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| The effect of different TP53 mutations on the chromosomal stability of a human colonic adenoma derived cell line with endogenous wild type TP53 activity, before and after DNA damage |
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| Author(s): Williams AC, Miller JC, Collard T, Browne SJ, Newbold RF, Paraskeva C |
| Source: GENES CHROMOSOMES & CANCER Volume: 20 Issue: 1 Pages: 44-52 Published: SEP 1997 |
| Times Cited: 9 References: 57 |
| Abstract: We examined the effect of loss of wild type TP53 activity on the chromosomal stability of a human colonic adenoma derived cell line (designated AA/Cl) by studying transfected variants which express different TP53 mutations. Using gross chromosomal aberrations as a measure of instability, we studied metaphase spreads of a vector control cell line (AA/PCMV) and variants expressing the 143(Val-Ala) mutation, which retain endogenous wild type TP53 activity, or the 273(Arg-His) TP53 mutation, which acts as a dominant negative. It was found that the proportion of cells with more than 4% aberrations was significantly greater in the AA/273p53/B cell line (an approximate 5-Fold increase) than in the vector control or the AA/143p53/A cell line. To investigate whether loss of TP53 dependent checkpoints also predisposed the cells to accumulate persistent chromosomal aberrations after DNA damage, cells were exposed to 5 Gy gamma radiation. Regardless of TP53 status, cells with radiation induced chromosomal damage were eliminated through a TP53 independent mechanism, suggesting that loss of TP53 activity did not permit the survival of these cells. In contrast, when exposed to low level gamma radiation (0.2 Gy), decreased wild type TP53 function and/or expression of mutant TP53 protein led to increased radioresistance (both in the non-dominant as well as the dominant mutant expressing cell lines). These findings suggest that loss of TP53 activity and/or acquisition of specific TP53 mutations can increase chromosomal instability and resistance to low level DNA damage in human colonic adenoma cells. This study emphasises the different biological consequences of individual TP53 mutations on the genotype of premalignant colorectal epithelial cells and subsequent implications for tumorigenic progression. (C) 1997 Wiley-Liss, Inc. |
| Document Type: Article |
| Language: English |
| Reprint Address: Williams, AC (reprint author), UNIV BRISTOL, SCH MED SCI, DEPT PATHOL & MICROBIOL, CRC, COLORECTAL TUMOR BIOL RES GRP, UNIV WALK, BRISTOL BS8 1TD, AVON ENGLAND |
Addresses:
1. BRUNEL UNIV, DEPT BIOL & BIOCHEM, UXBRIDGE UB8 3PH, MIDDX ENGLAND |
| Publisher: WILEY-LISS, DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 |
| Subject Category: Oncology; Genetics & Heredity |
| IDS Number: XU170 |
| ISSN: 1045-2257 |
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