Figure 3. Inhibition of IKK signaling suppresses cell growth and colony formation of mouse MLL leukemia cells.

(A and B) Mouse myeloid progenitors transformed by the indicated oncogenes (bone marrow c-kit⁺ cells transduced with MLL oncogene) were plated in methylcellulose medium with different concentrations of IKK inhibitor VII (A) or IV (B). Colonies were enumerated after 5 days and expressed relative to cells treated with vehicle (DMSO) alone.

(C and D) Mouse myeloid progenitors transformed by MLL-AF9 were stably transduced with lentiviral vectors expressing control shRNA or shRNAs targeting Ikkα, Ikkβ or Ikkγ. Protein (C) and relative mRNA (D) levels were determined by western blot analysis and qRT-PCR, respectively.

(E and F) Mouse MLL-AF9 transduced cells were treated as in panels C and D. Viable cell numbers at day 2 (E) and colony numbers at day 5 (F) were enumerated and expressed relative to the number obtained with control shRNA transduced cells.

(G) Mouse MLL-AF10 leukemia cells and bone marrow c-kit⁺ cells (normal hematopoietic progenitors) were plated in methylcellulose medium with different concentrations of IKK inhibitor VII. Colonies were enumerated after 5 days and expressed relative to cells treated with vehicle (DMSO) alone.

(H) The growth of mouse MLL-AF10 leukemia cells and c-kit⁺ cells was assessed after 2 days culture in the absence or presence of the indicated concentrations of IKK inhibitor VII. Results are expressed as relative cell number compared to vehicle treated cells. All error bars represent SD of triplicate analyses. See also Figure S3.