Fig. 4

GDF15 altered cell cycle related molecules through FOXO1 and C-myc. The mRNA levels of cell cycle-related genes in HeLa (a) and SiHa (b) cell lines was detected by quantitative real time-PCR. The total protein levels of GDF15, CyclinA1, CyclinE1, CyclinD1 and p21 and the nuclear protein FOXO1 and C-myc in HeLa and SiHa cell lines (c) were determined by western blotting and the quantitative analysis were presented (d and e). GDF15 was determined by western blotting and cell lysates from HeLa-GDF15 and SiHa-GDF15 cells was incubated with 0%, 25%,50% and 75% conditioned medium for 24 h (f) and the quantitative analysis are shown (g). A quantitative CHIP assay of the GDF15 promoter region in HeLa and SiHa cells is shown (h). Proposed model of the positive feedback relationship between GDF15 and C-myc in cervical cancer cells (i). The data were shown as the mean ± SD of three independent experiments. *p < 0.05, **p < 0.01 vs. control using One-Way ANOVA