Parthenolide inhibits the proliferation and induces the apoptosis of human uveal melanoma cells

AIM: To explore the effect of parthenolide(PTL) on human uveal melanoma(UM) cells(C918 and SP6.5 cells) and its molecular mechanism. METHODS: Carboxyfluorescein succinimidyl amino ester(CFSE) assays and cell counting kit-8(CCK-8) were performed to detect the cell viability. Flow cytometry was used to analyze cell cycle and apoptosis. Quantitative realtime polymerase chain reaction(qRT-PCR) and Western blot assays were performed to measure proliferation-related and apoptosis-related factors.RESULTS: Firstly, PTL decreased the viability of C918 and SP6.5 cells in a dose-dependent manner, and the effect of PTL on C918 cells was stronger than on SP6.5;however, it did not affect normal cells. Secondly, PTL increased the proportion of cell number at cell cycle G1 phase in C918 cells, and decreased the proportion of cell number at S phase, but the proportion did not change at G2 phase. In addition, PTL induced the apoptosis of C918 cells, and decreased the expressions of Cyclin D1, B-cell lymphoma-2(Bcl-2) and B-cell lymphoma-extra large(Bcl-XL). Also, PTL increased Cyclin inhibition protein 1(P21), Bcl-2-associated X protein(Bax), Cysteinyl aspartate specific proteinas-3(Caspase-3) and Caspase-9 expression. However, the expression of Caspase-8 was not changed. CONCLUSION: PTL inhibites proliferation and induces apoptosis in UM cells by arresting G1 phase and regulating mitochondrial pathway, however, it does not affect normal cells.