Effect of PPARγ on adherence of MM cells to bone marrow stromal cells. (A) Human KAS6/1 cells were labeled with calcein-AM. After 1 hour, the above fluorescence-labeled KAS6/1 cells were washed and added into HS-5 cell–coated 96-well plates. The cocultured cells were treated with 15-d-PGJ2 and incubated for 1, 2, or 4 hours. After washing, the fluorescence intensity of remaining labeled adhesive MM cells was tested using a fluorescence microplate reader. (B-E) HS-5 cells were cocultured with KAS6/1 cells in the presence or absence of 15-d-PGJ2 or troglitazone for 24 hours. Cells were harvested, washed with PBS, and stained with fluorescence-labeled antibodies. The expression of adhesion molecules was determined using a FACS Calibur flow cytometer. (B) HS-5 cell harvests were stained with FITC-IgG and PE-IgG control; (C) HS-5 cell harvests were stained with FITC-anti-CD138 and PE-anti-CD54; (D) KAS6/1 cell harvests were stained with FITC-labeled anti-CD138 and PE-anti-CD49d; and (E) HS-5 cell harvests were stained with mouse IgG isotype control or fluorescence-conjugated mouse antihuman antibodies against CD106 or CD54. KAS6/1 cell harvests were labeled with fluorescence-conjugated antibodies against CD49d or CD11a, respectively. Solid histogram indicates antigens for untreated cells; open histogram (blue), isotype control; open histogram (red), 15-d-PGJ2–treated cells; open histogram (green), troglitazone-treated cells.