Enhanced levels of deoxycytidine kinase and thymidine kinase 1 and 2 after pulsed low dose rate irradiation as an adaptive response to radiation.
After pulsed low dose rate irradiation the activities of deoxycytidine kinase and thymidine kinase 1 and 2 were increased 1.5-2-fold 6 h after treatment. Twenty-four hours after treatment the activities of these enzymes had returned to control levels. We presume that the increase of enzyme activities is part of an adaptive response to irradiation and that this increase could be an explanation for the increased survival in the initial part of the SW-1573 cell survival curve. The observation that not only S-phase specific thymidine kinase 1 but also mitochondrial thymidine kinase 2 increases, implies that both these enzymes play a role in an adaptive response of cells to irradiation.
Kreder
Natasja Castro
NC
Academic Medical Center, University of Amsterdam, Department of Radiotherapy, 1100 DE Amsterdam, The Netherlands.
van Bree
Chris
C
Peters
Godefridus J
GJ
Loves
Willem J P
WJ
Haveman
Jaap
J
D000220:Adaptation, Biological; D002294:Carcinoma, Squamous Cell / Q000201:enzymology*; D002470:Cell Survival; D003842:Deoxycytidine Kinase / Q000096:biosynthesis*; D004790:Enzyme Induction; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology*; D011829:Radiation Dosage; D013937:Thymidine Kinase / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured / Q000201:enzymology / Q000528:radiation effects*
C105339:thymidine kinase 2; D013937:Thymidine Kinase; C092717:thymidine kinase 1; D003842:Deoxycytidine Kinase