title: Lack of growth of a pregnancy-dependent mouse mammary tumor (TPDMT-4) in the absence of pituitary hormones.
abstract: Mammary tumors of line TPDMT-4, established in DDD mice, were characterized by growth during pregnancy and regression after parturition; this resulted in higher growth peaks in subsequent pregnancies in breeders and no growth in virgins. The effect of hypophysectomy on tumor growth in mice given 17beta-estradiol (E) and progesterone (P) or deoxycorticosterone acetate (DCA) was investigated. Growth of cancers occurred in E+P- and E+DCA-treated virgins, but not in cholesterol-treated virgins. Tumors did not grow to palpable sizes in cholesterol-, E+P-, and E+DCA-treated hypophysectomized virgins; this indicated that pituitary hormones were essential for tumor growth. Impalpable cholesterol-treated, 5 of 10 E+P-treated, and 3 of 6 E+DCA-treated hypophysectomized animals. The neoplasms showed ductal and tubular structures that were lined by a single layer of well-differentiated buoidal epithelium, which suggested that the tumor line might be derived from ductal cells.
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000494:pharmacology; D003900:Desoxycorticosterone / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D051379:Mice; D010902:Pituitary Gland / Q000502:physiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000473:pathology*; D011374:Progesterone / Q000494:pharmacology
chemical_list: D003900:Desoxycorticosterone; D011374:Progesterone; D004958:Estradiol; D002784:Cholesterol