胃癌组织TGF-β对miR-200c/141表达影响的研究

目的 TGF-β能够诱导肿瘤细胞发生上皮间质转化,促进肿瘤发生侵袭转移.miR-200c/141能够抑制上皮间质转化的发生.但TGF-β在胃癌中的表达情况及其对miR-200c/141表达影响尚不清楚.本研究旨在探讨胃癌组织中TGF-β表达水平与胃癌患者临床病理特征的关系,及对miR-200c和miR-141表达影响.方法 收集河北医科大学第四医院普外科2012-05-01-2013-01-01胃癌根治性手术切除标本64例,采用qRT-PCR技术检测TGF-β、miR-200c及miR-141在胃癌组织和配对癌旁非癌组织中的表达.分析TGF-β表达水平与胃癌患者临床病理特征的关系及与miR-200c和miR-141水平的相关性.TGF-β处理胃癌细胞株SGC-7901,观察其对miR-200c和miR-141表达的影响.结果 TGF-β在胃癌组织中的表达上调率为66.67%,其在胃癌组织中的表达显著高于癌旁非癌组织[Median,Interquartile Range(2.50,2.43:0.84,0.42);P=0.005].miR-200a、miR-200b、miR-429、miR-200c和miR-141在胃癌组织中的表达下调率分别为53.13%、48.44%、50.00%、78.13%和76.19.miR-200c和miR-141在胃癌组织中的表达显著低于癌旁非癌组织,均P<0.001.miR-200c和miR-141的表达存在正相关关系,r=0.840,P<0.001.TGF-β表达水平与miR-200c和miR-141的表达水平呈显著负相关关系,均P<0.001.TGF-β能够诱导胃癌细胞株SGC-7901中miR-200c和miR-141表达显著降低.TGF-β的表达水平与淋巴结转移情况及脉管瘤栓情况存在显著相关性,与患者性别、年龄、组织学分级、TNM分期、肿瘤侵袭深度和肿瘤远处转移情况无相关性,均P>0.05.     

miR-103与胃癌多药耐药作用机制探讨

目的 既往研究肿瘤耐药均集中在DNA水平,而DNA又影响mRNA及蛋白质表达.但是mRNA与编码蛋白质的表达并不成比例,而非编码RNA恰好能解释两者之间的不平衡.非编码RNA即微小RNA(microRNA,miRNA),是一类内源性短链非编码小分子核糖核苷酸,长度约18~25个核糖核苷酸,是转录后基因表达调节的关键分子,参与胃癌的发生发展.本研究旨在探讨miR-103在胃癌多药耐药中作用及其分子机制.方法 miRNA芯片筛选SGC7901/ADR及SGC7901细胞差异表达miRNA,应用qRT-PCR验证miR-103表达;将miR-103的拟似物及抑制物分别转染SGC7901/ADR及SGC7901细胞,MTT法检测转染前后对多柔比星敏感性变化;蛋白质印迹法检测miR-103对caveolin-1表达的影响.结果 miR-103在SGC7901/ADR细胞中表达(0.32±0.04)显著低于SGC7901细胞.miR-103拟似物转染SGC7901/ADR细胞后对多柔比星的敏感性较对照组显著提高,IC50由(18.83±0.32) μg/mL下降到(4.54±0.29) μg/mL,t=1.04,P<0.05;而miR-103抑制物转染SGC7901细胞后对多柔比星的敏感性显著降低,IC50由(1.65±0.03) μg/mL上升到(15.27±0.26) μg/mL,t=1.25,P<0.05.miR-103靶向作用于caveolin-1的3'-UTR,并在转录后水平负向调控caveolin-1表达.结论 miR-103通过靶向负调控caveolin-1表达,增加SGC7901/ADR细胞对多柔比星敏感性,从而逆转胃癌多药耐药.     

miR-206 enhances nasopharyngeal carcinoma radiosensitivity by targeting IGF1

Radioresistance remains a major problem in nasopharyngeal carcinoma (NPC) treatment. However, the underlying molecular mechanisms of NPC radioresistance remain poorly understood. The present study aimed to investigate the potential role and mechanism of miR-206 in NPC radioresistance. We observed that miR-206 was down-regulated in radioresistant NPC cells. Furthermore, restoration of miR-206 in CNE2-IR cells suppressed enhanced radiosensitivity of NPC cells. In contrast, inhibition of miR-206 in CNE2 cells reduced the radiosensitivity. We also found that miR-206 directly targeted IGF1 and inhibited the PI3K/AKT pathway. Our data demonstrate that miR-206 sensitizes NPC cell to irradiation by targeting IGF1, highlighting the therapeutic potential of miR-206 in NPC radiosensitization.     

miR-30c promotes Schwann cell remyelination following peripheral nerve injury

Differential expression of miRNAs occurs in injured proximal nerve stumps and includes miRNAs that are firstly down-regulated and then gradually up-regulated following nerve injury. These miRNAs might be related to a Schwann cell phenotypic switch. miR-30c, as a member of this group, was further investigated in the current study. Sprague-Dawley rats underwent sciatic nerve transection and proximal nerve stumps were collected at 1, 4, 7, 14, 21, and 28 days post injury for analysis. Following sciatic nerve injury, miR-30c was down-regulated, reaching a minimum on day 4, and was then upregulated to normal levels. Schwann cells were isolated from neonatal rat sciatic nerve stumps, then transfected with miR-30c agomir and co-cultured in vitro with dorsal root ganglia. The enhanced expression of miR-30c robustly increased the amount of myelin-associated protein in the co-cultured dorsal root ganglia and Schwann cells. We then modeled sciatic nerve crush injury in vivo in Sprague-Dawley rats and tested the effect of perineural injection of miR-30c agomir on myelin sheath regeneration. Fourteen days after surgery, sciatic nerve stumps were harvested and subjected to immunohistochemistry, western blot analysis, and transmission electron microscopy. The direct injection of miR-30c stimulated the formation of myelin sheath, thus contributing to peripheral nerve regeneration. Overall, our findings indicate that miR-30c can promote Schwann cell myelination fol-lowing peripheral nerve injury. The functional study of miR-30c will benefit the discovery of new therapeutic targets and the development of new treatment strategies for peripheral nerve regeneration.     

Berberine promotes ischemia-induced angiogenesis in mice heart via upregulation of microRNA-29b

Background: Berberine has several preventive effects on cardiovascular diseases. Increased expression of miR-29b has been reported to attenuate cardiac remodeling after myocardial infarction (MI). We hypothesized that berberine via an miR-29b-dependent mechanism promotes angiogenesis and improves heart functions in mice after MI.

Methods: The MI model was established in mice by ligation of left anterior descending coronary artery. The expression of miR-29b was examined by RT-qPCR. Angiogenesis was assessed by immunohistochemistry.

Results: Berberine increased miR-29b expression and promoted cell proliferations and migrations in cultured endothelial cells, which were abolished by miR-29b antagomir or AMP-activated protein kinase inhibitor compound C. In mice following MI, administration of berberine significantly increased miR-29b expressional level, promoted angiogenesis, reduced infarct size, and improved heart functions after 14 postoperative days. Importantly, these in vivo effects of berberine were ablated by antagonism of miR-29b.

Conclusion: Berberine via upregulation of miR-29b promotes ischemia-induced angiogenesis and improves heart functions.     

不明原因复发性流产患者绒毛组织中miR-210表达及其与血管新生因子的关系

目的:探讨不明原因复发性流产(URSA)患者绒毛组织中miR-210表达及其与血管新生因子的关系。方法:选取2014年3月至2016年4月在潍坊市益都中心医院产科行清宫术的URSA患者53例,同期选取正常早孕而终止妊娠的40例患者为对照组。实时荧光定量PCR法检测绒毛组织中miR-210、HIF-1α和VEGF表达,Western blot法检测绒毛组织中HIF-1α和VEGF蛋白表达,免疫组化法检测绒毛组织中MVD。结果:URSA患者绒毛组织中miR-210 mRNA相对表达量均低于对照组,且流产3次者的miR-210 mRNA相对表达量均低于流产≤3次的患者,差异均有统计学意义(P0.05)。URSA患者绒毛组织中HIF-1α和VEGF mRNA和蛋白相对表达量均低于对照组,且URSA患者中流产3次绒毛组织中HIF-1α和VEGF mRNA和蛋白相对表达量均低于流产≤3次的患者,差异均有统计学意义(P0.05)。URSA患者绒毛组织中MVD数(26.8±4.4)个,显著低于对照组的(37.2±5.1)个,差异有统计学意义(t=15.394,P0.001)。Pearson相关分析显示,URSA患者绒毛组织中miR-210与HIF-1α和VEGF表达均呈正相关(r=0.418和0.507,P0.05),与绒毛组织中MVD数呈正相关(r=0.472,P0.05)。结论:miR-210在URSA患者绒毛组织中呈低表达,且与流产次数有关,可能通过与HIF-1α和VEGF相互作用而减少MVD数量,导致URSA发生。     

B and T Lymphocyte Attenuator is a Target of miR-155 during Naive CD4+ T Cell Activation

Background: MicroRNA-155 (miR-155) is upregulated during T cell activation, but the exact mechanisms by which it influences CD4+ T cell activation remain unclear. Objective: To examine whether the B and T lymphocyte attenuator (BTLA) is a target of miR-155 during naïve CD4+ T cell activation. Methods: Firefly luciferase reporter plasmids pEZX-MT01-wild-type-BTLA and pEZX-MT01-mutant-BTLA were constructed. Lymphocytes were nucleofected with miR-155 inhibitor or negative control (NC). Then, naïve CD4+ CD62L+ helper T cells purified from lymphocytes were stimulated with immobilized antibody to CD3 and soluble antibody to CD28. miR-155 and BTLA expression were examined by real-time RT-PCR. Cell surface CD69 expression and IL-2 secretion were measured by ELISA and flowcytometry, respectively. Results: Luciferase reporter assay showed that miR-155 targeted the BTLA 3’UTR region. Compared with non-stimulated condition, both miR-155 and BTLA mRNA expression were upregulated after T cell activation. Similar results were observed for BLTA protein expression. Compared with NC, the miR-155 inhibitor decreased miR-155 by about 45%, but did not influence BTLA mRNA expression. Compared with NC, the miR-155 inhibitor decreased the surface BTLA expression by about 60%. Upregulation of BTLA in miR-155 knockdown CD4+ T cells did not influence the cell surface expression of CD69, an early activation marker (p=0.523). Similarly, IL-2 production was not changed. Conclusion: miR-155 is involved in the inhibition of BTLA during CD4+ T cell activation. These results might serve as a basis for an eventual therapeutic manipulation of this pathway to treat inflammatory and autoimmune diseases.     

miR-422a is an independent prognostic factor and functions as a potential tumor suppressor in colorectal cancer

AIM: To determine the expression of miR-422a in colorectal cancer (CRC) tissues and to further explore the prognostic value and function of miR-422a in CRC carcinogenesis.METHODS: miR-422a expression was analyzed in 102 CRC tissues and paired normal mucosa adjacent to carcinoma by quantitative real-time PCR. The relationship of miR-422a expression with clinicopathological parameters was also analyzed. Kaplan-Meier analysis and Cox multivariate analysis were performed to estimate the potential role of miR-422a. Cell proliferation, migration, and invasion were used for in vitro functional analysis of miR-422a.RESULTS: The levels of miR-422a were dramatically reduced in CRC tissues compared with normal mucosa (P < 0.05), and significantly correlated with local invasion (P = 0.004) and lymph node metastasis (P < 0.001). Kaplan-Meier survival and Cox regression multivariate analyses revealed that miR-422a expression (HR = 0.568, P = 0.015) and clinical TNM stage (HR = 2.942, P = 0.003) were independent prognostic factors for overall survival in CRC patients. Furthermore, in vitro experiments showed that overexpression of miR-422a inhibited the proliferation, migration, and invasion of SW480 and HT-29 cells.CONCLUSION: Down-regulation of miR-422a may serve as an independent prognosis factor in CRC. MiR-422a functions as a tumor suppressor and regulates progression of CRC.