Demonstration by DNA fingerprint analysis of genomic instability in mouse BALB 3T3 cells during cell transformation

Honma, Masamitsu; Mizusawa, Hiroshi; Sasaki, Kiyoshi; Hayashi, Makoto; Ohno, Tadao; Tanaka, Noriho; Sofuni, Toshio

doi:10.1016/0027-5107(94)90208-9

Cited by 10 publications

(3 citation statements)

References 52 publications

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“…This is especially true since there is now evidence that the effect occurs in vivo [34]. There is also the interesting question of whether the genetic instability leads to non-lethal events such as transformation in the cells, as has been suggested by several groups [35][36][37][38]. This would be particularly likely if normal cell death mechanisms were deregulated.…”

Section: Hpv-g Cells and Chinese Hamster Ovary Fibroblast (Cho Ki) Cementioning

confidence: 95%

Persistent expression of morphological abnormalities in the distant progeny of irradiated cells

Lyng¹,

O’Reilly²,

Cottell

et al. 1996

Radiation and Environmental Biophysics

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The phenomenon of delayed heritable lethal damage (often referred to as "lethal mutations") in the progeny of cells which survive irradiation is now well established, but little is known of the mechanism by which this cell death occurs. Current theories suggest a generalised genomic instability affecting all cells which leads to the production of some mutations which are lethal, or alternatively that a lethal mutation gene is activated, mutated or induced by radiation and leads to persistent and random cell death at high levels in the progeny. The aim of this study was to look at the morphology of progeny of irradiated cells at various times after irradiation to establish how widespread morphological abnormalities were in the population and whether there was any evidence that such abnormalities were clonal. Using two different cell lines, the results showed that morphological evidence possibly suggestive of apoptosis occurred in the cultures after all doses of radiation and up to 45 cell doublings after exposure. There was no evidence of a decrease in the numbers of damaged or dead cells in colonies with number of divisions after irradiation, or with decreasing original radiation dose. There was a significant dose-dependent increase in the number of cells with microvilli for both cell lines. The dose-dependency of this effect did not change with number of divisions after irradiation. It is clear that morphological evidence of cellular damage persists for several generations after the initial exposure. The effects are widespread in the cell population, and their constancy over time argues strongly for a general instability and against a clonal mechanism, since clonal descendants should die out and leave undamaged survivors. The lack of evidence for necrosis or senescence together with many morphological changes in the cultures suggestive of apoptosis could indicate an active mechanism of cell death. It is concluded that survivor populations of irradiated cells from two widely different mammalian cell lines demonstrate an altered phenotype including gross morphological changes. These result in a higher probability that cell division will fail to yield two healthy progeny.

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Section: Hpv-g Cells and Chinese Hamster Ovary Fibroblast (Cho Ki) Cementioning

confidence: 95%

Persistent expression of morphological abnormalities in the distant progeny of irradiated cells

Lyng¹,

O’Reilly²,

Cottell

et al. 1996

Radiation and Environmental Biophysics

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“…Mutation at serine 15 impaired the apoptotic activity of p53 (29) phosphorylation in the induction of apoptosis. Previous reports showed that MC induces DNA single strand breaks in CHO-KI cells (30) and DNA rearrangements in Balb/c 3T3 cells (31). Metabolites of PAHs such as MC and benzo(a)pyrene are capable of binding to cellular macromolecules including DNA (32).…”

Section: Mc-induced Activation Of P38 Mapk Was Dependent On Early P53mentioning

confidence: 99%

Mechanism of p53-dependent Apoptosis Induced by 3-Methylcholanthrene

Kwon¹,

Ueda

Ueno

et al. 2002

Journal of Biological Chemistry

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Polycyclic aromatic hydrocarbons (PAHs) such as 3-methylcholanthrene (MC) cause untoward effects including carcinogenesis. Here we investigated the effect of MC on apoptosis. MC induced apoptosis, preceded by serine 15 phosphorylation and accumulation of p53. MC failed to cause apoptosis in p53-deficient MG63 cells, whereas ectopic expression of p53 in MG63 cells restored the response to MC. Therefore, MC-induced apoptosis was dependent on p53. MC also activated p38 mitogen-activated protein kinase (MAPK) at 16 -24 h. Accumulation of p53 and p53 phosphorylated at serine 15 was not changed by SB203580, a specific inhibitor of p38 MAPK or overexpression of a dominant negative mutant of p38 MAPK at 8 h after MC treatment, whereas the accumulation was suppressed at 24 h. These results suggest that MC induces accumulation and phosphorylation of p53 via a p38 MAPK-independent (early) and p38 MAPK-dependent (late) pathway. SB203580 repressed MC-induced apoptosis. MC induced p38 MAPK activation in p53 expressing cells but not in p53-deficient cells, indicating that the p38 MAPK activation was dependent on early p53 activation. The current study shows that both p53 and p38 MAPK activation are required for MC-induced apoptosis and provides a novel model of a functional regulation between p53 and p38 MAPK in chemical stress-induced apoptosis.

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“…However, in cells malignantly transformed by ␥-irradiation or genotoxic carcinogens, MS mutations (MSMs) are observed more frequently than in nonmalignant immortalized cell lines (10,11). MSMs have also been found in various human tumors (12,13) and experimental animal tumors induced by chemical carcinogens (14,15).…”

mentioning

confidence: 99%

Minisatellite instability in severe combined immunodeficiency mouse cells

Imai¹,

Nakagama²,

Komatsu³

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

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We have recently found that okadaic acid, which shows strong inhibitor y activity on protein serine͞threonine phosphatases and tumor-promoting activity in vivo and in vitro, induces minisatellite mutation (MSM). Human tumors and chemically induced counterparts in experimental animals are also sometimes associated with MSM. In the present study, we demonstrated minisatellite (MS) instability in severe combined immunodeficiency (SCID) cells in which the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is impaired. Cells from a SCID fibroblast cell line transformed by simian virus 40 large tumor antigen, SC3VA2, and from an embryonal SCID fibroblast cell line, SC1K, were cloned and propagated to 10 7 to 10 8 cells, and then subjected to subcloning. After propagation of each subclone to 10 7 to 10 8 cells, DNA samples were digested with HinfI and analyzed by Southern blotting using the Pc-1 MS sequence as a probe. Under low-stringency conditions, about 40 MS bands were detected, with 45% ؎ 6% and 37% ؎ 3% of SC3VA2 and SC1K cells, respectively, having MSM. In contrast, cells from the RD13B2 cell line, which was established from SCVA2 by introducing human chromosome 8q fragments, on which DNA-PKcs is known to reside, to complement the SCID phenotype, showed a very low frequency of MSM (3% ؎ 3%). The high frequencies of MSM in SC3VA2 and SC1K were significant, with no difference between the two. The present study clearly demonstrates that MS instability exists in SCID fibroblasts, suggesting that DNA-PKcs might be involved in the stable maintenance of MS sequences in the genome.

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Demonstration by DNA fingerprint analysis of genomic instability in mouse BALB 3T3 cells during cell transformation

Cited by 10 publications

References 52 publications

Persistent expression of morphological abnormalities in the distant progeny of irradiated cells

Persistent expression of morphological abnormalities in the distant progeny of irradiated cells

Mechanism of p53-dependent Apoptosis Induced by 3-Methylcholanthrene

Minisatellite instability in severe combined immunodeficiency mouse cells

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