Chromosome Damage Assays

Pohl, H., and Reidy, J. A., 1989, Vitamin C intake influences the bleomycin-induced chromosome damage assay Implications for detection of cancer susceptibility and chromosome breakage syndromes, Mutat. Res. 224 247-52. 

An in-vitro test with mammalian cells (chromosomal damage or mouse lymphoma tk assay)... 

Monomethylhydrazine-induced mutagenesis was not observed in Ames Salmonella/ microsome with activation (Matheson et al. 1978). In vivo tests in mice (dominant lethal, revertants in host-mediated assay), and dogs (micronuclei) were negative (reviewed in Trochimowicz 1994). However, in vitro chromosomal damage in human and rat tissue has been demonstrated, although in vivo liver DNA damage (as determined by DNA alkaline elution) was equivocal (reviewed in Trochimowicz 1994). 

Chromosomal Physical damage to chromosomes (large ordered Chromosomal aberration assay assesses the potential for... 

The in vitro cytogenetic assay is a short-term mutagenicity test for detecting chromosomal damage in cultured mammalian cells. 

Dean, B.J. and Danford, N. (1984). Assays for the detection of chemically induced chromosome damage in cultures mammalian cells. In Mutagenicity Testing. A Practical Approach, (Venitt, S. and Parry, J.M., Eds.). IRL Press, Oxford, pp. 187-232. 

Under Guideline S2B, the following standard test battery is recommended (1) a test for gene mutation in bacteria, (2) an in vitro test with cytogenetic evaluation of chromosomal damage with mammalian cells or an in vitro mouse lymphoma thymidine kinase (TK) assay, and (3) an in vivo test for chromosomal damage using rodent hematopoietic cells. 

The in vivo micronucleus test is used for the detection of damage to chromosomes as well as the mitotic apparatus in bone marrow or peripheral blood cells of rodents. The assay system has been well standardized.14-17 The basic features of the test system are (1) the effect of the test chemical is observed in anucleated polychromatic erythrocytes (PCEs) (2) PCEs have a relatively short lifespan, so that any micronuclei they contain must have been generated as a result of recently induced chromosome damage (3) micronuclei are readily identifiable and their distribution is well defined and (4) the frequency of induced micronuclei in PCEs is dependent on sampling times. 

Although only limited data are available, the weight of evidence indicates that 1,2-diphenylhydrazine is genotoxic in animals. In particular, positive results were obtained in all assays with mammalian systems Overall, the available evidence suggests that 1,2- diphenylhydrazine may cause chromosomal damage or other genotoxic effects in humans. 

Positive results from the in vitro micronucleus test indicate that the test substance induces chromosome damage and/or damage to the cell division apparams, in cultured mammahan somatic cells. Immunochemical labehng (FISH fluorescence in sim hybridization) of kinetochores, or hybridization with general or chromosome specific centromeric/telomeric probes can provide useful information on the mechanism of micronucleus formation. Use of cytokinesis block facilitates the acquisition of the additional mechanistic information (e.g., chromosome nondisjunction) that can be obtained by FISH techniques. The micronucleus assay has a number of advantages over metaphase analysis performed to measure chromosome aberrations (see OECD TG 487 draft). 

An in vitro test with cytogenetic evaluation of chromosomal damage with mammalian cells OR an in vitro mouse lymphoma thymidine kinase assay... 

Benzyl chloride caused genetic mutations and chromosome-damaging effects in a wide variety of in vitro assays it was not mutagenic in vivo in the mouse micronucleus assay. ... 

Ethyl acetate was not mutagenic in bacterial assays it was not genotoxic in a number of in vivo assays but did cause chromosomal damage in hamster cells in vitroT ... 

MBT was not mutagenic in Ames bacterial assays, but it induced chromosomal damage in mammalian cells in culture. ... 

Mackay JM, Fox V, Griffiths K, et al Trichloroacetic acid Investigation into the mechanism of chromosomal damage in the in vitro human lymphocyte cytogenetic assay and the mouse bone marrow micronucleus test. Carcinogenesis 16(5) 1127-1133, 1995... 

Chloro-ort/20-toluidine gave variable results in the majority of bacterial tests for mutagenicity. While most of the mammalian tests were positive, chromosomal aberration assays gave conflicting results. These data overall indicate that 4-chloro-ort/2o-toluidine causes DNA damage in mammalian cells. 

IPEC-US (intended clinical route)a Acute oral and dermal toxicity, skin and eye irritation, and skin sensitization. Bacterial gene mutation and chromosome damage. ADME (intended route). 28-day toxicity (2 species by intended clinical route) Short-term use studies. 90-day toxicity (most appropriate species). Teratology (rat and/or rabbit). Genotoxicity assays. Additional assays (conditional) 1 Short-/midterm studies. One-generation reproduction. Chronic toxicity (rodent and nonrodent) and carcinogenicity (conditional)... 

Methyl acrylate appears to be clastogenic to mammalian cells in vitro. The preferential induction of small colonies rather than large ones in the mouse lymphoma L5178Y tk mutagenicity assay is thought to indicate that mutations arise from chromosomal damage rather than by point mutation. The clastogenic activity of methyl acrylate seen in vitro is not readily detected in vivo. 

The ability of furan to produce chromosome damage in mammalian cells cultured in vitro may be related to the toxicities discussed above as this activity is only evident when rat liver enzymes (S9 mix) are included in the in vitro assay (81MI10502). This is consistent with the enzyme-mediated formation of a DNA-reactive epoxide derivative (cf. Table 2). 

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