Potent homophthalimide-type inhibitors of B16F10/L5 mouse melanoma cell invasion

Recently, we developed a series of novel and patent amino-peptidase inhibit ors with a homophthalimide skeleton. Among them, N-(2,6-diethylphenyl)homop hthalimide (PIQ-22) possesses a specific aminopeptidase-inhibiting activity more potent than that of bestatin or actinonin, as assayed In terms of hyd rolysis of L-alanine 4-methylcoumaryl-7-amide (Ala-AMC) by human acute lymp hoblastic leukemia MOLT-4 cells. We show here that PIQ-22 and its 2,6-dimet hylphenyl derivative (PIQ-11) are more potent inhibitors of tumor cell inva sion than bestatin and actinonin in a Matrigel assay using mouse melanoma B 16F10/L5 cells.