Since the development of strains of mice with variations in the incidence of spontaneous mammary tumors, attempts have been made to demonstrate anatomic or physiologic differences between them that might be etiologically related to tumor formation. We have searched for such a variation in the urinary excretion rates of the so-called sex hormones because of the many observations linking these ag...

C3H and C3H backcross mice were given repeated injections of preparations from strain-specific or strain-related mammary tumors of recent spontaneous origin together with Freund's adjuvant. The effect of the course of injections on spontaneous mammary tumor development was studied. Pre t rea tment with mammary tumor tissue did not lead to a significant reduction in spontaneous mammary tumor inc...

A transplanted mammary fibroadenoma was found to grow in 95 per cent of intact adult female rats and the increment of tumor weights was progressive and logarithmic. The growth of the tumor was retarded by ovariectomy and still more when this was combined with adrenalectomy. In ovariectomized rats the growth of the tumor was stimulated by phenolic estrogens, this increase being enhanced when pro...

The chemopreventive effects of three agents, rexinoid bexarotene, tyrosine kinase inhibitor gefitinib, and celecoxib, were tested on mammary tumor development arising in p53-null mammary epithelium. The rexinoid bexarotene was the most efficacious inhibitor as it reduced mammary tumor development by 75% in virgin mice and significantly delayed mean tumor development by 98 days in hormone-stimul...

Lymphocytes from BALB/cCrgl mice react to mouse mam mary tumor virus-associated antigen(s) when tested in in vitro blastogenic transformation assays. These mice have a low incidence (<1%) of spontaneous mammary tumors and are free from complete mammary tumor virions. We have studied the nature of the lymphoid cells mediating the lymphocyte transformation reaction to purified mammary tumor virus...

OBJECTIVE Type 2 diabetes increases breast cancer risk and mortality, and hyperinsulinemia has been identified as a major factor linking these two diseases. Thus, we hypothesized that pharmacological reduction of elevated insulin levels would attenuate type 2 diabetes-mediated mammary tumor progression. RESEARCH DESIGN AND METHODS We studied mammary tumor development in MKR(+/+) mice, a nonob...

BACKGROUND Efficacy of withaferin A (WA), an Ayurvedic medicine constituent, for prevention of mammary cancer and its associated mechanisms were investigated using mouse mammary tumor virus-neu (MMTV-neu) transgenic model. METHODS Incidence and burden of mammary cancer and pulmonary metastasis were scored in female MMTV-neu mice after 28 weeks of intraperitoneal administration with 100 µg WA ...

Chemical induction of mammary tumors in mice requires usually a long latency period and is often complicated by high non-mammary tumor related mortality. Classically hormone stimulation has been used as the means to increase tumor incidence. The synthetic progestin medroxyprogesterone acetate (MPA) was postulated by some authors to increase mammary tumor incidence in various rodent models. Howe...

The Neu (ErbB2, HER2) member of the epidermal growth factor receptor family is implicated in many human breast cancers. We have tested the importance of increased angiogenic signaling in the NeuYD [mouse mammary tumor virus (MMTV)-Neu(ndl)-YD5] mammary tumor model. Transgenic mice expressing vascular endothelial growth factor (VEGF)(164) from the MMTV promoter were generated. These mice express...

The tumorigenicity of dexamethasone-treated tissuecultured mammary tumor cells was compared to that of untreated mammary tumor cells. The dexamethasone-induced cells progressed faster in normal syngeneic ani mals than did untreated mammary tumor cells. The fact that the growth rate differential was also observed in athymic mice suggests that T-lymphocyte-mediated im munity was not a factor in t...