Enhancer polymorphisms at the IKZF1 susceptibility locus for acute lymphoblastic leukemia impact B-cell proliferation and differentiation in both Down syndrome and non-Down syndrome genetic backgrounds
Fig 2
Homozygous microdeletions of SNPs in the rs58923657 non-risk haplotype result in significantly decreased IKZF1 expression and increased proliferation in human LCLs.
Expression of IKZF1 mRNA in (A) non-DS and (B) DS LCLs with CRISPR/Cas9 induced microdeletions of regions at rs62445866, rs6964969, rs6944602, rs10264390, and rs17133807. Dot plots show the log2 fold change of IKZF1 mRNA expression in SNP deletion clones normalized to WT clones in LCLs with non-risk allele status for each SNP. Results are mean ± SEM (n = 8 deletion clones per group). The differences between WT and SNP deletion groups were analyzed by one-way ANOVA. *P < 0.01; **P < 0.0001. (C) The effect on IKZF1 mRNA expression was compared for each SNP deletion between non-DS and DS clones. The differences were analyzed by one-way ANOVA. #P < 0.05. (D) Cellular proliferation in SNP deletion versus WT clones for 2 non-DS and 2 DS LCLs. Results are mean cell counts ± SEM (n = 3 clones per SNP deletion and 3 WT clones). Differences between WT and SNP deletion clones were analyzed by two-way ANOVA. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.