[Ataxia telangiectasia: effects of cycloheximide on G2 repair of chromosome damage in lymphocytes cultured in vitro]. 1992

J Pincheira, and M Bravo
Departamento de BiologĂ­a Celular, Facultad de Medicina, Universidad de Chile (Campus Norte), Santiago.

The chromosomal sensitivity to the spontaneous and induced DNA damage detected in lymphocytes from patients affected with ataxia telangiectasia (AT) might be related with disturbances in DNA repair mechanisms. We have studied the effect of caffeine, an inhibitor of G2 repair and the enlargement of G2 by 0.5 ug/ml cycloheximide on chromosomal aberration frequencies in AT lymphocytes, both in control and X-ray irradiated conditions. The increase of spontaneous and X-ray induced chromosomal aberrations by caffeine treatments during G2 in AT lymphocytes was higher than in control cells. The number of spontaneous and X-ray induced lesions repaired during G2 in AT cells was higher than in normal cells. The enlargement of G2 duration by 0.5 ug/ml cycloheximide decreased the spontaneous and X-ray induced chromosomal aberrations in AT cells, whereas no such effect was observed in control cells. We postulate that disturbances in the mechanism that control G2 duration might be involved in the high frequency of spontaneous and induced chromosomal aberrations detected in AT lymphocytes.

UI MeSH Term Description Entries
D007399 Interphase The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs). Interphases
D008214 Lymphocytes White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS. Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
D002110 Caffeine A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling. 1,3,7-Trimethylxanthine,Caffedrine,Coffeinum N,Coffeinum Purrum,Dexitac,Durvitan,No Doz,Percoffedrinol N,Percutaféine,Quick-Pep,Vivarin,Quick Pep,QuickPep
D002869 Chromosome Aberrations Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS. Autosome Abnormalities,Cytogenetic Aberrations,Abnormalities, Autosome,Abnormalities, Chromosomal,Abnormalities, Chromosome,Chromosomal Aberrations,Chromosome Abnormalities,Cytogenetic Abnormalities,Aberration, Chromosomal,Aberration, Chromosome,Aberration, Cytogenetic,Aberrations, Chromosomal,Aberrations, Chromosome,Aberrations, Cytogenetic,Abnormalities, Cytogenetic,Abnormality, Autosome,Abnormality, Chromosomal,Abnormality, Chromosome,Abnormality, Cytogenetic,Autosome Abnormality,Chromosomal Aberration,Chromosomal Abnormalities,Chromosomal Abnormality,Chromosome Aberration,Chromosome Abnormality,Cytogenetic Aberration,Cytogenetic Abnormality
D003513 Cycloheximide Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis. Actidione,Cicloheximide
D004260 DNA Repair The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones. DNA Damage Response
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001260 Ataxia Telangiectasia An autosomal recessive inherited disorder characterized by choreoathetosis beginning in childhood, progressive CEREBELLAR ATAXIA; TELANGIECTASIS of CONJUNCTIVA and SKIN; DYSARTHRIA; B- and T-cell immunodeficiency, and RADIOSENSITIVITY to IONIZING RADIATION. Affected individuals are prone to recurrent sinobronchopulmonary infections, lymphoreticular neoplasms, and other malignancies. Serum ALPHA-FETOPROTEINS are usually elevated. (Menkes, Textbook of Child Neurology, 5th ed, p688) The gene for this disorder (ATM) encodes a cell cycle checkpoint protein kinase and has been mapped to chromosome 11 (11q22-q23). Louis-Bar Syndrome,Ataxia Telangiectasia Syndrome,Ataxia-Telangiectasia,Telangiectasia, Cerebello-Oculocutaneous,Louis Bar Syndrome,Syndrome, Ataxia Telangiectasia,Syndrome, Louis-Bar
D066298 In Vitro Techniques Methods to study reactions or processes taking place in an artificial environment outside the living organism. In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In

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