Fig. 1
From: Targeting FLT3-TAZ signaling to suppress drug resistance in blast phase chronic myeloid leukemia
FLT3 activation in BP-CML cells promotes drug resistance to BCR::ABL1 TKI. A Analysis of the most highly increased AML driver genes in BP compared to CP-CML patients. The CML patients’ expression data were obtained from the NCBI Gene Expression Omnibus database (Accession no. GSE4170). Normal CD34 + cells (CD34), n = 7; CP, n = 57; AP, n = 9; BP, n = 33. p-values were calculated using one-way ANOVA with Bonferroni corrections for multiple comparisons. Error bars are means of ± SD. ****p < 0.0001. B qPCR analysis of FLT3 mRNA levels in CP (n = 18) and BP (n = 24) CML patient cells. p-values were calculated using Student’s t-test and error bars are means of ± SD. **p < 0.01. C-E Immunofluorescence images of the cell surface localization of FLT3 (green) in BMMC samples derived from BP-CML patients 2033, 2266, and 2084 (BP2) compared to CP-CML samples 1148, 1332 (CP1), and 2084 (CHR). DAPI (blue) was used as a nuclear marker. CHR, complete hematological response. F Immunofluorescence images of the ectopic expression of FLT3 (green) on the cell surface in K562 cells. DAPI (blue) was used as a nuclear marker. G Immunoblotting of downstream signaling components induced by dose-dependent FLT3 expression in K562 cells. H Immunoblotting of imatinib-induced apoptosis in K562-mock and -FLT3 cells. PARP cleavage was measured in cells treated with 1 μM imatinib for 6, 18, 24, 28 and 72 h. I and J Cell images at day 17 (I) and growth curves (J) of control and K562-FLT3 cells treated with 1 μM imatinib, 20 nM nilotinib, and 1 μM dasatinib. K Growth curves of K562-FLT3 cells combined with control cells at different ratios (left). Recovery times for each combination after 1 μM imatinib treatment were recorded when cell numbers reached 2 × 105 cells/well (right). L FACS analysis after dilution assay for the measurements of FLT3-positive cell percentages at day 0 and day 39. M Growth curves of K562-FLT3 cells with or without 20 ng/ml FLT3 ligand treatment. ns, not significant (p > 0.05). N Growth curves of control and K562-FLT3 cells treated with 1 μM imatinib with or without 20 ng/ml FLT3 ligand (left). Cell numbers were counted on day 13 (right). **p < 0.01, ***p < 0.001; ns, not significant (p > 0.05). J, M–N All p-values were calculated using Student’s t-test and error bars are means of triplicates ± SD. A p-value of less than 0.05 indicates a statistical difference