FIG 7.

Enforced MYC expression blocks granulocytic differentiation of HL-60 cells in response to ATRA. Naive HL-60 cells and those transduced with a MYC-expressing retrovirus or with a control vector were treated with 0.1 μM ATRA for 4 days and scored for immature versus mature granulocytic morphology. The Western blot shows c-Myc expression in transduced cells relative to that in vector control cells (inset) using anti-myc rabbit polyclonal antibody, A-14. Tubulin serves as a loading control. Statistical significance was determined by Wilcoxon-Mann-Whitney testing (*, P < 0.05).