Publication Date:
1990-06-01
Description:
The identification of ras oncogenes in human and animal cancers including precancerous lesions indicates that these genes participate in the early stages of neoplastic development. Yet, these observations do not define the timing of ras oncogene activation in the multistep process of carcinogenesis. To ascertain the timing of ras oncogene activation, an animal model system was devised that involves the induction of mammary carcinomas in rats exposed at birth to the carcinogen nitrosomethylurea. High-resolution restriction fragment length polymorphism analysis of polymerase chain reaction-amplified ras sequences revealed the presence of both H-ras and K-ras oncogenes in normal mammary glands 2 weeks after carcinogen treatment and at least 2 months before the onset of neoplasia. These ras oncogenes can remain latent within the mammary gland until exposure to estrogens, demonstrating that activation of ras oncogenes can precede the onset of neoplasia and suggesting that normal physiological proliferative processes such as estrogen-induced mammary gland development may lead to neoplasia if the targeted cells harbor latent ras oncogenes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kumar, R -- Sukumar, S -- Barbacid, M -- 1-RO1-CA48943/CA/NCI NIH HHS/ -- N01-CO-74101/CO/NCI NIH HHS/ -- New York, N.Y. -- Science. 1990 Jun 1;248(4959):1101-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, Squibb Institute for Medical Research, Princeton, NJ 08543.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2188364" target="_blank"〉PubMed〈/a〉
Keywords:
Adenofibroma/genetics
;
Animals
;
Animals, Newborn
;
Base Sequence
;
Carcinoma/genetics
;
Cell Transformation, Neoplastic/*genetics
;
Estrogens/physiology
;
Female
;
Gene Expression Regulation, Neoplastic/*physiology
;
Genes, ras/*physiology
;
Mammary Glands, Animal/growth & development
;
Mammary Neoplasms, Experimental/chemically induced/*genetics
;
Methylnitrosourea
;
Molecular Sequence Data
;
Mutation
;
Polymerase Chain Reaction
;
Rats
;
Rats, Inbred Strains
;
Sexual Maturation
;
Time Factors
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
