Breast cancer formation in transgenic animals induced by the whey acidic protein SV40 T antigen (WAP-SV-T) hybrid gene.
After injection of the whey acidic protein (WAP)-SV-T hybrid gene into fertilized mouse eggs, eight independent transgenic mouse lines were obtained. Females from three lines developed mammary carcinomas with high frequency, coinciding mostly with lactation. In contrast to the endogenous WAP gene, expression of the hybrid gene continued after lactation. The tumor cells had a very invasive growth characteristic. Tumor regression in vivo was not observed. However, after transfer into tissue culture 25% of the cells ceased to express the hybrid gene and acquired the growth characteristic of normal cells. It was possible to retransform these cells by injection of wild-type SV40 DNA, but not after transfer of the hybrid WAP-SV-T gene. Inactivation of the endogenous WAP and of the WAP-SV-T transgene did not correlate with DNA methylation.
Institut fuer Molekularbiologie und Biochemie, Freien Universitaet Berlin, Germany.
Y J
YJ
Tzeng
E
E
Guhl
M
M
Graessmann
A
A
Graessmann
D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D008325:Mammary Neoplasms, Experimental / Q000209:etiology*; D008745:Methylation; D051379:Mice; D008822:Mice, Transgenic; D008894:Milk Proteins / Q000235:genetics*; D013539:Simian virus 40 / Q000276:immunology*
D000952:Antigens, Polyomavirus Transforming; D008894:Milk Proteins; C024471:whey acidic proteins; D004247:DNA