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TNF-like weak inducer of apoptosis (TWEAK) is a member of the TNF family whose transcripts are expressed in various human tissues. Since TWEAK has a variety of biological activities, we investigated TWEAK sensitivity, expression, and physiological role in human hepatocellular carcinomas (HCCs). Tweak receptor was detected in four kinds of HCC cells. TWEAK significantly promoted cell proliferation and induced nuclear factor-kappaB activation in all HCC cells. Surprisingly, we found that HCC cells constitutively express TWEAK. In addition, soluble TWEAK was detected in culture medium. We found that TWEAK also promotes cell proliferation and induces the secretion of IL-8 and MCP-1 in human umbilical vein endothelial cell. Finally, culture medium from Sh-Hep1 cells incubated with anti-TWEAK antibody significantly inhibited endothelial cell tube formation. In conclusion, these results indicate that TWEAK might play a critical role in HCC cellular proliferation using both autocrine and paracrine mechanisms, and modulate tumor-related angiogenesis.

The peroxisome proliferator-activated receptor-gamma (PPARgamma) high-affinity ligand, 15-deoxy-Delta-12,14-PGJ(2) (15d-PGJ(2)), is toxic to malignant cells through cell cycle arrest and apoptosis induction. In this study, we investigated the effects of 15d-PGJ(2) on apoptosis induction and expression of apoptosis-related proteins in hepatocellular carcinoma (HCC) cells. 15d-PGJ(2) induced apoptosis in SK-Hep1 and HepG2 cells at a 50 micro M concentration. Pretreatment with the pan-caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethyl ketone (2-VAD-fmk), only partially blocked apoptosis induced by 40 micro M 15d-PGJ(2). This indicated that 15d-PGJ(2) induction of apoptosis was associated with a caspase-3-independent pathway. 15d-PGJ(2) also induced down-regulation of the X chromosome-linked inhibitor of apoptosis (XIAP), Bclx, and apoptotic protease-activating factor-1 in SK-Hep1 cells but not in HepG2 cells. However, 15d-PGJ(2) sensitized both HCC cell lines to TNF-related apoptosis-induced ligand-induced apoptosis. In SK-Hep1 cells, cell toxicity, nuclear factor-kappaB (NF-kappaB) suppression, and XIAP down-regulation were induced by 15d-PGJ(2) treatment under conditions in which PPARgamma was down-regulated. These results suggest that the effect of 15d-PGJ(2) was through a PPARgamma-independent mechanism. Although cell toxicity was induced when PPARgamma was down-regulated in HepG2 cells, NF-kappaB suppression and XIAP down-regulation were not induced. In conclusion, 15d-PGJ(2) induces apoptosis of HCC cell lines via caspase-dependent and -independent pathways. In SK-Hep1 cells, the ability of 15d-PGJ(2) to induce cell toxicity, NF-kappaB suppression, or XIAP down-regulation seemed to occur via a PPARgamma-independent mechanism, but in HepG2 cells, NF-kappaB suppression by 15d-PGJ(2) was dependent on PPARgamma.

AIM: To detect the expression of a proliferation-related ligand on human hepatocellular carcinoma (HCC) cell lines (SK-Hep1, HLE and HepG2) and in culture medium. METHODS: APRIL expression was analyzed by Western blotting in HCC cell lines. Effects of APRIL to cell count and angiogenesis were analyzed, too. RESULTS: Recombinant human APRIL (rhAPRIL) increased cell viability of HepG2 cells and, in HUVEC, rhAPRIL provided slight tolerance to cell death from serum starvation. Soluble APRIL (sAPRIL) from HLE cells increased after serum starvation, but did not change in SK-Hep1 or HepG2 cells. These cells showed down-regulation of VEGF after incubation with anti-APRIL antibody. Furthermore, culture medium from the HCC cells treated with anti-APRIL antibody treatment inhibited tube formation of HUVECs. CONCLUSION: Functional expression of APRIL might contribute to neovascularization via an upregulation of VEGF in HCC.

A systemic vitamin K analog, compound 5 (Cpd 5), possesses the ability to inhibit cell growth of tumor cells. Therefore, we investigated the effect of Cpd 5 in human hepatocellular carcinoma (HCC) cell lines and evaluatedits role in apoptosis. Human HCC cell lines were cultured and treated with Cpd 5. Apoptosis was assessed using DAPI staining and Annexin-V membrane staining. The expression of caspases, XIAP and Bcl-x L was also investigated. Cpd 5 decreased cell viability in a dose-dependent manner in two HCC cells (HLE and SK-Hep1) containing mutant p53, but not in the HepG2 cell line, which contained wild-type p53. Cpd 5-treated HLE and SK-Hep1 cells showed typical apoptotic features, nuclear condensation and nuclear fragmentation upon DAPI staining. Positive membranous staining for Annexin-V was also seen in these cells. Both caspase-8 and caspase-3 activities were up-regulated slightly. Pro-caspase-8 protein levels decreased slightly in both cells. Although the expression of Bcl-x L was not influenced by Cpd 5, that of XIAP decreased in HLE cells. However, the pan-caspase inhibitor, zVAD, could not significantly prevent Cpd 5-induced apoptosis and Cpd 5 could not augment TRAIL-induced apoptosis. These results demonstrate that Cpd 5 induced apoptosis in human HCC cell lines, mainly independently of caspase activities. This may contribute to its highly potent cytotoxicity toward HCC cells.

TNF-related apoptosis-inducing ligand (TRAIL), as well as Fas ligand, plays a pivotal role in lymphocyte cytotoxicity and the maintenance of immunological homeostasis in various tissues, but its physiological role in immune evasion of cancer cells remains unknown. We have previously shown strong resistance to TRAIL-induced cytotoxicity in human hepatocellular carcinomas (HCCs). The current study investigates the expression of TRAIL in HCCs. We found that three HCC cells, HepG2, Hep3B and Huh7 cells, constitutively express TRAIL mRNA and protein, as detected by reverse transcriptase PCR and Western blotting. Four of 10 human HCC tissues demonstrated positive staining for TRAIL, whereas non-tumor tissues showed little detectable staining. TRAIL expression on tumor cells was detected by flow cytometry and was dramatically induced after the addition of doxorubicin, a chemotherapeutic agent, or cytokine stimulation with TNF-alpha, IL-1beta or IL-18. This expression was induced principally via the NF-kappaB activation pathway, since IkappaB transfection significantly reduced TRAIL expression. In addition, the expressed TRAIL was functional. The TRAIL on HCC cells induced apoptosis in Jurkat cells that are sensitive to TRAIL-mediated apoptosis, and this process was specifically inhibited by recombinant TRAIL-receptors:Fc which binds to TRAIL. In conclusion, TRAIL expressed on the surface of HCC cells by cytokines or cytostatic drugs might contribute to an alternative mechanism that enables tumors to evade immune surveillance by inducing apoptosis of activated human lymphocytes.

The prognosis of icteric type hepatocellular carcinoma is extremely poor, not only because of obstructive jaundice, but also because of difficulties for early diagnosis. The aim of this study is to evaluate characteristics of icteric hepatocellular carcinoma for early diagnosis.Eight patients with icteric hepatocellular carcinoma among 326 patients with hepatocellular carcinoma in our hospitals were retrospectively examined by laboratory data, image studies and pathology studies.Most cases were already advanced, with a portal tumor thrombus at the time of diagnosis. Imaging studies fail to reveal tumors because this type of hepatocellular carcinoma has an irregular faint margin and has lost the characteristic pattern of hepatocellular carcinoma, such as capsular formation or early enhancement. Pathology observations demonstrated poorly or moderately differentiated hepatocellular carcinoma in all our cases.This type of hepatocellular carcinoma should be considered in cirrhotic patients with obstructive jaundice or in patients with high tumor marker levels even if image studies fail to reveal tumors. For better prognosis, combination therapies such as biliary drainage, support for portal flow as well as treatment for the hepatocellular carcinoma, are necessary.

A staging system for hepatocellular carcinoma was reported from Italy (CLIP). In this study, we evaluate the CLIP scoring system and establish a new scoring system for predicting the prognosis of patients with hepatocellular carcinoma. Patients (n=141) who were diagnosed and who underwent initial treatment at our single institution were recruited retrospectively into this study. We evaluated markers for prognosis, using a stratified Cox proportional hazard regression model and Kaplan-Meier survival analysis. CLIP score differentiated patients with different survival experiences by Kaplan-Meier estimated survival analysis. However, with respect the CLIP score, more than two thirds of patients were included in the early stage (CLIP 0-1), and the group with better prognosis than the survival rate of all patients was the only one with CLIP 0. Multivariate analysis revealed that des-gamma-carboxy prothrombin (DCP)/=100 mAU/ml (relative risk, 2.06; P=0.0218) was statistically significant as a predictor of poor survival. A new prognostic scoring system included DCP classified patients to 6 well-balanced groups (score 0-5). The new prognostic scoring system 0 group (14.9% of the cohort) and the CLIP score 0 group (34.0% of the cohort) had a median survival of 66.9 and 61.6 months. The new prognostic scoring system performs better for prediction of survival than either the CLIP score or the Child-Pugh stage. In conclusion, the described scoring system provides more accurate prognostic information than the CLIP scoring system. It may help physicians decide more appropriate clinical and therapeutic management.

Human hepatocellular carcinomas (HCCs) show resistance to apoptosis mediated by several death receptors. Because cellular FLICE/caspase-8-inhibitory protein (cFLIP) is a recently identified intracellular inhibitor of caspase-8 activation that potently inhibits death signaling mediated by all known death receptors, including Fas, TNF-receptor (TNF-R), and TNF-related apoptosis-inducing ligand receptors (TRAIL-Rs), we investigated the expression and function of cFLIP in human HCCs. We found that cFLIP is constitutively expressed in all human HCC cell lines and is expressed more in human HCC tissues than in nontumor liver tissues. Metabolic inhibitors, actinomycin D (ActD) or cycloheximide (CHX), dramatically rendered HCC cells sensitive to Fas-mediated apoptosis. Neither caspase-8 nor caspase-3 was activated by agonistic anti-Fas antibody alone, but both caspases were activated by Fas stimulation in the presence of ActD or CHX, indicating the importance of caspase-8 inhibitors that are sensitive to metabolic inhibitors. Actually, cFLIP expression was decreased in ActD or CHX treatment. cFLIP down-regulation induced by cFLIP antisense oligodeoxynucleotides sensitized HLE cells to Fas, TNF-R, and TRAIL-R-mediated apoptosis. Furthermore, cFLIP over-expression activated nuclear factor (NF)-kappaB and cFLIP down-regulation attenuated NF-kappaB activation induced by TNF-alpha or TRAIL. Pretreatment with pan-caspase-inhibitor, benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethyl ketone (Z-VAD-fmk), restored NF-kappaB activity attenuated by cFLIP down-regulation. cFLIP expression was increased by TNF-alpha, TRAIL, or vascular endothelial growth factor but decreased by wortmannin, indicating that cFLIP expression is regulated by both the NF-kappaB and phosphatidylinostiol-3 kinase (PI-3)/Akt pathways. These results suggest that cFLIP plays an important role in cell survival not simply by inhibiting death-receptor-mediated apoptosis but also by regulating NF-kappaB activation in human HCCs.

The efficacy of continuous arterial infusion chemotherapies via a subcutaneously implanted port has been reported in unresectable HCC cases. However, the regimens for this therapy are still controversial. Among these regimens, cisplatinum (CDDP) + 5-fluorouracil (5-FU) or epirubicin have been reported to have favorable effects.The efficacies of these two regimens are compared with regard to size of tumor, a tumor marker and survival rate in patients with unresectable HCC.Treatments with both the epirubicin (epirubicin group) and the CDDP + 5-FU (CDDP group) demonstrated significant tumoricidal effects as compared with conservative therapies (control group). Furthermore, the tumoricidal effects observed in the CDDP group were superior to that in the epirubicin group, despite a higher incidence of portal tumor thrombus in the CDDP group. Additionally, a longer survival was observed in the CDDP group relative to the epirubicin group.Arterial infusion chemotherapy using CDDP + 5-FU may be the superior regimen for advanced HCC, even with portal tumor thrombus complications.

The incidence of hepatocellular carcinoma (HCC) tends to decrease in sustained responders (SR) to interferon (IFN) therapy for chronic hepatitis C rather than in non-responders (NR). However, some SR develop HCC and their details and prognosis are not well-known, so we investigated such cases. Among 462 patients who underwent IFN therapy and were available for follow-up, 142 patients (30.7%) were SR and six of these (4.2%) developed HCCs. The interval between interferon therapy and diagnosis of HCC was 32-99 months (average 59.2 months). Five of the six cases were single HCCs sized 20-125 mm. The remainder was multiple HCCs. After initial treatment, five patients (83.3%) relapsed and three patients (60%) died due to the HCC. The interval between initial treatment and recurrence was 2-14 months (average 5.8 months). Among the three fatal cases, the interval between initial treatment and their death was 11-66 months (average 29.3 months). Though the prognosis of the one patient who did not relapse after initial treatment was good, the other five patients relapsed and three of them died due to the HCC. These results suggest that the prognosis of sustained responders who develop HCC after IFN therapy is not necessarily good, so close follow-up remains necessary, despite their response to IFN therapy.

Six patients with small size (< or =2.0 cm in diameter) hepatocellular carcinoma (HCC) on their liver surface underwent laparoscopic microwave coagulation therapy (LMCT) in our institute. All cases showed complete necrosis after LMCT alone and there were no major complications during the LMCT. During the follow-up period, one patient had recurrent HCC at the LMCT-treated lesion site and two patients had lesions at sites distant to the LMCT-treated site. Two out of these three patients had presented with severe liver dysfunction at admission and died within the follow-up period. LMCT is believed to be a useful and safe treatment for small size HCC on the liver surface, and treatment can achieve complete tumor necrosis. However, in severe liver dysfunction, the use of LMCT may have a negative influence on patient survival.

To analyze the risk factors of hepatocellular carcinoma (HCC) recurrence after radiofrequency ablation (RFA) treatment with HCV-associated hepatitis.Twenty-six patients with HCV-associated HCC who were followed-up for more than 12 mo were selected for this study. Risk factors for distant intrahepatic recurrences of HCC were evaluated for patients in whom complete coagulation was achieved without recurrence in the same subsegment as the primary nodule. Twelve clinical and tumoral factors were examined: Age, gender, nodule diameter, number of primary HCC nodule, Child-Pugh classification, serum platelet, serum albumin, serum AST, post RFA AST, serum ALT, post RFA ALT, post RFA treatment.Distant recurrences of HCC in remnant liver after RFA were observed in 14 cases and in the number of primary HCC nodules (P = 0.047), and the serum platelets (P = 0.030), the clear difference came out by the recurrence group and the non-recurrence group. The cumulative recurrence rates after 1 and 2 years were 30.8% and 86.8%, respectively for primary multinodular HCC, and 15.4% and 29.5% respectively, for primary uninodular HCC. In addition the 1-year recurrence rates for patients with serum albumin more than 3.4 g/dL and less than 3.4 g/dL were 23.1% for both, but the 2-years recurrence rates were 89.0% and 23.1%, respectively. The number of primary HCC nodules (relative risk, 6.970; P = 0.016) were found to be a statistically significant predictor for poor distant intrahepatic recurrence by univariate analysis.Patients who have multiple HCC nodules, low serum platelets and low serum albumin accompanied by HCV infection, should be carefully followed because of the high incidence of new HCC lesions in the remnant liver, even if coagulation RFA is complete.

Inflammatory pseudotumor (IPT) is a rare benign tumor of unknown origin, it has the appearance of a malignant tumor but has a benign histology and clinical course. Therefore, we studied five patients with IPT of the liver to determine what examination can aid in its diagnosis. Five cases of inflammatory pseudotumor of the liver were analyzed. All patients were examined by echography, computed tomography (CT), magnetic resonance imaging (MRI), endoscopic retrograde cholangiography (ERC) and angiography to diagnose the liver tumor. In all patients echography and CT scan showed a similar appearance while MRI showed a variable pattern. In two patients ERC showed a stenotic image of intra-hepatic bile ducts. In the angiographic study, the arterial phase in three patients showed a hypervascular tumor and in one patient, a hypovascular tumor. Vascular abnormality was presented in one patient. Similarly, portography in four patients showed some abnormality. We performed ultrasonography-guided percutaneous needle biopsy in two patients in order to diagnose IPT. Histological examinations of two patients were consistent with IPT. The other three patients underwent surgical treatment for a cholangiocellular carcinoma or abscess. It is difficult to diagnose IPT of the liver exclusively with an image examination. Ultrasonography-guided percutaneous liver biopsy should be performed in order to diagnose IPT by histology.