Fig 2: Cell growth curves of 293T-POLD1-WT and 293T-POLD1-R19H mutant cells. Cells were seeded in 96-well plates. The cell growth curves of 293T-POLD1-WT and 293T-POLD1-Mut mutant cells were determined by a CCK-8 assay. Data are shown as the mean ± standard deviation (SD) from four independent experiments. The data were compared by two-way ANOVA, with four independent experiments in each group; *p < .05, **p < .01, ***p < .005

Fig 3: Regulatory mechanism of CCCTC-binding factor (CTCF) on aging. CTCF binds to the DNA polymerase delta 1, catalytic subunit (POLD1) promoter, and stimulates POLD1 expression to inhibit the progression of aging. TSS, transcription start site.

Fig 4: Cell cycle analysis of 293T-POLD1-Mut, 293T-POLD1-WT, and GFP-control cells. Cells were stained with PI and then analyzed by flow cytometry. Data are shown as the mean ± standard deviation (SD) from four independent experiments. The data were compared by one-way ANOVA, with four independent experiments in each group; *p < .05, **p < .01, ***p < .005

Fig 5: The expression levels of POLD1 in 293T-POLD1-Mut cells. Cells were collected and lysed with RIPA buffer. After the protein concentration was determined, the lysates were subjected to Western blotting and probed with anti-POLD1 and anti-ß-actin antibodies