TPI-1

TPI-1, also known as Tyrosine Phosphatase Inhibitor 1, is a SHP-1 inhibitor; inhibits recombinant SHP-1 with an IC₅₀ of 40 nM. IC50 & Target: IC50: 40 nM (recombinant SHP-1)^[1] In Vitro: SHP-1 has been implicated as a potential cancer therapeutic target. TPI-1 is effective starting at 10 ng/mL in increasing SHP-1 phospho-substrates pLck-pY394. TPI-1 selectively increases SHP-1 phospho-substrates (pLck-pY394, pZap70 and pSlp76) in Jurkat T cells but has little effects on pERK1/2 or pLck-pY505. TPI-1 induces mouse splenic-IFNγ⁺ cells and induces IFNγ⁺ cells in human peripheral blood^[1]. In Vivo: TPI-1 inhibits the growth of B16 melanoma tumors in mice at a tolerated oral dose in a T cell-dependent manner but has little effects on B16 cell growth in culture. TPI-1 thus also increases pLck-pY394 and IFNγ⁺ cells in mice. TPI-1 also inhibits B16 tumor growth and prolongs tumor mice survival as a tolerated s.c. agent^[1].