The presence of DNA breaks and the formation of chromatid aberrations after incorporation of {sup 125}IdUrd may be necessary but are not sufficient to block cell cycle progression in G{sub 2} phase

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Radiation Research

DOI:https://doi.org/10.2307/3579190· OSTI ID:478293

Schneiderman, M H; Schneiderman, G S ^[1]; Muehlmann-Diaz, M C; Bedford, J S ^[2]

---

1. Univ. of Nebraska Medical Center, Omaha, NE (United States)
2. Colorado State Univ., Fort Collins, CO (United States)

Cell progression into mitosis and chromatid aberration frequencies were compared in two Chinese hamster ovary (CHO) cell lines after incorporation of {sup 125}IdUrd. Asynchronous, exponentially growing populations of CHO K1 and the DNA repair-deficient, radiation-sensitive CHO irs-20 cells were compared after a 10-min exposure to 14.8 kBq/ml {sup 125}IdUrd. Essentially no differences were seen for either end point between the cells of the two cell lines. As the cells in S phase at the time of labeling entered the mitotic cell selection window, the number of mitotic cells of each cell line declined to approximately 60% of the respective unlabeled control. Chromosome analysis of the mitotically selected cells indicated an {sup 125}I decay-dependent increase in the number of chromatid aberrations in cells of both cell lines. The appearance of aberrations together with the known rates of production and rejoining of DNA double-strand breaks show that cells are able to progress through G{sub 2} phase and into mitosis in the presence of such breaks. The data suggest that DNA damage may be necessary, but is not sufficient to cause a radiation-induced blockade of cell progression through G{sub 2} phase. 31 refs., 4 figs., 2 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 478293
• Journal Information: Radiation Research, Journal Name: Radiation Research Journal Issue: 1 Vol. 145; ISSN 0033-7587; ISSN RAREAE
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
CELL CYCLE
CHO CELLS
CHROMATIDS
CHROMOSOMAL ABERRATIONS
DNA
DNA REPAIR
GENETIC RADIATION EFFECTS
HUMAN CHROMOSOMES
IODINE 125
MITOSIS
MUTATION FREQUENCY
MUTATIONS
STRAND BREAKS