Up-regulation Of Protein Tyrosine Phosphatase 1B Induced By Tumor Necrosis Factor Alpha In Hepatocellular Carcinoma Cell

Objective:To investigate the effect and mechanism of TNF-a on PTP-1B inhepatocellular carcinoma HepG2 cells. Methods: After 24 hours treatment with differentconcentration of TNF-a,RT-PCR and Westernblot assay were used to measure PTP-1Bexpression ,and NF-κB luciferase reporter and Westemblot assay were used to detect NF-κBactivity and NF-κB p65 protein. HepG2 cell were treated with different concentration of TNF-aplus PDTC, a NF-κB specifical inhibitor for 24 hours, RT-PCR and westemblot assay wereperformed to detect PTP-1B expression. Results: Treatment of HepG2 cells with differentconcentration of TNF-a for 24 hours led to up regulation of PTP-1B and NF-κB activity in adoes-dependent manner, the highest responses was detectable in 15ug/L. Inhibition of NF-κB byPDTC can significantly attenuate TNF-a-induced hepatic PTP-1B expression. Conclusion: TNF-ainduces hepatic PTP-1B expression through transactivation of NF-κB.