Troglitazone decreases α5 integrin-dependent cell adhesion in K562 cells.

<p>(A) The extent of mAb SAM-1 (anti-α5) binding to K562 cells exposed to vehicle, 9-<i>cis</i>-RA, troglitazone, or 9-<i>cis</i>-RA and troglitazone for 72 hrs was assessed by flow cytometric analysis. SAM-1 was used at a concentration of 10 μg/mL. Cell surface levels of the α5 integrin subunit obtained with vehicle cells (<i>black histogram</i>), 9-<i>cis</i>-RA (<i>green histogram</i>), troglitazone (<i>red histogram</i>), 9-<i>cis</i>-RA and troglitazone (<i>purple histogram</i>), or an antibody isotype control (<i>blue histogram</i>) are shown. (B) K562 cells were treated with vehicle, 9-<i>cis</i>-RA, troglitazone, or 9-<i>cis</i>-RA and troglitazone for 72 hrs and subjected to FACS analysis. The mean fluorescent intensities (MFI) of integrin expression levels are shown for alpha 5 (<i>black bars</i>), beta 1 (<i>white bars</i>), alpha v beta 3 (<i>gray bars</i>), beta 3 (<i>diagonal bars</i>), alpha v beta 5 (<i>small grid bars</i>), and alpha 8 (<i>hatched bars</i>). Results are expressed as means ± SD, n = 3, LSD was used to test for differences among groups. Means followed by the same letter are not significantly different (P = 0.01). No statistical differences were observed in MFI values for αvβ3, β1, β3, αvβ5, or α8 integrins. (C) K562 cells cultured for 72 hours in the vehicle, 1 μM 9-<i>cis</i>-RA, 15 μM troglitazone, or 1 μM 9-<i>cis</i>-RA and 15 μM troglitazone were added to wells coated with 5 μg/mL of FN-120 in the presence of none (<i>white bars</i>), 1 (<i>hatched bars</i>), 5 (<i>gray bars</i>), 10 (<i>black bars</i>) μg/mL of SAM-1, or 10 μg/mL of isotype control (<i>diagonal bars</i>). Percent adhesion = ((adherent cells_(FN-120) – adherent cells_(BSA))/input cells) X 100. Results are expressed as means ± SD, n = 6, LSD was used to test for differences among groups. Means followed by the same letter are not significantly different (P = 0.01).