Hyperthermia inhibits transforming growth factor beta-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma cells.

BACKGROUND/AIMS: EMT plays an essential role in tumor progression and metastasis. Hyperthermia is a potent approach for cancers with low side effects. However, the effect of hyperthermia on EMT of cancer cells is unknown. METHODOLOGY: Cells were treated with TGF-β1 and epidermal growth factor for 96 h and then exposed to hyperthermia at 43°C for 0.5 h. Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by Western blot. The protein and mRNA expressions of Snail were detected with Western blot and RT-PCR. Cell migratory capacity was evaluated. RESULTS: TGF-β1 induced EMT in HepG2 cells, which was evidenced by morphological, molecular and functional changes, including the formation of spindle shape and the loss of cell contact. The expression of E-cadherin was decreased but the expression of vimentin increased; also, the migratory capability was increased by 2.1±0.19-fold as compared with untreated cells. However, those effects were inhibited by the treatment of hyperthermia. Furthermore, the protein and mRNA expressions of Snail induced by TGF-β1 were also significantly inhibited by hyperthermia treatment CONCLUSIONS: Hyperthermia can inhibit TGF-β1-induced EMT in HepG2 cells, suggesting that hyperthermia may alter the properties of metastatic potential in cancer cells and inhibit tumor metastasis.