c-H-ras-1 expression in 7,12-dimethyl benzanthracene-induced Balb/c mouse mammary hyperplasias and their tumors.
Dimethylbenzanthracene (DMBA)-induced mouse mammary tumors characteristically contain an activated c-H-ras-1 gene with an A----T transversion in the 61st codon which is expressed as a rapidly migrating p21 c-H-ras. The role of the activated c-H-ras-1 locus in the initiation of mammary neoplasia was analysed by studying seven transplantable, DMBA-induced Balb/c premalignant mammary hyperplasias. The DNAs from these hyperplasias had no evidence of activation of the c-H-ras-1 gene. One of the fifteen tumors arising from untreated hyperplastic outgrowths had a 61st codon mutation. In contrast, 67% of the tumors developing in DMBA-treated hyperplasias had the characteristic 61 codon mutation. All of the tumors with the characteristic mutation expressed the corresponding rapid p21 c-H-ras. These data suggest that although c-H-ras-1 activation may play an important role in neoplastic progression, it had no definable role in the initiation or the maintenance of the mammary hyperplasias studied here.
Cardiff
R D
RD
Department of Pathology, University of California School of Medicine, Davis 95616.
Gumerlock
P H
PH
Soong
M M
MM
Dandekar
S
S
Barry
P A
PA
Young
L J
LJ
Meyers
F J
FJ
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D003062:Codon; D004247:DNA / Q000032:analysis; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006965:Hyperplasia; D008321:Mammary Glands, Animal / Q000473:pathology*; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000235:genetics*; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D011230:Precancerous Conditions / Q000139:chemically induced / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000032:analysis; D016283:Proto-Oncogene Proteins p21(ras); D011519:Proto-Oncogenes
D003062:Codon; D004279:DNA, Viral; D011518:Proto-Oncogene Proteins; D015127:9,10-Dimethyl-1,2-benzanthracene; D004247:DNA; D016283:Proto-Oncogene Proteins p21(ras)