title: Ca2+ and calmodulin are involved in the processes conferring stability to DNA in proliferating neoplastic cells.
abstract: We have examined, in proliferating neoplastic cells, the effect on DNA of EGTA (a chelator of Ca2+) and W7 (an inhibitor of calmodulin). The treatment results in release of single-stranded DNA fragments (2-10 kb) from pre-labelled HMW DNA. When DNA from synchronized neoplastic cells in S phase is examined, almost all pre-labelled DNA appears as short fragments. However, fragmentation does not occur in growth-arrested cells or in normal cells. Furthermore, fragmentation can be prevented by incubating cells in excessive amounts of Ca2+. Hence Ca2+ and the Ca2+-binding protein calmodulin are involved in the processes conferring stability to DNA in proliferating neoplastic cells.
mesh_terms: D002118:Calcium / Q000502:physiology*; D002147:Calmodulin / Q000502:physiology*; D002455:Cell Division; D002478:Cells, Cultured; D004273:DNA, Neoplasm / Q000378:metabolism*; D004533:Egtazic Acid / Q000494:pharmacology; D006801:Humans; D007399:Interphase; D009369:Neoplasms / Q000235:genetics*; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D002147:Calmodulin; D004273:DNA, Neoplasm; D013449:Sulfonamides; D004533:Egtazic Acid; C017967:W 7; D002118:Calcium