Differential antigen expression and aberrant signaling via PI3/AKT, MAP/ERK, JAK/STAT, and Wnt/β catenin pathways in Lin-/CD38-/CD34+ cells in acute myeloid leukemia.

Acute myeloid leukemia is often called as stem cell disease that presents with treatment failure and poor disease outcome. Leukemic stem cells in acute myeloid leukemia (AML) are enriched in Lineage-/CD38-/CD34+ compartment of CD34-positive AML. Many markers important for stem cell biology have been reported for their association with leukemic stem cell population, but what remains clinically most important is a rapid identification of prognostic information. In this study, we evaluated four signal transduction pathways and thirteen markers on Lin-/CD38-/CD34+ population in AML. Expressions were compared in different AML subtypes, survival, and treatment outcome groups. We observed that markers important in homing, cell quiescence, and signal propagation such as CD44, CD96, CD90, WT-1, CD123 and CD25 were most significantly differentially expressed on Lin-/CD38-/CD34+ population in AML from their normal counterparts (P < 0.05, Mann-Whitney). Constitutive activation of phospho ERK, AKT, and STAT5 in these cells was associated with poor outcome. Also, an increased frequency of putative leukemic stem cell population shows negative impact on treatment outcome and overall survival, suggesting that initial evaluation of AML samples for pLSC frequency and constitutively activated signaling pathway can provide prognostic and therapeutic information at the time of diagnosis.