Abstract
Purpose
Estimating cancer risk associated with interplanetary space travel is complicated. Human exposure data to high atomic number, high-energy (HZE) radiation is lacking, so data from low linear energy transfer (low-LET) γ-ray radiation is used in risk models, with the assumption that HZE and γ-ray radiation have comparable biological effects. This assumption has been challenged by reports indicating that HZE radiation might produce more aggressive tumors. The goal of this research is to test whether high-LET HZE radiation induced tumors are more aggressive.
Materials and methods
Murine models of mammary and liver cancer were used to compare the impact of exposure to 0.2Gy of 300MeV/n silicon ions, 3 Gy of γ-rays or no radiation. Numerous measures of tumor aggressiveness were assessed.
Results
For the mammary cancer models, there was no significant change in the tumor latency or metastasis in silicon-irradiated mice compared to controls. For the liver cancer models, we observed an increase in tumor incidence but not tumor aggressiveness in irradiated mice.
Conclusion
Tumors in the HZE-irradiated mice were not more aggressive than those arising from exposure to low-LET γ-rays or spontaneously. Thus, enhanced aggressiveness does not appear to be a uniform characteristic of all tumors in HZE-irradiated animals.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Additional information
Funding
Notes on contributors
Eshwar B. Udho
Eshwar B. Udho is a Senior Scientist at Promega Corporation.
Shane M. Huebner
Shane M. Huebner is an Assistant Scientist at the University of Wisconsin – Madison.
Dawn M. Albrecht
Dawn M. Albrecht is a Senior Research Specialist at the University of Wisconsin – Madison.
Kristina A. Matkowskyj
Kristina A. Matkowskyj is an Associate Professor at the University of Wisconsin – Madison
Linda Clipson
Linda Clipson is a Researcher at the University of Wisconsin – Madison.
Catigan A. Hedican
Catigan A. Hedican was a Research Assistant at Promega Corporation.
Rachel Koth
Rachel Koth was a Research Assistant at Promega Corporation.
Santina M. Snow
Santina M. Snow is a Research Assistant at the University of Wisconsin – Madison.
Emily L. Eberhardt
Emily L. Eberhardt was an undergraduate research assistant at the University of Wisconsin – Madison.
Devon Miller
Devon Miller was an undergraduate research assistant at the University of Wisconsin – Madison.
Rachel Van Doorn
Rachel Van Doorn was an undergraduate research assistant at the University of Wisconsin – Madison.
Genti Gjyzeli
Genti Gjyzeli was an undergraduate research assistant at the University of Wisconsin – Madison.
Erin K. Spengler
Erin Spengler is an Associate Professor at the University of Wisconsin – Madison.
Douglas R. Storts
Douglas R. Storts is Head of Research at Promega Corporation.
Douglas H. Thamm
Douglas H. Thamm is a Professor at Colorado State University.
Elijah F. Edmondson
Elijah F. Edmondson, DVM PhD, is a veterinary pathologist at Frederick National Laboratory for Cancer Research.
Michael M. Weil
Michael M. Weil is a Professor at Colorado State University.
Richard B. Halberg
Richard B. Halberg is an Associate Professor at the University of Wisconsin – Madison.
Jeffery W. Bacher
Jeffery W. Bacher is a Senior Scientist at Promega Corporation and Adjunct Professor at University of Wisconsin – Madison.