General Patterns of DNA Repair and Their Possible Significance as Necessary Protection from Environmental Radiation Exposure

ObjectivesThe French nuclear worker cohort allows for the assessment of cancer risk associated with occupational radiation exposure, but workers are also exposed to medical and environmental radiation which can be of the same order of magnitude. This study aims to examine the impact of non-occupational radiation exposures on the dose-risk analysis between occupational radiation exposure and cancer mortality.MethodsThe cohort included workers employed before 1995 for at least one year by CEA, AREVA NC or EDF and badge-monitored for external radiation exposure. Monitoring results were used to calculate occupational individual doses. Scenarios of work-related X-ray and environmental exposures were simulated. Poisson regression was used to quantify associations between occupational exposure and cancer mortality adjusting for non-occupational radiation exposure.ResultsThe mean cumulative dose of external occupational radiation was 18.4 mSv among 59 004 workers. Depending on the hypotheses made, the mean cumulative work-related X-ray dose varied between 3.1 and 9.2 mSv and the mean cumulative environmental dose was around 130 mSv. The unadjusted excess relative rate of cancer per Sievert (ERR/Sv) was 0.34 (90% CI −0.44 to 1.24). Adjusting for environmental radiation exposure did not substantially modify this risk coefficient, but it was attenuated by medical exposure (ERR/Sv point estimate between 0.15 and 0.23).ConclusionsOccupational radiation risk estimates were lower when adjusted for work-related X-ray exposures. Environmental exposures had a very slight impact on the occupational exposure risk estimates. In any scenario of non-occupational exposure considered, a positive but insignificant excess cancer risk associated with occupational exposure was observed.

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P21 is a flexible, multi-functional protein. It governs various tumor cell activities, including autophagy. p21 is a possible radiotherapy target

10.31219/osf.io/ydkca ◽

2021 ◽

Author(s):

Moataz Dowaidar

Keyword(s):

Cell Cycle ◽

Dna Repair ◽

Tumor Microenvironment ◽

Tumor Cell ◽

Radiation Exposure ◽

Future Study ◽

Regulatory Role ◽

Post Translational Modification ◽

Functional Protein ◽

Cellular Processes

p21 is a versatile protein with a lot of different functions. P21 controls several cellular processes in the tumor, including cell cycle, DNA repair, apoptosis, senescence, autophagy, and the tumor microenvironment, in response to radiation exposure. The fact that it is engaged in both of these processes makes things much more puzzling. As a result, truly grasping p21 continues to be a challenge. Researchers have begun to pay attention to p21 and consider it a potential radiotherapeutic target because of its robust regulatory role. The methods by which p21 performs contradictory tasks should be the focus of future study, as well as how to control its oncogenicity selectively. In biological systems, p21 can play a range of roles according to its many post-translational modification sites. The ability to strike a balance between p21's many functions might be the secret to successful radiotherapy.

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