Glutathione metabolism is essential for self-renewal and chemoresistance of pancreatic cancer stem cells

Figure 1 Expression of glutathione metabolism genes positively correlates with a stemness signature in human pancreatic cancer samples and predicts poor outcome. A: Enrichment in CD133⁺ cells in sphere cultures vs adherent cultures, as determined by flow cytometry. Representative flow cytometry histograms of the indicated patient-derived xenograft models; B: Correlation of genes that were up-regulated in cancer stem cell-enriched cultures with a stemness signature defined by combined expression of the pluripotency-related genes NANOG, KLF4, SOX2 and OCT4. Pearson´s r and corresponding P values for individual correlations are shown; C: Disease-free survival in pancreatic cancer patients from upper and lower quartiles of expression of the indicated genes. Hazard ratio was calculated using the Cox Proportional Hazards model. Dotted lines represent the 95% confidence interval. Data in A and B were calculated using GEPIA2 (http://gepia2.cancer-pku.cn), using public data compiled in TCGA and GTEx. Sph: Sphere culture; Adh: adherent culture; HR: Hazard ratio.