Metastasis by cancer cells relies upon the acquisition of the ability to evade anoikis, a cell death process elicited by detachment from extracellular matrix (ECM). The molecular mechanisms that ECM-detached cancer cells use to survive are not understood. Striking increases in reactive oxygen species (ROS) occur in ECM-detached mammary epithelial cells, threatening cell viability by inhibiting ATP production, suggesting that ROS must be neutralized if cells are to survive ECM-detachment. Here, we report the discovery of a prominent role for antioxidant enzymes, including catalase and superoxide dismutase, in facilitating the survival of breast cancer cells after ECM-detachment. Enhanced expression of antioxidant enzymes in nonmalignant mammary epithelial cells detached from ECM resulted in ATP elevation and survival in the luminal space of mammary acini. Conversely, silencing antioxidant enzyme expression in multiple breast cancer cell lines caused ATP reduction and compromised anchorage-independent growth. Notably, antioxidant enzyme-deficient cancer cells were compromised in their ability to form tumors in mice. In aggregate, our results reveal a vital role for antioxidant enzyme activity in maintaining metabolic activity and anchorage-independent growth in breast cancer cells. Furthermore, these findings imply that eliminating antioxidant enzyme activity may be an effective strategy to enhance susceptibility to cell death in cancer cells that may otherwise survive ECM-detachment. Cancer Res; 73(12); 3704-15. Ó2013 AACR.
RTE seems to be a useful tool in the work-up of thyroid nodules to exclude papillary thyroid cancer. However, follicular carcinoma remains a challenging problem. CEUS did not improve the characterization of thyroid nodules in this preliminary study.
Many bacteria spread over surfaces by "swarming" in groups. A problem for scientists who study swarming is the acquisition of statistically significant data that distinguish two observations or detail the temporal patterns and two-dimensional heterogeneities that occur. It is currently difficult to quantify differences between observed swarm phenotypes. Here, we present a method for acquisition of temporal surface motility data using time-lapse fluorescence and bioluminescence imaging. We specifically demonstrate three applications of our technique with the bacterium Pseudomonas aeruginosa. First, we quantify the temporal distribution of P. aeruginosa cells tagged with green fluorescent protein (GFP) and the surfactant rhamnolipid stained with the lipid dye Nile red. Second, we distinguish swarming of P. aeruginosa and Salmonella enterica serovar Typhimurium in a coswarming experiment. Lastly, we quantify differences in swarming and rhamnolipid production of several P. aeruginosa strains. While the best swarming strains produced the most rhamnolipid on surfaces, planktonic culture rhamnolipid production did not correlate with surface growth rhamnolipid production.
Obesity is associated with increased morbidity and mortality as well as reduced metrics in quality of life.1 Both environmental and genetic factors are associated with obesity, though the precise underlying mechanisms that contribute to the disease are currently being delineated. 2,3 Several small animal models of obesity have been developed and are employed in a variety of studies. 4 A critical component to these experiments involves the collection of regional and/or total animal fat content data under varied conditions.Traditional experimental methods available for measuring fat content in small animal models of obesity include invasive (e.g. ex vivo measurement of fat deposits) and non-invasive (e.g. Dual Energy X-ray Absorptiometry (DEXA), or Magnetic Resonance (MR)) protocols, each of which presents relative trade-offs. Current invasive methods for measuring fat content may provide details for organ and region specific fat distribution, but sacrificing the subjects will preclude longitudinal assessments. Conversely, current non-invasive strategies provide limited details for organ and region specific fat distribution, but enable valuable longitudinal assessment. With the advent of dedicated small animal Xray computed tomography (CT) systems and customized analytical procedures, both organ and region specific analysis of fat distribution and longitudinal profiling may be possible. Recent reports have validated the use of CT for in vivo longitudinal imaging of adiposity in living mice. 5,6Here we provide a modified method that allows for fat/total volume measurement, analysis and visualization utilizing the Carestream Molecular Imaging Albira CT system in conjunction with PMOD and Volview software packages. Video LinkThe 3. Mice were anesthetized by Isofluorane (2.5% flow rate) and kept under at 2.5% via a nose-cone setup for imaging. Animals were positioned prone in the standard rat bed (M2M Imaging Inc. Cleveland, OH) in supplied with the Albira image station. Limbs were positioned lateral from the torso for a uniform CT acquisition. 4. After image acquisition was completed, mice were removed from the nose cone and returned to a recovery cage until ambulatory. Image Acquisition and Reconstruction1. Image acquisitions are performed using the Albira CT system (Carestream Molecular Imaging, Woodbridge, CT). Mice were anesthetized by Isofluorane (2.5% flow rate) and kept under at 2.5% via a nose-cone setup for imaging. Acquisitions were performed to scan a bed of 115 mm
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