ABSTRACT
Objective To evaluate the effect of fenretinide (4-HPR)-loaded liposomes (4-HPR-L) on the proliferation,apoptosis and migration of A375 and B16F10 melanoma cells.Methods A film-ultrasonic dispersion method was used to prepare 4-HPR-L.In vitro cultured A375 cells,as well as B16F10 melanoma cells,were divided into the following groups:blank control group treated with fresh culture medium alone,4-HPR groups treated with 4-HPR at concentrations of 0.1,1,15,30,50 and 70 mg/L separately,and 4-HPR-L groups treated with 4-HPR-L at concentrations of 0.1,1,15,30,50 and 70 mg/L separately.Cell counting kit-8 (CCK8) assay was conducted to detect cell proliferation,Hoechst33258 staining and flow cytometry to detect cell apoptosis,wound healing assay to evaluate cell migration ability,and laser scanning confocal microscopy to observe endocytic uptake of the liposomes.Statistical analysis was done by one-way analysis of variance (ANOVA) for intergroup comparison,and a two-sample t-test for comparisons between 2 groups with SPSS 20.0 software.Results Both 4-HPR and 4-HPR-L showed inhibitory effects on the proliferation of A375 and B16F10 melanoma cells.After 48-hour treatment,the survival rates of A375 cells in the 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR groups were (94.3 ± 1.4)％,(91.7 ± 2.5)％,(84.4 ± 2.5％),(78.8 ± 2.1)％,(59.0 ± 1.1)％ and (42.8 ± 2.0)％ respectively,and those in the 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR-L groups were (86.0 ± 0.2)％,(76.5 ± 0.6)％,(60.9 ± 1.5)％,(49.0 ± 0.5)％,(32.9 ± 0.2)％ and (18.9 ± 0.5)％ respectively.After 48-hour treatment,the survival rates of B16F10 cells in 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR groups were (95.4 ± 1.9)％,(90.5 ± 2.6)％,(77.0 ± 0.8％),(64.4 ± 3.5)％,(59.1 ± 2.9)％ and (49.9 ± 1.9)％ respectively,and those in the 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR-L groups were (88.4 ± 2.0)％,(80.9 ± 3.4)％,(60.9 ± 2.2)％,(51.5 ± 2.9)％,(41.1 ± 1.2)％ and (33.5 ± 2.4)％ respectively.The survival rates of A375 and B16F10 cells were significantly higher in the 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR groups than in the 4-HPR-L groups at the same concentrations (A375 cells:t =8.019,8.298,11.455,19.978,33.672,16.314 respectively,all P ＜ 0.01;B16F10 cells:t =3.573,3.153,9.953,4.019,8.097,7.53 respectively,all P ＜ 0.05).Hoechst33258 staining showed that the morphology of the melanoma cells in the control group and 4-HPR groups did not change obviously,but the cells.in the 4-HPR-L groups became smaller,with the cytoplasm concentrated,nuclei dissociated into fragments,and apoptotic bodies formed.Flow cytometry showed that the apoptosis rates of A375 and B16F10 cells were significantly higher in the 4-HPR-L groups than in the 4-HPR groups (all P ＜ 0.01).Cell wound healing assay showed that the inhibitory effect of 4-HPR-L on the migration of cells was stronger than that of 4-HPR,and 4-HPR-L could markedly decrease the degree of wound healing.Laser scanning confocal microscopy showed that C6 liposomes could be rapidly and successfully internalized into both A375 and B16F10 cells.Conclusion The 4-HPR-L can be internalized into A375 and B16F10 cells better than 4-HPR,effectively inhibit the proliferation and migration of A375 and B16F10 cells,and induce the apoptosis of these cells.
ABSTRACT
Objective To investigate the effect and molecular mechanisms of phosphatidylinositol-3 kinase(PI3K)inhibitor ZSTK474 on human melanoma A375 cells in vitro. Methods The effect of ZSTK474 on the proliferation of A375 cells was deter?mined by MTT assay.Flow cytometric analysis was carried out to examine effect of ZSTK474 on the cell cycle of A375 cells.Western-blot was conducted to evaluate the effect of ZSTK474 on the expression of the cell cycle related proteins,cyclin B1 and cdc2.Chou-Talalay method was used to evaluate the combination of ZSTK474 with PD0332991.Results In the MTT assay,ZSTK474 inhibited the proliferation of A375 cells in a dose-dependent manner with the IC50value of 1.535 μmol/L.Furthermore,ZSTK474 arrested the cell cycle progression of the A375 cells at the G2/M phase via downregulating the expression of cyclin B1 and cdc2 at 1 and 5 μmol/L. In the synergistic assay,the combination of ZSTK474 with PD0332991 in the ratio 8×IC50 ZSTK474:1×IC50 PD0332991showed a synergistic ef?fect,with the combination index(CI)values of 0.463 ± 0.113,0.658 ± 0.009 and 0.941 ± 0.034 for ED50、ED75and ED90,respectively. Conclusion ZSTK474 could inhibit the proliferation of A375 cells and arrest the cell cycle at the G2/M phase.The combination of ZSTK474 with PD0332991 could exert a synergistic effect.The precent result has revealed that the PI3K inhibitor ZSTK474 is likely to be applied alone or in combination with the CDK4/6 inhibitor PD0332991 for the human melanoma therapy.