UNLABELLED Inhibition of PARP is a promising therapeutic strategy for homologous recombination-deficient tumors, such as BRCA1-associated cancers. We previously reported that BRCA1-deficient mouse mammary tumors may acquire resistance to the clinical PARP inhibitor (PARPi) olaparib through activation of the P-glycoprotein drug efflux transporter. Here, we show that tumor-specific genetic inacti...

Heterozygous female mice carrying a targeted mutation of the Ets2 transcription factor gene were mated with a mouse strain that develops mammary tumors due to the expression of the polyoma virus middle T oncogene. Tumors from females with only one wild-type Ets2 gene were approximately one-half the size of tumors from controls. The smaller size of the tumors was correlated with a more different...

The cyclooxygenase (COX)-2 gene encodes an inducible prostaglandin synthase enzyme that is overexpressed in adenocarcinomas and other tumors. Deletion of the murine Cox-2 gene in Min mice reduced the incidence of intestinal tumors, suggesting that it is required for tumorigenesis. However, it is not known if overexpression of Cox-2 is sufficient to induce tumorigenic transformation. We have der...

Conditioned medium from cultures of 7,12-dimethylbenz(a)anthracene-induced rat mammary tumor cells contain factors that resemble sarcoma growth factor and other transforming growth factors in biological activity but differ in their physical properties. The mammary tumor factors (MTF) are acid stable and heat and protease sensitive. They inhibit the binding of epidermal growth factor, but not in...

BACKGROUND Accurate early diagnosis of lung metastases is important for establishing therapeutic measures. Therefore, the present study aimed to compare survey thoracic radiographs and computerized tomography (CT) scans to specifically identify lung metastases in female dogs with mammary tumors. METHODS Twenty-one female dogs, weighing 3 to 34 kg and aged from 5 years to 14 years and 10 month...

Prolactin binding in normal mammary glands and pregnancy-dependent mammary tumors and plasma prolactin levels were assayed near parturition in GR/A female mice. Mammary glands and tumors cut into 0.5-mm thick slices were incubated in Medium 199 containing 5 ng of 125I-labeled ovine prolactin at 37 degrees C for 2 hr, and specific prolactin binding was expressed in terms of the difference betwee...

Mammary tumorigenesis was surveyed in retired breeding females in four sublines of the C3H strain: in standard milk-transmitted early oncogenic mouse mammary tumor virus (MMTV)-infected C3H/He and C3H/Ki mice, and in standard milk-transmitted early oncogenic MMTV free C3Hf/He and C3Hf/Ki mice. All of 58 C3H/Ki mice and 98% (306 of 309) of the C3H/He mice developed palpable mammary tumors at ave...