Immunohistochemical staining of Smad3/Smad2 in HL-60 cells.

(A) Expression of Smad3 as detected by anti-Smad3 antibody in HL-60 cells untreated (white) or treated with 10 nM ATRA (gray striped), with 10 ng/mL TGF-β1 (black), or with both (black and white striped) for 18 hours as described. Original magnification × 200. (B-C) Following immunohistochemical staining, the percentage of cells with Smad2 (B) or Smad3 (C) staining predominantly or exclusively in the nucleus was determined among 1000 cells in 5 different fields. Values are expressed as the means ± SEMs of 3 experiments.