TCS 359, FLT3 receptor tyrosine kinase inhibitor

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

Flt3 also known as CD135 or FLT3 tyrosine kinase is a receptor tyrosine kinase that belongs to the class III receptor tyrosine kinase family. It has a molecular weight of approximately 160 kDa. This protein plays an important role in the development of hematopoietic stem and progenitor cells. Flt3 is expressed mainly in early progenitor cells within the bone marrow. Additionally it is present in some populations of mature cells in the peripheral blood and lymphoid organs.

Biological function summary

Flt3 functions as a receptor that is activated by binding to its ligand FLT3 ligand (FLT3L). This interaction stimulates the associated tyrosine kinase activity leading to auto-phosphorylation of Flt3 and subsequent downstream signaling. Flt3 does not form a heterocomplex rather it dimerizes upon ligand binding to initiate signaling cascades. These cascades promote cell proliferation differentiation and survival particularly impacting hematopoiesis and immune responses.

Pathways

Flt3 signaling impacts the internal signaling networks involving the MAPK/ERK and PI3K/AKT pathways both central to cell cycle regulation and apoptosis. Flt3 interacts functionally with proteins such as SHP2 and GRB2 in these pathways aiding signal transduction. The Flt3 receptor also shares functional motifs with KIT and PDGF receptors indicating shared regulatory mechanisms involved in cellular proliferation.

Flt3 mutations especially internal tandem duplications in Flt3/ITD are significant in acute myeloid leukemia (AML) leading to abnormal cell growth and survival. These mutations often co-occur with other genetic anomalies such as NPM1 mutations contributing to the oncogenic process. The abnormal activation of Flt3 kinase activity also has ramifications in myelodysplastic syndromes making it a target for therapeutic intervention with drugs such as anti-FLT3 inhibitors in the treatment regime.