ndi Xu

High expression of vanilloid receptor-1 is associated with better prognosis of patients with hepatocellular carcinoma

The vanilloid receptor-1 (VR1) is a ligand-gated, nonselective cation channel expressed predominantly by sensory neurons, but is also involved in carcinogenesis. To elucidate its role in hepatocarcinogenesis, we analyzed the expression of VR1 receptor in tumor and nontumor tissues from human hepatocellular carcinoma (HCC) samples. In situ hybridization analysis showed overexpression of VR1 mRNAs in 9/15 (60.0%) noncancer and 6/15 (40.0%) HCC samples. Immunohistochemistry of 62 HCC samples showed the expression of VR1 increased from normal liver or chronic hepatitis to cirrhosis. Marked expression of VR1 was noted in the majority [31/38 (81.6%)] of cirrhotic liver samples. In HCC, high expression of VR1 was observed in 30/62 (48.4%) cases. Clinicopathologic evaluation indicated a significant correlation between VR1 expression and histopathologic differentiation (P=0.001). Univariate analysis indicated that disease-free survival was significantly better in HCC patients with high versus those with low VR1 expression levels (P= 0.021). Our results indicate that VR1 has anti-HCC progression effects and can be potentially used as a prognostic indicator of HCC. The results suggest the potential beneficiary effects of VR1 expression on the prognosis of patients with HCC.

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.

Numb downregulation suppresses cell growth and is associated with a poor prognosis of human hepatocellular carcinoma

Numb, an endocytic adaptor, is a known cell fate determinant that participates in asymmetric cell division. The present study aimed to explore the potential roles of Numb in hepatocarcinogenesis. Numb expression was investigated in hepatocellular carcinomas (HCC) with reverse transcription-quantitative polymerase chain reaction and immunohistochemical examination; its association with the prognosis of HCC patients was analyzed. In addition, the effects of Numb deletion on proliferation of HCC cells and its relevant molecules were evaluated in Huh7 and HepG2 cells. Numb overexpression was observed in 62% of adjacent non-tumor tissues and 46% of tumor tissues. Overexpression of Numb in HCC was associated with histological grade, portal vein invasion and the number of tumors (P=0.001, 0.022 and 0.034 respectively). Multivariate analysis revealed that Numb expression was an independent prognostic indicator of HCC patients. Methylation of the Numb promoter contributed to hepatocarcinogenesis. In vitro assays demonstrated that Numb silencing resulted in inhibition of cell proliferation, induction of apoptosis, down-regulation of cyclin-dependent protein kinase 4 (CDK4) and S-phase kinase-associated protein 2 (SKP2), and upregulation of Bcl-2 homologous antagonist/killer (BAK) and cyclin-dependent kinase inhibitor 1 (p21). The present study suggests that downregulation of Numb inhibits colony formation and cell proliferation, induces apoptosis of HCC cells and independently predicts the poor prognosis of HCC patients. Thus, Numb has a potential role in the development and progression of HCC.

Splenectomy after partial hepatectomy accelerates liver regeneration in mice by promoting tight junction formation via polarity protein Par 3-aPKC

Aims: Several experimental studies have demonstrated that removal of the spleen accelerates liver regeneration after partial hepatectomy. While the mechanism of splenectomy promotes liver regeneration by the improvement of the formation of tight junction and the establishment of hepatocyte polarity is still unknown. Main methods: We analyzed the cytokines, genes and proteins expression between 70% partial hepatectomy mice (PHx) and simultaneous 70% partial hepatectomy and splenectomy mice (PHs) at predetermined timed points. Key findings: Compared with the PHx group mice, splenectomy accelerated hepatocyte proliferation in PHs group. The expression of Zonula occludens‐1 (ZO‐1) indicated that splenectomy promotes the formation of tight junction during liver regeneration. TNF‐&agr;, IL‐6, HGF, TSP‐1 and TGF‐&bgr;1 were essential factors for the formation of tight junction and the establishment of hepatocytes polarity in liver regeneration. After splenectomy, Partitioning defective 3 homolog (Par 3) and atypical protein kinase C (aPKC) regulate hepatocyte localization and junctional structures in regeneration liver. Significance: Our data suggest that the time course expression of TNF‐&agr;, IL‐6, HGF, TSP‐1, and TGF‐&bgr;1 and the change of platelets take part in liver regeneration. Combination with splenectomy accelerates liver regeneration by improvement of the tight junction formation which may help to establish hepatocyte polarity via Par 3‐aPKC. This may provide a clue for us that splenectomy could accelerate liver regeneration after partial hepatectomy of hepatocellular carcinoma and living donor liver transplantation.

Transient receptor potential vanilloid-type 2 targeting on stemness in liver cancer

The malignant phenotype of the cells resulting from human liver cancer is driven by liver cancer stem-like cells (LCSLCs). Transient Receptor Potential Vanilloid-type 2 channel (TRPV2) contributes to the progression of different tumor types, including liver cancer. In the current study, the TRPV2 expression levels give rise to the effect on stemness in liver cancer cell lines. TRPV2 knockdown in HepG2 cells enhanced spheroid and colony formation, and expression levels of CD133, CD44 and ALDH1 whereas the opposite effects were observed in TRPV2 enforced expression in SMMC-7721 cells. Furthermore, TRPV2 overexpression restored inhibition of spheroid and colony formation, and stem cell markers expression in HepG2 cells with TRPV2 silencing. The addition of the TRPV2 agonist probenecid and the TRPV2 antagonist tranilast suppressed and/or increased in vitro spheroid and colony formation, and stem cell marker expression of LCSLCs and/or liver cancer cell lines, respectively. Notably, probenecid and tranilast significantly inhibited or promoted tumor growth of HepG2 xenografts in the severe combined immunodeficiency (SCID) mouse model, respectively. TRPV2 expression at protein levels revealed converse correlation with those of CD133 and CD44 in human hepatocellular carcinoma (HCC) tissue. Collectively, the data demonstrate that TRPV2 exert effects on stemness of liver cancer and is a potential target in the treatment of human liver cancer patients.

Pharmacological inhibition of TRPV4 channel suppresses malignant biological behavior of hepatocellular carcinoma via modulation of ERK signaling pathway

TRPV4 (transient receptor potential vanilloid 4), a member of the TRP superfamily, has been reported to correlate with several different forms of cancers. However, the role of TRPV4 in human hepatocellular carcinoma (HCC) remains unclear. The present study demonstrated that elevated expression of TRPV4 was shown in HCC tumor tissues when compared with paired non-tumoral livers both in protein and mRNA levels. Furthermore, the enhanced expression of TRPV4 was highly associated with histological grade (P = 0.036) and the number of tumors (P = 0.045). Pharmacological inhibition of TRPV4 channels in HCC cells with the specific antagonist HC-067047 suppressed cell proliferation, induced apoptosis and decreased the migration capability by attenuating the epithelial-mesenchymal transition (EMT) process in vitro. The p-ERK expression was apparently repressed after treatment with the TRPV4 antagonist, further blockade of the ERK pathway with U0126 could significantly aggravate HCC cells apoptosis. In NOD-SCID mouse xenograft models, intraperitoneal injection of HC-067047 could obviously suppress tumor growth and induce apoptosis in vivo. Together, our studies showed that the antitumor effects caused by TRPV4 channel inhibition in HCC cell lines might be attributed to the suppression of EMT process and inactivation of p-ERK which induced subsequent cell apoptosis. Thus, pharmacological inhibition of TRPV4 channel may be an option for HCC treatment.