Ultraviolet irradiation of monkey cells enhances the repair of DNA adducts in alpha DNA

Journal Article · Thu Nov 01 04:00:00 EST 1984 · Carcinogenesis (N.Y.); (United States)

DOI:https://doi.org/10.1093/carcin/5.11.1505· OSTI ID:5948408

Leadon, S A; Hanawalt, P C

Excision repair of bulky adducts in alpha DNA of African green monkey cells has previously been shown to be deficient relative to that in the overall genome. We have found that u.v. irradiation of these cells results in the enhanced removal of both aflatoxin B1 (AFB1) and acetylaminofluorene (AAF) adducts from the alpha DNA sequences without affecting repair in the bulk of the DNA. The degree of enhanced removal of AFB1 is dependent upon the u.v. dose and the time interval between irradiation and AFB1 treatment. The u.v. enhancement is not inhibited by cycloheximide. Exposure of the cells to dimethylsulfate or gamma-rays does not affect AFB1 adduct repair. The formation and removal of N-acetoxy-2-acetylaminofluorene (NA-AAF) adducts from alpha and bulk DNA was studied in detail. A higher initial level of the acetylated C8 adduct of guanine was found in alpha DNA than in bulk DNA. Although both the acetylated and deacetylated C8 adducts were removed from the two DNA species, the level of repair was significantly greater in the bulk DNA. Irradiation of cells with u.v. prior to treatment with NA-AAF enhanced the removal of both adducts from alpha DNA with little or no effect on repair in bulk DNA. We conclude that the presence of u.v. photoproducts or some intermediate in their processing alters the chromatin structure of alpha DNA thereby rendering bulky adducts accessible to repair enzymes. In addition, the differential formation and repair of AAF adducts in alpha DNA compared with that in the bulk of the genome supports the hypothesis of an altered chromatin structure for alpha domains.

• Research Organization: Stanford Univ., CA
• OSTI ID: 5948408
• Journal Information: Carcinogenesis (N.Y.); (United States), Journal Name: Carcinogenesis (N.Y.); (United States) Vol. 5:11; ISSN CRNGD
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADDUCTS
AFLATOXIN
AMINES
ANIMAL CELLS
ANIMALS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
ANTIGENS
AROMATICS
AZAARENES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CHROMATIN
CONDENSED AROMATICS
CYCLOHEXIMIDE
DNA ADDUCTS
DNA REPAIR
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELECTROMAGNETIC RADIATION
FLUORENE
FUNGICIDES
GAMMA RADIATION
GUANINE
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROXY COMPOUNDS
IONIZING RADIATIONS
MAMMALS
MATERIALS
MONKEYS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
PESTICIDES
PRIMATES
PURINES
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
SULFATES
SULFUR COMPOUNDS
TOXIC MATERIALS
TOXINS
ULTRAVIOLET RADIATION
VERTEBRATES