miR-491-5p靶向FGFR4调节肝母细胞瘤细胞增殖和迁移

目的 探讨miR-491-5p靶向调节FGFR4对肝母细胞瘤增殖和迁移的影响及可能的作用机制。方法 采用qRT-PCR检测15例小儿肝母细胞瘤组织及其癌旁正常组织,正常肝细胞LO2和肝母细胞瘤细胞HuH-6中miR-491-5p和FGFR4 mRNA的表达;Western blot检测FGFR4蛋白表达;TargetScan数据库预测miR-491-5p靶点;双荧光素酶报告基因实验检测miR-491-5p与FGFR4的靶向关系。将mimic NC、miR-491-5p mimic、pcDNA3.1和pcDNA3.1-FGFR4质粒分别转染至HuH-6细胞后,采用qRT-PCR与Western blot检测FGFR4的表达,CCK-8实验检测细胞增殖能力,Transwell小室实验检测细胞迁移能力,Western blot检测GSK3β/β-catenin信号通路相关蛋白的表达。结果 小儿肝母细胞瘤组织和HuH-6细胞中miR-491-5p表达水平均低于癌旁正常组织及肝细胞LO2（P<0.05）,而FGFR4表达水平高于癌旁正常组织及肝细胞LO2（P<0.05）;TargetScan数据库预测显示miR-491-5p与FGFR4存在结合位点。与mimic NC组比较,过表达miR-491-5p可抑制FGFR4表达、HuH-6细胞增殖和迁移能力及p-GSK3β/GSK3β、p-β-catenin/β-catenin及p-C-myc/C-myc比值（均P<0.05）。与mimic+Pc组比较,过表达FGFR4可逆转过表达miR-491-5p对HuH-6细胞增殖、迁移及p-GSK3β/GSK3β、p-β-catenin/β-catenin和p-C-myc/C-myc比值的抑制作用（均P<0.05）。结论 miR-491-5p通过负向调控FGFR4抑制肝母细胞瘤细胞增殖和迁移,可能与GSK3β/β-catenin信号通路失活有关。       

食管鳞癌中LncRNA DLEU1的表达及对食管鳞癌细胞增殖和迁移的影响

目的研究长链非编码RNA淋巴细胞白血病缺失基因1(DLEU1)在食管鳞状细胞癌(ESCC)组织中的表达,及其对肿瘤细胞增殖和迁移的影响。方法收集58例手术切除的ESCC及其相应癌旁组织,RT-qPCR检测ESCC组织和细胞中DLEU1的表达水平。Log rank Test法分析ESCC组织中DLEU1的表达与患者临床病理特征的关系。Kaplan-Meier法分析DLEU1表达与ESCC患者生存的相关性。多变量Cox回归模型评估DLEU1对ESCC患者预后的影响。采用CCK-8和划痕愈合实验检测DLEU1对Eca9706细胞增殖和迁移的影响。结果ESCC组织中DLEU1高表达(P<0.01),其高表达与ESCC患者肿瘤大小、TNM分期和淋巴结转移呈显著相关性(均P<0.05)。DLEU1高表达与ESCC患者预后不良呈负相关(P<0.01),且是影响ESCC患者预后的独立危险因素(P<0.05)。与对照组相比,体外敲低DLEU1的表达可显著抑制Eca9706细胞的增殖和迁移能力(P<0.01)。结论DLEU1在ESCC组织中高表达,是影响ESCC患者预后的独立危险因素,且具有促进肿瘤细胞增殖和迁移的能力。     

Provider’s and User’s Perspective about Immunization Coverage among Migratory and Non-migratory Population in Slums and Construction Sites of Chandigarh

Strengthening routine immunization is a corner stone for countries to achieve the United Nations Millennium Development Goal 4 (MDG 4) which aims to reduce under-five mortality by two-thirds and MDG 5 improving maternal health compared to 1990 estimates by 2015. The poor urban newborns are more vulnerable to many health and nutrition problems compared to the non-poor urban counterparts. Therefore there is a need to strengthen health system to cater the needs of urban poor. Standardized WHO30*7 cluster sampling for slums and convenience sampling for construction sites. In depth interviews were conducted for user’s as well as provider’s perspective about immunization coverage. Two hundred ten children and 210 mothers were enrolled in slums and 100 were sampled from construction sites. The slum workers are considered as non-migratory groups whereas construction site workers are considered as migratory population. Among children, 23 % were fully immunized, 73 % were partially immunized and 3 % were unimmunized in non-migratory population whereas 3 % were fully immunized, 91 % were partially immunized and 6 % were unimmunized in migratory population. Among mothers, 43 and 39 % were fully immunized, 13 and 15 % partially immunized and 43 and 46 % were unimmunized in non-migratory and migratory population, respectively. The various reasons attributed for low coverage are (a) dissatisfaction of the users with the service delivery and procedural delays (bureaucracy), (b) lack of faith in health workers, (c) insistence upon ID/vaccination card/aadhar card by the health worker before vaccinating child and (d) ignorance of the need of immunization by the people and migration of the population.     

Conceptualizing the impacts of dual practice on the retention of public sector specialists - evidence from South Africa

Background

‘Dual practice’, or multiple job holding, generally involves public sector-based health workers taking additional work in the private sector. This form of the practice is purported to help retain public health care workers in low and middle-income countries’ public sectors through additional wage incentives. There has been little conceptual or empirical development of the relationship between dual practice and retention.

Methods

This article helps begin to fill this gap, drawing on empirical evidence from a qualitative study focusing on South African specialists. Fifty-one repeat, in-depth interviews were carried out with 28 doctors (predominantly specialists) with more than one job, in one public and one private urban hospital.

Results

Findings suggest dual practice can impact both positively and negatively on specialists’ intention to stay in the public sector. This is through multiple conceptual channels including those previously identified in the literature such as dual practice acting as a ‘stepping stone’ to private practice by reducing migration costs. Dual practice can also lead specialists to re-evaluate how they compare public and private jobs, and to overworking which can expedite decisions on whether to stay in the public sector or leave. Numerous respondents undertook dual practice without official permission.

Conclusions

The idea that dual practice helps retain public specialists in South Africa may be overstated. Yet banning the practice may be ineffective, given many undertake it without permission in any case. Regulation should be better enforced to ensure dual practice is not abused. The conceptual framework developed in this article could form a basis for further qualitative and quantitative inquiry.

Electronic supplementary material

The online version of this article (doi:10.1186/1478-4491-13-3) contains supplementary material, which is available to authorized users.     

Receptor protein tyrosine phosphatase beta/zeta is a functional binding partner for vascular endothelial growth factor

Background

Receptor protein tyrosine phosphatase beta/zeta (RPTPβ/ζ) is a chondroitin sulphate (CS) transmembrane protein tyrosine phosphatase and is a receptor for pleiotrophin (PTN). RPTPβ/ζ interacts with α_νβ₃ on the cell surface and upon binding of PTN leads to c-Src dephosphorylation at Tyr530, β₃ Tyr773 phosphorylation, cell surface nucleolin (NCL) localization and stimulation of cell migration. c-Src-mediated β₃ Tyr773 phosphorylation is also observed after vascular endothelial growth factor 165 (VEGF₁₆₅) stimulation of endothelial cells and is essential for VEGF receptor type 2 (VEGFR2) - α_νβ₃ integrin association and subsequent signaling. In the present work, we studied whether RPTPβ/ζ mediates angiogenic actions of VEGF.

Methods

Human umbilical vein endothelial, human glioma U87MG and stably transfected Chinese hamster ovary cells expressing different β₃ subunits were used. Protein-protein interactions were studied by a combination of immunoprecipitation/Western blot, immunofluorescence and proximity ligation assays, properly quantified as needed. RPTPβ/ζ expression was down-regulated using small interference RNA technology. Migration assays were performed in 24-well microchemotaxis chambers, using uncoated polycarbonate membranes with 8 μm pores.

Results

RPTPβ/ζ mediates VEGF₁₆₅-induced c-Src-dependent β₃ Tyr773 phosphorylation, which is required for VEGFR2-α_νβ₃ interaction and the downstream activation of phosphatidylinositol 3-kinase (PI3K) and cell surface NCL localization. RPTPβ/ζ directly interacts with VEGF₁₆₅, and this interaction is not affected by bevacizumab, while it is interrupted by both CS-E and PTN. Down-regulation of RPTPβ/ζ by siRNA or administration of exogenous CS-E abolishes VEGF₁₆₅-induced endothelial cell migration, while PTN inhibits the migratory effect of VEGF₁₆₅ to the levels of its own effect.

Conclusions

These data identify RPTPβ/ζ as a cell membrane binding partner for VEGF that regulates angiogenic functions of endothelial cells and suggest that it warrants further validation as a potential target for development of additive or alternative anti-VEGF therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0287-3) contains supplementary material, which is available to authorized users.     

Myricetin inhibits advanced glycation end product (AGE)-induced migration of retinal pericytes through phosphorylation of ERK1/2, FAK-1, and paxillin in vitro and in vivo

Advanced glycation end products (AGE) have been implicated in the development of diabetic retinopathy. Characterization of the early stages of diabetic retinopathy is retinal pericytes loss, which is the result of pericytes migration. In this study, we investigated the pathological mechanisms of AGE on the migration of retinal pericytes and confirmed the inhibitory effect of myricetin on migration in vitro and in vivo. Migration assays of bovine retinal pericytes (BRP) were induced using AGE-BSA and phosphorylation of Src, ERK1/2, focal adhesion kinase (FAK-1) and paxillin were determined using immunoblot analysis. Sprague-Dawley rats (6 weeks old) were injected intravitreally with AGE-BSA and morphological and immunohistochemical analysis of p-FAK-1 and p-paxillin were performed in the rat retina. Immunoblot analysis and siRNA transfection were used to study the molecular mechanism of myricetin on BRP migration. AGE-BSA increased BRP migration in a dose-dependent manner via receptor for AGEs (RAGE)-dependent activation of the Src kinase-ERK1/2 pathway. AGE-BSA-induced migration was inhibited by an ERK1/2 specific inhibitor (PD98059), but not by p38 and Jun N-terminal kinase inhibitors. AGE-BSA increased FAK-1 and paxillin phosphorylation in a dose- and time-dependent manner. These increases were attenuated by PD98059 and ERK1/2 siRNA. Phosphorylation of FAK-1 and paxillin was increased in response to AGE-BSA-induced migration of rat retinal pericytes. Myricetin strongly inhibited ERK1/2 phosphorylation and significantly suppressed pericytes migration in AGE-BSA-injected rats. Our results demonstrate that AGE-BSA participated in the pathophysiology of retinal pericytes migration likely through the RAGE-Src-ERK1/2-FAK-1-paxillin signaling pathway. Furthermore, myricetin suppressed phosphorylation of ERK 1/2-FAK-1-paxillin and inhibited pericytes migration.     

三氧化二砷诱导胰腺癌细胞系PC-3凋亡及其抑制转移的作用

目的:探讨三氧化二砷(亚砷酸,As2O3)注射液诱导人类胰腺癌细胞凋亡及其抑制转移的作用机制.方法:用AS2O3处理人胰腺癌细胞株PC-3,通过流式细胞仪观察细胞的凋亡率及生长周期的变化;用免疫组织化学的方法,检测凋亡相关基因蛋白Fas,Fas-L,Bc1-2和Bax及转移相关基因蛋白CD44和nm23表达的变化.结果:流式细胞仪检测显示明显的凋亡峰出现,并使细胞周期主要被阻滞在S期(14.9%-63.7%);免疫组化结果显示,Bc1-2( ～ ),CD44( ～ )基因的表达下调,Fas( ～ )、Fas-L(-～ )及nm23( ～ )基因的表达上调.结论:As2O3注射液可诱导人类胰腺癌细胞株PC-3凋亡并具有抑制转移作用,这可能与调节Bc1-2,Fas,Fas-L及CD44,nm23蛋白的表达有关.     

Effect of RAGE and its ligands on CD4+ T cells北大核心CSCD

RAGE (receptor for advanced glycation end products) is a multiligand receptor on the cell surface. Ligand-RAGE interactions activate several signal transduction pathways that propagate cellular oxidative stress and inflammatory response. RAGE expressed on the CD4+ T cells has been identified as a central transduction receptor which affects the activation, proliferation, migration and differentiation of the cells. In addition, blockade of RAGE suppressed the development of multiple immune-related disorders mediated by CD4+ T cells. These studies highlight the importance of RAGE and its ligands for CD4+ T cells. This article briefly reviews the role of RAGE and its ligands on the proliferation, migration and differentiation of CD4+ T cells and summarizes the related research progress.     

Gastric cancer-derived mesenchymal stem cells prompt gastric cancer progression through secretion of interleukin-8

Background

Bone marrow mesenchymal stem cells (BM-MSCs) have been identified to be closely associated with tumor growth and progression. However, the roles of tumor-resident MSCs in cancer have not been thoroughly clarified. This study was to investigate the regulating effect of gastric cancer-derived MSCs (GC-MSCs) on gastric cancer and elucidate the underlying mechanism.

Methods

GC-MSCs were isolated from primary human gastric cancer tissues and characterized. The effect of GC-MSCs on gastric cancer cell proliferation was analyzed by MTT assay and colony formation assay. Transwell migration assay was performed to evaluate the influence of GC-MSCs in gastric cancer cell migration. The regulating effects of interactions between gastric cancer cells and GC-MSCs on their pro-angiogenic abilities were analyzed in a co-culture system, with the expression, and secretion of pro-angiogenic factors detected by RT-PCR and Luminex assay. Tube formation assay was used to further validate the angiogenic capability of gastric cancer cells or GC-MSCs. Cytokine profiles in the supernatant of GC-MSCs were screened by Luminex assay and neutralizing antibody was used to identify the key effective cytokines. The activations of Akt and Erk1/2 in gastric caner cells were detected by Western blot.

Results

GC-MSC treatment enhanced the proliferation and migration of BGC-823 and MKN-28 cells, which was more potently than MSCs from adjacent non-cancerous tissues (GCN-MSCs) or bone marrow (BM-MSCs). Higher expression levels of pro-angiogenic factors were detected in GC-MSCs than GCN-MSCs or BM-MSCs. After 10 % GC-MSC-CM treatment, BGC-823, and MKN-28 cells expressed increased levels of pro-angiogenic factors and facilitated tube formation more potently than cancer cells alone. Furthermore, GC-MSCs produced an extremely higher level of interleukin-8 (IL-8) than GCN-MSCs or BM-MSCs. Blockade of IL-8 by neutralizing antibody significantly attenuated the tumor-promoting effect of GC-MSCs. In addition, 10 % CM of IL-8-secreted GC-MSCs induced the activations of Akt or Erk1/2 pathway in BGC-823 and MKN-28 cells.

Conclusion

Tumor-resident GC-MSCs promote gastric cancer growth and progression more efficiently than GCN-MSCs or BM-MSCs through a considerable secretion of IL-8, which could be a possible target for gastric cancer therapy.     

行为学训练对大鼠海马梗死后齿状回区神经干细胞迁移能力的影响

目的 研究行为学训练对大鼠海马梗死后齿状回区多聚唾液酸神经细胞黏附分子（PSA-NCAM）表达及对神经干细胞迁移能力的影响。方法 将68只SD大鼠随机分为训练组（32只）、制动组（32只）及正常对照组（4只）。采用光化学法将训练组及制动组大鼠制成单侧海马区梗死模型，训练组大鼠于造模1 d后给予水迷宫训练，制动组大鼠于造模1 d后给予制动处理，观察各组大鼠海马齿状回区及梗死灶周围PSA-NCAM在不同时间点（实验后3，7，14，21，28，35，42及49 d）的表达情况。结果 正常对照组大鼠海马齿状回区PSA-NCAM有一定程度表达；与正常对照组比较，训练组在3，7，21及28 d时及制动组在14 d时其梗死侧齿状回区PSA-NCAM表达均有显著增高（P〈0．05）；而且训练组大鼠3，7，21及28 d时的PSA-NCAM表达显著高于制动组（P〈0．05）。训练组梗死灶对侧齿状回区PSA-NCAM表达在28 d及35 d时均明显高于正常对照组（P〈0．05），并且在第28天时也明显高于同期制动组（P〈0．01）。制动组及训练组大鼠脑梗死灶周边区均未见PSA-NCAM表达。结论 行为学训练能显著增强PSA-NCAM在脑梗死大鼠海马齿状回区的表达，而且还可增强神经干细胞的迁移能力，促进神经功能恢复。