Project description:In this study, we have used techniques from cell biology, biochemistry, and genetics to investigate the role of the tyrosine phosphatase Shp2 in tumor cells of MMTV-PyMT mouse mammary glands. Genetic ablation or pharmacological inhibition of Shp2 induces senescence, as determined by the activation of senescence-associated β-gal (SA-β-gal), cyclin-dependent kinase inhibitor 1B (p27), p53, and histone 3 trimethylated lysine 9 (H3K9me3). Senescence induction leads to inhibition of self-renewal of tumor cells and blockage of tumor formation and growth. A signaling cascade was identified that acts downstream of Shp2 to counter senescence: Src, Focal adhesion kinase and Map kinase inhibit senescence by activating the expression of S-phase kinase-associated protein 2 (Skp2), Aurora kinase A (Aurka), and the Notch ligand Delta-like 1 (Dll1), which block p27 and p53. Remarkably, the expression of Shp2 and of selected target genes predicts human breast cancer outcome. We conclude that therapies which rely on senescence induction by inhibiting Shp2 or controlling its target gene products may be useful in blocking breast cancer. For Shp2 ablation, primary mammary tumor cells from MMTV-PyMT;Shp2fl/fl mice were transduced with retroviruses expressing control GFP or CreERT2-GFP, and GFP-positive cells were purified by FACS and cultured as mammospheres for 1 week. Mammospheres were then treated with 50 nM 4-OHT for 2 hours, cultured for another 5 days, and subjected to RNA isolation. For pharmacological inhibition, primary mammary tumor cells from the same mice were cultured as mammospheres for 10 days and then treated with the Shp2 inhibitor GS493 for another 2 days. Mammospheres were then subjected to RNA isolation. Each group contains 3 replicates.
Project description:In this study, we have used techniques from cell biology, biochemistry, and genetics to investigate the role of the tyrosine phosphatase Shp2 in tumor cells of MMTV-PyMT mouse mammary glands. Genetic ablation or pharmacological inhibition of Shp2 induces senescence, as determined by the activation of senescence-associated ?-gal (SA-?-gal), cyclin-dependent kinase inhibitor 1B (p27), p53, and histone 3 trimethylated lysine 9 (H3K9me3). Senescence induction leads to inhibition of self-renewal of tumor cells and blockage of tumor formation and growth. A signaling cascade was identified that acts downstream of Shp2 to counter senescence: Src, Focal adhesion kinase and Map kinase inhibit senescence by activating the expression of S-phase kinase-associated protein 2 (Skp2), Aurora kinase A (Aurka), and the Notch ligand Delta-like 1 (Dll1), which block p27 and p53. Remarkably, the expression of Shp2 and of selected target genes predicts human breast cancer outcome. We conclude that therapies which rely on senescence induction by inhibiting Shp2 or controlling its target gene products may be useful in blocking breast cancer. Primary mammary tumor cells from MMTV-PyMT mice were cultured as mammospheres for 10 days and then treated with specific inhibitors of Notch (DAPT), MEK1 (U0126), FAK (TAE226), or Src (PP2) for another 2 days. Mammospheres were then subjected to RNA isolation. Each group contains 3 replicates.
Project description:In this study, we have used techniques from cell biology, biochemistry, and genetics to investigate the role of the tyrosine phosphatase Shp2 in tumor cells of MMTV-PyMT mouse mammary glands. Genetic ablation or pharmacological inhibition of Shp2 induces senescence, as determined by the activation of senescence-associated β-gal (SA-β-gal), cyclin-dependent kinase inhibitor 1B (p27), p53, and histone 3 trimethylated lysine 9 (H3K9me3). Senescence induction leads to inhibition of self-renewal of tumor cells and blockage of tumor formation and growth. A signaling cascade was identified that acts downstream of Shp2 to counter senescence: Src, Focal adhesion kinase and Map kinase inhibit senescence by activating the expression of S-phase kinase-associated protein 2 (Skp2), Aurora kinase A (Aurka), and the Notch ligand Delta-like 1 (Dll1), which block p27 and p53. Remarkably, the expression of Shp2 and of selected target genes predicts human breast cancer outcome. We conclude that therapies which rely on senescence induction by inhibiting Shp2 or controlling its target gene products may be useful in blocking breast cancer.
Project description:In this study, we have used techniques from cell biology, biochemistry, and genetics to investigate the role of the tyrosine phosphatase Shp2 in tumor cells of MMTV-PyMT mouse mammary glands. Genetic ablation or pharmacological inhibition of Shp2 induces senescence, as determined by the activation of senescence-associated β-gal (SA-β-gal), cyclin-dependent kinase inhibitor 1B (p27), p53, and histone 3 trimethylated lysine 9 (H3K9me3). Senescence induction leads to inhibition of self-renewal of tumor cells and blockage of tumor formation and growth. A signaling cascade was identified that acts downstream of Shp2 to counter senescence: Src, Focal adhesion kinase and Map kinase inhibit senescence by activating the expression of S-phase kinase-associated protein 2 (Skp2), Aurora kinase A (Aurka), and the Notch ligand Delta-like 1 (Dll1), which block p27 and p53. Remarkably, the expression of Shp2 and of selected target genes predicts human breast cancer outcome. We conclude that therapies which rely on senescence induction by inhibiting Shp2 or controlling its target gene products may be useful in blocking breast cancer.
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:To investigate the role of NR1D1 in the progression of breast cancer, mammary gland tumor tissues were obtained from 14 weeks old FVB Nr1d1+/+;PyMT and Nr1d1-/-;PyMT mice and the gene expression patterns were analyzed by RNA-seq.
Project description:In this study, through coupling of our ISDoT tissue decellularisation technology with quantitative mass spectrometry, we explored the changing tumour matrisome during mammary tumourigenesis in the PyMT breast cancer model compared to age-matched healthy control mammary gland