Clinical significance of transient receptor potential vanilloid 2 expression in human hepatocellular carcinoma

Transient receptor potential vanilloid 2 (TRPV2), one of the members of TRP (transient receptor potential) superfamily of ion channels, has been suggested to contribute to pain associated with inflammation or neuropathy. To investigate its role in hepatocarcinogenesis, we examined the expression of TRPV2 in human hepatocellular carcinoma (HCC) samples and analyzed the association of TRPV2 expression with its clinical significance. TRPV2 expression in 55 HCC patients was examined by immunohistochemistry, and the correlation between TRPV2 levels and clinicopathologic parameters was analyzed. Thirteen paired HCC specimens and their nontumor counterparts were investigated by quantitative real-time polymerase chain reaction (RT-PCR) and Western blotting, respectively. Quantitative RT-PCR and Western blotting analysis revealed that expression of TRPV2 at both the mRNA and protein levels were increased in cirrhotic livers compared with chronic hepatitis, whereas that also occurred in moderately and well-differentiated tumors compared with that of poorly differentiated tumors. Immunohistochemistry of the 55 HCC samples showed that the expression of TRPV2 increased when going from normal liver or chronic hepatitis to cirrhosis. Increased TRPV2 expression was observed in tissues of liver cirrhosis (31/37, 83.8%). In HCC, increased expression of TRPV2 was identified in 16/55 (29%) cases. Clinicopathologic assessment suggested a significant association between TRPV2 expression and portal vein invasion and histopathologic differentiation (P = 0.036 and 0.001, respectively). Our data suggest that TRPV2 plays a role in human hepatocarcinogenesis and might be a prognostic marker of patients with HCC.