RESUMO
AIM:To observe the influences of IL-6 and AG490 on the growth of Raji cell line ( Burkitt lym-phoma cell, BL).METHODS:Raji cells were cultured.IL-6, an activator of signal transducer and activator of transcrip-tion 3 (STAT3), and AG490, a specific inhibitor of STAT3 were added into the medium respectively .The expression of STAT3 and survivin at mRNA and protein levels was detected by real-time PCR and Western blot .The cell viability was measured by MTT assay .Apoptosis and cell cycle were examined by flow cytometry .RESULTS:IL-6 or AG490 affected the growth of Raji cells significantly in a dose-dependent manner (P<0.05).The mRNA expression of STAT3 and sur-vivin in Raji cells was higher in IL-6 group, and lower in the AG490 group than that in the corresponding control group . The statistical differences were found in the mRNA expression of STAT 3 and survivin among different IL-6 or AG490 groups (P<0.05).The concentration dependent relationship was also presented in IL-6 and AG490 groups by the regression a-nalysis.The results of Western blot showed that the protein levels of phosphorylated STAT 3 (p-STAT3), STAT3 and sur-vivin were increased in IL-6 group, and decreased in AG490 group.The apoptotic rate of Raji cells was gradually reduced with the increasing concentration of IL-6.The opposite results were detected in the Raji cells treated with AG 490.There was significant difference in constitute of the cell cycle between the groups treated with IL -6 or AG490 and corresponding control group.The cells at G1-phase and G1/S were significantly increased , while those at S-phase had no obvious change under treating with AG490.The cells at S-phase decreased obviously in the Raji cells treated with IL-6.CONCLUSION:IL-6 and AG490 distinctly affect the growth of Raji cells .The mechanism may be associated with the activation of STAT 3 and survivin.