Project description:The aim of this investigation was to study the consequences of interfering with soluble epoxide hydrolase (sEH) expression on tumor growth and metastasis in genetically modified animals that spontaneously generate tumors without the exogenous application of high concentrations of epoxide mediators or inhibitors. Therefore, breast cancer development was studied in mice expressing the polyoma middle T oncogene (PyMT) under the control of the mouse mammary tumor virus promoter, to induce spontaneous mammary tumors. To facilitate the study of endogenous sEH activity in tumor growth, PyMT mice were then crossed with sEH-/- mice to generate sEH-deficient mice that spontaneously generate breast tumors (so called PyMTsEH mice). For these analyses, primary tumors were removed from 20 week old mice.
Project description:This SuperSeries is composed of the following subset Series: GSE30864: Gene expression of polyoma middle T antigen induced mammary tumors [AKXD x PyMT] GSE30865: Gene expression of polyoma middle T antigen induced mammary tumors [NZB x PyMT] GSE31223: Gene expression of polyoma middle T antigen induced mammary tumors [RNA_Seq : MOLF x PyMT] Refer to individual Series
Project description:Conventional transgenic and knockout models do not allow selective introduction of oncogenic alterations into the progenitor population of mammary cells; thus, the role of progenitor cells in mammary tumorigenesis is yet unknown. By generating transgenic mice expressing tva – encoding the receptor for avian leukosis virus subgroup A (ALV/A) – from the Keratin 6a (K6) gene promoter, we found that K6+ mammary cells are bipotential progenitor cells, but not stem cells. These K6+ cells were readily induced to form tumors by intraductal injection of RCAS (an ALV/A-derived vector) carrying the gene encoding polyoma middle T antigen. Compared with tumors induced by the same oncogene-expressing virus in transgenic mice expressing tva from the commonly used MMTV LTR or other murine models of breast cancer, tumors in this K6-tva line were unique in that they resemble the normal breast-like subtype of human breast cancer. Consequently, these observations suggest that the cell of origin affects mammary tumor phenotypes. This K6-tva model may be useful for preclinical testing of targeted therapy for normal-like breast cancers in patients. Keywords: Three group comparison We carried out Affymetrix array analysis of five RCAS-PyMT-induced tumors each from K6-tva mice and MMTV-tva mice, as well as five mammary tumors from MMTV-PyMT transgenic mice.
Project description:Conventional transgenic and knockout models do not allow selective introduction of oncogenic alterations into the progenitor population of mammary cells; thus, the role of progenitor cells in mammary tumorigenesis is yet unknown. By generating transgenic mice expressing tva – encoding the receptor for avian leukosis virus subgroup A (ALV/A) – from the Keratin 6a (K6) gene promoter, we found that K6+ mammary cells are bipotential progenitor cells, but not stem cells. These K6+ cells were readily induced to form tumors by intraductal injection of RCAS (an ALV/A-derived vector) carrying the gene encoding polyoma middle T antigen. Compared with tumors induced by the same oncogene-expressing virus in transgenic mice expressing tva from the commonly used MMTV LTR or other murine models of breast cancer, tumors in this K6-tva line were unique in that they resemble the normal breast-like subtype of human breast cancer. Consequently, these observations suggest that the cell of origin affects mammary tumor phenotypes. This K6-tva model may be useful for preclinical testing of targeted therapy for normal-like breast cancers in patients. Keywords: Three group comparison
Project description:Junction Adhesion Molecule-A (JAM-A) is present on leukocytes and platelets where it promotes cell adhesion and motility. We are interested in an interaction between JAM-A and tumor progression/metastases. To address this point, we mated JAM-A-/- mice and mouse mammary tumor model MMTV-PyMT mice which, which express polyoma middle T antigen under the control of mouse mammary tumor virus. MMTV-PyMT mice show 100% penetration of mammary tumor and highly metastases to lung. MMTV-PyMT mice without JAM-A show less primary tumor progression, therefore JAM-A enhance primary tumor progression. Then we are addressing the molecular mechanism of this phenomenon by in vivo. Furthermore, we would like to examine JAM-A deficient MMTV tumor signature.
Project description:Junction Adhesion Molecule-A (JAM-A) is present on leukocytes and platelets where it promotes cell adhesion and motility. We are interested in an interaction between JAM-A and tumor progression/metastases. To address this point, we mated JAM-A-/- mice and mouse mammary tumor model MMTV-PyMT mice which, which express polyoma middle T antigen under the control of mouse mammary tumor virus. MMTV-PyMT mice show 100% penetration of mammary tumor and highly metastases to lung. MMTV-PyMT mice without JAM-A show less primary tumor progression, therefore JAM-A enhance primary tumor progression. Then we are addressing the molecular mechanism of this phenomenon by in vivo. Furthermore, we would like to examine JAM-A deficient MMTV tumor signature. Each 3 MMTV-PyMT JAm-A+/+ (JamA+) and 3 MMTV JAM-A-/- (JamA-) mammary tumor were resected at early stages of tumor development for RNA extraction and hybridization on Affymetrix microarrays.
Project description:In this experiment, we have tested the effect of microRNA-203 as a potential differentiation inducer in breast cancer organoids, derived from the PyMT mouse model. MMTV-PyVT transgenic mice express the Polyoma Virus middle T antigen under the direction of the mouse mammary tumor virus promoter/enhancer. Hemizygous MMTV-PyMT females develop palpable mammary tumors which metastasize to the lung. These mice have high penetrance of early onset of mammary cancer compared to other mammary tumor models. PyMT mice were crossed with miR-203 knock-in mice, where miR-203 expression is induced upon DOX treatment. Thus, organoids derived from the mammary gland tumors of such mouse model where evaluated in vitro. miR-203 expression was therefore induced by Doxycycline in vitro, and compared to other well-defined differentiation media for breast cancer tissue, such as the mammary epithelial cell culture media and kit (CC-2551B; Lonza).
Project description:We developed an inducible degradation system for murine polyoma small T antigen (PyST) to study the effects of PyST on gene expression. We examined changes in expression following ectopic expression of tagged antigen and following their degradation in the MCF10A human mammary epithelial cell line.