Figure 2

JAG1 mediates pro-survival signaling through activation of canonical NOTCH2 signaling. (a) Relative JAG1 expression in 47 fresh frozen MB primary samples. Values represent the fold-change in JAG1 mRNA expression compared to that in normal cerebellum samples (defined as 1). (b) JAG1 mRNA (upper panel) and protein (lower panel) expression in the indicated MB cell lines. mRNA values represent the fold-change in JAG1 mRNA expression compared to that in normal cerebellum samples (defined as 1). (c) Protein expression of JAG1, NICD2, and HES1 in DAOY cells at 72 hours after treatment with JAG1 siRNA compared to control siRNA. (d) HES1 mRNA relative expression in DAOY cells upon JAG1 siRNA treatment at the indicated time-points. Values represent the percent decrease in HES1 mRNA relative to the control. (e) Correlation between JAG1 and HES1 mRNA expression in a dataset of 103 MB tumors[25]. r: Pearson’s value; p: p values. Proliferation (f), cell viability (g), caspase 3/7 activation (h), and histone-associated DNA fragments (i) of DAOY cells at 48 hours after JAG1 siRNA treatment or at the indicated time-points compared to control siRNA. Percent decrease in the number of colonies (j) and neuro-spheres (k) formed by DAOY cells 72 and 120 hours, respectively, following JAG1 siRNA treatment compared to control siRNA. (k, right panel) Representative image of DAOY-derived neuro-spheres upon treatment with JAG1 siRNA and control siRNA.