Gene expression from fibroblast-like synoviocytes (FLS) of three patients with rheumatoid arthritis (RA) that were cultured in four conditions: control medium (Basal), ATRA, TNF and ATRA+TNF.

The aim of this study was to investigate the response of FLS from RA patients to retinoic acid and retinoic acid combined with the central cytokine of RA, TNF. FLS from six RA patients were cultured for 12h in serum-deprived medium with 0.05% DMSO (Basal), 5mM ATRA, 10ng/ml TNF or 5mM ATRA+10ng/ml TNF. RNA was extracted and pooled (two pools of three patients each).