Effect of epigallocatechin-3-gallate on JAK/STAT tyrosine phosphorylation of HSC 4 cells
2003 Volume 66 Issue 1 Pages 105-111
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2003 Volume 66 Issue 1 Pages 105-111
Green tea has been reported to have various biological effects, such as inhibition of tumor invasion, inhibition of cell proliferation, and induction of apoptosis. Epigallocatechin-3-gallate (EGCG) and epicatechin (EC) are major components of green tea flavanol. However, the effect of EGCG/EC on intracellular signal transduction is unknown. Interleukin-6 (IL-6) is a cytokine that has various effects on cellular activation. To determine the influence of IL-6 and EGCG/EC on cellular signal transduction, we investigated tyrosin phosphorylation of Janus Kinase (JAK) /Signal-transducer and activator of transcription (STAT) on HSC 4 cells treated with IL-6 and/or EGCG/EC.
We found that IL-6 induced upregulation of JAK/STAT tyrosine phosphorylation, while EGCG/EC inhibited upregulation of JAK/STAT tyrosine phosphorylation induced by IL-6. In addition, EGCG/EC induced apoptosis of HSC 4 cells. These findings indicate that EGCG is useful as an antitumor agent. Shika Igaku (J Osaka Odontol Soc) 2003 Mar; 66(1): 105-111.
