Search results for "Pimonidazole"
showing 6 items of 6 documents
Tissue gradients of energy metabolites mirror oxygen tension gradients in a rat mammary carcinoma model
2001
Abstract Purpose: It has been shown that oxygen gradients exist in R3230AC tumors grown in window chambers. The fascial surface is better oxygenated than the tumor surface. The purpose of the present study was to determine whether gradients exist for energy metabolites and other end points related to oxygen transport. Methods and Materials: Imaging bioluminescence was used to measure ATP, glucose, and lactate in cryosections of R3230AC tumors. Mean vessel density and hypoxic tissue fraction were assessed using immunohistochemistry. Tumor redox ratio was assessed by redox ratio scanning. Results: Lactate content and hypoxic fraction increased, whereas ATP, glucose, redox ratio, and vessel de…
The Microenvironment of Cervical Carcinoma Xenografts: Associations with Lymph Node Metastasis and Its Assessment by DCE-MRI.
2013
Poor disease-free and overall survival rates in locally advanced cervical cancer are associated with a tumor micro-environment characterized by extensive hypoxia, interstitial hypertension, and high lactate concentrations. The potential of gadolinium diethylenetriamine pentaacetic acid-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the microenvironment and microenvironment-associated aggressiveness of cervical carcinomas was investigated in this preclinical study. CK-160 and TS-415 cervical carcinoma xenografts were used as tumor models. DCE-MRI was carried out at 1.5 T, and parametric images of K (trans) and v e were produced by pharmacokinetic analysis o…
Co-localisation of hypoxia and perfusion markers with parameters of glucose metabolism in human squamous cell carcinoma (hSCC) xenografts
2009
Purpose: To examine relationships between tumour hypoxia, perfusion and metabolic microenvironment at themicroregional level in three different human squamous cell carcinomas (hSCC). Materials and methods: Nude mice bearing FaDu, UT-SCC-15, and UT-SCC-5 hSCC were injected with pimonidazole hypoxia and Hoechst perfusion markers. Bioluminescence imaging was used to determine spatial distribution of glucose and lactate content in serial tumour sections. Metabolite levels were grouped in 10 concentration ranges. Images were co-registered and at each concentration range the proportion of area stained for pimonidazole and Hoechst was determinedin 1113 tumours per tumour line. Results: The spatia…
Carbonic anhydrase IX expression and tumor oxygenation status do not correlate at the microregional level in locally advanced cancers of the uterine …
2005
Abstract Purpose: Carbonic anhydrase IX (CA IX) can be induced by hypoxia in vitro and shows an immunohistochemical expression pattern that is predominantly found in perinecrotic tumor areas and correlates with exogenous markers of hypoxia, such as pimonidazole. CA IX might therefore serve as an endogenous marker of tumor hypoxia, although comparisons of CA IX immunostaining with direct oxygenation measurements using pO2 microsensors have thus far yielded contradictory results. Experimental Design: Because tumor heterogeneity may be among the factors responsible for the discrepancy between the two methods, CA IX expression in tissue samples originating from oxygen microelectrode tracks of l…
Pimonidazole labelling and response to fractionated irradiation of five human squamous cell carcinoma (hSCC) lines in nude mice: The need for a multi…
2006
To investigate the influence on local control after fractionated radiotherapy of hypoxia measured in unirradiated tumours using the hypoxic marker Pimonidazole, using multivariate approaches.Five human squamous cell carcinoma lines (FaDu, UT-SCC-15, UT-SCC-14, XF354, and UT-SCC-5) were transplanted subcutaneously into the right hind-leg of NMRI nude mice. Histological material was collected from 60 unirradiated tumours after injection of Pimonidazole. The relative hypoxic area within the viable tumour area (Pimonidazole hypoxic fraction, pHF) was determined in seven serial 10 microm cross-sections per tumour by fluorescence microscopy and computerized image analysis. Local tumour control wa…
Inhibition of tumor lactate oxidation: consequences for the tumor microenvironment.
2011
Abstract Background and purpose Tumor cells are recognized as being highly glycolytic. However, recently it was suggested that lactate produced in hypoxic tumor areas may be taken up by the monocarboxylate transporter MCT1 and oxidized in well-oxygenated tumor parts. Furthermore, it was shown that inhibition of lactate oxidation using the MCT1 inhibitor α-cyano-hydroxycinnamate (CHC) can radio-sensitize tumors possibly by forcing a switch from lactate oxidization to glycolysis in oxygenated cells, which in turn improves tumor oxygenation and indirectly kills radio-resistant hypoxic tumor cells from glucose starvation. Material and methods To provide direct evidence for the existence of a ta…