TPI-1 (tyrosine phosphatase inhibitor 1) is a SHP-1 inhibitor (IC50 = 40nM) and can be used to study melanomas[1].
TPI-1 (0.01μg/ml, 0.1μg/ml, 1μg/ml, and 3μg/ml; 10min) selectively increases SHP-1 phospho-substrates in Jurkat T cells at low nM (0.01-0.1μg/ml)[1]. TPI-1 (5μM, 30min) increased macrophage phagocytosis through activating STAT3 and STAT6 signaling pathways[2]. TPI-1 (5μM, 2h) could reverse the decreased phosphorylation of both ERK and STAT3 and restore NK cell cytotoxicity under hypoxia in the NK cell line KHYG-1[3].
TPI-1 (1 or 3mg/kg/day, 4 days, s.c.) increases spleen pLck-pY394 and IFNγ+ cells in C57BL/6J mice[1]. TPI-1 (3mg/kg/d, 5 days/week, terminated by the third week, p.o.) inhibited tumor growth, inducing approximately 83% growth inhibition (p < 0.002) compared to the control in the B16 melanoma mouse model[1].
References:
[1] Kundu S, Fan K, Cao M, et al. Novel SHP-1 inhibitors tyrosine phosphatase inhibitor-1 and analogs with preclinical anti-tumor activities as tolerated oral agents. The Journal of Immunology. 2010 Jun 1;184(11):6529-36.
[2] Shen Q, Zhao L, Pan L, et al. Soluble SIRP-alpha promotes murine acute lung injury through suppressing macrophage phagocytosis. Frontiers in Immunology. 2022 May 12;13:865579.
[3] Teng R, Wang Y, Lv N, et al. Hypoxia Impairs NK Cell Cytotoxicity through SHP‐1‐Mediated Attenuation of STAT3 and ERK Signaling Pathways. Journal of Immunology Research. 2020;2020(1):4598476.