[D-Arg1,D-Phe5,D-Trp7,9,Leu11]Substance P (trifluoroacetate salt) (Synonyms: D-Phe5SP, L-756,867, SPD-D)

[D-Arg¹,D-Phe⁵,D-Trp^7,9,Leu¹¹]Substance P (SPD-D) is an analog of substance P and a broad-spectrum neuropeptide antagonist with anticancer activity.¹ It blocks intracellular calcium increases induced by vasopressin, bradykinin , gastrin , and galanin in H-510 small cell lung carcinoma (SCLC) cells. SPD-D also blocks vasopressin- and bradykinin-induced MAPK signaling in H-510 SCLC cells in a concentration-dependent manner. It inhibits DNA synthesis in a panel of cancer cell lines (IC₅₀s = 20-50 μM) and reduces colony formation of HC12, ICR-SC112, HX149, and NCI-H226 cancer cells in vitro (IC₅₀s = 0.5-6.5 μM).² In vivo, SPD-D (2.1 μg, s.c.) inhibits tumor growth in HC12 and ICR-SC112 SCLC mouse xenograft models.³

1.Seckl, M.J., Higgins, T., Widmer, F., et al.[D-Arg1,D-Trp5,7,9,Leu11]substance P: A novel potent inhibitor of signal transduction and growth in vitro and in vivo in small cell lung cancer cellsCancer Res.57(1)51-54(1997) 2.Everard, M.J., Macaulay, V.M., Miller, J.L., et al.In vitro effects of substance P analogue [D-Arg1, D-Phe5, D-Trp7,9, Leu11] substance P on human tumour and normal cell growthBr. J. Cancer65(3)388-392(1992) 3.Everard, M.J., Macaulay, V.M., Millar, J.L., et al.[D-Arg1, D-Phe5, D-Trp7,9, Leu11] substance P inhibits the growth of human small cell lung cancer xenografts in vivoEur. J. Cancer29A(10)1450-1453(1993)