Relationship of the cellular and molecular effects of alpha-particle irradiation to radon-induced lung cancer
- Case Western Reserve Univ., Cleveland, OH (United States)
The exact processes involved in radon-induced lung cancer have not as yet been delineated, but it is thought that DNA damage induced by alpha particles emitted by radon decay products is responsible for the carcinogenic effects. Although the molecular and cellular damage induced by alpha particles has been found to be similar to that induced by low-LET radiation, the RBE for the alpha-induced effects is greater than unity. The efficiency with which alpha irradiation induces damage is thought to result from the production of lesions which are irreparable, as evidenced by the deficiency in cellular recovery processes and the presence of a relatively large fraction of unrepaired chromosome breaks and DNA double-strand breaks following exposure of cells to alpha radiation. The irreparable DNA lesions may consist of locally multiply damaged sites caused by the deposition of large quantities of energy in a small volume of DNA. However, even though a fraction of the lesions is irreparable, not all lesions are lethal, since alpha radiation has been found to be both mutagenic and carcinogenic. In some strains of cells, the ratio of mutagenic to lethal lesions is greater after exposure to alpha radiation than to low-LET radiation. Generally, large deletions have been found in a greater percentage of alpha-radiation-induced mutants than in low-LET-radiation-induced mutants. It is possible that the carcinogenic effects of alpha irradiation are the result of deletions which cause the activation of oncogenes or the inactivation of tumor suppressor genes.
- DOE Contract Number:
- FG02-88ER60658
- OSTI ID:
- 44898
- Report Number(s):
- CONF-901010--Pt.2; CNN: Grant R37 CA15901; Grant P30 CA 43703
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mutagenicity of radon and radon daughters
Mutagenicity of radon and radon daughters. Annual progress report