[Fragmentation of Ehrlich ascites carcinoma DNA during influences causing aggregation of cytoskeletal proteins].
Upon exposures of Ehrlich ascites carcinoma cells to heat shock (44 degrees, 1 hr), oxidative stress or energy deprivation, their DNA undergoes fragmentation (35-45% after 5 hrs of incubation) which is considered as a hallmark of apoptosis. Prior to DNA fragmentation the cells exhibited blebbing (55-90% after 1 hr), thus being suggestive of cytoskeletal damage and a 1.5-2-fold increase in the Triton-insoluble protein concentration (protein aggregation) after 3 hrs. Rapid cell death (75% after 4 hrs) occurred only under oxidative stress. Electrophoresis of the Triton-insoluble protein fraction revealed that the common feature of all stress exposures used in this study was a dramatic increase in the aggregation of cytoskeletal proteins--actin and the 57 kDa protein. No dependence of DNA fragmentation on intracellular Ca2+ increase was found. Both DNA fragmentation and protein aggregation were suppressed by glucose, whereas Zn2+, an endonuclease inhibitor, suppressed only DNA fragmentation without any effect on protein aggregation. It is suggested that cytoskeletal damage may trigger tumor cell apoptosis.
V L
VL
Gabaĭ
A E
AE
Kabakov
Iu M
IuM
Makarova
V A
VA
Mosina
A F
AF
Mosin
D000818:Animals; D017209:Apoptosis; D002286:Carcinoma, Ehrlich Tumor / Q000235:genetics* / Q000473:pathology; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000378:metabolism*; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D006358:Hot Temperature; D017830:Octoxynol; D010084:Oxidation-Reduction
D003598:Cytoskeletal Proteins; D004273:DNA, Neoplasm; D003902:Detergents; D017830:Octoxynol
Fragmentatsiia DNK astsitnoĭ kartsinomy Erlikha pri vozdeĭstviiakh, vyzyvaiushchikh agregatsiiu belkov tsitoskleta.