Agilent Technologies

About: Agilent Technologies is a company organization based out in Santa Clara, California, United States. It is known for research contribution in the topics: Signal & Mass spectrometry. The organization has 7398 authors who have published 11518 publications receiving 262410 citations. The organization is also known as: Agilent Technologies, Inc..

Noninvasive positron emission tomography and fluorescence imaging of CD133+ tumor stem cells

Abstract: A technology that visualizes tumor stem cells with clinically relevant tracers could have a broad impact on cancer diagnosis and treatment. The AC133 epitope of CD133 currently is one of the best-characterized tumor stem cell markers for many intra- and extracranial tumor entities. Here we demonstrate the successful noninvasive detection of AC133+ tumor stem cells by PET and near-infrared fluorescence molecular tomography in subcutaneous and orthotopic glioma xenografts using antibody-based tracers. Particularly, microPET with 64Cu-NOTA-AC133 mAb yielded high-quality images with outstanding tumor-to-background contrast, clearly delineating subcutaneous tumor stem cell-derived xenografts from surrounding tissues. Intracerebral tumors as small as 2–3 mm also were clearly discernible, and the microPET images reflected the invasive growth pattern of orthotopic cancer stem cell-derived tumors with low density of AC133+ cells. These data provide a basis for further preclinical and clinical use of the developed tracers for high-sensitivity and high-resolution monitoring of AC133+ tumor stem cells.

High-Throughput Profiling of the Serum N-Glycome on Capillary Electrophoresis Microfluidics Systems: Toward Clinical Implementation of GlycoHepatoTest

Abstract: We developed a 3 h procedure for preparing serum N-glycans and labeling them with 8-aminopyrene-1,3,6-trisulfonic acid (APTS) by sequential addition of reagents to the serum and incubation in a polymerase chain reaction (PCR) thermocycler. Moreover, we succeeded in analyzing these samples by capillary electrophoresis on three commercial microfluidics-based platforms: the MCE-202 MultiNA, the 2100 Bioanalyzer, and a modified prototype of the eGene system which were originally designed for nucleic acid separation and detection. Although these instruments use short separation channels, our technical improvements made it possible to reliably measure the N-glycans constituting GlycoHepatoTest. This test comprises a panel of biomarkers that allows follow-up of liver fibrosis patients starting from the early stage. In this way and for the first time, we demonstrate a clinical glycomics assay on an affordable, robust platform so that clinical chemistry laboratories can exploit glycomics in the diagnosis and monitoring of chronic liver disease. Another potential application is the rapid screening of the N-glycosylation of recombinant glycoproteins produced for pharmaceutical use.

Deubiquitination of EGFR by Cezanne-1 contributes to cancer progression.

Abstract: Once stimulated, the epidermal growth factor receptor (EGFR) undergoes self-phosphorylation, which, on the one hand, instigates signaling cascades, and on the other hand, recruits CBL ubiquitin ligases, which mark EGFRs for degradation. Using RNA interference screens, we identified a deubiquitinating enzyme, Cezanne-1, that opposes receptor degradation and enhances EGFR signaling. These functions require the catalytic- and ubiquitin-binding domains of Cezanne-1, and they involve physical interactions and transphosphorylation of Cezanne-1 by EGFR. In line with the ability of Cezanne-1 to augment EGF-induced growth and migration signals, the enzyme is overexpressed in breast cancer. Congruently, the corresponding gene is amplified in approximately one third of mammary tumors, and high transcript levels predict an aggressive disease course. In conclusion, deubiquitination by Cezanne-1 curtails degradation of growth factor receptors, thereby promotes oncogenic growth signals.

Transcriptional profiling of reporter genes used for molecular imaging of embryonic stem cell transplantation.

Abstract: Stem cell therapy offers exciting promise for treatment of ischemic heart disease Recent advances in molecular imaging techniques now allow investigators to monitor cell fate noninvasively and repetitively Here we examine the effects of a triple-fusion reporter gene on embryonic stem (ES) cell transcriptional profiles Murine ES cells were stably transfected with a self-inactivating lentiviral vector carrying a triple-fusion (TF) construct consisting of fluorescence, bioluminescence, and positron emission tomography (PET) reporter genes Fluorescence-activated cell sorting (FACS) analysis allowed isolation of stably transfected populations Microarray studies comparing gene expression in nontransduced control ES cells vs stably transduced ES cells expressing triple fusion (ES-TF) revealed some increases in transcriptional variability Annotation analysis showed that ES-TF cells downregulated cell cycling, cell death, and protein and nucleic acid metabolism genes while upregulating homeostatic and anti-apoptosis genes Despite these transcriptional changes, expression of the TF reporter gene had no significant effects on ES cell viability, proliferation, and differentiation capability Importantly, transplantation studies in murine myocardium demonstrated the feasibility of tracking ES-TF cells in living subjects using bioluminescence and PET imaging Taken together, this is the first study to analyze in detail the effects of reporter genes on molecular imaging of ES cells