Up-regulation of glypican-3 in human hepatocellular carcinoma.

AIM: To investigate the expression and significance of glypican-3 (GPC3) in human hepatocellular carcinoma (HCC). MATERIALS AND METHODS: DNA chips were used to measure the expression of mRNAs for members of the glypican and syndecan families of heparan sulfate proteoglycans (HSPGs) in normal liver tissue, non-tumor tissues and HCC. GPC3 protein expression was investigated by immunohistochemical staining in the tissues samples and Western blotting in human HCC cell lines. In addition, the levels of GPC3 protein in the blood were determined by ELISA. RESULTS: Only the expression of GPC3 was found to be markedly elevated in HCCs. In the human HCC cell lines, GPC3 expression was consistently observed, and was mainly located in the cell membrane and cytoplasm. Immunohistochemistry showed a tendency for overall staining of the cytoplasm of cells in the liver carcinoma tissues, but the cell membrane was preferentially stained in poorly differentiated HCC when compared with well-differentiated HCC. Moreover, the cell membrane was preferentially stained in metastatic lesions of HCC when compared with primary HCC lesions. Non-tumor tissues and cholangiocellular carcinoma tissues were not stained. In addition, using HepG2 cells, AG490 and piceatannol, which are signal transducer and activator of transcription 3 (STAT3) inhibitors, each increased the amount of GPC3 mRNA expressed. Assay of the circulating levels of GPC3 protein in chronic liver disease and HCC found that serum GPC3 protein levels were significantly elevated in the latter. CONCLUSION: GPC3 is highly expressed in HCC, and its expression pattern differs according to the degree of cell differentiation. In addition, the expression of GPC3 is regulated by Janus kinase-STAT signaling. GPC3 shows potential as a tumor biomarker for HCC that can be used for molecularly targeted therapy.

Functional cell surface expression of toll-like receptor 9 promotes cell proliferation and survival in human hepatocellular carcinomas.

Toll-like receptor 9 (TLR9) is a pattern-recognition receptor that is involved in immune signaling and plays a crucial role in cell survival through recognition of various bacterial and viral components including unmethylated CpG-DNA. TLR9 expression and function in cancer cells are not well understood. We investigated the expression of TLR9, and the function of TLR9 signaling, in hepatocellular carcinoma (HCC) cells following stimulation with CpG-oligodeoxynucleotides (ODNs). Positive immunohistochemical staining for TLR9 was observed in 85.7% of HCC tissues. Western blot analysis revealed that TLR9 was expressed both on the cell membrane and in the cytoplasm of HCC cell lines. Full-length TLR9 was predominantly expressed on the membrane rather than in the cytoplasm, whereas multiple cleaved forms of TLR9 were predominantly expressed in the cytoplasm rather than on the membrane. Cell surface stimulation of TLR9 promoted cell proliferation, and, furthermore, the TLR9 agonists, CpG-ODNs, reduced the cytotoxicity of the anti-cancer drug adriamycin (ADM) via up-regulation of apoptosis inhibitors such as survivin, Bcl-xL, XIAP and cFLIP, in HCC cell lines. Although cell surface stimulation of TLR9 did not activate either the NF-kappaB signaling pathway or the type-I IFN secretion pathway, gene chip microarray analysis indicated that TLR9 agonists closely regulated multiple oncology-related genes and transcription factors involved in tumorigenesis and cancer progression. In conclusion, our results indicate that functional cell surface expression of TLR9 in human HCC may play an important role in tumorigenesis and cancer progression.

Dual topology of functional Toll-like receptor 3 expression in human hepatocellular carcinoma: differential signaling mechanisms of TLR3-induced NF-kappaB activation and apoptosis.

Toll-like receptor 3 (TLR3) is a pattern-recognizing receptor that is involved in immune signaling and plays a crucial role in survival by being able to recognize various viral components including double-stranded RNA (dsRNA). TLR3 expression and function in cancer cells are not well understood. We investigated the expression of TLR3 in hepatocellular carcinoma (HCC) cells and the function of TLR3 signaling by stimulation and transfection with polyinosinic-polycytidylic acid (Poly I:C), a synthetic form of dsRNA. TLR3 mRNA was expressed in HCC tissues as well as in non-tumor tissues. Positive immunohistochemical staining for TLR3 was observed in 52.7% of HCC tissues, and in HCC cells we found both membranous and cytoplasmic expression of TLR3. While cell surface stimulation of TLR3 with Poly I:C did not affect cell viability, it did activate NF-kappaB levels. In contrast, cytoplasmic stimulation with transfected Poly I:C significantly induced apoptosis accompanied by the down-regulation of anti-apoptotic protein. Transfected Poly I:C also synergistically augmented TRAIL-induced apoptosis, but only with low levels of transfected Poly I:C was IFN-beta production not observed. In conclusion, our results indicate that TLR3 expression in HCC plays an important role with regard to cell survival and proapoptotic activity. Endogenously expressed TLR3 may provide new clinical prospects for TLR3 agonists as cytotoxic agents in HCC.

Splenectomy improves liver function in patients with liver cirrhosis.

BACKGROUND/AIMS: Partial splenic embolization or splenectomy has been reported to improve liver function as well as hypersplenism. The aim of this study was to evaluate the effects of splenectomy in patients with liver cirrhosis (LC) on liver function. METHODOLOGY: Twelve consecutive patients with LC were followed for more than 6 months using laboratory examinations, ultrasonography (US) and computed tomography. Portal blood flow was measured using color Doppler US before and after splenectomy in 6 cases. RESULTS: Hypersplenism was improved in all patients. Protein synthesis in the liver was improved, which significantly correlated with these patients' increased liver volume. Having a large spleen and a low serum alanine aminotransferase (ALT) levels are predictive factors for favorable improvement of liver function after splenectomy. Splenectomy was safely carried out in all patients without major complications except for portal thrombus occurred in 4 patients, but did not affect liver function if it was well treated. CONCLUSIONS: Splenectomy improved liver function in patients with LC, and could be a supportive and bridging therapy for patients waiting for liver transplantation, especially with large spleen and lower ALT levels.

Protective role of interleukin-18 against Fas-mediated liver injury.

Interleukin (IL)-18 plays an important role in the pathogenesis of several liver diseases as well as Fas-mediated apoptosis. However, the effects of IL-18 on Fas-mediated liver injury have not been well elucidated. Therefore, we examined the effects of IL-18 on Fas-mediated apoptosis in in vitro and in vivo experiments. We found that recombinant IL-18 protected mouse hepatocellular carcinoma cell lines, BNL5, from Fas-mediated apoptosis in a dose-dependent manner with up-regulation of both nuclear factor (NF) kappaB and X-linked inhibitors of apoptosis (XIAP). IL-18 transgenic (Tg) mice were also protected from Fas-mediated liver injury and this was further confirmed by histological study and TUNEL staining. In IL-18 Tg mice, up-regulation of XIAP and down-regulation of caspase 3 were observed after injection of anti-Fas, which was consistent with the in vitro findings. These results suggest that IL-18 suppresses Fas-mediated apoptosis of hepatocytes by up-regulation of NFkappaB and XIAP, following inhibition of caspase-3 activity. This observation raises the possibility that IL-18 could be a therapeutic strategy for Fas-mediated liver injury as a negative regulator of XIAP.

Primary biliary cirrhosis following chemotherapy for Hodgkin's lymphoma.

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease primarily affecting middle-aged women. Although little is known about the etiology of PBC, it may be induced by an autoimmune response. Here, we describe a rare case of appearance of PBC following chemotherapy for Hodgkin's lymphoma.

Cervical mycotic aneurysm in a patient with alcoholic cirrhosis.

We report a case of 65-year-old man with alcoholic cirrhosis and diabetes mellitus, in whom a cervical mycotic aneurysm suddenly developed after sepsis with methicillin-resistant staphylococcus aureus. Severe infection associated with alcoholic cirrhosis may cause a typical mycotic aneurysm.

Jak inhibitor induces S phase cell-cycle arrest and augments TRAIL-induced apoptosis in human hepatocellular carcinoma cells.

Signal transducer and activator of transcription 3 (STAT3) is constitutively activated in various cancers and plays a crucial role in oncogensis, including the activation of genes encoding apoptosis inhibitors and cell-cycle regulators. We investigated the biological significance of the Janus kinase (Jak)-STAT pathway in human hepatocellular carcinoma (HCC). Constitutive activation of STAT3 was seen in 49.4% of human HCC specimens and in HCC cell lines. Jak inhibitor AG490 inhibited activation of STAT3 and markedly reduced cell viability without significant apoptosis. AG490 also induced S phase cell-cycle arrest with down-regulation of cyclin D1, A, E and up-regulation of p21, p27, phospho-Chk2. AG490 also inhibited caspase inhibitory proteins, such as XIAP and survivin, and augmented TRAIL-induced apoptosis. Our study suggests that the Jak-STAT pathway plays an important role in cell-cycle progression and resistance to apoptosis. Inhibition of the Jak-STAT pathway may thus be a therapeutic target for HCC.

Tubulointerstitial nephritis associated with IgG4-related autoimmune disease.

Autoimmune pancreatitis is a chronic fibroinflammatory condition primarily affecting the pancreas. Recent accumulating evidence suggested that autoimmune pancreatitis is a systemic autoimmune disease (immunoglobulin G4 [IgG4]-related autoimmune disease) affecting various organs with dense infiltration of IgG4-positive mononuclear cells. Tubulointerstitial nephritis is still a mysterious disease with an unknown cause. We report 2 cases of tubulointerstitial nephritis associated with autoimmune pancreatitis. In these patients, dense infiltrations of IgG4-positive mononuclear cells were observed in renal interstitium, with high serum IgG4 levels. Furthermore, in patient 1, who had sclerosing cholangitis, serum alkaline phosphatase and serum creatinine levels changed synchronously. Steroid therapy was followed by improved renal function and serum IgG4 levels in both patients. Because tubulointerstitial nephritis associated with IgG4-related autoimmune disease shows a favorable response to steroids and the renal dysfunction and pancreatic dysfunction are reversible, awareness of this entity is necessary for early diagnosis and prompt treatment. In addition, these cases support the hypothesis that IgG4-related autoimmune disease could be one cause of tubulointerstitial nephritis.

Cellular apoptosis susceptibility protein and proliferation in human hepatocellular carcinoma.

The cellular apoptosis susceptibility protein (CAS) is the human homologue of the product of the essential yeast chromosome segregation gene, CSE1, and has important roles in tumor necrosis factor (TNF)-induced apoptosis and cell proliferation. In this study, we used immunoblotting and immunohistochemistry to look at CAS expression in human hepatocellular carcinoma (HCC) cells. We also studied the correlation between CAS expression and cell proliferation. To do this, we studied the expression of proliferating cell nuclear antigen (PCNA) by immunostaining and at apoptosis by in situ nick end-labeling (TUNEL), followed by calculation of the PCNA labeling index (PCNA LI) and TUNEL labeling index (TUNEL LI). CAS was constitutively expressed in human HCC cell lines and was primarily confined to the cytoplasm of the cells. PCNA LI and TUNEL LI were significantly higher in HCC than in non-tumor tissue (p<0.01); however, the ratio of TUNEL LI/PCNA LI in HCC was significantly lower than that of non-tumor tissue. Immunohistochemistry revealed that the staining intensity score of CAS in HCC was significantly higher than that of non-tumor tissue (p<0.05). These results indicate that there is an augmentation of pro-liferative activity and apoptosis in HCC tissue, as compared to non-tumor tissue. There was a significant positive correlation between CAS and PCNA LI (p<0.05). In addition, we observed an inverse relationship between CAS expression and TUNEL LI, although the correlation did not reach statistical significance. These results suggest that CAS is expressed at higher levels in human HCC tissue than in non-tumor tissue. CAS may be associated with cell proliferation rather than apoptosis, and further, CAS might play an important role in the development of human HCCs.