Fig. 1

TOPBP1 expression is upregulated in patients with PDAC and associated with higher histological grade and shorter survival durations. A Patients with high TOPBP1 expression levels have worse overall survival (OS) than those with low TOPBP1 expression levels (n = 172, p = 0.0083) based on datasets from The Cancer Genome Atlas (TCGA). P-values were derived from the Kaplan–Meier survival analysis. B Patients with high TOPBP1 expression levels have worse OS than those with low TOPBP1 expression levels based on the Gene Expression Omnibus (GEO) datasets (n = 65, p = 0.038). P-values were derived from the Kaplan–Meier survival analysis. C TOPBP1 expression is higher in PDAC tissues with G3–G4 pathological stage compared to G1–G2 pathological stage in TCGA datasets (n = 179, paired t-test, p = 0.003). D Immunohistochemistry (IHC) showing TOPBP1 expression predominantly localized to pancreatic ductal tumor cells within the tumor. E Quantitative real-time PCR analysis of TOPBP1 expression in 58 pairs of PDAC tissues (tumor) compared to normal tissues (normal). F TOPBP1 expression levels in PDAC tissues based on IHC scores. G Patients with high TOPBP1 expression levels had a worse prognosis (OS) than those with low TOPBP1 levels (n = 47, Kaplan–Meier survival analysis, p < 0.0001) based on our center's patient data. H TOPBP1 expression in various PDAC cell lines analyzed by western blotting. I TOPBP1 expression in various PDAC cell lines analyzed by western blotting. Data shown are the mean ± SEM. Statistical analyses were performed with one-way ANOVA (*p < 0.05 and **p < 0.01 versus control)