Association and contribution of ERK to IL-6-induced activation of signal transducer and activator of transcription in a human myeloma cell line.
OBJECTIVE
To investigate the regulation effect of protein kinase ERK on the activation of transcription factor STAT3 in response to IL-6 in the Sko-007 human myeloma cell line.


METHODS
Electrophoretic mobility shift assay (EMSA) and immunoprecipitation (IP) were used to show the activation of STAT3 and ERK in Sko-007 cells in the presence and absence of IL-6. Antisense oligonucloetides of ERK (ERK-AS) were transfected into Sko-007 cells to specifically inhibit the expression and activity of ERK. The changes in the activation of STAT3 in the transfected cells were also exhibited by EMSA. Direct binding between STAT3 and ERK was analyzed by co-IP.


RESULTS
Both STAT3 and ERK were activated in Sko-007 cells stimulated with IL-6. ERK-AS inhibited STAT3 activation by IL-6. Moreover, activated ERK could form a complex with STAT3 in Sko-007 cells.


CONCLUSIONS
ERK can bind STAT3 directly and be required for its maximal activation in Sko-007 cells stimulated by IL-6.
Song
L
L
Department of Molecular Immunology, Institute of Basic Medical Sciences, Academy of Military Medical Sciences, Beijing 100850, China. lunsong@yahoo.com
Shen
B
B
Li
Y
Y
D016373:DNA, Antisense / Q000235:genetics; D004268:DNA-Binding Proteins / Q000187:drug effects* / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D015850:Interleukin-6 / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D009101:Multiple Myeloma / Q000378:metabolism* / Q000473:pathology; D011233:Precipitin Tests; D011485:Protein Binding; D050796:STAT3 Transcription Factor; D015534:Trans-Activators / Q000187:drug effects* / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000187:drug effects
D016373:DNA, Antisense; D004268:DNA-Binding Proteins; D015850:Interleukin-6; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D020928:Mitogen-Activated Protein Kinases