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31.
目的:探讨辐射对豚鼠鼻黏膜结构及微血管的损伤。方法:选择健康豚鼠84只,随机分为对照组(12只)及照射组(72只)。均在同样条件下喂养。将照射组豚鼠置于直线加速器射线内照射,每周1次,每次照射5Gy,计3周,总剂量15Gy,建立辐射损伤动物模型。分别于照射后0.5、1.0、2.0、3.0、5.0、6.0个月处死动物12只,随机取6只做鼻腔黏膜微血管铸型,另6只做病理检查。对照组在假照射后6个月处死动物,随机各选6只分别做鼻黏膜微血管铸型检查和病理检查。结果:照射组豚鼠的鼻黏膜辐射后早期表现为急性炎症反应,黏膜大量坏死、脱落,电镜下见仅少部分黏膜表面还被覆着正常的纤毛结构。以后黏膜开始修复,至6个月时基本结束,但大部分黏膜失去了正常的纤毛柱状上皮结构特点,部分区域甚至代为组织转化的鳞状上皮;微血管铸型可见,早期改变为毛细血管扩张充血及血管内皮细胞肿胀,以后逐渐出现毛细血管的扭曲变形、闭塞及中断,毛细血管数量大量减少,致血液回流障碍,微静脉萎瘪。后期部分区域出现新生的毛细血管,但结构紊乱,不具备微循环的功能。结论:鼻黏膜的损伤、晚期的鳞状上皮组织转化以及鼻黏膜微循环的破坏是放疗后鼻腔功能障碍的病理学基础。  相似文献   
32.
Matrix Metalloproteinases in Breast Cancer   总被引:1,自引:0,他引:1  
Abstract: Matrix metalloproteinases (MMPs) represent a class of enzymes able to degrade numerous extracellular matrix macromolecules facilitating tumor invasion and metastasis. The principal MMPs involved in breast pathology are analyzed with their various roles and functions: gelatinases A and B, stromelysin-3, collagenase-3, and MT-MMP1 (membrane type MMP). In vivo and in vitro studies clearly demonstrate an important cooperation between tumor and stromal cells for the expression of these MMPs in breast carcinomas. The large expression of MMPs plead in favor of a major role of these enzymes in breast carcinoma progression and their detection may be used in some cases as a prognostic indicator. Studies now are in progress, directed toward the modulation of these MMPs and their inhibitors with new therapeutic agents to block tumoral invasion and metastasis due to these enzymes.?  相似文献   
33.
目的:联合临床检验指标及影像学特征构建一种能够术前识别胃癌浆膜浸润的模型。方法:选取2015年1月至2019年12月温州医科大学附属第一医院经病理证实的656例胃癌患者,采用随机数字表法分为建模组(394例)和验证组(262例)。收集建模组患者的脾脏影像学资料,对收集的数据进行套索回归并选取差异有统计学意义的特征来构建浆膜浸润预测模型。在最大约登指数下取肿瘤浸润风险评分截断值将患者分为高危组(238例)和低危组(418例),然后与其他浸润相关因素如BMI、年龄、性别、高血压、糖尿病等进行单变量和多变量Logistic回归分析,结合显著的独立影响因素共同建立可视化的浆膜浸润预测列线图。结果:将患者以肿瘤浸润评分≤-0.335分为低危组,>-0.335为高危组,经验证组验证,建模组和验证组的诊断准确性较为一致(P<0.001)。经浸润影响因素的单变量和多变量Logistic回归分析发现,影像组学肿瘤浸润评分(OR=2.9,95%CI=2.1~4.2,P<0.001)、术前低白蛋白(OR=1.3,95%CI=1.2~3.1,P=0.003)、血小板与淋巴细胞比值(OR=1.8,95%CI=1.2~2.7,P=0.004)、肿瘤分化程度(OR=2.6,95%CI= 1.8~3.7,P<0.001)是浆膜浸润的独立影响因素。基于这4个指标建立的预测模型能够较为准确地预测浆膜浸润风险,其AUC值为0.733。结论:基于脾脏影像的肿瘤浸润评分联合其他临床因素可准确预测胃癌浆膜浸润与否,提高诊断精度。  相似文献   
34.
目的探讨沉默环状RNA hsa_circ_0124696(circROBO1)对鼻咽癌CNE2细胞侵袭与肺转移的影响机制。 方法qRT-PCR检测鼻咽癌及癌旁组织中circROBO1表达。采用干扰小RNA(siRNA)沉默鼻咽癌CNE2细胞中circROBO1的表达,Transwell及HE染色检测circROBO1对CNE2细胞迁移能力和体内肺转移的影响。TargetScan在线软件预测circROBO1下游miR-217与下游靶基因KRAS的靶向结合位点,双荧光素酶报告基因实验验证两者之间的靶向调控关系。蛋白免疫印迹检测siRNA沉默CNE2细胞中circROBO1表达对KRAS的影响。 结果鼻咽癌组织中circROBO1表达高于癌旁组织(P<0.05)。与转染si-circNC的对照组相比,si-circROBO1组鼻咽癌CNE2细胞侵袭与体内肺转移能力均显著降低(P<0.05)。circROBO1下游miR-217与KRAS之间存在靶向结合位点,并且circROBO1可影响KRAS的蛋白和mRNA表达量。 结论沉默circROBO1通过miR-217下调KRAS抑制鼻咽癌CNE2细胞侵袭与肺转移。  相似文献   
35.
Epithelial junctions play crucial roles during metazoan evolution and development by facilitating tissue formation, maintenance, and function. Little is known about the role of distinct types of junctions in controlling epithelial transformations leading to invasion of neighboring tissues. Discovering the key junction complexes that control these processes and how they function may also provide mechanistic insight into carcinoma cell invasion. Here, using the Drosophila ovary as a model, we show that four proteins of the basolateral junction (BLJ), Fasciclin-2, Neuroglian, Discs-large, and Lethal-giant-larvae, but not proteins of other epithelial junctions, directly suppress epithelial tumorigenesis and invasion. Remarkably, the expression pattern of Fasciclin-2 predicts which cells will invade. We compared the apicobasal polarity of BLJ tumor cells to border cells (BCs), an epithelium-derived cluster that normally migrates during mid-oogenesis. Both tumor cells and BCs differentiate a lateralized membrane pattern that is necessary but not sufficient for invasion. Independent of lateralization, derepression of motility pathways is also necessary, as indicated by a strong linear correlation between faster BC migration and an increased incidence of tumor invasion. However, without membrane lateralization, derepression of motility pathways is also not sufficient for invasion. Our results demonstrate that spatiotemporal patterns of basolateral junction activity directly suppress epithelial invasion by organizing the cooperative activity of distinct polarity and motility pathways.  相似文献   
36.
37.
The omptins are a family of enterobacterial surface proteases/adhesins that share high sequence identity and a conserved beta-barrel fold in the outer membrane. The omptins are multifunctional, and the individual omptins exhibit differing virulence-associated functions. The Pla plasminogen activator of Yersinia pestis contributes by several mechanisms to bacterial invasiveness and the systemic, uncontrolled proteolysis in plague. Pla proteolytically activates the human proenzyme plasminogen and inactivates the antiprotease alpha2-antiplasmin, and its binding to laminin localizes the uncontrolled plasmin activity onto basement membranes. These properties enhance bacterial migration through tissue barriers. Pla also degrades circulating complement proteins and functions in bacterial invasion into human epithelial cells. PgtE of Salmonella enterica and OmpT of Escherichia coli have been shown to degrade cationic antimicrobial peptides from epithelial cells or macrophages. PgtE and SopA of Shigella flexneri appear important in the intracellular phases of salmonellosis and shigellosis, whereas functions of OmpT have mainly been associated with protein degradation in E. coli cells. The differing virulence roles and functions have been attributed to minor sequence variations at the surface-exposed regions important for substrate recognition, to the dependence of omptin functions on lipopolysaccharide, and to the different regulation of omptin expression.  相似文献   
38.
This study examined the behaviour of nine human malignant oral keratinocyte cell lines following orthotopic transplantation to the floor of the mouth of athymic mice. Tumourigenesis, local spread, and metastatic dissemination were correlated with known cellular responses to transforming growth factor-beta 1 (TGF-beta 1). Six of nine cell lines were tumourigenic; four of these cell lines showed local spread which was characterized by vascular and bone invasion. Metastatic spread was uncommon, with only 9% of animals with primary tumours developing metastases and these were almost exclusively found in the regional lymph nodes; there was one pulmonary metastasis and no liver deposits. Tumour cell behaviour did not reflect the clinical stage of the original tumours. Cell lines that were resistant to TGF-beta 1-induced growth inhibition were more likely to form primary tumours, exhibit local spread, and metastasize than cells that were growth-inhibited by the ligand. The data demonstrate that tumourigenicity and tumour behaviour in this orthotopic mouse model varied between cell lines and that the pattern of local invasion and metastasis was similar to that seen in human oral cancer. Furthermore, cell lines that were refractory to the growth inhibitory effects of TGF-beta 1 behaved more aggressively than cells that underwent ligand-induced cell-cycle arrest.  相似文献   
39.
The acquisition of a metastatic phenotype by epithelial cells implicates a series of changes altering their differentiation, their overall behavior and morphology. In the present study, we have examined the relationships between the cellular morphology, E-cadherin expression, matrix metalloproteinases expression and in vitro invasive properties in two human bronchial immortalized cell lines. The (16HBE14o-) cell line which did not show any invasive abilities in the Boyden chamber assay displayed a typical epithelial morphology in monolayer, expressed high levels of E-cadherin and synthesized neither MMP-2 and MT1-MMP nor vimentin. In contrast, the BZR cell line which was highly invasive displayed a more elongated phenotype in monolayer, did not produce E-cadherin but expressed vimentin, MMP-2 and MT1-MMP. Our data therefore suggest that the metastatic progression of broncho-pulmonary cancer cells results in a cellular dedifferentiation and the gain of some mesenchymal attributes (loss of E-cadherin and expression of vimentin) associated with enhanced degradative properties (expression of metalloproteinases).© Rapid Science 1998  相似文献   
40.
Ovarian cancer cells disseminate by attachment to the peritoneal mesothelial cell surface of the abdominal cavity. We therefore investigated the influence of conditioned medium (CM) from human peritoneal tissues and mesothelial cells on the secretion of matrix metalloproteinases (MMPs) by ovarian cancer cells. The molecular weights of MMPs stimulating factors derived from human peritoneal tissues and mesothelial cells were estimated using microconcentrators with various cut-off membranes. Human peritoneal tissues were obtained from 12 surgical patients, and mesothelial cells were isolated from three peritoneal specimens. Exposure to CM from peritoneal tissue caused a concentration-dependent increase of the MMP-2 and MMP-9 bands in CM from NOM1 ovarian cancer cells, as shown by zymography. There was a significant difference in the increase of MMP-2 and MMP-9 (2.46-fold and 7.14-fold, respectively, at 0.4mg/ml protein; P < 0.005). CM from mesothelial cells also significantly increased the secretion of MMP-9 by NOM1 cells. The molecular size of possible MMP-9-stimulating factors secreted by peritoneal tissues and mesothelial cells was above M 100000. Further, CM of peritoneal tissues and mesothelial cells also induced the invasiveness of NOM1 cells. These findings suggest that mesothelial cells may secrete some factors which predominantly induce the MMP-9 production and increase invading cell numbers.  相似文献   
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