Figure 3: JAG1 is a unique NF-κB-inducible NOTCH ligand in basal-like breast cancers.

(a) HEY1 and HEY2 mRNA expression levels in CSCs are higher than in the non-CSC population and are further enhanced by NF-κB activation in HCC1937 cells. Total RNA fractions were prepared from CSC and non-CSC cells, and a real-time reverse transcriptase PCR (RT–PCR) analysis was performed (n=3, mean±s.d.; Student’s t-test). (b) Real-time RT–PCR analysis of NOTCH ligands and RELB mRNA expression (n=3, mean±s.d.; Student’s t-test) in control, IκBαSR and IKKβ-expressing cells was performed in two basal-like cell lines. (c) Western blotting analyses of JAG1 protein regulated by NF-κB. (d) Real-time PCR analysis of NOTCH ligands and of RELB mRNA expression (n=3, mean±s.d.; Student’s t-test) in TNFα-treated basal-like subtype cells. (e) Western blotting analyses of JAG1 protein induced by TNFα treatment. (f) Real-time PCR analysis of JAG1 and RELB mRNA expression (n=3, mean±s.d.; Student’s t-test) in cells treated with 10 ng ml⁻¹ TNFα for the indicated times. (g) Western blotting of JAG1 expression in cells treated with 10 ng ml⁻¹ TNFα for the indicated times. All data are representative of three independent experiments. ND, not detected; NS, not significant. *P<0.05, **P<0.01 and ***P<0.001 (a,b,d,f).