Antitumoral action of the neurokinin-1 receptor antagonist L-733 060 on human melanoma cell lines

Abstract
Melanoma represents 1% of all cancers and accounts for approximately 65% of skin cancer deaths. At present, effective treatment does not exist. Substance P (SP) is a neuropeptide expressed in invasive malignant melanomas. We studied the in vitro growth inhibitory capacity of the potent and long-acting neurokinin-1 (NK1) receptor antagonist L-733 060 at concentration ranges of 2.5–20 μM, 10–30 μM and 20–50 μM in the melanoma cell lines COLO 858, MEL H0 and COLO 679, respectively. A Coulter counter was used to determine the number of viable cells, and the tetrazolium compound 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)2-(4-sulphophenyl)-2H-tetrazolium, inner salt (MTS) colorimetric method was used to evaluate cell proliferation. L-733 060 inhibited the growth of all three cell lines in a dose-dependent manner. The 50% inhibition concentration (IC50) was 8.7 μM at 48 h and 7.1 μM at 96 h for COLO 858, 27.5 μM at 24 h and 18.9 μM at 48 h for MEL H0, and 33.8 μM at 30 h and 31.5 μM at 72 h for COLO 679. These findings indicate that the NK1 receptor antagonist L-733 060 acts as an antitumoral agent. This action, shown here for the first time, suggests that the NK1 receptor antagonist L-733 060 could be a promising therapeutic drug in the treatment of the human melanoma.