Elastin turnover in malignant solid tumors

Abstract

Desmosine, a crosslinking amino acid unique to elastin, was investigated as a possible biomarker for cancer. Twenty-eight normal controls, median age 67 years, had a median value for urine desmosine of 43.5 picomoles desmosine/mg creatinine. The median for 19 untreated cancer subjects of similar age was significantly higher (175 picomoles desmosine/mg creatinine, p?<?0.001). Urine desmosine levels in 55 subjects currently receiving chemotherapy, as well as 67 individuals who had survived cancer and were currently clinically disease free, were not significantly different from controls. Our findings indicate that elastin is being turned over in malignant solid tumors, releasing significantly elevated levels of desmosine in the urine.     

ROCK介导缓激肽开放SD大鼠血肿瘤屏障

目的利用ROCK的特异性抑制剂Y-27632,研究ROCK是否介导缓激肽开放血肿瘤屏障。方法应用ROCK的特异性抑制剂Y-27632预处理大鼠原代脑微血管内皮细胞后,用缓激肽诱导血肿瘤屏障开放,测量跨内皮阻抗值(TEER),辣根过氧化物酶(HRP)渗漏量,分析血肿瘤屏障的通透性的改变;应用Western-blot法检测紧密连接相关蛋白ZO-1的表达;应用免疫荧光方法观察原代大鼠脑微血管内皮细胞紧密连接相关蛋白ZO-1和丝状肌动蛋白结构和分布的改变。结果 Y-27632显著抑制缓激肽诱导TEER值的降低,HRP的升高;Y-27632显著抑制ZO-1的表达;Y-27632抑制ZO-1由内皮细胞的边缘向细胞质转移,抑制丝状肌动蛋白由细胞膜边缘向细胞中央区分布,应力纤维形成明显减少。结论 ROCK介导缓激肽开放血肿瘤屏障。     

过表达miR-34a增加血肿瘤屏障通透性机制的研究

目的探讨过表达miR-34a增加血肿瘤屏障通透性的机制。方法将miR-34a模拟物转染至培养的人脑微血管内皮细胞NKIM-6,采用实时荧光定量PCR方法检测miR-34a的表达。用miR-34a模拟物转染的NKIM-6细胞和U87胶质瘤细胞建立体外血肿瘤屏障模型,跨内皮电阻测量系统检测血肿瘤屏障跨内皮阻抗值的变化;western blot和免疫荧光法检测体外血肿瘤屏障NKIM-6细胞中,紧密连接相关蛋白ZO-1和claudin-5的表达。结果经miR-34a模拟物转染后,NKIM-6细胞中miR-34a的表达水平显著升高;血肿瘤屏障跨内皮阻抗值显著下降;体外血肿瘤屏障NKIM-6细胞中紧密连接相关蛋白ZO-1和claudin-5的表达水平分别显著降低,在细胞膜上呈不连续分布。结论过表达miR-34a显著增加血肿瘤屏障的通透性,其机制之一可能与降低紧密连接相关蛋白相关。     

RMP7介导血肿瘤屏障通透性增加的机制研究

目的研究miR-200b是否参与RMP7介导的血肿瘤屏障(BTB)通透性增加及可能机制。方法测量跨内皮阻抗值(TEER)、辣根过氧化物酶(HRP)渗漏量,分析血肿瘤屏障的通透性的改变,应用RealTime PCR检测RMP7作用BTB后大鼠脑微血管内皮细胞(ECs)miR-200b的表达,应用miR-200b mimic和miR-200b inhibitor分别转染GECs(ECs和U87脑胶质瘤细胞共培养的细胞)后分析血肿瘤屏障的通透性的改变;应用Western blot检测紧密连接相关蛋白zonula occludens-1(ZO-1)的表达;应用免疫荧光方法观察GECs紧密连接相关蛋白ZO-1和丝状肌动蛋白(F-actin)结构和分布的改变。结果 CRMP7诱导TEER值显著降低,HRP显著升高;RMP7作用GECs后,使GECs内源性miR-200b表达显著降低;miR-200b mimic和miR-200b inhibitor成功转染到GECs中;miR-200b mimic显著抑制RMP7诱导TEER值的降低,HRP的升高,以及ZO-1的表达,抑制ZO-1由内皮细胞的边缘向细胞质转移,抑制丝状肌动蛋白由细胞膜边缘向细胞中央区分布,分布于细胞边缘的F-actin明显增加,应力纤维形成明显减少;miR-200b inhibitor结果与miR-200c mimic实验结果相反。结论 MiR-200b参与RMP-7介导的BTB通透性增加。     

RhoA在内皮-单核细胞激活多肽-Ⅱ增强血肿瘤屏障通透性中的作用

目的探索信号分子RhoA在内皮-单核细胞激活多肽-Ⅱ(endothelial monocyte activating polypeptide-Ⅱ,EMAP-H)增强血肿瘤屏障(blood-tumor barrier,BTB)通透性中的作用。方法采集出生3~5d的Wistar胎鼠的大脑皮质,应用酶消化法及葡聚糖离心法获得脑微血管段后,接种于培养皿中进行脑微血管内皮细胞(brain microvascular endothelial cells,BMECs)原代培养;将BMECs与C6脑胶质瘤细胞共培养,构建体外BTB模型;共培养后的BMECs随机分成3组(每组6例):对照组、EMAP-Ⅱ组和C3 exoenzyme+EMAP-Ⅱ组。测定跨内皮阻抗值和辣根过氧化物酶流量评估各组BTB通透性变化情况;Western blot法检测BMECs上紧密连接相关蛋白ZO-1的表达水平;免疫荧光法检测ZO-1和细胞骨架蛋白F-actin在BMECs上的分布与表达。结果与对照组相比较,EMAP-Ⅱ组BTB通透性显著增高,ZO-1和F-actin在BMECs上的表达水平显著降低,应力纤维形成明显增多;EMAP-Ⅱ的上述作用受到RhoA抑制剂C3 exoenzyme预处理的显著抑制。结论信号分子RhoA在EMAP-Ⅱ增强BTB通透性中发挥着重要的作用。     

Nogo-B受体在恶性实体肿瘤发病中的抑制和促进作用

Nogo-B是网状蛋白家族4的重要成员,广泛表达于中枢神经系统及外周组织。研究显示,Nogo-B能与Nogo受体1（NgR1）、Nogo-B特异性受体（NgBR）和配对免疫球蛋白样受体B（PirB）3种不同的受体结合,受体通过RhoA/Rho相关蛋白激酶（ROCK）、磷脂酰肌醇-3激酶/蛋白激酶B（PI3K/Akt）、磷酸腺苷活化激酶α/肝X受α（AMPAα/LXRα）、细胞外信号调节激酶（ERK）、上皮-间质转化（EMT）以及未折叠蛋白反应（UPR）等多个信号通路,在血管生成、增殖和凋亡以及侵袭和迁移等肿瘤发生和发展过程中发挥抑制和促进的双重作用。了解Nogo-B受体参与肿瘤发病的机制将会为治疗药物的开发提供新的思路。我们将对Nogo-B及其受体的基本结构和表达以及Nogo-B受体信号通路在恶性实体肿瘤发生和发展中的抑制和促进作用等方面的最新研究进展做一简要综述。     

Prognostic impact of lncRNA-ATB expression in malignant solid tumors: A meta-analysis

PurposeNumerous studies have reported the prognostic role of lncRNA-ATB high expression in solid tumours, but its prognostic effect is still uncertain. Therefore, the purpose of this meta-analysis was to further comprehensively verify the prognostic role of the lncRNA-ATB high expression in solid tumours.MethodsA literature search was performed using the electronic platforms to obtain relevant research studies published up to 31 May 2019. Confidence intervals of research endpoints in each study were extracted and merged. All data analysis was performed using Stata12.0 software.ResultsA total of 2120 patients with solid cancers in 14 studies were enrolled in our meta-analysis eventually. The analysis results revealed that high expression of lncRNA-ATB was related to lower OS (HR:1.46, P < 0.001), shorter DFS(HR:1.73, P < 0.001), and earlier RFS (HR:2.67, P < 0.001). Besides, the high expression of lncRNA-ATB has a considerable risk of lymph node metastasis (OR:2.13, P = 0.017)and perineural invasion (OR:1.58, P = 0.018).ConclusionsMeta-analysis showed that the high lncRNA-ATB expression was a poor prognostic marker in multiple cancer types. The high expression of lncRNA-ATB symbolizes the high risk of lymph node metastasis and perineural invasion in cancer patients.     

Effect of intracarotid infusion of etoposide: modification of the permeability of the blood-brain barrier and the blood-tumor barrier in rat brain tumor model

The effect of intracarotid infusion of etoposide on the permeability of the blood-brain barrier (BBB) and brain-tumor barrier (BTB) was investigated using a model of rats injected with C6 glioma cells. Fifty four glioma-bearing rats were divided into 3 groups and treated with 0, 3, or 15 mg/kg of etoposide infused into the internal carotid artery. BBB or BTB permeability was evaluated qualitatively by the leakage of Evans blue (6 animals in each group) or quantitatively by the diffusion of carboplatin [cis-diammine (1,1-cyclobutane-dicarboxylato) platinum(II); CBDCA] (12 animals in each group) into the normal brain or the tumor tissue. BBB and BTB disruption augmented significantly in proportion to the dose of etoposide. The degree of disruption of BTB was greater than that of BBB, but the rate of disruption of BBB in proportion to increasing the dose of etoposide was higher than that in the BTB. Histopathologically, no obvious changes were observed in the animals of either the control group or the 3 mg/kg group but degenerative changes in the neurons of the hippocampus of the infused hemisphere were seen in the 15 mg/kg group. This change is thought to be caused by apoptosis because of the positive reaction with TdT-mediated dUTP-biotin nick-end labeling (TUNEL) method. Our results suggest that intracarotid infusion of etoposide can increase drug delivery of concurrent antitumor agents into tumor tissue, but cerebral parenchymal cell damage is expected with a higher dosage of etoposide. Therefore, the dosage of etoposide for intracarotid infusion should be lower than 15 mg/kg in order to reduce neurotoxicity of both etoposide and concurrent anticancer drugs.     

A simple method of chromosomal analysis for malignant solid tumors.

A case of essential thrombocythemia with a partial deletion of the long arm of chromosome 11, del(11)(q21) as a sole chromosomal anomaly is reported. Rearrangement of chromosome 11 at band 11q21 has been reported in six patients with chronic myeloproliferative disorders: four with post-polycythemic myelofibrosis, one with myelofibrosis with myeloid metaplasia, and one with Ph+ chronic myeloid leukemia in blastic phase. Except for the last patient, all patients had been treated with 32P and/or an alkylating agent prior to cytogenetic examination. This is the first report of the 11q21 abnormality in essential thrombocythemia seen at diagnosis.     

地塞米松预处理对氧糖剥夺大鼠血脑屏障通透性的影响

目的探讨地塞米松(dexamethasone,DEX)对氧糖剥夺(oxygen glucose deprivation,OGD)条件下大鼠血脑屏障通透性的影响。方法提取纯化大鼠脑微血管内皮细胞,建立血脑屏障OGD模型。在OGD不同时间点(0、30、60 min),以及DEX预处理OGD 60min时,应用辣根过氧化物酶渗漏实验分析血脑屏障的通透性;应用RT-PCR和western blot法分析大鼠脑微血管内皮细胞的紧密连接相关蛋白claudin-5的mRNA和蛋白的表达变化;同时应用免疫荧光方法观察细胞膜上claudin-5的变化。结果与对照组相比,OGD 30、60min,辣根过氧化物酶流量均显著升高;与OGD 60min相比,DEX预处理显著降低了辣根过氧化物酶流量。与对照组相比,OGD30、60min,claudin-5的mRNA和蛋白表达水平均显著降低;与OGD 60min相比,DEX预处理显著增加了claudin-5的mRNA和蛋白表达。免疫荧光观察claudin-5在细胞膜上的表达,与对照组相比,OGD 60min时claudin-5的表达明显减少,DEX预处理后显著增加了claudin-5的表达。结论 DEX预处理降低了OGD条件下的血脑屏障通透性,其机制之一是DEX增加紧密连接相关蛋白claudin-5的表达。     

Age variation in the upper limit of hearing

Summary The upper limit of hearing was measured in 6105 otologically normal ears of subjects ranging in age from 5 to 89 years. The results are as follows: in each age group from 5 to 59 years in both sexes, the upper limit of hearing showed an approximately normal distribution if a logarithmic scale was used for the upper limit of hearing axis. The mode of the distribution shifted to a lower frequency with increasing age. Over age 60 years, the distribution became much wider. Standard upper limit age curves were established by calculating 10th, 25th, 50th, 75th and 90th percentiles for each age group. From early childhood where no age variation was recognized in conventional audiometry, deterioration of the upper limit of hearing was already in progress. This deterioration was slight between ages 25 and 39 but at ages over 40 it was accelerated and led to so-called presbycousis. The upper limit of hearing was found to be one of the best parameters for showing the quantitative age-related changes in hearing.     

Increasing the pore size of electrospun scaffolds

Electrospinning has gained much attention in the past decade as an effective means of generating nano- to micro-scale polymer fibers that resemble native extracellular matrix. High porosity, pore interconnectivity, and large surface area to volume ratio of electrospun scaffolds make them highly conducive to cellular adhesion and growth. However, inherently small pores of electrospun scaffolds do not promote adequate cellular infiltration and tissue ingrowth. Cellular infiltration into the scaffold is essential for a range of tissue engineering applications and is particularly important in skin and musculoskeletal engineering. Pore size, porosity, and pore interconnectivity dictate the extent of cellular infiltration and tissue ingrowth into the scaffold; influence a range of cellular processes; and are crucial for diffusion of nutrients, metabolites, and waste products. A number of electrospinning techniques and postelectrospinning modifications have, therefore, been developed in order to increase the pore size of electrospun scaffolds. Diverse techniques ranging from simple variations in the electrospinning parameters to complex methodologies requiring highly specialized equipment have been explored and are described in this article.     

Magnification of the pore size in biodegradable collagen sponges

In tissue engineering cells are often combined with a carrying structure with collagen being a suitable material to form a 3D-scaffold. A process to manufacture collagen sponges with an adjustable and homogeneous structure has been developed at the Helmholtz-Institute. Using this process, collagen suspensions are frozen directionally and subsequently vacuum-dried. One clinical application in which these scaffolds can be used is soft tissue reconstruction. Various soft tissue defects require an adequate replacement, e.g. in the case of severe burn wounds, or after tumour resections. Collagen (type I) sponges, which are cultured with preadipocytes, may be used to regenerate such defects. In this case, pore sizes of approximately 100 microm are desired to allow a complete differentiation of preadipocytes into adipocytes. Based on known technology to manufacture collagen sponges with an adjustable and homogeneous pore structure, research on the increase of pore size beyond the previous limit of 40 microm was necessary in order to enable soft tissue replacement. A scaffold with an average pore size of 100 microm was obtained.     

Angiogenesis in malignant tumors

Angiogenesis is the formation of new blood vessels from the existing vascular network. It is a complex, multi-step process involving extracellular matrix remodeling, endothelial cell migration and proliferation, capillary differentiation, and anastomoses. Angiogenesis is crucial for tumor progression and metastasizing. Intratumor microvessel density is believed to reflect the degree of angiogenesis in carcinomas. Angiogenesis is also very important in many preneoplastic lesions.