Association of ASNS methylation with L-asparaginase sensitivity in BCP-ALL cell lines. (A) Dose-response curves of L-asparaginase in 83 BCP-ALL cell lines. The color of the curve represents the percent methylation of ASNS in each cell line. (B) Median dose-response curves of L-asparaginase. Box plots indicate cell viabilities in highly (red), intermediately (yellow), and weakly (blue) methylated cell lines at each concentration. Each P value in a Mann-Whitney U test is indicated at the top of each panel. (C) Association between log IC₅₀ value and ASNS gene methylation. Red circles, yellow rhomboids, and blue squares demonstrate highly, intermediately, and weakly methylated cell lines, respectively. (D) Induction of ASNS gene expression by L-asparaginase (1 IU/mL) 12-hour treatment in highly, intermediately, and weakly methylated cell lines. P values in a Student t test are indicated. (E-F) Association between ASNS methylation and ASNS expression in BCP-ALL cell lines cultured in the (E) absence or (F) presence of 1 IU/mL of L-asparaginase for 12 hours. (G) Association between ASNS methylation and basal ASNS protein expression in BCP-ALL cell lines. In panels B-G, asterisks indicate significance in a Mann-Whitney U test. In C, E, F, and G, correlation coefficients and P values are shown at the top of each panel. ***P < .001; **P < .01; *P < .05.