TMPRSS4 Drives Angiogenesis in Hepatocellular Carcinoma by Promoting HB-EGF Expression and Proteolytic Cleavage.

BACKGROUND AND AIMS

Heparin-binding epidermal growth factor (HB-EGF), a member of the epidermal growth factor family, plays a pivotal role in the progression of several malignancies, but its role and regulatory mechanisms in hepatocellular carcinoma (HCC) remain obscure. Here, we report that transmembrane protease serine 4 (TMPRSS4) significantly enhanced the expression and proteolytic cleavage of HB-EGF to promote angiogenesis and HCC progression.

APPROACH AND RESULTS

A mechanistic analysis revealed that TMPRSS4 not only increased the transcriptional and translational levels of HB-EGF precursor, but also promoted its proteolytic cleavage by enhancing matrix metallopeptidase 9 expression through the EGF receptor/Akt/mammalian target of rapamycin/ hypoxia-inducible factor 1 α signaling pathway. In addition, HB-EGF promoted HCC proliferation and invasion by the EGF receptor/phosphoinositide 3-kinase/Akt signaling pathway. The level of HB-EGF in clinical samples of serum or HCC tissues from patients with HCC was positively correlated with the expression of TMPRSS4 and the microvessel density, and was identified as a prognostic factor for overall survival and recurrence-free survival, which suggests that HB-EGF can serve as a potential therapeutic target for HCC. More importantly, we provide a demonstration that treatment with the HB-EGF inhibitor cross-reacting material 197 alone or in combination with sorafenib can significantly suppress angiogenesis and HCC progression.

CONCLUSIONS

HB-EGF can be regulated by TMPRSS4 to promote HCC proliferation, invasion, and angiogenesis, and the combination of the HB-EGF inhibitor cross-reacting material 197 with sorafenib might be used for individualized treatment of HCC.