Biomaterial Database

Effect of inhibition of DNA synthesis on recovery of X-irradiated L5178Y-S cells. I. Aphidicolin. 1989

M Kapiszewska, and C S Lange

Institute of Molecular Biology, Jagiellonian University, Krakow, Poland.

Irradiated L51 78Y-S cells (LY-S) were characterized by an exponential survival curve and the potentiation effect of split--dose irradiation. Previously we showed [13] that in LY-S cells the reduction of DNA replicative synthesis rate affected the balance between the fixation and repair of sublethal damage (SLD) and of potentially lethal damage (PLD) in favor of repair. We report here that a block of DNA synthesis by aphidicolin (APC), an inhibitor of DNA polymerase alpha, was sufficient to protect LY-S cells from fixation of PLD and SLD induced by X-rays. Treatment with APC 0.5 micrograms/ml for 2 h, efficiently inhibited DNA replication (95%) with minimal effect on survival. Inhibition of DNA synthesis by combined irradiation and APC was not significantly different from APC treatment alone. The level of protection by APC was dependent on the length of time between irradiation and APC application. An opposite effect was observed when the drug treatment had proceeded irradiation: The killing effect of X-ray increased. The effect of aphidicolin treatment remained even after removal of APC and was dependent on the drug concentration and time between drug removal and irradiation. These results are interpreted as indicating that X-ray damage was fixed in LY-S cells, because of their lack of ability to maintain the nucleotide pool balance, and that fixation took place during progression through the cell cycle.

UI	MeSH Term	Description	Entries
D007940	Leukemia L5178	An experimental lymphocytic leukemia of mice.	Lymphoma L5178,L5178, Leukemia,L5178, Lymphoma
D011836	Radiation Tolerance	The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS.	Radiation Sensitivity,Radiosensitivity,Sensitivity, Radiation,Tolerance, Radiation,Radiation Sensitivities,Radiation Tolerances,Radiosensitivities,Sensitivities, Radiation,Tolerances, Radiation
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D004224	Diterpenes	Twenty-carbon compounds derived from MEVALONIC ACID or deoxyxylulose phosphate.	Diterpene,Diterpenes, Cembrane,Diterpenes, Labdane,Diterpenoid,Labdane Diterpene,Norditerpene,Norditerpenes,Norditerpenoid,Cembranes,Diterpenoids,Labdanes,Norditerpenoids,Cembrane Diterpenes,Diterpene, Labdane,Labdane Diterpenes
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D004273	DNA, Neoplasm	DNA present in neoplastic tissue.	Neoplasm DNA
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured