A5054772831- Protein Kinase Regulation and GTPase Signaling
- Electrochemical Analysis and Applications
- Analytical Chemistry and Sensors
- Microtubule and mitosis dynamics
- Receptor Mechanisms and Signaling
- Cellular Mechanics and Interactions
- Cancer-related Molecular Pathways
- Melanoma and MAPK Pathways
- Ubiquitin and proteasome pathways
- Conducting polymers and applications
- Retinoids in leukemia and cellular processes
- Electrochemical sensors and biosensors
- Advanced biosensing and bioanalysis techniques
- X-ray Diffraction in Crystallography
- bioluminescence and chemiluminescence research
- Crystallization and Solubility Studies
- Force Microscopy Techniques and Applications
- Metabolism, Diabetes, and Cancer
- Metal complexes synthesis and properties
- Bioactive natural compounds
- Peptidase Inhibition and Analysis
- 14-3-3 protein interactions
- Cancer, Hypoxia, and Metabolism
- Biochemical and Molecular Research
- Sirtuins and Resveratrol in Medicine
Queens College, CUNY
2008-2022
The Graduate Center, CUNY
2006-2022
City University of New York
2006-2022
Queens University of Charlotte
2006-2018
New York Proton Center
2009
The University of Texas at Austin
2007-2008
National Institutes of Health
2008
Science Applications International Corporation (United States)
2008
National Cancer Institute
2008
Augusta University
2005-2006
The production of reactive oxygen and nitrogen species (ROS RNS) in human cells is implicated various diseases, including cancer. Micrometer-sized electrodes coated with Pt black platinized nanoelectrodes have previously been used for the detection primary ROS RNS biological systems. In this Article, we report development carbon well-characterized geometry use them as scanning electrochemical microscopy (SECM) tips to measure inside noncancerous metastatic breast cells. By performing...
There is a significant current interest in development of new techniques for direct characterization the intracellular redox state and high-resolution imaging living cells. We used nanometer-sized amperometric probes combination with scanning electrochemical microscope (SECM) to carry out spatially resolved experiments cultured human breast With tip radius approximately 1,000 times smaller than that cell, an probe can penetrate cell travel inside it without apparent damage membrane. The data...
The ability to manipulate ultrasmall volumes of liquids is essential in such diverse fields as cell biology, microfluidics, capillary chromatography, and nanolithography. In it often necessary inject material high molecular weight (e.g., DNA, proteins) into living cells because their membranes are impermeable molecules. All techniques currently used for microinjection plagued by two common problems: the relatively large injector size volume injected fluid, poor control amount material. Here...
The release of reactive oxygen and nitrogen species (ROS/RNS) by macrophages undergoing phagocytosis is crucial for the efficiency immune system. In this work, platinized carbon nanoelectrodes were used to detect, characterize, quantify first time intracellular production rates four primary ROS/RNS (i.e., H2O2, ONOO–, NO•, NO2–) inside single phagolysosomes living RAW 264.7 murine stimulated interferon-γ lipopolysaccharide (IFN-γ/LPS) mimic an in vivo inflammatory activation. time-dependent...
Resistive-pulse sensing is a technique widely used to detect single nanoscopic entities such as nanoparticles and large molecules that can block the ion current flow through nanopore or nanopipette. Although species of interest, e.g., antibodies, DNA, biological vesicles, are typically produced by living cells, so far, they have only been detected in bulk solution since no localized resistive-pulse systems has yet reported. In this report, we nanopipette scanning conductance microscopy...
Heterometallic compounds as anticancer agents demonstrating<italic>in vivo</italic>potential for the first time. Titanocene–gold derivatives: promising candidates renal cancer.
Electrochemical methods have been widely used to monitor physiologically important molecules in biological systems. This report describes the first application of scanning electrochemical microscope (SECM) probe redox activity individual living cells. The possibilities measuring rate and investigating pathway transmembrane charge transfer are demonstrated. By this approach, significant differences detected responses given by nonmotile, nontransformed human breast epithelial cells, cells with...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDynamics of the internalization phosphodiester oligodeoxynucleotides in HL60 cellsC. A. Stein, John L. Tonkinson, Li Ming Zhang, Leonid Yakubov, James Gervasoni, Robert Taub, and Susan RotenbergCite this: Biochemistry 1993, 32, 18, 4855–4861Publication Date (Print):May 11, 1993Publication History Published online1 May 2002Published inissue 11 1993https://pubs.acs.org/doi/10.1021/bi00069a022https://doi.org/10.1021/bi00069a022research-articleACS...
Extracellular vesicles (EVs) released from biological cells have attracted considerable interest due to their potential for cancer diagnostics and important role in cell signaling. Most previously reported studies been concerned with the detection of EVs biofluids analysis proteins nucleic acids they contain. Electrochemical resistive-pulse (ERP) sensing enables direct single a specific reactive oxygen nitrogen species such vesicles. Here, we demonstrate applicability ERP distinguish between...
Scanning electrochemical microscopy (SECM) was used to image fields of different types human breast cells in monolayer culture. The goal these experiments demonstrate the possibility distinguishing between nontransformed epithelial (MCF-10A) and metastatic (MDA-MB-231) by their redox activities. Imaging densely packed SECM requires approaches that differ from previously reported with well-separated single cells. combination optical fluorescence microscopies locate individual a homogeneous or...
Forty-six advanced-stage human breast carcinoma specimens were evaluated by immunohistochemistry for PKCα expression and compared with 25 samples of normal adjacent tissue. For tissue, the median staining ductal epithelia was moderate intensity. No observed 67% tumor specimens, only 4% showed intensities greater than in Faint to stroma, inflammatory cells, fibroblasts tumors but absent These findings demonstrate that downregulation protein occurs epithelial cells advanced ( p<0.001).
Micromolar concentrations of N-octylhydroxylamine dramatically increase the induction period in conversion linoleic acid to 13(S)-hydroperoxy-cis-9,trans-11-octadecadienoic (13-HPOD) catalyzed by soybean lipoxygenase 1. The produced is abolished 13-HPOD but not corresponding hydroxy acid. Addition a catalytic amount mixture and results consumption approximately 1 mumol 13-HPOD/mumol present. These can be explained model which oxidizes enzyme from an inactive ferrous form active ferric form,...
A major therapeutic obstacle in clinical oncology is intrinsic or acquired resistance to therapy, leading subsequent relapse. We have previously shown that systemic administration of different cytotoxic drugs can induce a host response contributes tumor angiogenesis, regrowth and metastasis. Here we characterize the single dose local radiation, its contribution progression show plasma from locally irradiated mice increases migratory invasive properties colon carcinoma cells. Furthermore,...
Scanning electrochemical microscopy (SECM) has recently been employed for probing the redox properties of individual mammalian cells. It was shown that intracellular activity can be probed noninvasively by measuring rate mediator regeneration cell. Depending on species (e.g., formal potential, ionic charge, and hydrophobicity), different steps limit reaction. This paper describes evaluation several factors determine rates process. These include concentration centers, mixed potential inside...
Engineered overexpression of protein kinase Calpha (PKCalpha) was previously shown to endow nonmotile MCF-10A human breast cells with aggressive motility. A traceable mutant PKCalpha (Abeyweera, T. P., and Rotenberg, S. A. (2007) Biochemistry 46, 2364-2370) revealed that alpha6-tubulin is phosphorylated in expressing vitro by wild type PKCalpha. Gain-of-function, single site mutations (Ser-->Asp) were constructed at each PKC consensus (Ser158, Ser165, Ser241, Thr337) simulate...
Protein kinase C (PKC) undergoes specific inactivation by nanomolar concentrations of calphostin C. Both PKC-alpha (a Ca(2+)-dependent conventional isoform) and PKC-epsilon Ca(2+)-independent novel are similarly inactivated (75-100 nM produced 50% inhibition), suggesting that requires a site common to both classes PKC. We therefore performed studies identify critical region in the regulatory domain required for A series N-terminal-truncation mutants bovine expressed Saccharomyces cerevisiae...
Blue light from dental photopolymerization devices has significant biological effects on cells. These may alter normal cell function of tissues exposed during placement oral restorations, but recent data suggest that some light-induced also be therapeutically useful, for example in the treatment epithelial cancers. Reactive oxygen species (ROS) appear to mediate blue cells, sources ROS (intra- versus extracellular) and their respective roles cellular response are not known. In current study,...
Diacylglycerol-lactone (DAG-lactone) libraries generated by a solid-phase approach using IRORI technology produced variety of unique biological activities. Subtle differences in chemical diversity two areas the molecule, combination which generates what we have termed "chemical zip codes", are able to transform relatively small space into larger universe activities, as membrane-containing organelles within cell appear be decode these codes". It is postulated that after binding protein kinase...