猪去氧胆酸对体外培养肝癌细胞HepG2 uPAR的影响

[目的]探讨中药清开灵注射液中主要有效成分之一的猪去氧胆酸对肝癌细胞HepG2上清液中uPAR的影响。[方法]将猪去氧胆酸逐个稀释为从10到30000倍的9个稀释倍数,采用MTT法测定各浓度药液的细胞增殖抑制率,ELISA法检测HepG2细胞uPAR的表达,观察药物各浓度下对细胞生长活力和uPAR表达的影响。[结果]猪去氧胆酸对HepG2细胞具有一定的增殖抑制作用,同时可使细胞培养上清中uPAR水平显著下降。[结论]清开灵注射液降低肝癌细胞uPAR活性表达的能力与其有效成分之一的猪去氧胆酸有关,猪去氧胆酸具有一定体外抑制肝癌细胞HepG2转移的能力。     

急性髓系白血病中uPA和uPAR的表达及意义

目的观察急性髓系白血病人骨髓单个核细胞uPAR（CD87）的表达及血浆uPA的水平,并探讨其临床意义。方法用ELISA法测定22例急性髓系白血病患者（观察组）及34例良性血液病患者（对照组）血浆中uPA表达水平,用流式细胞学技术测定骨髓单个核细胞uPAR水平,比较两组之间的表达差异。结果血浆中uPA水平和骨髓单个核细胞uPAR水平急性髓系白血病组均高于良性血液病组,差异具有显著性（P〈0.05）;pearson相关分析显示uPA表达水平及uPAR水平之间存在正相关性（观察组r1=0.614,对照组r2=0.921;P〈0.05）。结论急性髓系白血病患者血浆uPA水平及骨髓单个核细胞uPAR表达均升高,二者具有协同表达关系,联合检测对于急性髓系白血病的病情监控和预后分析有临床指导意义。     

Urokinase plasminogen activator receptor levels in Behcet's disease

Purpose

To determine urokinase plasminogen activator receptor (uPAR) concentrations in Behcet patients with and without ocular involvement; and to investigate the associations between uPAR levels and clinical manifestations of Behcet's disease.

Methods

Sixty-four patients with Behcet's disease (31 patients with and 33 patients without ocular involvement) and 23 healthy control subjects were included in this study. A complete ophthalmologic examination was performed. Venous blood was collected from all patients and control subjects. Serum uPAR levels were determined by using human uPAR immunoassay (Quantikine) kits.

Results

There was no statistically significant difference in serum uPAR levels between the patients and the control subjects (p > 0.05). There were no statistically significant correlations between uPAR levels and age, gender, duration of the disease, clinical manifestations (genital ulcer, arthritis, skin lesions, ocular and vascular involvements) and activity of the disease.

Conclusion

This finding is important since this is the first study regarding uPAR levels in Behcet's disease.     

Plasminogen activators and inhibitor type-1 in alveolar osteitis

Alveolar osteitis (AO) is characterized by excess fibrinolysis, leading to early dissociation of the clot that normally follows tooth extraction. Nonetheless, scarce information is available on the fibrinolytic system in AO. In this study, we report on the differential composition of postextraction wound healing tissue and of peri-alveolar gingival epithelium from normal healing and AO patients in terms of plasminogen activators, plasminogen activator inhibitor-type 1, and urokinase-type plasminogen activator receptor. Plasminogen activators were studied by overlay zymography, western blotting, and enzyme-linked immunosorbent assay (ELISA). Plasminogen activator inhibitor-type 1 and urokinase receptor were measured by ELISA. In AO, the fibrinolytic activity of wound healing tissue was accounted for by an increase ( approximately 85%) of urokinase-type plasminogen activator, whereas tissue-type plasminogen activator was unchanged. Plasminogen activator inhibitor-type 1 showed a 6.7-fold increase in AO. These results point to key roles of urokinase in AO hyper-fibrinolysis and of plasminogen activator inhibitor type-1 in slowing down the healing response. Peri-alveolar gingival epithelium in AO showed an overall decrease of all the components of the fibrinolytic system, including the urokinase receptor, which indicates a decrease of the migration properties of epithelial cells.     

Targeting podocyte-associated diseases

Injury to the podocytes is the initiating cause of many renal diseases, leading to proteinuria with possible progression to end-stage renal disease. Podocytes are highly specialized cells, with an important role in maintaining the glomerular filtration barrier and producing growth factors for both mesangial cells and endothelial cells. With their foot processes they cover the glomerular basement membrane, and form slit diaphragms with neighboring podocytes.Human podocytopathies include focal and segmental glomerulosclerosis, minimal change disease, membranous nephropathy, collapsing glomerulopathy and diabetic nephropathy. Research in the last two decades has demonstrated great progress in understanding the molecular mechanisms leading to podocytopathies. These include single gene defects in slit diaphragm proteins, but also discovery of apoptotic, enzymatic and other pathways involved in podocyte injury. With this progress, a great number of animal models is now available to study either specific podocytopathies, e.g. in mouse models with single gene mutations, or more general podocyte injury patterns, such as the lipopolysaccharide or protamine sulfate model of foot process effacement.In this review, the morphology of the glomerulus will be discussed, with a focus on the podocyte, its interactions with surrounding cells, and the highly differentiated slit diaphragm separating the apical from the basal membrane. We also provide an overview of human podocytopathies and animal models to study these diseases. In the last part we discuss targeted therapies addressing pathways and proteins affected in podocyte injury.     

Patent focus on cancer chemotherapeutics. IV Angiogenesis agents: April 2001 - August 2001

Angiogenesis refers to the formation of capillary blood vessels from existing blood vessels: a process that is believed to be a key driver in cancer growth and metastasis. Angiogenesis inhibition represents an active area of cancer drug discovery, with several agents and approaches now entering late clinical development. This review summarises the key aspects of recent patent applications referring to cancer chemotherapy and cancer drug discovery that involve inhibition or modulation of angiogenesis. The scope includes applications that have been published between April and August 2001. The review covers the main mechanism-based approaches such as MMPIs, inhibitors of the growth factor signalling pathways, integrin antagonists and urokinase inhibitors.     

The receptor for urokinase-plasminogen activator (uPAR) controls plasticity of cancer cell movement in mesenchymal and amoeboid migration style

The receptor for the urokinase plasminogen activator (uPAR) is up-regulated in malignant tumors. Historically the function of uPAR in cancer cell invasion is strictly related to its property to promote uPA-dependent proteolysis of extracellular matrix and to open a path to malignant cells. These features are typical of mesenchymal motility. Here we show that the full-length form of uPAR is required when prostate and melanoma cancer cells convert their migration style from the “path generating” mesenchymal to the “path finding” amoeboid one, thus conferring a plasticity to tumor cell invasiveness across three-dimensional matrices. Indeed, in response to a protease inhibitors-rich milieu, prostate and melanoma cells activated an amoeboid invasion program connoted by retraction of cell protrusions, RhoA-mediated rounding of the cell body, formation of a cortical ring of actin and a reduction of Rac-1 activation. While the mesenchymal movement was reduced upon silencing of uPAR expression, the amoeboid one was almost completely abolished, in parallel with a deregulation of small Rho-GTPases activity. In melanoma and prostate cancer cells we have shown uPAR colocalization with β1/β3 integrins and actin cytoskeleton, as well integrins-actin co-localization under both mesenchymal and amoeboid conditions. Such co-localizations were lost upon treatment of cells with a peptide that inhibits uPAR-integrin interactions. Similarly to uPAR silencing, the peptide reduced mesenchymal invasion and almost abolished the amoeboid one. These results indicate that full-length uPAR bridges the mesenchymal and amoeboid style of movement by an inward-oriented activity based on its property to promote integrin-actin interactions and the following cytoskeleton assembly.     

uPAR Controls Vasculogenic Mimicry Ability Expressed by Drug-Resistant Melanoma Cells

Malignant melanoma is a highly aggressive skin cancer characterized by an elevated grade of tumor cell plasticity. Such plasticity allows adaptation of melanoma cells to different hostile conditions and guarantees tumor survival and disease progression, including aggressive features such as drug resistance. Indeed, almost 50% of melanoma rapidly develop resistance to the BRAFV600E inhibitor vemurafenib, with fast tumor dissemination, a devastating consequence for patients’ outcomes. Vasculogenic mimicry (VM), the ability of cancer cells to organize themselves in perfused vascular-like channels, might sustain tumor spread by providing vemurafenibresistant cancer cells with supplementary ways to enter into circulation and disseminate. Thus, this research aims to determine if vemurafenib resistance goes with the acquisition of VM ability by aggressive melanoma cells, and identify a driving molecule for both vemurafenib resistance and VM. We used two independent experimental models of drug-resistant melanoma cells, the first one represented by a chronic adaptation of melanoma cells to extracellular acidosis, known to drive a particularly aggressive and vemurafenib-resistant phenotype, the second one generated with chronic vemurafenib exposure. By performing in vitro tube formation assay and evaluating the expression levels of the VM markers EphA2 and VE-cadherin by Western blotting and flow cytometer analyses, we demonstrated that vemurafenib-resistant cells obtained by both models are characterized by an increased ability to perform VM. Moreover, by exploiting the CRISPR-Cas9 technique and using the urokinase plasminogen activator receptor (uPAR) inhibitor M25, we identified uPAR as a driver of VM expressed by vemurafenib-resistant melanoma cells. Thus, uPAR targeting may be successfully leveraged as a new complementary therapy to inhibit VM in drug-resistant melanoma patients, to counteract the rapid progression and dissemination of the disease.