Action of X-Rays on Mammalian Cells

Abstract

Survival curves of normal human cells from a variety of tissues exposed to varying doses of x-irradiation have been constructed, which permit definition of the intrinsic radiation sensitivity of the reproductive power of each cell type. The mean lethal dose of x-irradiation for all the cells employed, including those from normal and cancerous organs, those exhibiting diploid and polyploid chromosome number; those from embryonic and adult tissues, including recently isolated cells and cultures which had been maintained in vitro for many years, and cells exhibiting either epithelioid or fibroblastic morphology, was found to be contained between the limits of 50 to 150 r. Other similarities in the pattern of radiation effects, such as giant formation and abortive colonial growth, in these cells and that of the HeLa S3, previously studied, confirm the hypothesis that the pattern of reaction to x-irradiation previously elucidated, is representatative, at least in over-all outline, for a large variety of human cells. While the radiation survival curves of various human cells are similar in the gross, small but important characterizing differences have been found. All epithelioid cells so far studied are approximately 2-hit, and more radioresistant than the fibroblast-like cells whose survival data correspond to a mean lethal dose of around 60 r, and which so far can be fitted by either 1-hit or 2-hit curves. The earlier prediction that the major radiobiologic damage to mammalian cells is lodged in the genetic apparatus was confirmed by the demonstration of high frequency of mutants among the survivors of doses of 500 to 900 r. All the data on the x-radiosensitivity of these cells can be explained on the basis of a defect resulting from primary damage localized in one or more chromosomes. These considerations afford a convincing explanation of several aspects of the mammalian radiation syndrome.

Radiobiological Response of Cervical Cancer Cell Line in Low Dose Region: Evidence of Low Dose Hypersensitivity (HRS) and Induced Radioresistance (IRR)

“…Previously, The HRS/IRR response has been studied in SiHa cell line that showed no evidence of HRS [9].The transition dose was found to be 28 cGy for Co60 beam, 25 cGy for 6 MV and 40 cGy for 15 MV photon. The cellular effects of ionizing radiation were described initially by Puck and Marcus [10][11][12]. They first observed the formation of giant cells in HeLa cell colonies following exposure to radiation.…”

The impact of melatonin and carbon ion irradiation on cancer stem cells

“…Clonogenic survival assays have assessed radiosensitivity and establish predictive models for treatment result [100,101]. In the study of Chiblak and colleagues, human primary glioma stem cells (GSC or brain tumor stem cells) spheroid cultures were established from tumor specimens of six consenting glioblastoma patients [28].…”

Beta irradiation: new uses for an old treatment: a review

“…6 In 1932, Desjardins noted that a proportion of irradiated cells exhibited either a temporary inhibition of metabolic activity, or a complete and permanent disintegration, and in 1957, Puck et al demonstrated that the growth of normal fibroblasts in vitro could be inhibited by radiation. 7,8 In the eye, radiation has been shown to inhibit corneal wound healing, with prominent effects on fibroblast proliferation. 9 Radiation therapy has also been utilised as a means of preventing proliferative vitreoretinopathy (PVR).…”