Fig. 3.
Induction of globin gene expression by different chemical agents in K562 cells.
Cells were treated with hemin, hydroxyurea, butyrate, phenylacetate, 5-azacytidine, or phenylacetate plus hydroxyurea for 4 days. For Northern blot analysis, total RNA was prepared, subjected to agarose gel electrophoresis and blotted on nylon membranes. Blots were hybridized with a 32P-labeled probe of the γ-globin coding region. After stripping, blots were rehybridized with a β-actin probe. Hemoglobin and protein concentrations of total cell extracts were determined as described. A shows results from butyrate-sensitive K562s cells and B results from butyrate-resistant K562r cells.