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Neovascularization plays a critical role in the growth and metastatic spread of tumors and involves recruitment of circulating endothelial progenitor cells

A colorimetric nucleic acid based test for label-free pathogen detection has been developed and used for the detection of the Zika virus. The test relies on nucleic acid sequence-based amplification (NASBA) of a viral RNA followed by interrogation of the amplicon by a cascade of deoxyribozymes constituting a visual split deoxyribozyme (vsDz) probe. The probe consists of a split phosphodiesterase deoxyribozyme, which forms its catalytic core upon binding to a specific amplicon fragment. The catalytically active complex recognizes and cleaves an inhibited peroxidase-like deoxyribozyme (PDz), thereby activating it. Active PDz catalyzes hydrogen peroxide-mediated oxidation of a colorless substrate into a colored product, thereby generating a visible signal. Viral RNA (10 6 copies/mL or higher) triggers intense color within 2 hr. The test selectively differentiates between Zika and closely related dengue and West Nile viruses. The reported technology combines isothermal amplification and visual detection and therefore represents a basis for the future development of a cost-efficient and instrument-free method for point-of-care nucleic acid analysis.

In a previous report, the recombinant kringle domain (UK1) of the urokinase type plasminogen activator (uPA) showed antiangiogenic activity. Here, we investigated in vivo antitumor effects of the UK1 of human uPA employing a brain tumor model. The systemic administration of UK1 purified from pichia expression (10 and 50 mg/kg/day intraperitoneally for 25 days) led to suppress the growth of a U87 human glioma xenograft, implanted into the brains of male BALB/cSlc nude mice, by 35% and 80%, respectively. In the immunohistochemical analysis, the tumors treated with UK1 showed decreased vascularity and expression of angiogenesis-related factors including vascular endothelial growth factor (VEGF), angiogenin, M alignant gliomas, the most common primary brain tumors, are extremely aggressive and highly angiogenic tumors with a very poor prognosis despite available intensive therapies including surgery, irradiation and chemotherapy.(1,2) Angiogenesis is an important feature associated with malignant glioma growth and progression.(3) The blood-brain barrier or blood-tumor barrier, which hinders drug delivery to brain tumors, is considered to be one of the main problems associated with systemic chemotherapy of brain tumors.(1,4) Angiogenesis inhibition, targeting endothelial cells rather than tumor cells, may especially be suitable for the treatment of malignant gliomas. Several antiangiogenic therapies have shown antitumor effects only in the preclinical setting but not in clinical studies. (5,6) It is important to investigate a new antiangiogenic molecule and its action mechanism for the development of antiangiogenic tumor therapy.Urokinase-type plasminogen activator (uPA) belonging to a protein family that contains a kringle domain plays an important role in inflammation, invasion, angiogenesis, and tumor metastasis by pericellular plasminogen activation.(7-9) uPA is a multidomain protein composed of a carboxyl-terminal protease domain and an amino-terminal fragment (ATF) which can be further subdivided into a growth factor-like domain (aa 4 -43) and a kringle domain (aa 45-135, UK1). uPA is highly expressed in malignant brain tumors;(10) its binding to the uPA receptor (uPAR) is enhanced by tumor progression and invasion by proteolysis of the extracellular matrix.(11) The ATF fragment of uPA has been reported to inhibit glioma growth and invasion properties in vivo.(12) Interestingly, in our previous study, we demonstrated that the kringle domain (Asp 45 -Lys 135 ), a subdomain of ATF, possesses an antiangiogenic activity, possibly with a different mechanism of ATF. (13,14) Thus, it warrants further investigation for its antitumor effect and action mechanisms.Here, we report that systemic administration of UK1 efficiently suppressed in vivo malignant glioma growth in nude mice, and reduced the expression of angiogenesis-related factors in tumor tissues. Materials and MethodsCell culture. Human malignant glioma cell lines U87, A172 and U373 were purchased from the American Type Culture Collection (ATCC, Manassas, VA)....

Abstract. The two-kringle domain of tissue-type plasminogen activator (TK1-2) has been identified as a novel angiogenesis inhibitor. In the previous study, purified Pichia-derived TK1-2 has been shown to suppress in vivo growth of human lung and colon cancer cells. Here, we demonstrate that E. coliderived non-glycosylated TK1-2 suppresses tumor growth more potently than Pichia-derived TK1-2 and prolongs the survival of tumor bearing mice. The recombinant TK1-2 prepared through E. coli expression, His-tag affinity chromatography and in vitro refolding was injected intraperitoneally once daily into nude mice 7 days after subcutaneous implantation with PC14 lung cancer cells (n=10). Measurement of tumor volumes indicated that low-dose TK1-2 treatment (10 mg/kg) suppressed tumor growth by approximately 85.2% (p<0.01), while high-dose TK1-2 treatment (50 mg/kg) even more potently inhibited tumor growth (>93.8%) (p<0.005). Treatment of TK1-2 also prolonged the survival of tumor-bearing mice in a dose-dependent fashion. In an independent HCT116 xenograft model, E. coli-derived TK1-2 was more effective in suppressing tumor growth than Pichia-derived TK1-2. Immunohistochemical analysis of tumor tissue also revealed that the expression of VEGF, SMA-·, TNF-· and angiogenin was less positive in the E. coli-derived TK1-2-treated group than in the Pichia-derived TK1-2-treated group. These results suggest that E. coli-derived refolded, non-glycosylated TK1-2 can be used more effectively as an anti-cancer agent.