SV40 T-antigen induces breast cancer formation with a high efficiency in lactating and virgin WAP-SV-T transgenic animals but with a low efficiency in ovariectomized animals.

摘要: The whey acid protein (WAP) is a major mouse milk and its gene expression induced by various lactotrophic hormones (eg, estrogen, progesterone). Transgenic animals harboring the early SV40 coding region (T/t-antigen) under transcriptional control of WAP promoter develop breast cancer after first lactation period. tumor cells synthesize T-antigen with high efficiency indicating that WAP-SV-T escapes down-regulation However about 5-10% tumors became negative during progression was only demonstrable PCR analysis. Both positive expressed estrogen progesterone receptor at comparable rate, hormone levels do not determine transgene. Furthermore, are restricted to pregnancy-lactation Virgin also express both genes low 70% these developed tumors. rate however strongly reduced in ovariectomized animals, ovary play critical role formation.