@entity11517 oncogene expression directed by a milk protein gene promoter: tissue specificity, hormonal regulation, and XXXX induction in @entity19 .

@entity1 @entity18243 @entity11517 @entity19 @entity5
The activated @entity1 @entity11517 oncogene was subjected to the control of the promoter region of the @entity19 @entity18243 ( @entity18243 ) gene, which is expressed in mammary epithelial cells in response to lactogenic hormones. The @entity18243 -ras gene was stably introduced into the @entity19 germ line of five @entity19 (one male and four females). @entity18243 -ras expression was observed in the mammary glands of lactating females in two lines derived from female founders. The tissue-directed and hormone-dependent @entity18243 expression was conferred on the @entity11517 oncogene. The signals governing @entity18243 expression are located within 2.5 kilobases of 5' flanking sequence. The other two lines derived from female founders did not express the chimeric gene. In the line derived from the male founder, the @entity18243 -ras gene is integrated into the Y chromosome. Expression was found in the salivary gland of male animals only. After a long latency, @entity18243 -ras-expressing @entity19 developed @entity5 . The @entity5 arose in tissues expressing @entity18243 -ras--i.e., mammary or salivary glands. Compared to the corresponding nonmalignant tissues, @entity18243 -ras expression was enhanced in the @entity5 .
