TGF beta1 and related-Smads contribute to pulmonary metastasis of hepatocellular carcinoma in mice model

BACKGROUND Recent studies indicate that Transforming Growth Factor beta (TGF β) correlated with pulmonary metastasis of cancers. However, the correlation between TGF β and pulmonary metastasis of hepatocellular carcinoma (HCC) is till unknown. METHODS We detected the in vitro and in vivo expression levels of TGF β1/Smads by Real-time PCR and Western blot in MHCC97-H and MHCC97-L cell lines, which are HCC cell lines and have higher and lower pulmonary metastatic potential respectively. RESULTS TGF β1 mRNA level in MHCC97-L tumors were higher than that in MHCC97-H tumors, (2.81±1.61 vs. 1.24±0.96, P=0.002), TGF β1 protein level in MHCC97-L tumors were also higher than that in MHCC97-H tumors (1.37±0.95 vs. 0.32±0.22, P<0.001). In addition, the TGF β1 mRNA level positively correlated with pulmonary metastasis, and the relations between TGF β1 and Smads were also found (R2=0.12 and 0.40, respectively). CONCLUSIONS Our results suggest that TGF β/ Smads promote pulmonary metastasis of HCC.