Fig 1.
Selective high expression of c-kit in AML1/ETO-positive AML cell lines and patients.
(A) qPCR showing c-kit expression in myeloid leukemia cell lines. CML-BC: chronic myeloid leukemia in blast crisis. Bars indicate the mean±SEM from three independent experiments. ABL1 levels were measured for normalization. (B) Normalized c-kit expression in pretreatment samples of 461 patients with de novo AML (GEO database, GSE6891). The gene expression was determined using gene-expression arrays (Affymetrix HGU133 Plus 2.0 GeneChips), which reflected by the intensity of hybridization of labeled mRNA to the gene chip. Median values are depicted by the horizontal lines. The Mann-Whitney U test was used to compare expression levels between groups. (C) qPCR showing c-kit expression level in bone marrow samples from untreated AML patients at diagnosis and healthy donors. ABL1 levels were measured for normalization. Median values are depicted by the horizontal lines. The Mann-Whitney U test was used to compare expression levels between groups.
Fig 2.
Positive correlation between AML1/ETO and c-kit expression levels in AML1/ETO-positive AML.
(A) The patients described in Fig 1C were divided into high and low c-kit expression groups, which described in detail in statistical analysis. The threshold is depicted as a dashed line. Patient characteristics are described in Table 1. (B) Stratification of AML1/ETO-positive AML patients with high and low c-kit expression according to c-kit mutation status. (C) Correlation between c-kit and AML1/ETO levels in AML1/ETO-positive AML patients was assessed by the Spearman rank correlation coefficient. Gene expression was detected by qPCR. ABL1 levels were measured for normalization. Black circles indicate AML patients carrying wtc-kit.
Table 1.
Comparison of clinical and biologic variables of AML patients according to c-kit expression.
Fig 3.
Higher expression of c-kit in AML1/ETO-positive AML predicts more inferior prognosis.
(A-C) Kaplan-Meier estimate for OS and EFS in indicated patient subgroups. Survival curves were compared using log-rank test.
Table 2.
Multivariate analysis for OS and EFS and bootstrap resampling for variable in the multivariate model.