2-(2,5-dichlorophenyl)cyclohexa-2,5-diene-1,4-dione

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. It 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 < sup> + cells in human peripheral blood.

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. It 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 sc agent.