One powerful model system is the genetically modified mouse where several genes induce mammary carcinoma when expressed alone or in combination.
Furthermore, Cao et al. have shown that PRDX1 protects the tumor suppressive function of PTEN phosphatase, likely due to the presence of a reactive oxygen species (ROS) sensitive cysteine in the catalytic domain, and reduces predisposition of genetically modified mice to develop Ras-induced mammary tumors [ 6].
Studies in genetically modified mice have suggested a role for the EGFR pathway in mammary development and neoplastic transformation (Luetteke et al, 1999).
The C57Bl6 strain is of particular interest because it is widely used to study mammary gland development and in the generation of genetically modified mice.
Previous studies in sheep, humans, and genetically modified mice have pointed to inflammatory conditions as a cofactor enabling prion replication in disparate tissues, including liver, pancreas, skeletal muscle, mammary gland, and kidney [11], [25], [8].
Nicotine addiction and nicotinic receptors: lessons from genetically modified mice.
Genetically modified mice mimicking ODDD (oculodentodigital dysplasia), a disease characterized by reduced Cx43 (connexin 43 -mediated gap junctional intercellular communication, represent an in vivo model to assess the role of Cx43 -mediatedy gapnd development and function.
Studies in genetically modified mice revealed that: 1) a PR knockout mouse shows dramatically reduced susceptibility to carcinogenesis [ 15], 2) progesterone increases genomic instability in p53 null mouse models of breast cancer [ 16], and 3) treatment of Brca-1-deficient mice with the anti-progestin mifepristone (RU486) prevented mammary tumorigenesis [ 17].
BSA = bovine serum albumin; FACS = fluorescence-activated cell sorting; FCS = fetal calf serum; FITC = fluorescein isothiocyanate; HA = hemagglutinin; IFN = interferon; IU = infectious units; MEM = modified Eagle's medium; MMTV = mouse mammary tumor virus; PBS = phosphate-buffered saline; VEE = Venezuelan equine encephalitis virus; VRP = virus-like replicon particles.
