Split-dose exposures versus dual ion exposure in human cell neoplastic transformation

  title={Split-dose exposures versus dual ion exposure in human cell neoplastic transformation},
  author={Paula V. Bennett and Noelle C Cutter and Betsy M. Sutherland},
  journal={Radiation and Environmental Biophysics},
Since radiation fields of space contain many-fold more protons than high atomic number, high energy (HZE) particles, cells in astronaut crews will experience on average several proton hits before an HZE hit. Thus radiation regimes of proton exposure before HZE particle exposure simulate space radiation exposure, and measurement of the frequency of neoplastic transformation of human primary cells to anchorage-independent growth simulates an initial step in cancer induction. Although previous… 
Neoplastic Transformation In Vitro by Mixed Beams of High-Energy Iron Ions and Protons
Results indicated an additive interaction under all conditions with no evidence of an adaptive response, with the one possible exception of 10 cGy iron ions followed immediately by 1 Gy protons.
Response of Primary Human Fibroblasts Exposed to Solar Particle Event Protons
Analysis of the data based on particle fluence showed that lethality and transforming potential per particle clearly increased with increasing linear energy transfer (LET) and thus with the decreasing energy of protons, and that the biological response was determined not only by LET but also type of radiation, e.g. particles and photons.
Gamma-H2AX foci in cells exposed to a mixed beam of X-rays and alpha particles
The repair kinetics of large foci after mixed beam exposure was significantly different from predicted based on the effect of the single dose components, and it is hypothesized that the presence of low X-ray-induced damage engages the DNA repair machinery leading to a delayed DNA damage response to the more complex DNA damage induced by alpha particles.
Targeted and non-targeted effects from combinations of low doses of energetic protons and iron ions in human fibroblasts
These data provide the first evidence of interactions between targeted and non-targeted DNA damage caused by dual exposure to low doses of energetic protons and iron ions.
Cellular effects after exposure to mixed beams of ionizing radiation
The purpose of this study was to analyse the cytogenetic effect of exposing human peripheral blood lymphocytes (PBL) to a mixed beam of alpha particles and X-rays. Whole blood collected from one
Low-dose energetic protons induce adaptive and bystander effects that protect human cells against DNA damage caused by a subsequent exposure to energetic iron ions
Exposure of normal human fibroblasts to a low mean absorbed dose of 20 cGy protects the irradiated cells against chromosomal damage induced by a subsequent exposure to a mean absorbeddose of 50 cGy from 1 GeV/u iron ions and shows that protective adaptive responses can spread from cells targeted by low-LET space radiation to bystander cells in their vicinity.
Evaluation of Histone Deacetylase Inhibitors as Radiosensitizers for Proton and Light Ion Radiotherapy
The results of these in vitro studies cast doubt on the clinical efficacy of using HDACi as radiosensitizers for light ion-based hadron radiotherapy given the mixed results on their radiosensitization effectiveness and related possibility of increased second cancer induction.
Exposure of the Bone Marrow Microenvironment to Simulated Solar and Galactic Cosmic Radiation Induces Biological Bystander Effects on Human Hematopoiesis.
The first in-depth examination to define changes that occur in mesenchymal stem cells present in the human BM niche following exposure to accelerated protons and iron ions is performed and provides compelling evidence that simulated SEP/GCR exposures can also contribute to defective hematopoiesis/immunity through "biological bystander effects".
Chromosomal aberrations in peripheral blood lymphocytes exposed to a mixed beam of low energy neutrons and gamma radiation.
  • A. Wójcik, G. Obe, +5 authors W. Sauerwein
  • Medicine
    Journal of radiological protection : official journal of the Society for Radiological Protection
  • 2012
The results indicate that for this endpoint there is no synergism between the high and low LET radiations.
Simultaneous induction of dispersed and clustered DNA lesions compromises DNA damage response in human peripheral blood lymphocytes
The results substantiate the idea that exposure to mixed beams presents a challenge for the cellular DDR system, especially with respect to the question if it is due to an augmented level of initial damage or impaired DNA repair.


Proton-HZE-Particle Sequential Dual-Beam Exposures Increase Anchorage-Independent Growth Frequencies in Primary Human Fibroblasts
Investigation of effects of dual ion irradiations on human cells found anchorage-independent growth frequencies were similar to those expected for additivity, however, irradiation of cells with either an iron or a titanium particle first followed by protons produced only additive levels.
Human cell transformation in the study of sunlight-induced cancers in the skin of man.
Partial reversal of potential transforming lesions by photoreactivation suggests that pyrimidine dimers, as well as other lesions, are important in UV transformation of human cells.
L-selenomethionine modulates high LET radiation-induced alterations of gene expression in cultured human thyroid cells.
A dramatic effect of SeM is revealed on alterations of gene expression caused by space radiation, which provides a basis for furthering knowledge about radiation-induced molecular and cellular changes that lead to cellular transformation and death.
Examination of the oncogenic potential of H19 gene in HeLa x normal human fibroblast hybrid cells.
It is suggested that expression of the H19 gene may be necessary but is not sufficient to confer the tumorigenic phenotype in HeLa x fibroblast hybrids.
Space Radiation Cancer Risks and Uncertainties for Mars Missions
An uncertainty assessment within the linear-additivity model is discussed using the approach of Monte Carlo sampling from subjective error distributions that represent the lack of knowledge in each factor to quantify the overall uncertainty in risk projections.
Human cell transfection with skin cancer DNAs
A DNA transfection system using human cells as recipients is developed, which may allow identification of the genes and specific sequences altered in sunlight-induced human skin cancers.
  • R. J. Wang
  • Chemistry, Medicine
    Photochemistry and photobiology
  • 1975
Fluorescent lamps are utilized in virtually every laboratory working with human and mammalian cells in culture and the results raised the question of possible effects of such fluorescent light on mammalian cells, since exposure of the cells to the light illuminating the laboratory is ditticult to avoid.