TSA and ionizing radiation increase surface expression of co-stimulatory molecules in SW620 cells more than 5AZA. (A-D) 41BBL, and (E-H) OX40L protein expression on the surface of SW620 cells was evaluated by flow cytometry. Cells were either untreated (DMSO), or treated with 5-Aza-dC (20 uM), TSA (125 nM) or 10Gy radiation (IR). Adherent cells were harvested 24 hr post treatment, and stained with PE-labeled antibody to human OX40L or 41BBL. Isotype control stained cells were analyzed for each treatment group individually and set to 5% positive. Isotype control staining is shown as the gray filled histogram and protein specific staining is shown as black line histogram for the FACS plot data graphed in A and E. Experiments were repeated twice with similar results.