Cardiac hypertrophy can lead to heart failure, and is induced either by physiological stimuli eg postnatal development, chronic exercise training or pathological stimuli eg pressure or volume overload. Majority of new therapies for heart failure has mixed outcomes. A combined mouse model and oligo-array approach are used to examine whether phosphoinositide 3-kinase (p110-alpha isoform) activity is critical for maintenance of cardiac function and long-term survival in a setting of heart failure. The significance and expected outcome are to recognise genes involved in models of heart failure ie pathological- vs physiology-hypertrophy, and examine the molecular mechanisms responsible for such activity.
PI3K(p110 alpha) protects against myocardial infarction-induced heart failure: identification of PI3K-regulated miRNA and mRNA.
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View SamplesBreast cancer metastasis to bone is a critical determinant of long-term survival after treatment of primary tumors. We used a mouse model of spontaneous bone metastasis to determine new molecular mechanisms. Differential transcriptome comparisons of primary and metastatic tumor cells revealed that a substantial set of genes suppressed in bone metastases were highly enriched for promoter elements for the type I interferon (IFN) regulatory factor, Irf7, itself suppressed in mouse and human metastases. The critical function of the Irf7 pathway was demonstrated by restoration of exogenous Irf7 or systemic interferon administration, which significantly reduced bone metastases and prolonged metastasis-free survival. Using mice deficient in the type I receptor (Ifnar1-/-) or mature B, T and NK cell responses (NOD Scid IL-2r-/- mice), we demonstrated that Irf7-driven suppression of metastasis was reliant on IFN signaling to host immune cells. Metastasis suppression correlated with decreased accumulation of myeloid-derived suppressor cells and increased CD4++, CD8 T cells and NK cells in the peripheral blood and was reversed by depletion of CD8+ cells and NK cells. Clinical importance of our findings was demonstrated as increased primary tumor Irf7 expression predicted prolonged bone and lung metastasis-free survival. Thus we report for the first time, a novel innate immune pathway, intrinsic to breast cancer cells, whose suppression in turn restricts systemic immunosurveillance to enable metastasis. This pathway may constitute a novel therapeutic target for restricting breast cancer metastases.
Silencing of Irf7 pathways in breast cancer cells promotes bone metastasis through immune escape.
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