Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.108 (TAT)
 2,389 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Schwannoma tumors, which occur sporadically and in patients with neurofibromatosis, account for 8% of intracranial tumors and can only be treated by surgical removal. Most schwannomas have biallelic mutations in the NF2 tumor suppressor gene. We previously showed that schwannoma-derived Schwann cells exhibit membrane ruffling and aberrant cell spreading when plated onto laminin, indicative of fundamental F-actin cytoskeletal defects. Here we expand these observations to a large group of sporadic and NF2-related tumors and extend them to schwannomatosis-derived tumors. Mutation at NF2 correlated with F-actin abnormalities, but the extent of morphological change did not correlate with the type of NF2 mutation. We used a recently described molecular strategy, TAT-mediated protein transfer, to acutely introduce the NF2 protein, merlin, into primary human schwannoma cells in an attempt to reverse the cytoskeletal phenotype. Abnormal ruffling and cell spreading by cells with identified NF2 mutations were rapidly reversed by introduction of TAT-merlin. The effect is specific to TAT-merlin isoform 1, the growth-suppressive isoform of merlin. TAT-merlin isoform 2, a TAT-merlin mutant (L64P), and merlin lacking TAT were ineffective in reversing the cytoskeletal phenotype. Results show that merlin isoform 1 is sufficient to restore normal actin organization in NF2-deficient human tumor cells, demonstrating a key role for merlin in the NF2 phenotype. These results lay the foundation for epigenetic complementation studies in NF2 mouse models and possibly for experiments to evaluate the utility of merlin transduction into patients as protein therapy.
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PMID:The neurofibromatosis type 2 gene product, merlin, reverses the F-actin cytoskeletal defects in primary human Schwannoma cells. 1180 6

Understanding of the mechanisms by which systemically administered nanoparticles achieve delivery across biological barriers remains incomplete, due in part to the challenge of tracking nanoparticle fate in the body. Here, we develop a new approach for "barcoding" nanoparticles composed of poly(lactic-co-glycolic acid) (PLGA) with bright, spectrally defined quantum dots (QDs) to enable direct, fluorescent detection of nanoparticle fate with subcellular resolution. We show that QD labeling does not affect major biophysical properties of nanoparticles or their interaction with cells and tissues. Live cell imaging enabled simultaneous visualization of the interaction of control and targeted nanoparticles with bEnd.3 cells in a flow chamber, providing direct evidence that surface modification of nanoparticles with the cell-penetrating peptide TAT increases their biophysical association with cell surfaces over very short time periods under convective current. We next developed this technique for quantitative biodistribution analysis in vivo. These studies demonstrate that nanoparticle surface modification with the cell penetrating peptide TAT facilitates brain-specific delivery that is restricted to brain vasculature. Although nanoparticle entry into the healthy brain parenchyma is minimal, with no evidence for movement of nanoparticles across the blood-brain barrier (BBB), we observed that nanoparticles are able to enter to the central nervous system (CNS) through regions of altered BBB permeability - for example, into circumventricular organs in the brain or leaky vasculature of late-stage intracranial tumors. In sum, these data demonstrate a new, multispectral approach for barcoding PLGA, which enables simultaneous, quantitative analysis of the fate of multiple nanoparticle formulations in vivo.
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PMID:Optical barcoding of PLGA for multispectral analysis of nanoparticle fate in vivo. 2826 36