BACKGROUND: Inhibitor of growth 4 (ING4) plays a role in regulating the cell cycle, apoptosis, cell invasion and migration, but the mechanisms involved remain to be elucidated. OBJECTIVE: To explore how ING4 affects human malignant melanoma A375 cells. METHODS: Recombinant lentiviral vectors (A375/pLenO-GTP-ING4) were constructed and transfected into A375 cells (experimental group). The impact of ING4 on the proliferation and apoptosis of A375 cells was investigated in in vitro and in vivo experiments in mice using the MTT assay and flow cytometry. RESULTS: In the experimental group, optical density was lower and apoptotic cells were more frequent from days 2-5 (p = 0.000 and p < 0.01); there were smaller xenografts and more apoptotic cells in mice (all p < 0.05); moreover, increased levels of Fas, cleaved caspase-8 and caspase-3, and decreased levels of FasL and procyclic acidic repetitive protein were observed in vitro and in vivo. CONCLUSION: ING4 might suppress proliferation and enhance apoptosis in human malignant melanoma cells by activating Fas-induced apoptosis in a caspase-8-dependent pathway.
BACKGROUND:Inhibitor of growth 4 (ING4) plays a role in regulating the cell cycle, apoptosis, cell invasion and migration, but the mechanisms involved remain to be elucidated. OBJECTIVE: To explore how ING4 affects humanmalignant melanoma A375 cells. METHODS: Recombinant lentiviral vectors (A375/pLenO-GTP-ING4) were constructed and transfected into A375 cells (experimental group). The impact of ING4 on the proliferation and apoptosis of A375 cells was investigated in in vitro and in vivo experiments in mice using the MTT assay and flow cytometry. RESULTS: In the experimental group, optical density was lower and apoptotic cells were more frequent from days 2-5 (p = 0.000 and p < 0.01); there were smaller xenografts and more apoptotic cells in mice (all p < 0.05); moreover, increased levels of Fas, cleaved caspase-8 and caspase-3, and decreased levels of FasL and procyclic acidic repetitive protein were observed in vitro and in vivo. CONCLUSION:ING4 might suppress proliferation and enhance apoptosis in humanmalignant melanoma cells by activating Fas-induced apoptosis in a caspase-8-dependent pathway.