Project description:Inactivation of RAR-b, which has been reported as a tumor suppressing gene by numerous studies, results in protective effect against the tumorigenesis induced by activated ErbB2. Moreover, tissue recombination indicates that the RAR-b deficient-microenvironment, rather than the RAR-b status of mammary epithelial cells, plays a key-determining role in the initiation and progression of the mammary carcinoma. Ablation of RAR-b extensively modulates the remodeling of stroma during tumor progression through suppressing the activation and transdifferetiation of myofibroblasts. RNA microarray has been employed to identify the gene expression signature in the mammary stroma of our RAR-b null animals. We want to find out the underlining mechanism of the protective effects resulted from Rarb abliton. A global gene expression profile of mouse mammary stroma was obtained on total RNA from the cleared mammary fat pads (stroma) of both RAR-b KO (n=3) and their wild type (n=3) littermates at the age of four weeks.
Project description:Stat1-null mice (129S6/SvEvTac-Stat1tm1Rds homozygous) uniquely develop estrogen-receptor-positive mammary tumors with incomplete penetrance and long latency. We studied the growth and development of the mammary glands in Stat1-null mice. Stat1-null MGs have faulty branching morphogenesis with abnormal terminal end buds. The Stat1-null MG also fails to sustain growth of 129S6/SvEv wild-type and null epithelium. These abnormalities are partially reversed by added progesterone and prolactin. Transplantation of wild-type bone-marrow into Stat1-null mice does not reverse the mammary gland developmental defects. Media conditioned by Stat1-null epithelium-cleared mammary fat pads does not stimulate epithelial proliferation whereas it is stimulated by conditioned media derived from either wild-type or progesterone and prolactin-treated Stat1-null epithelium-cleared mammary fat pads. Microarrays and multiplex cytokine protein assays showed that the mammary gland of Stat1-null mice had lower levels of growth factors that have been implicated in normal mammary gland growth and development. Transplanted Stat1-null tumors and their isolated cells also grow slower in Stat1-null mammary gland compared to wild-type recipient mammary gland. Stat1-null hosts responded to tumor transplants with granulocytic infiltrates while wild-type hosts show a mononuclear response. These studies demonstrate that growth of normal and neoplastic Stat1-null epithelium primarily depends on the hormonal milieu and factors, such as cytokines, from the mammary stroma.
Project description:MaSC enriched P4 subpopulation with high/low expression of Dll1, were isolated from mammary gland of Dll1-mCherry mice, and sorted for high/low Dll1 expression based on mCherry red fluroscense. Mammary gland associated macrophages were isolated from Dll1cKO mice (C57/B6 strain) and the wild type littermates. Total RNA samples were prepared from these samples and the transcription profiles were compared between these samples to conclude that Dll1 in MaSC is critical to mediate interaction to macrophageal niche and in turn supports the proper MaSC function.
Project description:Inactivation of RAR-b, which has been reported as a tumor suppressing gene by numerous studies, results in protective effect against the tumorigenesis induced by activated ErbB2. Moreover, tissue recombination indicates that the RAR-b deficient-microenvironment, rather than the RAR-b status of mammary epithelial cells, plays a key-determining role in the initiation and progression of the mammary carcinoma. Ablation of RAR-b extensively modulates the remodeling of stroma during tumor progression through suppressing the activation and transdifferetiation of myofibroblasts. RNA microarray has been employed to identify the gene expression signature in the mammary stroma of our RAR-b null animals. We want to find out the underlining mechanism of the protective effects resulted from Rarb abliton.
Project description:Stat1-null mice (129S6/SvEvTac-Stat1tm1Rds homozygous) uniquely develop estrogen-receptor-positive mammary tumors with incomplete penetrance and long latency. We studied the growth and development of the mammary glands in Stat1-null mice. Stat1-null MGs have faulty branching morphogenesis with abnormal terminal end buds. The Stat1-null MG also fails to sustain growth of 129S6/SvEv wild-type and null epithelium. These abnormalities are partially reversed by added progesterone and prolactin. Transplantation of wild-type bone-marrow into Stat1-null mice does not reverse the mammary gland developmental defects. Media conditioned by Stat1-null epithelium-cleared mammary fat pads does not stimulate epithelial proliferation whereas it is stimulated by conditioned media derived from either wild-type or progesterone and prolactin-treated Stat1-null epithelium-cleared mammary fat pads. Microarrays and multiplex cytokine protein assays showed that the mammary gland of Stat1-null mice had lower levels of growth factors that have been implicated in normal mammary gland growth and development. Transplanted Stat1-null tumors and their isolated cells also grow slower in Stat1-null mammary gland compared to wild-type recipient mammary gland. Stat1-null hosts responded to tumor transplants with granulocytic infiltrates while wild-type hosts show a mononuclear response. These studies demonstrate that growth of normal and neoplastic Stat1-null epithelium primarily depends on the hormonal milieu and factors, such as cytokines, from the mammary stroma. Stat1-null mammary glands were compared to 129SvEv WT mammary glands with respect to development, gene expression profiles, growth factors and histology.
Project description:The study of the differential expression profile in bone tissues between Tnni2del175k mutant mice and their wild-type littermates using mRNA array.