A study was made of DNA of different animal species with various radiosensitivity: guinea pig, man, rat and rabbit. It was shown that the radioresistance of the organism increases with increasing relative content of a rapidly reassociating fraction in DNA. As the kinetic complexity of moderately repetitive sequences increases and the total percentage of meaddle and unique DNA fractions grows, the radioresistance of the organism decreases.
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Int J Mol Sci
December 2024
Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Classical radiation biology as we understand it clearly identifies genomic DNA as the primary target of ionizing radiation. The evidence appears rock-solid: ionizing radiation typically induces DSBs with a yield of ~30 per cell per Gy, and unrepaired DSBs are a very cytotoxic lesion. We know very well the kinetics of induction and repair of different types of DNA damage in different organisms and cell lines.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Regenerative Medicine, National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, 249036 Obninsk, Russia.
The evolution of man on Earth took place under conditions of constant exposure to background ionizing radiation (IR). From this point of view, it would be reasonable to hypothesize the existence of adaptive mechanisms that enable the human organism to safely interact with IR at levels approximating long-term natural background levels. In some situations, the successful operation of molecular mechanisms of protection against IR is observed at values significantly exceeding the natural background level, for example, in cancer cells.
View Article and Find Full Text PDFBiomedicines
December 2024
Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Despite attempts at improving survival by employing novel therapies, progression in glioma is nearly universal. Precision biomarkers are critical to advancing outcomes; however, biomarkers for glioma are currently unknown. Most data on which the field can draw for biomarker identification comprise tissue-based analysis requiring the biospecimen to be removed from the tumor.
View Article and Find Full Text PDFCancers (Basel)
December 2024
Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC 27599, USA.
Radiotherapy (RT) is an integral component in the multidisciplinary management of patients with head and neck squamous cell carcinoma (HNSCC). Significant advances have been made toward optimizing tumor control and toxicity profiles of RT for HNSCC in the past two decades. The development of intensity modulated radiotherapy (IMRT) and concurrent chemotherapy established the standard of care for most patients with locally advanced HNSCC around the turn of the century.
View Article and Find Full Text PDFMed Oncol
December 2024
Department of Bio-Sciences and Technology, MMEC, Maharishi Markandeshwar (Deemed to Be University), Mullana, India.
Gastrointestinal cancer is a malignant condition of the gastrointestinal tract (GI) which affect multi-organs of digestive system, such as esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum, and anus. Gastrointestinal cancer is a 5th most common malignant cancer and 4th major cause in cancer-related mortality rate. Various significant facilities are available that have reduced the radio-resistance, chemo-resistance, and their adverse side effects.
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