Inhibition of in vivo tumorigenicity and invasiveness of a human glioblastoma cell line transfected with antisense uPAR vectors

Our previous studies showed that glioblastomas express increased urokinase-type plasminogen activator receptors (uPARs) in comparison to low-grade gliomas (Yamamoto et al., Cancer Res., 54, 5016-5020, 1994). To explore whether downregulation of uPAR inhibits tumor formation and invasiveness, a human glioblastoma cell line was transfected with a cDNA construct corresponding to 300 bp of the human uPAR's 5¢ end in an antisense orientation, resulting in a reduced number of uPA receptors. Co-culture studies with tumor spheroids and fetal rat brain aggregates showed that antisense SNB19-AS1 cells expressing reduced uPAR failed to invade fetal rat brain aggregates. Intracerebral injection of SNB19-AS1 stable transfectants failed to form tumors and were negative for uPAR expression in nude mice. Thus uPAR appears in this model to be essential for tumorigenicity and invasion of glioblastomas in vivo.     

uPAR在人毛囊发育中的表达及其规律

目的 探讨人胚胎毛囊形成发育过程中,尿激酶型纤溶酶原激活剂受体（uPAR）的表达及其规律。方法 用免疫细胞化学和原位杂交分别对人胚胎毛囊起始期、延长期、分化期和胎毛阶段的表皮及毛囊的uPAR蛋白及mRNA的表达进行了检测,用图像分析系统进行了定量测定。结果 uPAR在起始期和延长期的整个毛囊中有表达,在分化期和胎毛前期毛囊的外根鞘有表达。在起始期、延长期、分化期和胎毛阶段前期表皮的基底层、最外层细胞有阳性表达。阳性表达在延长期最高,呈现出先增后减的趋势。结论 uPAR与角质形成细胞的增殖和迁移密切相关。     

uPA、uPAR、nm23-H1在大肠癌中的表达及其与肿瘤侵袭和转移的关系

 目的探讨尿激酶型纤溶酶原激活剂(uPA)、尿激酶型纤溶酶原激活剂受体(uPAR)和nm23H1基因蛋白在大肠癌中的表达及其与肿瘤侵袭和淋巴结转移的关系。方法应用免疫组化SABC法,对121例大肠癌手术根治标本进行uPA、uPAR和nm23H1基因蛋白测定。结果uPA、uPAR和nm23H1阳性表达率分别为62%、74%和48%。uPA和uPAR高表达与大肠癌侵袭和淋巴结转移关系密切(P<0.05)。nm23H1基因蛋白的低表达与大肠癌分化程度和淋巴结转移密切相关(P<0.05)。大肠癌中uPA和nm23H1蛋白表达呈负相关(P<0.05)。结论uPA、uPAR和nm23H1基因蛋白表达与大肠癌侵袭和转移有显著相关性;同时检测uPA和nm23H1表达状况,可作为预测大肠癌淋巴结转移及预后的有用指标。     

uPA、uPAR、PAI-1血浆含量与卵巢恶性肿瘤的相关性研究

目的：探讨尿激酶型纤溶酶原激活物（uPA）及其受体（uPAR）和抑制剂（PAI-1）血浆含量与卵巢恶性肿瘤之间的关系。方法：收集52例卵巢恶性肿瘤患者血液标本,以30例健康人作对照,用ELISA法分别检测uPA、uPAR和PAI-1的含量。结果：uPA、uPAR在卵巢恶性肿瘤各期之间均有极显著性差异（P〈0．01）,PAI-1在卵巢恶性肿瘤FIGO Ⅰ～Ⅲ期的含量逐渐升高,但在FIG0Ⅳ期时显著下降（P〈0．05）。患者组uPA、uPAR、PAI-1均较对照组升高,差异极显著（P〈0．01）。结论uPA、uPAR在卵巢恶性肿瘤患者可作为预后的判断指标,PAI-1与卵巢恶性肿瘤的分期有一定的相关性。     

uPAR和HER2在乳腺浸润性导管癌中的表达及其相关性

目的:探讨乳腺浸润性导管癌尿激酶型纤溶酶激活物受体(uPAR)和人类表皮生长因子2(HER2)表达、相关性及临床意义。方法:采用免疫组织化学技术检测15例正常乳腺组织和60例原发性乳腺浸润性导管癌中尿激酶型纤溶酶激活物(uPA)、uPAR和HER2基因的表达。结果:乳腺浸润性导管癌组织uPA和uPAR蛋白表达的总阳性率分别为60.00%和63.33%,而支持组织无表达,uPAR的阳性表达与乳腺癌转移淋巴结个数有关;HER2表达总阳性率为67%,有淋巴结转移者其阳性率(65.22%)明显高于无淋巴结转移者(35.14%)(P<0.05);与uPAR阴性表达的癌组织相比,uPAR阳性的癌组织中HER2表达阳性率显著升高(84.21%±36.36%,P<0.05),uPAR与HER2之间的表达高度相关。结论:uPAR和HER2蛋白在乳腺浸润性导管癌中高度表达,且密切相关;HER2过度表达与乳腺浸润性导管癌淋巴结转移有关,而uPAR表达与转移的淋巴结个数有关。     

血清VEGF、VEGF C和uPAR水平与口腔鳞状细胞癌的关系

目的通过检测口腔鳞状细胞癌(OSCC)患者血清中血管内皮生长因子(VEGF)、血管内皮生长因子C(VEGF C)和尿激酶型纤溶酶原激活剂受体(uPAR)的水平,探讨其与OSCC病理学改变和淋巴结转移的关系。方法用酶联免疫吸附分析法检测91例OSCC患者和50例健康人血清中VEGF、VEGF C和uPAR的水平。结果OSCC患者血清VEGF、VEGF C、uPAR含量显著高于健康对照组,差异有统计学意义(P<0.01),血清VEGF、VEGF C和uPAR水平与口腔癌患者的病理分级、浸润方式和淋巴结转移无显著相关性。结论血清VEGF、VEGF C和uPAR水平可为监测口腔癌的发生发展提供实验依据,但对判断OSCC的转移无显著意义。     

Plasminogen activator inhibitor-1 is an aggregate response factor with pleiotropic effects on cell signaling in vascular disease and the tumor microenvironment

In hemostasis, the serine protease inhibitor (serpin) plasminogen activator inhibitor-1 (PAI-1) functions to stabilize clots via inhibition of tissue plasminogen activator (tPA) with subsequent inhibition of fibrinolysis. In tissues, PAI-1 functions to inhibit extracellular matrix degradation via inhibition of urokinase plasminogen activator (uPA). Elevated levels of PAI-1 in the vasculature and in tissues have long been known to be associated with thrombosis and fibrosis, respectively. However, there is emerging evidence that PAI-1 may participate in the pathophysiology of a number of diseases such as atherosclerosis, restenosis, and cancer. In many of these disease states, the canonical view of PAI-1 as an inhibitor of tPA and uPA cannot fully account for a mechanism whereby PAI-1 contributes to the disease. In these cases, one must consider recent data, which indicates PAI-1 can directly promote pro-proliferative and anti-apoptotic signaling in a variety of cell types. Given the wide variety of inflammatory, hormonal, and metabolic signals that increase PAI-1 expression, it is important to consider mechanisms by which PAI-1 can directly participate in disease etiology.     

uPA‐uPAR molecular complex is involved in cell signaling during neuronal migration and neuritogenesis

Background: In the development of the central nervous system (CNS), neuronal migration and neuritogenesis are crucial processes for establishing functional neural circuits. This relies on the regulation exerted by several signaling molecules, which play important roles in axonal growth and guidance. The urokinase‐type plasminogen activator (uPA)—in association with its receptor—triggers extracellular matrix proteolysis and other cellular processes through the activation of intracellular signaling pathways. Even though the uPA‐uPAR complex is well characterized in nonneuronal systems, little is known about its signaling role during CNS development. Results : In response to uPA, neuronal migration and neuritogenesis are promoted in a dose‐dependent manner. After stimulation, uPAR interacts with α₅‐ and β₁‐integrin subunits, which may constitute an αβ‐heterodimer that acts as a uPA‐uPAR coreceptor favoring the activation of multiple kinases. This interaction may be responsible for the uPA‐promoted phosphorylation of focal adhesion kinase (FAK) and its relocation toward growth cones, triggering cytoskeletal reorganization which, in turn, induces morphological changes related to neuronal migration and neuritogenesis. Conclusions : uPA has a key role during CNS development. In association with its receptor, it orchestrates both proteolytic and nonproteolytic events that govern the proper formation of neural networks. Developmental Dynamics 243:676–689, 2014. © 2014 Wiley Periodicals, Inc.     

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.