Depletion of TRAF6 impairs MDS and AML cell viability. (A) Microarray analysis was performed on TF-1 cells after knockdown of TRAF6 (as in Figure 6A). Gene set enrichment analysis was performed, and the profile of the P53 signaling gene set is shown. (B) Knockdown of TRAF6 mRNA and protein by shTRAF6 was confirmed by quantitative PCR (supplemental Figure 5) and immunoblot analysis, respectively. (C) The indicated cell lines transduced with shCTL or shTRAF6 were evaluated for cell viability using the MTT assay. Cell viability is shown at the indicated days after transduction. (D) Cell viability of transduced HL60 and AML-03 patient cells was measured by annexin V/propidium iodide staining. Knockdown of TRAF6 mRNA in AML-03 was confirmed by quantitative PCR and showed > 50% reduced expression (not shown). (E) Hematopoietic stem/progenitor cell colony-forming potential of the indicated cell lines and MDS/AML patient BM cells after knockdown of TRAF6 was determined in methylcellulose. Colonies were evaluated after 10 days. *P < .05.