Françoise Hoffschir

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Data on aneuploidy from a prospective study on a large number of lymphocyte metaphases (over 1000 in 72-h and 100 in 48-h cultures) per individual from eight healthy donors of various ages are reported. Chromosome losses were dependent on culture time, being significantly more frequent in 72-h than in 48-h cultures. All donors exhibited various degrees of(More)
A prospective study of structural rearrangements occurring in normal lymphocytes was carried out. For each of two newborns and four young and two old adults, about 1000 metaphases from 72-h and 120 from 48-h cultures were studied. The frequency of rearrangements between bands 7p14, 7q35, 14q11.2 or 14q12 and 14qter, which is on the average about 0.003, is(More)
The activity of superoxide dismutases (SOD) 1 and 2 was analysed in correlation with mRNA and chromosome content in 6 SV40-transformed (TF) and in non-transformed (NF) human fibroblast cell lines. Total SOD activity was fairly constant, whereas the ratio SOD2/SOD1 was much lower in TF than in NF. The decrease in SOD2 activity was correlated with a low mRNA(More)
The SW620IR1 cell line was derived from SW620 human colon cells surviving to ionizing radiations. It shows an increased radiosensitivity and a higher yield of spontaneous chromosomal aberrations. In order to check whether altered reactive oxygen intermediates (ROI) metabolism is involved in this inherited phenotype, we compared the two cell lines for their(More)
A karyotype study of seven SV40-transformed human fibroblast cell lines was performed using R-banding. Although large variations existed from line to line and, to a lesser degree, from cell to cell in a given line, many common features were found. The most characteristic were chromosome imbalances. Some of the chromosomes or chromosome segments present in(More)
The increased number of manned space missions has made it important to estimate the biological risks encountered by astronauts. As they are exposed to cosmic rays, especially ions with high linear energy transfer (LET), it is necessary to estimate the doses they receive. The most sensitive biological dosimetry used is based on the quantification of(More)
Telomerase represents a relevant target for cancer therapy. Molecules able to stabilize the G-quadruplex (G4), a structure adopted by the 3'-overhang of telomeres, are thought to inhibit telomerase by blocking its access to telomeres. We investigated the cellular effects of four new 2,6-pyridine-dicarboxamide derivatives displaying strong selectivity for G4(More)
The G-overhangs of telomeres are thought to adopt particular conformations, such as T-loops or G-quadruplexes. It has been suggested that G-quadruplex structures could be stabilized by specific ligands in a new approach to cancer treatment consisting in inhibition of telomerase, an enzyme involved in telomere maintenance and cell immortality. Although the(More)
Telomere maintenance is essential to preserve genomic stability and involves several telomere-specific proteins as well as DNA replication and repair proteins. The kinase ATR, which has a crucial function in maintaining genome integrity from yeast to human, has been shown to be involved in telomere maintenance in several eukaryotic organisms, including(More)
Cancer stem cells are increasingly recognized as major therapeutic targets. We report here the isolation of glioma stem cells (GSCs) maintaining telomere length through a telomerase-independent mechanism known as alternative lengthening of telomeres (ALTs). TG20 cells were isolated from a glioblastoma multiforme, which had the ALT phenotype. They have no(More)