The
Tyr-Ile-Gly-Ser-Arg (
YIGSR)
peptide derived from the
laminin B1 chain has been shown to decrease
tumor growth and
metastasis. Utilizing the multimeric
antigen peptide system assembled on a branched
lysine core, we synthesized several sizes of multimeric
YIGSR, (CH3CO-Tyr-Ile-Gly-Ser-Arg-Gly)16-Lys8-Lys4-Lys2 -
Lys-Gly [(Ac-YIGSRG)16 K8K4K2KG] (designated Ac-Y16), (Ac-YIGSRG)8K4K2KG (Ac-Y8), and (Ac-YIGSRG)4K2KG (Ac-Y4), and related
peptides, Ac-(YIGSRG)4-NH2 (Ac-Y4L) and Ac-YIGSR-NH2 (Ac-Y1) and evaluated their
biological activities in inhibiting
tumor growth and
metastasis. Coinjection of 0.2 mg/mouse of Ac-Y16 i.v. with B16-F10 mouse
melanoma cells inhibited lung colony formation by 97%, whereas 0.2 mg/mouse of Ac-Y1 inhibited by 50%. The larger the
peptide (Ac-Y16 > Ac-Y8 > Ac-Y4 > Ac-Y1), the more inhibitory effect there was on lung
metastasis. Ac-Y16 also inhibited the growth of s.c.-injected B16-F10
tumors. These data demonstrate that the multimeric
YIGSR peptides strongly enhanced the activity of
YIGSR in inhibiting
tumor growth and
metastasis and suggest that these compounds are potentially useful for clinical applications.