Treatment with the herbal formula Songyou Yin inhibits epithelial-mesenchymal transition in hepatocellular carcinoma through downregulation of TGF-β1 expression and inhibition of the SMAD2/3 signaling pathway

It was previously reported that treatment with the herbal formula Songyou Yin (SYY) may serve a role in attenuating epithelial-mesenchymal transition (EMT). In the present study, the effect of treatment with SYY on transforming growth factor-β1 (TGF-β1)-induced EMT was investigated and the potential underlying molecular mechanisms were evaluated. MHCC97H cells were pretreated with SYY for 4 weeks and subsequently named MHCC97HSYY cells. Simultaneously, MHCC97H cells were cultured for 4 weeks without SYY and used as a negative control. Western blot analysis and enzyme-linked immunosorbent assays demonstrated that treatment with SYY inhibited EMT-associated changes and TGF-β1 expression in MHCC97H cells. MHCC97H and MHCC97HSYY cells were treated with 10 ng/ml TGF-β1 to induce EMT. The results of the present study demonstrated that pretreatment with SYY markedly inhibited TGF-β1-induced morphological changes, and reversed the expression of the EMT markers E-cadherin and N-cadherin. In addition, expression levels of the TGF-β1 downstream proteins, phosphorylated mothers against decapentaplegic homologs (p-SMAD)2 and 3, were reduced. Transwell assays indicated that pretreatment with SYY inhibited TGF-β1-induced cancer cell invasion and migration. The results of the present study indicate that SYY inhibited EMT through attenuation of TGF-β1 expression, and downregulation of p-SMAD2 and 3.