Brain metastasis is an important cause of mortality in breast cancer patients. A key event during brain metastasis is the migration of cancer cells through blood-brain barrier (BBB). However, the molecular mechanism behind the passage through this natural barrier remains unclear. Here we show that cancer-derived extracellular vesicles (EVs), mediators of cell-cell communication via delivery of ...

We present the first chosen-ciphertext secure public-key encryption schemes resilient to continuous tampering of arbitrary (efficiently computable) functions. Since it is impossible to realize such a scheme without a self-destruction or key-updating mechanism, our proposals allow for either of them. As in the previous works resilient to this type of tampering attacks, our schemes also tolerate ...

Oxyhemoglobin is the species of hemoglobin in erythrocyte hemolysates that inhibits the diazo reaction. Ferric hemoglobin derivatives and species with relatively low molecular mass do not interfere. Conversion of oxyhemoglobin to acid hematin under assay reaction conditions is associated with rapid destruction of bilirubin, which accounts for the diazo reaction error. The most probable mechanis...

Leaf senescence is the terminal stage in the development of perennial plants. Massive physiological changes occur that lead to the shut down of photosynthesis and a cessation of growth. Leaf senescence involves the selective destruction of the chloroplast as the site of photosynthesis. Here, we show that 13-lipoxygenase (13-LOX) accomplishes a key role in the destruction of chloroplasts in sene...

BACKGROUND A subset of signaling pathways play exceptionally important roles in embryonic and post-embryonic development, and mis-regulation of these pathways occurs in most human cancers. One such pathway is the Wnt pathway. The primary mechanism keeping Wnt signaling off in the absence of ligand is regulated proteasomal destruction of the canonical Wnt effector ßcatenin (or its fly homolog Ar...

Multiphoton imaging of the sub-cellular distribution of photosensitizers can provide important clues to their mechanism of action in tumors. We have used this tool to study distribution and pharmacology of photosensitizers in murine hepatoma tumor cells dosed with various photosensitizers. Upon photoactivation, Rose Bengal yields nearly immediate photolytic release of lysosomal enzymes, resulti...

There is a prominent circadian rhythm of bioluminescence in many species of light-emitting dinoflagellates. In Lingulodinium polyedrum a daily synthesis and destruction of proteins is used to regulate activity. Experiments indicate that the amino acids from the degradation are conserved and incorporated into the resynthesized protein in the subsequent cycle. A different species, Pyrocystis lunu...