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Abstract Purpose  The aim of this study was to demonstrate the ability to use human clinical positron emission tomography/computed tomography (PET/CT) to detect and investigate head and neck cancers chemically induced by 4-nitroquinoline-1-oxide (4-NQO) in a rat model. Study design  The study design was prospective animal research. Procedures  A head and neck squamous cell carcinoma was established in 20 immunocompetent rats, who drank a 4-NQO solution during 16 weeks. 2-Deoxy-2-[F-18]fluoro-d-glucose (FDG)-PET/CT was performed for five of them, 34 weeks after the start of the experiment to characterize the tumors. A day following the FDG-PET/CT, rats were euthanized and pathological features were evaluated by hematoxylin–eosin staining. Results  All rats had head and neck tumor at various locations at 34 weeks. Among the five rats selected for having FDG-PET/CT, the clinical examination detected exophytic tumors grown in the oral cavity for three of them (one on the inferior lip, one on the hard palate, and one on the internal side of the cheek). FDG-PET/CT confirmed the presence of those tumors and detected ones located on the base of tongue for three of them. Tumor extensions were characterized and tumor metabolic volumes were measured. The smallest lesion detected measured 3 × 3 × 4 mm. Pathologic examination using hematoxylin–eosin staining confirmed squamous cell carcinoma. Conclusions  This study demonstrated that FDG-PET/CT is a feasible examination to detect occult primary tumors in rat models. It is useful to follow tumor progression and evaluate therapeutics efficacy. [ABSTRACT FROM AUTHOR]

Abstract As they scavenge reactive oxygen species, antioxidants were studied for their ability to interfere with apoptotic processes. However, their mechanisms of action remain unclear. In this study, we measured the expression of two Bcl-2 family members, Bax and Bcl-2, in a human endothelial like cell-line overexpressing the organic hydroperoxide-scavenging enzyme glutathione peroxidase (GPX1), in the absence of any apoptotic/oxidant stimulus. ECV304 were stably transfected with the GPX1 cDNA and used for quantification of Bax (pro-apoptotic) and Bcl-2 (antiapoptotic) mRNA and protein levels, by quantitative RT-PCR and Western-blot. We found that, compared to control cells, cells from a clone showing a 13.2 fold increase in GPX1 activity had unchanged mRNA or protein Bcl-2 levels but expressed 42.6% and 46.1% less Bax mRNA and Bax protein respectively. Subsequently to Bax decrease, the Bax/Bcl-2 ratio, reflecting the apoptotic state of the cells, was also lower in cells overexpressing GPX1. Noticeably, the mRNA and the protein level of the cell-cycle protein p53, known to activate Bax expression, was unchanged. Our study showed that overexpressing an antioxidant gene such as GPX1 in endothelial cells is able to change the basal mRNA and protein Bax levels without affecting those of p53 and Bcl-2. This phenomenon could be useful to antiatherogenic therapies which use antioxidants with the aim of protecting the vascular wall against oxidative stress injury. [ABSTRACT FROM AUTHOR]