Radiation-induced genomic instability: radiation quality and dose response

LE Smith, S Nagar, GJ Kim, WF Morgan - Health physics, 2003 - journals.lww.com
LE Smith, S Nagar, GJ Kim, WF Morgan
Health physics, 2003journals.lww.com
Genomic instability is a term used to describe a phenomenon that results in the
accumulation of multiple changes required to convert a stable genome of a normal cell to an
unstable genome characteristic of a tumor. There has been considerable recent debate
concerning the importance of genomic instability in human cancer and its temporal
occurrence in the carcinogenic process. Radiation is capable of inducing genomic instability
in mammalian cells and instability is thought to be the driving force responsible for radiation …
Abstract
Genomic instability is a term used to describe a phenomenon that results in the accumulation of multiple changes required to convert a stable genome of a normal cell to an unstable genome characteristic of a tumor. There has been considerable recent debate concerning the importance of genomic instability in human cancer and its temporal occurrence in the carcinogenic process. Radiation is capable of inducing genomic instability in mammalian cells and instability is thought to be the driving force responsible for radiation carcinogenesis. Genomic instability is characterized by a large collection of diverse endpoints that include large-scale chromosomal rearrangements and aberrations, amplification of genetic material, aneuploidy, micronucleus formation, microsatellite instability, and gene mutation. The capacity of radiation to induce genomic instability depends to a large extent on radiation quality or linear energy transfer (LET) and dose. There appears to be a low dose threshold effect with low LET, beyond which no additional genomic instability is induced. Low doses of both high and low LET radiation are capable of inducing this phenomenon. This report reviews data concerning dose rate effects of high and low LET radiation and their capacity to induce genomic instability assayed by chromosomal aberrations, delayed lethal mutations, micronuclei and apoptosis.
* Radiation Oncology Research Laboratory, University of Maryland, 655 W. Baltimore Street, Baltimore, MD 21201-1559;† Graduate Program in Human Genetics, University of Maryland, 655 W. Baltimore Street, Baltimore, MD 21201-1559;‡ Molecular and Cellular Biology Graduate Program, University of Maryland, 655 W. Baltimore Street, Baltimore, MD 21201-1559.
Lippincott Williams & Wilkins