Early-phase occurrence of K+ and Cl- efflux in addition to Ca 2+ mobilization is a prerequisite to apoptosis in HeLa cells.

Sustained rise in cytosolic Ca(2+) and cell shrinkage mainly caused by K(+) and Cl(-) efflux are known to be prerequisites to apoptotic cell death. Here, we investigated how the efflux of K(+) and Cl(-) as well as the rise in cytosolic Ca(2+) occur prior to caspase activation and are coupled to each other in apoptotic human epithelial HeLa cells. Caspase-3 activation and DNA laddering induced by staurosporine were abolished by blockers of K(+) and Cl(-) channels or cytosolic Ca(2+) chelation.

Apoptotic Volume Decrease (AVD) Is Independent of Mitochondrial Dysfunction and Initiator Caspase Activation.

Persistent cell shrinkage is a major hallmark of apoptotic cell death. The early-phase shrinkage, which starts within 30-120 min after apoptotic stimulation and is called apoptotic volume decrease (AVD), is known to be accomplished by activation of K+ channels and volume-sensitive outwardly rectifying (VSOR) Cl- channels in a manner independent of caspase-3 activation. However, it is controversial whether AVD depends on apoptotic dysfunction of mitochondria and activation of initiator caspases.

MiR-107 and MiR-185 can induce cell cycle arrest in human non small cell lung cancer cell lines.

Background: MicroRNAs (miRNAs) are short single stranded noncoding RNAs that suppress gene expression through either translational repression or degradation of target mRNAs. The annealing between messenger RNAs and 5' seed region of miRNAs is believed to be essential for the specific suppression of target gene expression. One miRNA can have several hundred different targets in a cell.

Prerequisite role of persistent cell shrinkage in apoptosis of human epithelial cells.

Persistent cell volume reduction is a major hallmark of apoptosis. Recent studies have demonstrated that cell volume reduction is not a passive, secondary event of the apoptotic cell death process. Whole-cell shrinkage, termed apoptotic volume decrease (AVD), takes place soon after stimulation with apoptogen and precedes caspase activation, DNA and cell fragmentation in a variety of cell types including human epithelial cells.

Dysfunction of regulatory volume increase is a key component of apoptosis.

Sustained cell shrinkage is a major hallmark of apoptotic cell death. In apoptotic cells, whole cell volume reduction, called apoptotic volume decrease (AVD), proceeds until fragmentation of cells. Under non-apoptotic conditions, human epithelial HeLa cells exhibited a slow regulatory volume increase (RVI) after osmotic shrinkage induced by exposure to hypertonic solution.

Cell culture in a closed nano-space.

The minimum size of a closed nano-space in which cells can survive was determined using 4-nl nanowells. One or two cells could divide in the nanowell. Our results suggest that the cell division activity in the nano-space is determined by the conflict between intercellular effects and consumption of substrates.

Dual roles of plasmalemmal chloride channels in induction of cell death.

Even under anisotonic conditions, most cells can regulate their volume by mechanisms called regulatory volume decrease (RVD) and increase (RVI) after osmotic swelling or shrinkage, respectively. In contrast, the initial processes of necrosis and apoptosis are associated with persistent swelling and shrinkage. Necrotic volume increase (NVI) is initiated by uptake of osmolytes, such as Na+, Cl- and lactate, under conditions of injury, hypoxia, ischaemia, acidosis or lactacidosis.

LTRPC2 Ca2+-permeable channel activated by changes in redox status confers susceptibility to cell death.

Redox status changes exert critical impacts on necrotic/apoptotic and normal cellular processes. We report here a widely expressed Ca2+-permeable cation channel, LTRPC2, activated by micromolar levels of H2O2 and agents that produce reactive oxygen/nitrogen species. This sensitivity of LTRPC2 to redox state modifiers was attributable to an agonistic binding of nicotinamide adenine dinucleotide (beta-NAD+) to the MutT motif.