Fig 2: The effect of sFRP4 on glucose-uptake in CSCs: CSCs were isolated in various glucose concentrations and treated with sFRP4 (250 pg) for 24 h. Cellular uptake was detected with Glucose Uptake-glo assay. (A) MDA231 CSCs; (B) MCF7 CSCs; (C) PC-3 CSCs; and (D) LnCap CSCs. Statistical analysis was performed using ANOVA for analysis variance with Bonferroni test for comparison showing significance as *** p < 0.001; ** p < 0.01; * p < 0.05. Data are mean ± standard error of mean from three independent experiments.

Fig 3: Effect of sFRP4 on CSC cell surface markers: Using Immunofluorescence, CD44+/CD24−/CD133+/Ki67/ABCG2 were detected in all the tumor cell line-derived CSCs. sFRP4 in combination with doxorubicin/cisplatin showed disruption of the spheres. Nuclei were counterstained with Hoechst 33342 (blue). (a,b) CD44+/CD24− breast tumor cell line CSCs (MDA231/MCF7). (c,d) Prostate tumor cell line derived CSCs. PC3 expressed CD44+/CD133+/Ki67/ABCG2. LnCap was negative for CD44+. (e–g) CD44+/CD133+/Ki67/ABCG2 observed in ovary tumor cell line-derived CSCs (A2780 P/CIS/ADR). Immunofluorescence images are representative from 3 independent experiments. (Scale bar: 100 μm).

Fig 4: Redox signature with sFRP4 treatment of CSCs: Comparison of NAD+/NADH ratio in CSCs with no, low, and high glucose content. (A) MDA231 CSCs; (B) MCF7 CSCs; (C) PC-3 CSCs; and (D) LnCap CSCs were treated with sFRP4 for 24 h. Statistical analysis was performed using ANOVA for analysis variance with Bonferroni test for comparison showing significance as *** p < 0.001; ** p < 0.01; * p < 0.05. Data are mean ± standard error of mean from three independent experiments.

Fig 5: Effect of Secreted Frizzled Related Protein-4 on Cancer Stem Cells morphology: CSCs were isolated from breast and prostate tumour cell lines with increasing glucose concentrations and treated with sFRP4 (250 pg). The sFRP4 treatment results in disruption of the CSC sphere. (Scale bar: 100 μm). Images are representative of all the experiments.