Disease relevance of Ang3

• HIF-1alpha null mutant embryos exhibit clear morphological differences by embryonic day (E) 8.0, and by E8.5 there is a complete lack of cephalic vascularization, a reduction in the number of somites, abnormal neural fold formation and a greatly increased degree of hypoxia (measured by the nitroimidazole EF5) [1].
• Similarly, the central region of multicenter spheroids, composed of EMT6 mouse mammary sarcoma cells, was selectively visualized by immunohistochemistry after the spheroids were incubated for 4 h in 0.5 mM EF5 [2].
• On the basis of the prediction that tumor ischemia should result from therapeutic angiogenesis inhibition, tumor cell hypoxia was evaluated as a marker of ischemia using the EF5 [2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)aceta mide] approach [3].
• 9L rat glioma cells pretreated with EF5 under hypoxic, compared with aerobic, conditions were readily discriminated immunochemically using fluorochrome-conjugated secondary antibodies which recognize the ELK2-4 antibody subtype (IgG1) [2].
• METHODS AND MATERIALS: Using the murine fibrosarcoma line KHT-C, five techniques of measuring oxygen levels-the Eppendorf pO2 Histograph, EF5 binding, the comet assay, a paired survival assay, and an in vivo growth delay assay-were assessed [4].

High impact information on Ang3

• We prevented retinal vessel development by raising newborn mice in a high-oxygen atmosphere, which leads, paradoxically, to retinal hypoxia (confirmed by using the oxygen-sensing reagent EF5) [5].
• An increased apoptotic index of tumor cells in endostatin-treated tumors [3.2 +/- 0.5% versus 1.9 +/- 0.3% (P < 0.05)] was observed in conjunction with a significant decrease in tumor perfused vessels (DiOC7 staining), and an increase in tumor cell hypoxia (EF5 staining) [6].
• Frozen tumor tissue sections, triple-stained for HIF-1alpha, the endothelial cell marker CD31, and EF5, were imaged using wide-field multiparameter immunofluorescence microscopy [7].
• Labeling with the compound EF5 in a normal PM indicated no segmental hypoxia; this argued that oxygen deprivation was unlikely to be the cause of synchronous apoptosis [8].
• In vitro, tamoxifen did not modify the oxygen-dependent metabolism of EF5, indicating that the increased EF5 binding in tamoxifen-treated tumors reflects a physiological decrease in tissue oxygenation [9].

Chemical compound and disease context of Ang3

• Tamoxifen treatment increased hypoxia in the tumors, as measured by EF5 binding (P = 0.01 by Mann-Whitney test) [9].
• Immunofluorescent analysis of tumor sections and quantitative assessment with flow cytometry indicate colocalization between beta-hCG and 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetamide (EF5) and beta-hCG and pimonidazole, two extrinsic markers for tumor hypoxia [10].
• Therefore, we examined this with the hypoxia marker EF5 and found that nelfinavir leads to increased oxygenation within tumor xenografts [11].
• The effect of acute and chronic hypoxia on EF5 adduct formation (binding) was studied in the brain of newborn rats exposed to global hypoxia (8% O2 for 30, 90 or 150 min) and in the brain of chronically hypoxic rat pups with congenital cardiac defects (Wistar Kyoto) [12].
• Total vessels were identified using CD31 staining, perfused vessels by DiOC(7) staining, hypoxia by EF5/Cy3 uptake, and necrosis by haematoxylin and eosin staining [13].

Biological context of Ang3

• The results showed that allowing the mice to breathe carbogen (5% CO2/95% O2) prior to irradiation reduced clonogenic cell survival approx. 6-fold and led to an absence of cells binding high levels of EF5 [14].
• Second, hypoxic development is quantified in adjacent sections using immunohistochemical detection of a fluorescently conjugated monoclonal antibody (ELK3-51) to a nitroheterocyclic hypoxia marker (EF5), thereby providing information relating to both the oxygen consumption rates and the effective oxygen diffusion distances [15].
• These results correlated well with measurements of tumor cell oxygenation measured by nitroimidazole (EF5) binding and were consistent with assessments of tumor blood flow by contrast enhanced ultrasound and tumor histology [16].
• The effect of this treatment on radiation response (clonogenic and growth delay studies), tumor oxygenation (needle electrode pO2 and 2-[2-nitro-1H-imidazol-1-yl]-N-(2,2,3,3,3-pentafluoropropyl) acetamide (EF5) binding), and tumor bioenergetics and pH (31P NMR spectroscopy) was examined [17].
• For intact tissues treated with EF5 in vivo, we need to correct for possible variations in drug exposure (AUC) [18].

Anatomical context of Ang3

• Here we report on the spatial relationship between HIF-1alpha and the nitroimidazole hypoxia marker EF5 in cervical carcinoma xenografts, and on their spatial relationship to tumor blood vessels [7].
• Using the hypoxia marker nitroimidazole EF5, we detected hypoxic cells in the ischemic border of the neocortex [19].
• At the peak of OFT apoptosis in the mouse, the OFT myocardium was relatively hypoxic, as indicated by specific and intense EF5 staining and HIF1alpha nuclear localization, and was surrounded by the developing vasculature as in the chicken embryo [20].
• Detection of individual hypoxic cells in multicellular spheroids by flow cytometry using the 2-nitroimidazole, EF5, and monoclonal antibodies [21].

Associations of Ang3 with chemical compounds

• A pentafluorinated derivative [EF5; 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetam ide] of etanidazole was synthesized with the expectation of lessening some of the non-oxygen-dependent variability in adduct formation observed previously with other nitroaromatic compounds [2].
• A hypoxia-sensing compound based on the 2-nitroimidazole structure (EF5), together with immunohistochemical studies targeting endothelial cells were used to examine the relative oxygen tension in tuberculous granulomatous tissues in mice [22].
• Biodistribution of the nitroimidazole EF5 (2-[2-nitro-1H-imidazol-1-yl]-N-(2,2,3,3,3-pentafluoropropyl) acetamide) in mice bearing subcutaneous EMT6 tumors [23].
• As in published studies for HIF-1alpha and the hypoxic marker EF5, the colocalization of HIF-1alpha and pimonidazole in double-staining experiments was low [24].
• Three hours after injection of EF5 (30 mg/kg), tumors from the following three stages were excised: androgen-dependent, regressed tumors 7 days after castration, and androgen-independent [25].

Analytical, diagnostic and therapeutic context of Ang3

• EF5 was administered to mice bearing ME180 and SiHa cervical cancer xenografts [7].
• METHODS AND MATERIALS: Total anatomic blood vessels were quantified using image analysis of CD31 stained frozen sections, perfused vessels by i.v. injection of fluorescent DiOC(7), and tumor hypoxia was measured using the EF5 hypoxia marker [26].
• CONCLUSIONS: The correlations found between EF5 binding and the comet assay with the radiobiological assays suggest that these techniques have potential for predicting outcome following radiation treatment [4].
• Immunohistochemical staining and perfusion markers were used to quantify tumor vasculature, uptake of the hypoxia marker EF5 to assess the distribution of hypoxia, and intravascular HbO(2) measurements to determine oxygen availability [27].
• Direct immunofluorescence was used to detect adducts of EF5 or of a platinated derivative cis-[PtCl2(NH3)EF5] in SCCVII cells treated under aerobic or hypoxic conditions [28].

References