siRNA Mediated Genetic Perturbation of Primary Human Leukemia Stem and Progenitor Cells.

Acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) are aggressive hematologic malignancies with poor outcomes. Leukemia stem and progenitor cells (LSPCs) are a subset of cells within the bulk tumor thought to be responsible for initiating disease and causing relapse. LSPCs evade chemotherapy partially due to their quiescent state. Therefore, studying this cell subpopulation is critical to identify new disease targets that can better the outcomes of AML/MDS patients. The use of RNAi and genetic approaches is technically challenging in primary leukemia cells and particularly LSPCs. Overcoming this technical hurdle could greatly expand the breath of pre-clinical and mechanistic examination of LSPCs. In this study, we describe a methodology to efficiently introduce siRNA, resulting in effective gene knock down in LSPCs. After isolation of LSPCs from primary patient samples, we showed that electroporation of these cells does not affect cell viability significantly. Further, using siGLO green transfection indicator, we show that RNA is introduced into the nucleus of these cells. siRNA transfection leads to efficient knockdown of target genes and has subsequent biological relevant activity. We have identified a method to effectively knock down genes in leukemia stem and progenitor cells, opening up new avenues to examine LSPC biology in human specimens.