Project description:Spleen tyrosine kinase (Syk)del/del mice suppressed atherosclerosis and Sykdeldel macrophages showed cell migration impairment. To investigate the Syk-associated genes in cell migration, we analyzed RNA-Seq of bone marrow monocytes.
Project description:This study revealed pathogenic role of pre-BCR-independent SYK activation in high-risk B-ALL. Intensified and central nervous system (CNS)-directed chemotherapy has significantly improved outcomes for pediatric B-acute lymphoblastic leukemia (B-ALL), but confers significant late-effect morbidities. Moreover, many patients suffer relapses, underscoring the need to develop novel, molecularly targeted B-ALL therapies. Using a mouse model, we showed that leukemic B-cells require pre-B-cell receptor (pre-BCR)-independent spleen tyrosine kinase (SYK) signaling in vivo. In diagnostic samples from human B-ALL patients, SYK and downstream targets were phosphorylated regardless of pre-BCR expression or genetic subtype. Two small molecule SYK inhibitors, fostamatinib and BAY61-3606, attenuated growth of 69 B-ALL samples, including high-risk (HR) subtypes. Orally administered fostamatinib significantly reduced high disease burden after xenotransplantation of HR B-ALL samples into immune-deficient mice, and decreased leukemia dissemination into spleen, liver, kidneys and the CNS of recipients. Thus, SYK activation sustains growth of multiple HR B-ALL subtypes, suggesting that SYK inhibitors may improve outcomes for HR and relapsed B-ALL. B-cell leukemia samples (3) from a mutant mouse model were compared to sorted or cultured preB or proB cells from normal mice using Affymetrix GeneChip arrays.
Project description:This study revealed pathogenic role of pre-BCR-independent SYK activation in high-risk B-ALL. Intensified and central nervous system (CNS)-directed chemotherapy has significantly improved outcomes for pediatric B-acute lymphoblastic leukemia (B-ALL), but confers significant late-effect morbidities. Moreover, many patients suffer relapses, underscoring the need to develop novel, molecularly targeted B-ALL therapies. Using a mouse model, we showed that leukemic B-cells require pre-B-cell receptor (pre-BCR)-independent spleen tyrosine kinase (SYK) signaling in vivo. In diagnostic samples from human B-ALL patients, SYK and downstream targets were phosphorylated regardless of pre-BCR expression or genetic subtype. Two small molecule SYK inhibitors, fostamatinib and BAY61-3606, attenuated growth of 69 B-ALL samples, including high-risk (HR) subtypes. Orally administered fostamatinib significantly reduced high disease burden after xenotransplantation of HR B-ALL samples into immune-deficient mice, and decreased leukemia dissemination into spleen, liver, kidneys and the CNS of recipients. Thus, SYK activation sustains growth of multiple HR B-ALL subtypes, suggesting that SYK inhibitors may improve outcomes for HR and relapsed B-ALL.
Project description:We performed quantitative and qualitative proteomic analysis by nano LC-MS/MS to investigate global changes in the proteome of monocytes isolated from patients' peripheral blood by immunomagnetic separation. Cells were isolated from patients at different stages of non-related and chronic kidney disease-related atherosclerosis compared to healthy controls.
Project description:Fms-like tyrosine kinase 3 (Flt3) is a regulator of hematopoietic progenitor cells. It is a target of tyrosine kinase inhibitors (TKIs) used for acute myeloid leukemia treatment. Flt3 and its ligand (Flt3L) are expressed in the heart and cardiac side effects occur under Flt3-targeting TKIs. Whether Flt3/Flt3L also regulate cardiac progenitor cells (CPCs), however, is not known. The cardiac side population (SP) is a pool of heterogenous CPCs that can give rise to all cardiac lineages, hence contributing to cardiovascular homeostasis. Here we show that SP-CPCs produce and are responsive to Flt3L. Compared to wild-type, SP-CPCs from flt3L-/- mice are less abundant, with less contribution of CD45-CD34+ cells, and lower expression of gene sets related to epithelial-to-mesenchymal transition, cardiovascular development and stem cell differentiation. Upon culturing and compared to wild-type, flt3L-/- Sca1+CD31- SP-CPCs show increased proliferation and less vasculogenic commitment, but differentiation can be induced in the presence of receptor tyrosine kinase-activating growth factors. The observed differences are associated with decreased microvascularisation and global systolic function of flt3L-/- hearts. Thus, Flt3 contributes to a receptor tyrosine kinase signature necessary for the maintenance and functionality of SP-CPCs. These findings have potential implications regarding cardiovascular side effects observed under TKI therapy.
Project description:Tyrosine kinase activity profiling of metatstatic malignant melanoma and normal skin tissue samples was performed using peptide kinase arrays. All samples were run in triplicates with and withouth inhbitor PLX4032 and Sutent Malate in order to identify how tyrosine kinases responds to kinase inhibitor treatment, ex vivo.