Chinese hamster cells gene mutation testing

In mammalian assays, glycidol has been tested in human lymphocytes and Chinese hamster cells in vitro for induction of chromosomal aberrations and sister chromatid exchanges. It was also tested in vivo in the mouse micronucleus assay. All test results were positive, as were those of gene mutation assays using Chinese hamster V79 cells and mouse lymphoma L5178Y cells. An in-vivo assay to detect chromosomal aberrations in mouse bone-marrow cells gave negative results. 

One system uses mouse lymphoma cells and detects mutations that cause deficiency of thymidine kinase (TK). Another uses Chinese hamster cells and detects mutations in the gene that produces hypoxanthine-guanine phosphoribosyl transferase (HGPRT). Both tests cure efficient, are widely applied, and can be completed in a few weeks. Although not as simple, rapid, and efficient as the Salmonella tests, they have the advantage of being done in a eukaryote. Mammalian-cell cultures cure also used to test for chromosomal mutation. 

Genotoxicity tests were performed with senna fruit, senna leaf extract, sennosides, rhein, and aloe-emodin. Senna fruit, sennosides, and rhein did not increase mutation frequencies in the following test systems bacterial systems, mammalian cell culture tests, mouse lymphoma test, chromosome aberration test with Chinese hamster ovary (CHO) cells, bone marrow micronucleus test, chromosome aberration tests, and melanoblast cell test. With aloe-emodin, mutagenic effects were observed only in vitro in the chromosome aberration test with CHO cells and in the Salmonella reverse mutation test. In the in vitro gene mutation test with V79 cells, no mutagenic potential of aloe-emodin was observed. In vivo studies indicated no mutagenic activity of aloe-emodin, and aloe-emodin did not induce unscheduled DNA synthesis in an ex vivo assay performed with hepato-cytes of male rats (Heidemann et al. 1993). 

Chinese Hamster CHO/Hgprt System. Chinese hamster ovary (CHO) cells have 21 or 22 chromosomes with one intact X chromosome and a large acrocentric marker chromosome (Natarajan and Obe, 1982). The use of these cells in mammalian mutation experiments was first reported by Hsie et al. (1975), and was refined into a quantitative assay for mutagenicity testing by O Neill. The performance of this system has been reviewed by the USA EPA Gene-Tox Program. The experimental procedure for this assay is similar to the V79/Hgprt system already described, and for more detailed descriptions the reader is referred to Li et al. (1987). 

Instituto di Ricerche Biomediche. 1986b. Study of the capacity of the test article para-dichlorobenzene to induce gene mutation in V79 Chinese hamster lung cells. Experiment No. 1030. 

Parmar, D., Srivastava, S.P., Singh, G.B. Seth, PK. (1995) Testicular toxicity of di(2-ethylhexyl) phthalate in developing rats. Vet. hum. Toxicol., 37, 310-313 Party, E.M. (1985) Tests for the effects on mitosis and the mitotic spindle in Chinese hamster primary liver cells (CHl-L) in cnlture. Prog. Mutat. Res., 5, 479 85 Party, J.M. Eckardt, F. (1985) The detection of mitotic gene conversion, point mutation and mitotic segregation nsing the yeast Saccharomyces cerevisiae strain D7. Prog. Mutat. Res., 5, 261-269... 

In cultured mammalian cells, acrylonitrile induced DNA strand breakage, gene mutation, sister chromatid exchanges and chromosomal aberrations, but not aneuploidy or unscheduled DNA synthesis in rat hepatocytes, at least if the silver grain counting method was used. [Studies using the less reliable scintillation counting method have not been summarized.] Cell transformation was induced in several test systems and gap-junctional intercellular communication was inhibited in one study with Chinese hamster V79 cells. 

Carver, J.H., Salazar, E.P, Knize, M.G. Wandres, D.L. (1981) Mutation induction at multiple gene loci in Chinese hamster ovary cells the genetic activity of 15 coded carcinogens and non-carcinogens. In de Serres, F.J. Ashby, J., eds. Evaluation of Short-Term Tests for Carcinogens. Report of the International Collaborative Program (Progress in Mutation Research, Vol. 1), Amsterdam, Elsevier, pp. 594-601... 

There was no evidence of genotoxicity in the standard genotoxicity test battery bacteria reverse mutation (Ames) tests, forward gene mutations in mammalian (Chinese hamster ovary AS42) cells, or mouse bone marrow MN test... 

Phosphine has been reported as negative for induction of reverse gene mutations up to cytotoxic doses in the Ames assay Salmonella typhimurium). Increased chromosomal aberrations were reported in Chinese hamster ovary (CHO) cells exposed to 2500 and 5000 ppm of phosphine without activation with the S9 fraction. Chromosomal aberrations in CHOs were also reported in cells tested with S9 activation at 2500 ppm, but not 5000 ppm. 

DIPE has been tested for genotoxic activity in bacterial mutation assays, a yeast assay for mitotic gene conversion, and in tests using rat liver and Chinese hamster ovary cells with structural chromosome damaging the end point. Negative responses were observed in the bacterial and yeast assays. 

Cytogenetic examination of bone marrow cells showed no increase in aberrations in maternal and neonatal rats following maternal oral exposure to a DeBDE and NoBDE mixture. In vitro assays found that DeBDE did not induce gene mutations in several bacterial tests (Ames assays) or in mammalian cells. DeBDE also did not induce chromosomal aberrations in Chinese hamster ovary cells. However, exposure to the congeners 2,2, 4,4 -tetra-BDE, 3,4-diBDE, and 2-monoBDE caused increased recombinogenic activity at the HGPRT locus in several cell lines. 

Differently from gene mutations, structural chromosome aberrations exert only deleterious effects on both somatic and germ cells. Thus, the in vitro chromosome aberration test (CAvit) has been designed in order to identify agents that induce structural chromosomal changes in cultured mammalian somatic cells. This assay is usually carried out in human peripheral lymphocytes and cell lines such as Chinese hamster ovary (CHO) cells or Chinese hamster... 

The genotoxicity of PCBs has been tested in in vivo and in vitro studies with generally negative results. End points that have been examined in these studies include gene mutations in bacteria and Chinese hamster V79 cells, chromosomal aberrations in human lymphocytes and rat and mouse bone marrow cells and spermatogonia, micronuclei in mouse bone marrow cells, and dominant lethal mutations in rat sperm cells. 

Jet fuel A induced gene mutation in mouse cells in theL5178Y thymidine kinase mouse lymphoma-cell assay in the presence but not in the absence of metabolic activation (mouse or rat liver S9), as reviewed by IARC (1989). Straight-run kerosene has also tested positive in the mouse lymphoma assay in the presence of metabolic activation (as summarized by Koschier 1999). MD API 81-07, a hydrodesulfurized kerosene, was not mutagenic in the mouse lymphoma assay (API 1984, as reviewed by Skisak 1991), nor did it induce SCE in Chinese hamster ovary cells (API 1988a, as reviewed by Skisak 1991). 

Life Science Research (1989) Gene mutation in Chinese hamster V79 cells, test sub-stance MtBE. Report No. 216002-M-03589. Life Science Research, Roma Toxicology Centre, S.P.A.R.K, Rome, Italy... 

---