Antagonistic effect between two IL-6 signal transduction pathways in a human myeloma cell line-U266

Objective To investigate the IL-6 signal transduction pathways and their regulation mechanism in a human myeloma cell line-U266. Methods Electrophoretic mobility shift assay (EMSA) was used to detect the activation of the transcription factors (TFs)-STAT3 and NF-IL-6 by IL-6. Cells were treated with chemical agents or transfected with the expression plasmids for the two TFs or the anti-sense oligonucleotide for protein kinase involved in one IL-6 signal transduction pathway. The change of the activation state of another IL-6 signal transduction pathway was also exhibited by EMSA. Results Two IL-6 signal transduction pathways (JAK/STAT and Ras/NF-IL-6) can be activated by IL-6 of different dose in U266 cells. When one of the two signal transduction pathways was up-regulated, the other one was down-regulated. Conclusion There is an antagonistic effect between the activation of two IL-6 signal transduction pathways in U266 cells.