A possible role for K+ channels in tumor cell injury. Membrane vesicle shedding and nuclear DNA fragmentation.
Mastocytoma P815 tumor cells subjected to low temperature (O degrees C/l h) and shifted to 22 degrees or 37 degrees C undergo morphological, physiological and biochemical changes which are analogous to those induced by immune effector cells, i.e., changes in cell-surface morphology and membrane permeability, elevated O2 consumption rates and nuclear DNA fragmentation [18-21]. Utilizing this low-temperature shift method for the induction of cell injury, we investigated the possible role of K+ channels in this process. Results show that the two classical K+ channel blockers, tetraethylammonium (TEA) and 4-aminopyridine (4-AP), inhibited the low temperature-induced cell-surface membrane vesicle shedding as well as the nuclear DNA-fragmentation process. These results indicate that K+ channel function is required for tumor-cell injury as manifested by nuclear DNA fragmentation and cell-surface membrane vesicle (MV) shedding.
D015761:4-Aminopyridine; D000631:Aminopyridines / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000648:ultrastructure; D002467:Cell Nucleus / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000378:metabolism*; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D012515:Mast-Cell Sarcoma; D051379:Mice; D008855:Microscopy, Electron, Scanning; D011188:Potassium / Q000378:metabolism*; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
D000631:Aminopyridines; D004273:DNA, Neoplasm; D007473:Ion Channels; D013757:Tetraethylammonium Compounds; D019789:Tetraethylammonium; D015761:4-Aminopyridine; D011188:Potassium