Increased sensitivity of African American triple negative breast cancer cells to nitric oxide-induced mitochondria-mediated apoptosis.

BackgroundBreast cancer is a complex heterogeneous disease where many distinct subtypes are found. Younger African American (AA) women often present themselves with aggressive form of breast cancer with unique biology which is very difficult to treat. Better understanding the biology of AA breast tumors could lead to development of effective treatment strategies. Our previous studies indicate that AA but not Caucasian (CA) triple negative (TN) breast cancer cells were sensitive to nitrosative stress-induced cell death. In this study, we elucidate possible mechanisms that contribute to nitric oxide (NO)-induced apoptosis in AA TN breast cancer cells.MethodsBreast cancer cells were treated with various concentrations of long-acting NO donor, DETA-NONOate and cell viability was determined by trypan blue exclusion assay. Apoptosis was determined by TUNEL and caspase 3 activity as well as changes in mitochondrial membrane potential. Caspase 3 and Bax cleavage, levels of Cu/Zn superoxide dismutase (SOD) and Mn SOD was assessed by immunoblot analysis. Inhibition of Bax cleavage by Calpain inhibitor, and levels of reactive oxygen species (ROS) as well as SOD activity was measured in NO-induced apoptosis. In vitro and in vivo effect of NO treatment on mammary cancer stem cells (MCSCs) was assessed.Results and discussionNO induced mitocondria-mediated apoptosis in all AA but not in CA TN breast cancer cells. We found significant TUNEL-positive cells, cleavage of Bax and caspase-3 activation as well as depolarization mitochondrial membrane potential only in AA TN breast cancer cells exposed to NO. Inhibition of Bax cleavage and quenching of ROS partially inhibited NO-induced apoptosis in AA TN cells. Increase in ROS coincided with reduction in SOD activity in AA TN breast cancer cells. Furthermore, NO treatment of AA TN breast cancer cells dramatically reduced aldehyde dehydrogenase1 (ALDH1) expressing MCSCs and xenograft formation but not in breast cancer cells from CA origin.ConclusionsEthnic differences in breast tumors dictate a need for tailoring treatment options more suited to the unique biology of the disease

Stereochemistry‐Controlled Supramolecular Architectures of New Tetrahydroxy‐Functionalised Amphiphilic Carbocyanine Dyes

The syntheses of novel amphiphilic 5,5′,6,6‐tetrachlorobenzimidacarbocyanine (TBC) dye derivatives with aminopropanediol head groups, which only differ in stereochemistry (chiral enantiomers, meso form and conformer), are reported. For the achiral meso form, a new synthetic route towards asymmetric cyanine dyes was established. All compounds form J aggregates in water, the optical properties of which were characterised by means of spectroscopic methods. The supramolecular structure of the aggregates is investigated by means of cryo‐transmission electron microscopy, cryo‐electron tomography and AFM, revealing extended sheet‐like aggregates for chiral enantiomers and nanotubes for the mesomer, respectively, whereas the conformer forms predominately needle‐like crystals. The experiments demonstrate that the aggregation behaviour of compounds can be controlled solely by head group stereochemistry, which in the case of enantiomers enables the formation of extended hydrogen‐bond chains by the hydroxyl functionalities. In case of the achiral meso form, however, such chains turned out to be sterically excluded

The effect of adding inhaled corticosteroids to tiotropium and long-acting beta(2)-agonists for chronic obstructive pulmonary disease (Review)

BackgroundLong-acting bronchodilators comprising long-acting beta(2)-agonists and the anticholinergic agent tiotropiumare commonly used, either on their own or in combination, for managing persistent symptoms of chronic obstructive pulmonary disease. Patients with severe chronic obstructive pulmonary disease who are symptomatic and who suffer repeated exacerbations are recommended to add inhaled corticosteroids to their bronchodilator treatment. However, the benefits and risks of adding inhaled corticosteroid to tiotropium and long-acting beta2-agonists for the treatment of chronic obstructive pulmonary disease are unclear.ObjectivesTo assess the relative effects of adding inhaled corticosteroids to tiotropium and long-acting beta2-agonists treatment in patients with chronic obstructive pulmonary disease.Search strategyWe searched the Cochrane Airways Group Specialised Register of trials (February 2011) and reference lists of articles.Selection criteriaWe included parallel group, randomised controlled trials of three months or longer comparing inhaled corticosteroid and long-acting beta(2)-agonist combination therapy in addition to inhaled tiotropium against tiotropium and long-acting beta2-agonist treatment for patients with chronic obstructive pulmonary disease (COPD).Data collection and analysisTwo review authors independently assessed trials for inclusion and then extracted data on trial quality and the outcome results. We contacted study authors for additional information. We collected information on adverse effects from the trials.Main resultsOne trial (293 patients) was identified comparing tiotropium in addition to inhaled corticosteroid and long-acting beta(2)-agonist combination therapy to tiotropium plus long-acting beta2-agonist. The study was of good methodological quality, however it suffered from high and uneven withdrawal rates between the treatment arms. There is currently insufficient evidence to know how much difference the addition of inhaled corticosteroids makes to people who are taking tiotropium and a long-acting beta(2)-agonist for COPD.Authors' conclusionsThe relative efficacy and safety of adding inhaled corticosteroid to tiotropium and a long-acting beta(2)-agonist for chronic obstructive pulmonary disease patients remains uncertain and additional trials are required to answer this question

Wait-time Distributions for Photoelectric Detection of Light

Wait-time distributions for the $n$th photo-detection at a detector illuminated by a stationary light beam are studied. Both unconditional measurements, initiated at an arbitrary instant, and conditional measurements, initiated upon a photo-detection, are considered. Simple analytic expressions are presented for several classical and quantum sources of light and are used to quantify and compare photon sequences generated by them. These distributions can be measured in photon counting experiments and are useful in characterizing and generating photon sequences with prescribed statistics. Effects of non-unit detection efficiency are also discussed, and curves are presented to illustrate the behavior

Eagle: End-to-end Deep Reinforcement Learning based Autonomous Control of PTZ Cameras

Existing approaches for autonomous control of pan-tilt-zoom (PTZ) cameras use multiple stages where object detection and localization are performed separately from the control of the PTZ mechanisms. These approaches require manual labels and suffer from performance bottlenecks due to error propagation across the multi-stage flow of information. The large size of object detection neural networks also makes prior solutions infeasible for real-time deployment in resource-constrained devices. We present an end-to-end deep reinforcement learning (RL) solution called Eagle to train a neural network policy that directly takes images as input to control the PTZ camera. Training reinforcement learning is cumbersome in the real world due to labeling effort, runtime environment stochasticity, and fragile experimental setups. We introduce a photo-realistic simulation framework for training and evaluation of PTZ camera control policies. Eagle achieves superior camera control performance by maintaining the object of interest close to the center of captured images at high resolution and has up to 17% more tracking duration than the state-of-the-art. Eagle policies are lightweight (90x fewer parameters than Yolo5s) and can run on embedded camera platforms such as Raspberry PI (33 FPS) and Jetson Nano (38 FPS), facilitating real-time PTZ tracking for resource-constrained environments. With domain randomization, Eagle policies trained in our simulator can be transferred directly to real-world scenarios.Comment: 20 pages, IoTD