Fig. 3.

AML cell lines with KDM6A loss show high H3K27 tri-methylation and increased AraC resistance. a Identification of KDM6A aberrations in AML cell lines HL60, OCI-AML3, MM-6, and THP-1. MM-1 serves as a WT control. Bar thickness ranging from 0 to 2 indicates the copy number (CN) status. Haploidy (CN = 1) in cell lines from male patients is due to the X-chromosomal localization of KDM6A. HL-60, the only cell line derived from a woman has lost one of its X chromosomes. b Western blot for KDM6A expression and global H3K27 mono-, di- and tri-methylation levels in KDM6A WT and mutant human leukemia cell lines. α-Tubulin and total H3 were used as loading controls. Blots are representative of three independent experiments. MW, molecular weight. c Negative correlation between KDM6A protein expression and global H3K27me3 level in KDM6A WT and mutant human leukemia cell lines (Pearson’s correlation; r = −0.76, *P = 0.0042). Mean values of three independent analyzes are shown. d Comparison of AraC IC₅₀ values between KDM6A WT and mutant male AML cell lines. To determine their respective IC₅₀ values, AML cell lines were treated with increasing concentrations of AraC for 72 h. Mean of IC₅₀ values from at least three independent experiments ± standard deviation (s.d.) are shown. Unpaired, two-tailed Student’s t-test; *P = 0.044