Regulatory effects of glutamate receptor antagonists on the proliferation and migration of WM451LU malignant melanoma cells and their related mechanisms

Objective To evaluate regulatory effects of glutamate receptor antagonists on the proliferation and migration of WM451LU malignant melanoma cells, and to explore their related mechanisms. Methods WM451LU cells at exponential growth phase were classified into 3 groups to be treated with the glutamate receptor antagonist MK-801 at 100 μmol/L(MK-801 group), the glutamate receptor antagonist CPCCOEt at 10 μmol/L(CPCCOEt group), or culture medium(control group). After 24-hour treatment, methyl thiazolyl tetrazolium(MTT)assay was performed to determine cell proliferation rates, scratch assay to evaluate the migration activity of cells, and Western-blot analysis to measure expression levels of proliferating cell nuclear antigen(PCNA), protein kinase Cα(PKCα)both on cell membrane and in cytoplasm, and phosphorylated mitogen-activated protein kinase(p-MAPK). Results After 24-hour treatment, cell proliferation rates were significantly decreased in the MK-801 group and CPCCOEt group compared with the control group(63% ± 3.1% and 60% ± 2.4% vs. 100% ± 1.1%, both P < 0.05). The scratch assay showed that cell-free zones in the control group gradually narrowed over time, and the scratch wound tended to close. However, the cell-free zones in the MK-801 group and CPCCOEt group narrowed more slowly compared with the control group, and were still wide after 24-hour culture with no obvious closure of the scratch. The MK-801 group and CPCCOEt group both showed significantly decreased expressions of PCNA(77.0% ± 5.4% and 72.0% ± 4.2% respectively), PKCα on the cell membrane(0.12 ± 0.02 and 0.14 ± 0.02 respectively), and p-MAPK(0.48 ± 0.03 and 0.36 ± 0.04 respectively)compared with the control group(PCNA: 100.0% ± 1.3%; PKCα: 0.38 ± 0.01; p-MAPK: 1.00 ± 0.02; all P < 0.05). Conclusion In vitro suppression of glutamate receptors can inhibit the proliferation and migration of WM451LU cells, likely through the mediation of the PKCα-MAPK signaling pathway. Key words: Melanoma, experimental; Receptors, glutamate; Cell proliferation; Protein kinase C-alpha; Mitogen-activated protein kinases