CUX1 RNA and protein levels are haploinsufficient in AML cells with loss of 7q22. (A) CUX1 expression levels in RNA-sequenced leukemia samples. Samples are divided into those with −7/del(7)(q22) (●) and other samples (○). Each circle represents an individual sample. P value calculated by Wilcoxon rank test. (B) Quantitative RT-PCR of CUX1 in RNA from primary patient samples. A19 and A35 have a normal karyotype, and A56 and T52 have −7/del(7q). One representative experiment of 3 independent experiments is shown. Samples with −7/del(7q) have 45.8% ± 2.4% of the level of CUX1 expressed by other samples (P = .045, comparing the mean within 1 experiment, A19 and A35 vs A56 and T52). (C) Protein lysates from human AML cell lines were probed for CUX1 protein by Western blot. UoCM1, Mono7, and KG-1 have −7/del(7q) karyotypes. HeLa, K562, and Kasumi-1 cell lines were used as controls. The full-length p180 protein isoform of CUX1 is shown. The same blot was probed for and normalized to β-actin. Error bars represent ± SEM from 3 independent experiments.