BACKGROUND: In the present study, we aimed to understand the expression and 
methylation levels of the suppressor of cytokine signaling 3 (SOCS3) in 
rheumatoid arthritis (RA) synovial fibroblasts.
METHOD: The RA model was established using Freund's complete adjuvant, and then 
the synovial fibroblasts were isolated and cultured. Next, RNA extraction and 
reverse transcription were performed. The SOCS3 transcription level was detected 
using qPCR, and SOCS3 protein expression was detected using western blotting 
(WB). Lastly, methylation-specific PCR (MSP) was performed.
RESULTS: The RA model was successfully demonstrated. SOCS3 gene (p < .01) and 
protein expression levels were significantly increased in the RA rat group 
compared to in the wild type (WT) group. However, no significant difference was 
observed in the MSP products between the RA and WT groups.
CONCLUSION: The increased expression of the SOCS3 can be correlated with the 
development of RA.