Menin binds the PTN promoter and increases H3K27 trimethylation. (A) A schematic representation of the PTN gene loci and amplicons used for ChIP assays. (B-F) ChIP assays using one of the antibodies against menin, H3K4m3, H3K27m3, SUZ12, RNA pol II, and control IgG in Men1-/- and Men1+/+ MEF cells. PCR was carried out using primers for each amplicon. (G) A549 cells were stably transfected with vector expressing a shRNA against either Luc or EZH2. EZH2 knockdown and PTN expression were determined by RT-PCR. (H-I) EZH2 knockdown and total H3K27m3 level were detected by Western blot, and the effect of EZH2 knockdown on secreted PTN protein was determined by ELISA.