Abstract: Objective: To determine the effects of Lyn inhibitor Bafetinib on the proliferation and apoptosis of human malignant melanoma cell UACC62. Methods: The cells were cultured in vitro, then they were treated with various concentrations and selected the suitable concentration that can advance further experiments. The proliferation of cells were detected by CCK-8 and Clone formation assays. The expression of Lyn, apoptosis-related proteins (Bcl-2, Bax, Beclin) and related-signaling pathway proteins were detected by Western blot. Results: Bafetinib inhibited the cell viability of melanoma cell UACC62 in a dose-dependent manner within a certain concentration range. The OD scores and clone numbers of UACC62 cells in Bafetinib-treated group were 1.05±0.08 and 49±8.53, which were lower than that in the control group (2.04±0.07 and 288±7.68 ) ( P＜0.05). The expression of P-ERK, Beclin1, Bax, Bcl-2 and Lyn in the experimental cells were 0.30，3.25, 2.23，0.53, 0.29 timesless or more than that in the control cells. Conclusion: Lyn inhibitor Bafetinib inhibited UACC62 cell proliferation and promoted UACC62 cell apoptosis through the ERK signaling pathway.

Key words: Lyn, Bafetinib, malignant melanoma, proliferation, apoptosis