期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1990
卷号：87
期号：17
页码：6902-6906
DOI：10.1073/pnas.87.17.6902
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We analyzed the normal/mutated allelic ratio of the Ha-ras-1 gene in mouse skin squamous cell carcinomas induced by initiation with dimethylbenz[a]anthracene and promotion with phorbol 12-myristate 13-acetate. DNA for these studies was obtained from short-term tumor cultures (24-72 hr) to eliminate the contribution of stromal and inflammatory cells to the sample. The allelotypic analysis was performed in 25 squamous cell carcinomas by quantitative radio-analysis of the Xba I restriction fragment length polymorphism as detected by BS9, a v-Ha-ras probe, and rehybridization of the Southern blots with probes for chromosomes 7 and 8. Approximately 85% of the tumors presented overrepresentation of the mutated allele in the form of 1 normal/2 mutated (12 tumors), 0 normal/3 mutated (4 tumors), 0 normal/2 mutated (3 tumors), and gene amplification (3 tumors). No tumor was found with a 2 normal/1 mutated allelic ratio. These results support our previous cytogenetic studies, indicating that trisomy of chromosome 7 is present in the majority of these tumors and show that nonrandom duplication of the chromosome carrying the mutated Ha-ras-1 allele appears to be a major mechanism by which the mutated gene is overrepresented.
