The histone methyltransferase MLL specifically regulates HoxA9 and HoxD3 expression. (A-B) HUVECs were transfected with 2 different siRNAs against MLL (I and II) or scrambled oligonucleotides. (A) RT-PCR analysis of MLL and Hox mRNA expression. Representative gels are shown. GAPDH is shown as loading control. (B) Quantitative analysis of MLL and Hox gene expression using real-time PCR. Data are shown as percent scrambled and mean ± SEM. *P < .01 versus scrambled, #P < .05 versus scrambled, n = 3. (C-D) HUVECs were transfected with siRNA against MLL or scrambled oligonucleotides. (C) Western blot analysis of HoxA9 expression. Samples were taken at several time points following siRNA transfection as indicated. Tubulin is shown as loading control. (D) Western blot analysis of HoxD3 expression. Tubulin is shown as loading control.