Abstract: Cui Aili, Jin Zhehu Department of Dermatology, Yanbian University Hospital, Yanji 133000, Jilin, China Corresponding author: Jin Zhehu, Email: Jinzh_621@163.com 【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.

Key words: Melanoma, experimental, Fenretinide, Liposomes, Cell proliferation, Apoptosis, Cell movement, A375 cell, B16F10 cell