The effects of glutamate receptor blockade on melanocytic transformation were studied in vitro. Riluzole, an inhibitor of glutamate signaling or the noncompetitive metabotropic glutamate receptor-1 (GRM1) antagonist, BAY 36-7620 induced considerable inhibition of colony formation and invasion in GRM1-expressing melanoma lines. No effect was seen on a GRM1-negative melanoma line. Moreover, riluzole and BAY 36-7620 inhibited fresh melanoma tumor growth when cultured on a nylon mesh. These agents were much less effective in preventing cell overgrowth from normal moles. These data indicate GRM1 to be a valid target for drug development in melanoma research (Le, M.N. et al. J Invest Dermatol 2010, 130: 2240).