Elevated H3K27 trimethylation levels in the proximal promoter of the retained CTNNA1 allele. (A) A diagram of the human CTNNA1 genomic locus and the regions analyzed by ChIP. TSS indicates transcriptional start site. (B) ChIP analyses of histone modifications with the indicated antibodies in HL-60 and NB4 leukemia cell lines. (C-D) Semiquantitative RT-PCR and ChIP analyses of CTNNA1 expression and histone modifications in HL-60 cells treated with TSA for the indicated time. (E) Semiquantitative RT-PCR and ChIP analyses of CTNNA1 expression and H3K27me3 in HL-60 cells treated with DAC for the indicated times. (F) ChIP analyses of CTNNA1 promoter for H3K27me3 enrichment in FACS-sorted LICs (CD34⁺CD38⁻CD123⁺lineage⁻) from patient samples with or without del(5q). Enrichment of H3K27me3 was calculated by: [ChIP-P1E1(LICs)/INPUT-P1E1(LICs)]/[ChIP-P1E1(HL-60)/INPUT-P1E1(HL-60)]. ● represents case V with del(5q), which expresses a normal amount of CTNNA1.⁷