Malignant transformation of Bloom syndrome B-lymphoblastoid cell lines by carcinogens.
AUTOR(ES)
Shiraishi, Y
RESUMO
Three types of Bloom syndrome B-lymphoblastoid cell lines, as well as one derived from a normal person, treated with 4-nitroquinoline-N-oxide and N-methyl-N'-nitro-N-nitrosoguanidine (0.3 micrograms/ml for 24 hr), were studied for tumorigenicity in nude mice, colony formation in soft agar, cytogenetic changes, and immunoglobulin markers. When normal and Bloom syndrome cells with normal sister chromatid exchange (SCE) levels and karyotypes (type I) were treated with carcinogens, no significant changes occurred in the immunoglobulin profile and karyotype, only rare colony formation was seen, and no tumors were produced. In contrast, when Bloom syndrome cells with high SCE levels (type II with normal karyotype and type III with an abnormal karyotype) were treated with carcinogens, tumors were produced in 22 of 53 nude mice injected; a high rate of colony formation in soft agar was seen; the cells exhibited virtual loss of immunoglobulin markers; and structural changes in chromosomes 1, 2, 3, 4, 5, 7, 11, 14, and 15 were found in the tumors in addition to the original chromosome abnormalities present in the injected cells. It appears that Bloom syndrome B-lymphoblastoid cell lines with high levels of SCE are highly susceptible to the action of carcinogens, as evidenced by tumor formation in nude mice and colony formation in agar. Apparently, the carcinogens were capable of transforming only those cells that had a critical level of SCE (approximately 140 per cell) and not those with only mildly increased levels (approximately 13 per cell).
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=390507Documentos Relacionados
- Cancer antigens are expressed in a carcinogen-transformed Bloom syndrome B-lymphoblastoid cell line.
- Induction of gamma-interferon activity by elevated temperatures in human B-lymphoblastoid cell lines.
- Incorrect Use of “Immortalization” for B-Lymphoblastoid Cell Lines Transformed by Epstein-Barr Virus
- Variable Methylation of the Epstein-Barr Virus Wp EBNA Gene Promoter in B-Lymphoblastoid Cell Lines
- Bloom syndrome B-lymphoblastoid cells are hypersensitive towards carcinogen and tumor promoter-induced chromosomal alterations and growth in agar.