in progression of cancer. However, the underlying mechanisms of miRNAs in non small cell lung cancer are still poorly understood. The aim of this study was to investigate the expression level of microRNA-126 (miR-126) and microRNA-133b (miR-133b) and also their association with clinicopathological features in patients with non small cell lung cancer (NSCLC). Methods: Total RNA was purified from NSCLC tissues and adjacent non-tumor tissues and then quantitative real-time PCR (qRT-PCR) was used to evaluate the expression rate of microRNAs. Furthermore, the association of miR-126 and miR-133b level with clinicopathological features and prognosis were evaluated. Results: Our findings showed that expression of miR-126 was decreased in NSCLC tissues compared with adjacent non-tumor tissues. On the other hand, a lower expression of miR-133b was seen in NSCLC tissues when compared with adjacent non-tumor tissues. In term of miR-126, our results showed that miR-126 was associated with tumor stage and lymph nodes metastasis (P<0.05). In term of miR-133b, our finding indicated that decreased expression of miR-133b was correlated with advanced tumor stage and lymph nodes metastasis (P<0.05). Kaplan-Meier analysis and log-rank test indicated that patients with low expression of miR-126 and miR-133b had a shorter overall survival (log-rank test; P<0.05). Multivariate Cox proportional hazards model revealed that low expression of miR-126 and miR-133b, advanced tumor stage and lymph nodes metastasis were independent prognostic factors for overall survival of NSCLC patients. Conclusions: These findings suggested that miR-126 and miR-133b might play a key role in the progression and metastasis of NSCLC and would be applied as a novel therapeutic agent.     

Involvement of epigenetics and microRNA-29b in the urethane induced inception and establishment of mouse lung tumors

Epigenetic changes are correlated with tumor development showing aberrations in DNA methylation and histone modifications. To find the early changes, we evaluated the epigenetic events from early to late stage of the urethane induced lung tumor development in mouse model and tried to correlate the molecular events with the progression of tumor. We addressed the hypothesis by examining the tumor development, status of DNMTs, HDACs and MBDs, DNA methylation and expression of microRNA-29b during 1 to 36 weeks after urethane exposure that included the period before and after the tumor appearance. Tumors did not appear after 1 or 4 weeks but well defined tumors appeared after 12 weeks and larger tumors appeared at 36 weeks which was prevented by IP6. DNMT1, DNMT3a and DNMT3b were upregulated after urethane exposure at the time of no tumor till the tumor developed and showed its upregulated functional activity. DNMTs are shown to be the targets of microRNA-29b and we showed that microRNA-29b was downregulated in the line of DNMT upregulation. HDAC, the histone modifier, also showed progressive upregulation. Periodic increase in methyl binding proteins, MBD2, supported the expression of gene silencing pathways in terms of the downregulation of tumor suppressor genes, p16 and MLH1. All these molecular alterations were protected in the presence of IP6. Our results showed that the key steps of epigenetics, DNMTs, mir29b, and HDAC1, are altered both before and after the development of tumors.     

miR-200c-3p靶向CCNE2抑制肾母细胞瘤细胞增殖

目的 预测和验证miR-200c-3p的靶基因并探讨其对肾母细胞瘤增殖的抑制作用。方法 应用生物信息学软件对miR-200c-3p在肾母细胞瘤中的靶基因进行预测,建立SK-NEP-1及G401的miR-200c-3p过表达及抑制表达的稳定细胞系。实验设未转染组（Blank）、模拟物阴性对照组（mimic NC）、miR-200c-3p模拟物组（miR-200c-3p mimic）、抑制剂阴性对照组（inhibitor NC）及miR-200c-3p抑制剂组（miR-200c-3p inhibitor）。采用 RT-PCR及Western blot方法检测CCNE2在SK-NEP-1及G401不同组中的表达水平,荧光素酶报告基因检测miR-200c-3p 和CCNE2的靶向关系,细胞计数盒（CCK-8）和软琼脂克隆形成实验检测miR-200c-3p对SK-NEP-1及G401细胞增殖的抑制作用。结果 生物信息学方法预测CCNE2为miR-200c-3p的靶基因之一。RT-PCR实验结果示肾母细胞瘤细胞中miR-200c-3p模拟物组的CCNE2的表达水平低于模拟物阴性对照组（P<0.05）;荧光素酶报告基因检测证实CCNE2是miR-200c-3p的靶基因（P<0.01）。Western blot示在肾母细胞瘤细胞中miR-200c-3p模拟物组的CCNE2蛋白的表达水平低于模拟物阴性对照组（P<0.05）;CCK-8和软琼脂克隆形成实验证实miR-200c-3p对肾母细胞瘤细胞的增殖能力有明显抑制作用（P<0.01）;而miR-200c-3p抑制剂组结果相反。结论 miR-200c-3p通过靶基因 CCNE2抑制肾母细胞瘤细胞的增殖。     

骨肉瘤中miR-194的表达水平及其与临床病理参数的关系

目的探讨骨肉瘤中miR-194的表达水平及其与临床病理参数的关系。方法应用荧光定量实时PCR分析68例冻存的骨肉瘤组织及其对应的癌旁组织标本中miR-194的表达水平,并分析其与临床病理参数及患者预后的关系。结果与癌旁组织相比,骨肉瘤组织中miR-194的表达显著降低(t=8.408,P<0.001)。随着临床分期的增加,miR-194表达水平逐渐降低,miR-194表达下调与临床分期有关(χ2=15.859,P=0.001)。软组织浸润患者miR-194表达水平显著低于无软组织浸润患者(χ2=21.580,P<0.001)。与无转移患者相比,转移患者miR-194表达水平显著降低(χ2=14.071,P<0.001)。miR-194高表达组中位生存时间为30.40个月,累积生存率为81.48%(22/27);而低表达组中位生存时间为23.71个月,累积生存率为58.54%(24/41);两组比较差异有统计学意义(χ2=4.138,P=0.042)。结论骨肉瘤患者组织中miR-194表达水平明显降低,与临床分期、软组织浸润、肿瘤转移等临床病理特征有关,其低表达与患者预后不良密切相关。     

MicroRNA-34a通过上调Cdc42和Rac1促进人晶状体上皮细胞衰老和凋亡

目的:观察MicroRNA-34a对人晶状体上皮细胞系SRA01/04衰老和凋亡的影响及作用机制。方法:qRT-PCR检测年龄相关性白内障(ARC)晶状体和透明晶状体上皮细胞中MicroRNA-34a表达水平,采用脂质体转染试剂盒将MicroRNA-34a mimics(过表达组)、MicroRNA-34a inhibitors(抑制组)和空脂质体(对照组)转染至SRA01/04细胞,qRT-PCR检测MicroRNA-34a的表达量;采用β-半乳糖苷酸(SA-β-gal)染色检测转染后细胞的衰老情况。Annexin V-FITC/PI双染色流式细胞仪检测MicroRNA-34a对人晶状体细胞系SRA01/04细胞凋亡的影响;蛋白免疫印迹检测Cdc42、Rac1蛋白的表达。结果:透明晶状体前囊膜组织中MicroRNA-34a的表达量显著低于ARC晶状体前囊膜组织(P<0.05);MicroRNA-34a过表达组、对照组、MicroRNA-34a抑制组SA-β-gal阳性率分别为(87.56±2.34)%、(12.22±2.74)%、(3.45±0.45)%。MicroRNA-34a过表达组明显高于对照组,而MicroRNA-34a抑制组SA-β-gal阳性率明显低于对照组(P<0.05);MicroRNA-34a抑制组、对照组和MicroRNA-34a过表达组的细胞凋亡率分别为(5.87±1.22)%、(12.26±2.14)%、(29.45±3.12)%,MicroRNA-34a抑制组细胞凋亡率明显低于对照组,而MicroRNA-34a过表达组细胞凋亡率明显高于对照组(P<0.05);MicroRNA-34a过表达组中Cdc42和Rac1的表达明显高于对照组(P<0.05),MicroRNA-34a抑制组中Cdc42和Rac1的表达明显低于对照组(P<0.05)。结论:MicroRNA-34a可能通过上调Cdc42和Rac1促进人晶状体上皮细胞衰老和凋亡。     

MicroRNA-96对人视网膜色素上皮细胞增殖与迁移的影响

目的：探讨MicroRNA-96（miR-96）对人视网膜色素上皮（RPE）细胞增殖和迁移的影响。方法：实验研究。通过RNA原位杂交检测人胚胎眼（20周）石蜡切片中RPE层miR-96的表达情况。将miR-96和阴性对照（NC）通过阳离子脂质体介导转染人眼RPE细胞,采用细胞增殖实验（MTS）、流式细胞术和Transwell实验分别检测细胞增殖、细胞周期以及细胞迁移能力。通过生物信息学及Western blot法确定miR-96作用的靶基因。应用Western blot检测miR-96对细胞增殖迁移相关信号通路蛋白（Akt、ERK）及细胞周期相关蛋白（p-Cdc2、CyclinD2、p-Rb）表达的影响。组间数据比较采用独立样本t检 验。结果：MiR-96在人眼RPE细胞中有表达。MTS结果显示,转染NC、miR-96后,人眼RPE细胞的相对增殖速率分别为100%、74%±2%,差异有统计学意义（t=42.174,P=0.002）。流式细胞术检测结果显示,转染miR-96后阻滞在G1期的RPE细胞显著多于转染NC后,且差异有统计学意义（t= -18.444,P=0.003）。Transwell实验结果显示,与转染NC相比,转染miR-96能显著抑制RPE细胞的迁移,差异具有统计学意义（t=6.754,P=0.002）。进而,明确了MITF是miR-96作用的靶基因。Western blot检测结果显示,转染miR-96后细胞中细胞周期相关蛋白p-Rb（t=11.211,P=0.002）、p-Cdc2（t=9.133, P=0.003）、CyclinD2（t=7.542,P=0.005）以及迁移相关信号通路蛋白p-ERK（t=16.699,P<0.001）,p-Akt （t=23.552,P<0.001）的表达水平均降低。结论：miR-96通过作用于靶基因MITF,并调控细胞周期和迁移相关蛋白的表达从而抑制人RPE细胞的增殖和迁移。     

Overexpression of microRNA-124 promotes the neuronal differentiation of bone marrow-derived mesenchymal stem cells

microRNAs(miRNAs) play an important regulatory role in the self-renewal and differentiation of stem cells. In this study, we examined the effects of miRNA-124(miR-124) overexpression in bone marrow-derived mesenchymal stem cells. In particular, we focused on the effect of overexpression on the differentiation of bone marrow-derived mesenchymal stem cells into neurons. First, we used GeneChip technology to analyze the expression of miRNAs in bone marrow-derived mesenchymal stem cells, neural stem cells and neurons. miR-124 expression was substantially reduced in bone marrow-derived mesenchymal stem cells compared with the other cell types. We constructed a lentiviral vector overexpressing miR-124 and transfected it into bone marrow-derived mesenchymal stem cells. Intracellular expression levels of the neuronal early markers β-III tubulin and microtubule-associated protein-2 were significantly increased, and apoptosis induced by oxygen and glucose deprivation was reduced in transfected cells. After miR-124-transfected bone marrow-derived mesenchymal stem cells were transplanted into the injured rat spinal cord, a large number of cells positive for the neuronal marker neurofilament-200 were observed in the transplanted region. The Basso-Beattie-Bresnahan locomotion scores showed that the motor function of the hind limb of rats with spinal cord injury was substantially improved. These results suggest that miR-124 plays an important role in the differentiation of bone marrow-derived mesenchymal stem cells into neurons. Our findings should facilitate the development of novel strategies for enhancing the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for spinal cord injury.     

雌二醇联合孕激素对卵巢癌细胞凋亡及microRNA-15a表达的影响

目的 探讨雌二醇（E2）联合孕激素（P4）对microRNA-15a （miR-15a）表达的影响。方法 采集手术中切除的卵巢癌组织标本进行细胞培养,分3个处理组：E2组,P4组和雌二醇联合孕激素（E2+P4）组。激素处理后,MTT法检测细胞存活率;流式细胞技术检测细胞凋亡与细胞周期;qRT-PCR法检测Bcl-2,Bax和miR-15a的相对表达量。结果 高浓度（浓度均为10^-4 mol·L^-1）的E2,P4,E2+P4能够降低卵巢癌细胞的存活率,并表现为时间依赖性;低浓度（≤ 10^-8 mol·L^-1） E2能够提高卵巢癌细胞的存活率。与对照组相比,高浓度E2,P4和E2+P4能够增加卵巢癌细胞的凋亡率（P<0.001）,并且E2+P4的作用最明显;低浓度E2能够抑制肿瘤细胞的凋亡（P<0.001）。E2,P4和E2+P4对细胞周期的影响没有统计学差异。高浓度的E2,P4和E2+P4能够下调Bcl-2的表达（P<0.05或P<0.001）,上调Bax的表达（P<0.001）;但是低浓度E2作用却相反。高浓度的E2+P4能够促进miR-15a的表达（P<0.001）。结论 高浓度的E2,P4和E2+P4能够降低细胞的存活率促进细胞凋亡,下调Bcl-2的表达,上调Bax的表达;低浓度E2的作用则相反;高浓度的E2+P4能够促进miR-15a的表达。     

Inhibition of microRNA-17-5p reduces the inflammation and lipid accumulation,and up-regulates ATP-binding cassette transporterA1 in atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease of the arterial wall. Macrophages are considered to be closely associated with the development and progression of AS. However, the precise mechanism of miR-17-5p in the macrophages under AS remains incompletely clarified. This study investigated the regulatory effect of miR-17-5p on the inflammation and lipid accumulation in mouse macrophages both in vivo and in vitro. It was found that miR-17-5p was highly expressed with lowered ATP-binding cassette transporterA1 (ABCA1) level in the peripheral blood leucocytes (PBLs) of AS patients. Moreover, the level of miR-17-5p was up-regulated in the macrophages of ApoE^?/? mice fed with a high-cholesterol diet. Furthermore, we injected miR-17-5p antagomir into AS mice or transfected miR-17-5p inhibitors into mouse macrophage RAW264.7 cells. Results showed that downregulation of miR-17-5p significantly reduced the production of inflammatory cytokines, inhibited the lipid accumulation and up-regulated ABCA1, and activated peroxisome proliferator-activated receptor (PPAR) γ/Liver X receptor (LXR) α signaling pathway. Additionally, ABCA1 was found to be a target of miR-17-5p by directly binding to 3′-untranslated region (3′-UTR) of its mRNA. Our study indicates a novel regulatory mechanism for miR-17-5p by interacting with ABCA1, which could be a therapy-target for the treatment of AS.