MTH1, an 8-oxo-2'-deoxyguanosine triphosphatase, and MYH, a DNA glycosylase, cooperate to inhibit mutations induced by chronic exposure to oxidative stress of ionising radiation.

Our previous results showed that in addition to the immediate interaction of ionising radiation with DNA (direct and indirect effect), low-dose and chronic low-dose rate of irradiation induce endogenous oxidative stress. During oxidative stress, free radicals react with DNA, nucleoside triphosphates (dNTPs), proteins and lipids, and modify their structures. The MYH and MTH1 genes play important roles in preventing mutations induced by 8-hydroxy-guanine, which is an oxidised product of guanine.

Interaction of low and high LET radiation in TK6 cells-mechanistic aspects and significance for radiation protection.

Most environmental, occupational and medical exposures to ionising radiation are associated with a simultaneous action of different radiation types. An open question remains whether radiations of different qualities interact with each other to yield effects stronger than expected based on the assumption of additivity. It is possible that DNA damage induced by high linear energy transfer (LET) radiation will lead to an opening of the chromatin structure making the DNA more susceptible to attack by reactive oxygen species (ROS) generated by the low LET radiation.

Studies of adaptive response and mutation induction in MCF-10A cells following exposure to chronic or acute ionizing radiation.

A phenomenon in which exposure to a low adapting dose of radiation makes cells more resistant to the effects of a subsequent high dose exposure is termed radio-adaptive response. Adaptive response could hypothetically reduce the risk of late adverse effects of chronic or acute radiation exposures in humans. Understanding the underlying mechanisms of such responses is of relevance for radiation protection as well as for the clinical applications of radiation in medicine.

Mutations and chromosomal aberrations in hMTH1-transfected and non-transfected TK6 cells after exposure to low dose rates of gamma radiation.

The aim of the present study was to analyse the dose rate effect of gamma radiation at the level of mutations, chromosomal aberrations, and cell growth in TK6 cells with normal as well as reduced levels of hMTH1 protein. TK6 cells were exposed to gamma radiation at dose rates ranging from 1.4 to 30.

Radioprotective effect of hypothermia on cells - a multiparametric approach to delineate the mechanisms.

Purpose: Low temperature (hypothermia) during irradiation of cells has been reported to have a radioprotective effect. The mechanisms are not fully understood. This study further investigates the possible mechanisms behind hypothermia-mediated radioprotection.

Reduction of 8-oxodGTP in the nucleotide pool by hMTH1 leads to reduction in mutations in the human lymphoblastoid cell line TK6 exposed to UVA.

UVA has been suggested to play an important role in UV-induced mutagenesis. The mechanisms by which UVA induces mutations are still a matter of debate. Our aim was to investigate the protective capacity of hMTH1, a nucleotide pool sanitization enzyme with 8-oxodGTPase activity.