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Background: The transcription factor Nrf2 is a key regulator of the cellular antioxidant response, and its activation by chemoprotective agents has been proposed as a potential strategy to prevent cancer. However, activating mutations in the Nrf2 pathway have been found to promote tumorigenesis in certain models. Therefore, the role of Nrf2 in cancer remains contentious., Methods: We employed a well-characterized model of stepwise human mesenchymal stem cell (MSC) transformation and breast cancer cell lines to investigate oxidative stress and the role of Nrf2 during tumorigenesis. The Nrf2 pathway was studied by microarray analyses, qRT-PCR, and western-blotting. To assess the contribution of Nrf2 to transformation, we established tumor xenografts with transformed MSC expressing Nrf2 (n = 6 mice per group). Expression and survival data for Nrf2 in different cancers were obtained from GEO and TCGA databases. All statistical tests were two-sided., Results: We found an accumulation of reactive oxygen species during MSC transformation that correlated with the transcriptional down-regulation of antioxidants and Nrf2-downstream genes. Nrf2 was repressed in transformed MSC and in breast cancer cells via oncogene-induced activation of the RAS/RAF/ERK pathway. Furthermore, restoration of Nrf2 function in transformed cells decreased reactive oxygen species and impaired in vivo tumor growth (P = 0.001) by mechanisms that included sensitization to apoptosis, and a decreased hypoxic/angiogenic response through HIF-1α destabilization and VEGFA repression. Microarray analyses showed down-regulation of Nrf2 in a panel of human tumors and, strikingly, low Nrf2 expression correlated with poorer survival in patients with melanoma (P = 0.0341), kidney (P = 0.0203) and prostate (P = 0.00279) cancers., Conclusions: Our data indicate that oncogene-induced Nrf2 repression is an adaptive response for certain cancers to acquire a pro-oxidant state that favors cell survival and in vivo tumor growth.

Chemical exchange saturation transfer (CEST) imaging has been used experimentally in a large range of applications. However, full quantification of CEST effects in vivo using standard imaging sequences is time consuming as a large number of saturation frequency offsets, each followed by an imaging readout, are required to define a z spectrum. Furthermore, outside the brain, the presence of fat can confound the interpretation of z spectra. A novel acquisition and post-processing technique is presented in this study, named exchange-modulated point-resolved spectroscopy (EXPRESS), which aims to address these limitations and to enable spatially localised, high signal-to-noise measurements of CEST effects in vivo. Using amide proton exchange (APT) measurements in tumours, it is demonstrated that the acquisition of two-dimensional EXPRESS spectra composed of chemical shift and saturation frequency offset dimensions allows the correction of CEST data containing both fat and water signals, which is a common confounding property of tissues found outside the brain., (Copyright © 2011 John Wiley & Sons, Ltd.)

The use of a novel all-optical photoacoustic scanner for imaging the development of tumor vasculature and its response to a therapeutic vascular disrupting agent is described. The scanner employs a Fabry-Perot polymer film ultrasound sensor for mapping the photoacoustic waves and an image reconstruction algorithm based upon attenuation-compensated acoustic time reversal. The system was used to noninvasively image human colorectal tumor xenografts implanted subcutaneously in mice. Label-free three-dimensional in vivo images of whole tumors to depths of almost 10 mm with sub-100-micron spatial resolution were acquired in a longitudinal manner. This enabled the development of tumor-related vascular features, such as vessel tortuosity, feeding vessel recruitment, and necrosis to be visualized over time. The system was also used to study the temporal evolution of the response of the tumor vasculature following the administration of a therapeutic vascular disrupting agent (OXi4503). This revealed the well-known destruction and recovery phases associated with this agent. These studies illustrate the broader potential of this technology as an imaging tool for the preclinical and clinical study of tumors and other pathologies characterized by changes in the vasculature.

A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for three-dimensional in vivo (3D) skin imaging is described. The system employs an integrated, all optical detection scheme for both modalities in backward mode utilizing a shared 2D optical scanner with a field-of-view of ~13 × 13 mm(2). The photoacoustic waves were detected using a Fabry Perot polymer film ultrasound sensor placed on the surface of the skin. The sensor is transparent in the spectral range 590-1200 nm. This permits the photoacoustic excitation beam (670-680 nm) and the OCT probe beam (1050 nm) to be transmitted through the sensor head and into the underlying tissue thus providing a backward mode imaging configuration. The respective OCT and PAT axial resolutions were 8 and 20 µm and the lateral resolutions were 18 and 50-100 µm. The system provides greater penetration depth than previous combined PA/OCT devices due to the longer wavelength of the OCT beam (1050 nm rather than 829-870 nm) and by operating in the tomographic rather than the optical resolution mode of photoacoustic imaging. Three-dimensional in vivo images of the vasculature and the surrounding tissue micro-morphology in murine and human skin were acquired. These studies demonstrated the complementary contrast and tissue information provided by each modality for high-resolution 3D imaging of vascular structures to depths of up to 5 mm. Potential applications include characterizing skin conditions such as tumors, vascular lesions, soft tissue damage such as burns and wounds, inflammatory conditions such as dermatitis and other superficial tissue abnormalities.

Objectives: A pilot study was undertaken to examine the feasibility of auditing and developing a national database of acupuncture practice in the United Kingdom., Methods: One hundred forty-five (145) practitioners, members of the British Acupuncture Council, were invited to participate in the study. Those who accepted were given training and then asked to record demographic and treatment outcomes data on new patients attending their practices over a 3-month period. Two questionnaires, the Measure Your Own Medical Outcomes Profile and the College of Integrated Chinese Medicine outcome questionnaire, were compared. Baseline health status was assessed and repeated patient feedback questionnaires employed., Results: Of the 31 (21%) of practitioners who responded, only 9 (6%) eventually contributed data. A total of 69 patients participated in the study: 43 (68%) of the patients were female, and 46 (73%) were aged between 30 and 59. More than half (52%) had had their presenting problem for over 5 years and most (78%) were affected daily by it. Nineteen (30%) had had prior acupuncture treatment for their condition. The main categories of complaints reported were musculoskeletal and psychologic. Thirty-two (32) out of 41 (78%) patients with completed final outcomes data recorded moderate or major benefit in their main complaint, with no reports of deterioration., Conclusions: Although willing to be involved, practitioners found the research process time-consuming and were concerned how it could be balanced against the demands of a busy practice and the interests of patients. For a national audit study to succeed, the process would have to be simplified and practitioners encouraged to engage; collection of such information could then help to provide much-needed data on acupuncture treatment in the United Kingdom.

The Brn-3a POU family transcription factor is able to induce the expression of genes encoding anti-apoptotic proteins such as Bcl-2 and Bcl-x and protects neuronal cells from apoptosis. This effect is opposed by the pro-apoptotic p53 protein which completely inhibits the ability of Brn-3a to activate the Bcl-2 and Bcl-x promoters. Here we demonstrate that Brn-3a is able to stimulate p53 expression. Thus, in co-transfection experiments, Brn-3a activates the p53 promoter acting via a region from +22 to +67, located between the most proximal (+1) and the most distal (+105) transcriptional start sites. Similarly, reduction of Brn-3a expression using anti-sense constructs reduces endogenous p53 expression in human neuroblastoma or cervical carcinoma cell lines growing in vitro and as tumours in nude mice whilst increasing Brn-3a levels enhances p53 expression. These results suggest the existence of a negative feedback loop in which elevated Brn-3a expression induces the expression of p53 which, in turn, antagonises the anti-apoptotic activity of Brn-3a., (Copyright 2002 Elsevier Science Ireland Ltd.)

The cellular Brn-3a transcription factor is known to activate transcription of the genes encoding the human papilloma virus E6 and E7 proteins and is over-expressed in women with cervical neoplasia. We show that cervical cell lines with reduced Brn-3a expression show a greatly reduced ability to form tumours in nude mice compared to control cells and also show reduced expression of the HPV E6 and cellular Bcl-2 oncogenes. These effects are also observed in cervical cells over-expressing the related Brn-3b factor, which is known to antagonize activation of HPV gene expression by Brn-3a. These results demonstrate, for the first time, that inhibition of Brn-3a expression or enhanced Brn-3b expression can inhibit cervical cell-derived tumour growth in vivo as well as in vitro. Hence they establish Brn-3a as a key factor in cervical tumorigenesis and as a potential therapeutic target in human cervical neoplasia.

Unlabelled: Single-chain Fv (scFv) antibody fragments have potential for clinical imaging because of their rapid tumor penetration and high tumor-to-tissue ratios at early time points. ScFvs clear rapidly from the circulation so radiolabels such as 99mTc which have short half-lives are desirable, but the free thiol groups necessary for labeling with 99mTc are not normally found on these molecules., Methods: We constructed a vector which enabled a free cysteine to be linked to the C-terminus of scFvs. MFE-23, a scFv directed against carcinoembryonic antigen (CEA), was cloned into this vector and cys-tagged MFE-23 was labeled with 99mTc using a D-glucarate transfer method., Results: The radiolabeled product was stable in vivo and in vitro and showed favorable tumor-to-blood ratios in vivo at early time points (4:1 at 24 hr and 8:1 at 48 hr), although high kidney levels were also detected., Conclusion: Our study demonstrates an effective method to enable scFvs radiolabeling with 99mTc and also shows the potential of using a 99mTc-labeled scFv for clinical imaging studies.