background: h2ax is a histone variant that is systematically found and ubiquitously distributed throughout the genome. dna double-strand breaks (dsbs) induce phosphorylation of h2ax at serine 139 (γh2ax), an immunocytochemical assay with antibodies recognizing γh2ax has become the gold standard for the detection of dsbs. the importance of this assay to investigate different individual responses...

Introduction: Hydroxyapatite nanoparticles inhibit the growth of various cancer cells. The inhibitory effect of these nanoparticles on breast cancer cells of mcf7 has also been reported. However, no studies have been done on the effect of the hydroxyapatite nanoparticles on the radiation sensitivities of the MCF7 cell Line. Our goal in this study is to investigate the effect of...

The liver colony method is based on the observation that intravenous injection of an appropriate number of LS/BL cells into isologous non-irradiated hosts leads to the formation of colonies of proliferating cells in the livers of these animals. The relationship between the number of cells injected and the number of colonies appearing in the livers was determined. This technique was used to meas...

In this study, we evaluated the role of tumor cell and tumor stroma sensitivity as determinants of radiation-induced tumor growth delay. A DNA double-strand break repair–defective DNA-PKcs / tumor cell line and its radioresistant DNAPKcs–transfected counterpart were used to initiate tumors in nude and hypersensitive severe combined immunodeficient (SCID) mice. Insertion of the human DNA-PKcs ge...

In this study, we evaluated the role of tumor cell and tumor stroma sensitivity as determinants of radiation-induced tumor growth delay. A DNA double-strand break repair-defective DNA-PKcs(-/-) tumor cell line and its radioresistant DNA-PKcs(+/+)-transfected counterpart were used to initiate tumors in nude and hypersensitive severe combined immunodeficient (SCID) mice. Insertion of the human DN...

Cell cycle checkpoints regulate progression through the cell cycle. In yeast, loss of the G2 checkpoint by mutation of the rad9 gene results in increased genetic instability as well as increased sensitivity to ionizing radiation. In contrast, comparing clonogenic survival of cells which are isogeneic except for p53 functional status, we find that loss of a G1 checkpoint in mammalian cells is no...