FIGURE 4 from The TERT Promoter is Polycomb-Repressed in Neuroblastoma Cells with Long Telomeres

TERT is a bona fide MYCN target. A, Alignments of DNA methylation from WGBS and MYCN-ChIP-seq in three MYCN-amplified neuroblastoma O-PDX models and cell line (SKNBE2) showing that MYCN binding overlaps with the hypomethylated region in the TERT promoter. The core promoter is shaded in red and THOR is shaded in yellow. B, Western blot analysis for MYCN and GAPDH (loading control) in different indicated doxycycline-inducible engineered cell lines to ectopically express MYCN in non–MYCN-amplified cells (left) or to express three different MYCN-shRNAs (indicated as A, B, C) in MYCN-amplified neuroblastoma cells (right). Relative MYCN band intensities in cells expressing MYCN-shRNA are indicated on top of the blots. C, A schematic representation of Luciferase reporter construct. The long construct contains the luciferase gene, and the TERT promoter core and THOR sequences, while the short construct does not contain the THOR promoter sequence. D, Fold change of Luciferase luminescence for the short construct (top) and the long construct (bottom) compared with control vehicle-treated controls. E, Fold change of TERT expression in the same cells measured by qRT-PCR. *, P < 0.05, error bars represent SD.