Comparison of the expression profile of apoptosis-associated genes in rheumatoid arthritis and osteoarthritis

The purpose of this study was to employ microarray analysis to evaluate differential gene expression in synovial tissue samples obtained from patients with rheumatoid arthritis (RA) or osteoarthritis (OA) to study the expression profile of apoptosis-associated genes in these tissues. Four samples were obtained from RA-affected patients and three from osteoarthritis patients. After total RNA was extracted from synovial tissue, the RNA was processed using two-cycle target labeling, followed by hybridization and scanning procedure. The GeneChip Human Genome U133 Plus 2.0 containing 900471 gene loci was used and eight genes associated with apoptosis were identified with a selected p value < 0.05 and a twofold change in expression in rheumatoid samples compared to osteoarthritis tissues. Anti-apoptotic genes were generally upregulated whereas apoptotic genes were downregulated suggesting that these genes may play a role in the pathogenesis of RA. Furthermore, these genes may serve as novel therapeutic targets for the treatment of RA.