Proadrenomedullin N-terminal 20 peptide (PAMP) inhibits proliferation of human neuroblastoma TGW cells

AbstractWe investigated the effects of proadrenomedullin N-terminal 20 peptide (PAMP) and adrenomedullin (AM) on the growth of human neuroblastoma TGW cells. Both PAMP and AM inhibited growth and DNA synthesis in neuroblastoma cells. Calcitonin gene-related peptide (CGRP)8–37, an antagonist to CGRP, abolished the inhibitory effect of AM on growth and DNA synthesis of neuroblastoma cells but did not affect that of PAMP. AM22–52, an antagonist to AM, also reversed the effect of AM. On the other hand, pertussis toxin (PTX) and ω-conotoxin GIVA blocked the effect of PAMP alone. Thus, PAMP inhibits the growth of neuroblastoma cells by inhibiting N-type Ca2+ channels through PTX-sensitive G protein-coupled receptors, which is different mechanism of AM-induced inhibition of the cell growth