The role of the tumor necrosis factor (TNF)--Fas L and HCV in the development of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a major public health problem in Egypt due to the high prevalence of hepatitis C viral (HCV) infection. The mechanism by which HCV exerts its carcinogenic effect on the liver is not yet understood. Previous research has suggested that perturbations of the Fas-Fas L tumor necrosis system could result in uncontrolled cancerous cell growth in the liver. This study aims to assess the relationship of Fas ligand (Fas L) to HCC. A total of 28 cases (HCC) and 56 controls (28 cirrhosis and 28 chronic hepatitis) were included in the study. Sera and tissue biopsies were tested for HCV antibody and HCV-RNA. Fas ligand expression in tissue was examined immunohistochemically using a rabbit purified polyclonal antibody. Levels of soluble Fas L were determined in serum by ELISA. The HCC cases were graded as: 17.9% Grade I, 32.1% Grade II, 35.7% Grade III and 14.3% were Grade IV. Among the cases, 81% had evidence of cirrhosis. All the cases and controls were positive for HCV-RNA. Tissue and serum PCR results were identical within the same subjects. Fas ligand cytoplasmic expression was more pronounced in HCC than in cirrhosis, and in cirrhosis more than in chronic hepatitis. This expression was higher with increasing grades of malignancy and in tissues adjacent to the tumor, than in those without nearby tumor. Soluble Fas L levels were higher in cases than in controls, with similar results as that of immunohistochemical expression. These results suggest that HCV and Fas ligand play a key role in hepatocarcinogenesis, consistent with the hypothesis that HCV induces overexpression of Fas ligand in the liver cells, resulting in escape from killing by the immune system cells, with subsequent uncontrolled growth of tissue and the development of malignancy.     

Impact of epidermal growth factor receptor and transforming growth factor–α on hepatitis C virus‐induced hepatocarcinogenesis

Epidermal growth factor receptor system plays a central hepato‐protective and pro‐regenerative role in liver. Transforming growth factor‐α (TGF‐α) is an important autocrine growth regulator of hepatocytes that plays a role in development of hepatocellular carcinoma (HCC) among patients with chronic hepatitis C (CHC). This study was done on 40 core liver biopsies from patients with CHC, 20 liver specimens from HCC cases on top of CHC as well as five normal controls. All were immunohistochemically stained with epidermal growth factor receptor (EGFR) and TGF‐α antibodies. Some selected HCC cases were submitted for FISH technique to detect EGFR gene alteration. By immunohistochemistry EGFR and TGF‐α were overexpressed in HCC and cirrhotic cases compared to CHC cases without cirrhosis. Also, their expression was stronger in CHC cases with higher grades of activity and stages of fibrosis compared to lower ones. FISH positive results for EGFR were detected in 33.3% of the examined HCC cases. EGFR and TGF‐α can be used as predictive markers for activity, fibrosis, and carcinogenesis in CHC patients. Overexpression of EGFR in HCC patients can be promising in selecting those who can get benefit from anti‐EGFR target therapy.     

Clinical significance of serum soluble Fas, Fas ligand and fas in intrahepatic lymphocytes in chronic hepatitis C

Hepatitis C Virus (HCV) is a major etiological agent of chronic hepatitis, cirrhosis and hepatocellular carcinoma. Fas-mediated apoptosis is the major cause of hepatocyte damage during liver disease. The present work was performed to study the fas system (Fas-FasL and soluble Fas) in chronic hepatitis C infection. Also, to correlate the degree of liver cell damage with the Fas system. The study was carried out on 45 patients positive for HCV RNA by nested RT-PCR in addition to 13 HCV negative control subjects. Wedge liver biopsies samples were obtained from patients and controls during abdominal operations for determination of cellular expression of Fas and Fas-L on hepatocytes and infiltrating lymphocytes respectively by flow cytometry. Histological activity index (HAI) was determined in chronic HCV patients. Also blood samples were taken from patients and controls for determination of sFas. There was statistically insignificant difference in Fas expression in hepatocytes of patients (P = 0.34) in comparison to control. Meanwhile, there was a statistically significant decrease in FasL expression in patients compared to control (P< 0.001) and statistically significant increase in soluble Fas in patients compared to control (P < 0.001). The HAI of liver fibrosis for all patients were within mild score with mean +/- SD 4 +/- 0.5. From this study, we could conclude that Fas system is one of the important pathways regulating the response to HCV infection. Increased serum sFas in HCV patients is accompanied by down-regulation of Fas/Fas-L expression resulting in inhibition of apoptosis in liver cells as a process for elimination of virus infected cells and this may ultimately leads to chronicity of the disease.     

Significance of pSmad2/3 and Smad4 in hepatitis C virus‐related liver fibrosis and hepatocellular carcinoma

Chronic hepatitis C (CHC) is a major public health problem, especially in Egypt. Risk of hepatocellular carcinoma (HCC) development increases as hepatitis C virus (HCV)‐related liver diseases progress. Smads act as substrates for the transforming growth factor‐beta (TGF‐β) family of receptors. This study aims to assess hepatic expression of pSmad2/3 and Smad4 in CHC with different stages of fibrosis and grades of necro‐inflammation as well as in HCC on top of CHC. This study was done on 33 core liver biopsies from patients with CHC (15 with early fibrosis and 18 with late fibrosis), 15 liver specimens from HCC cases on top of CHC, as well as five normal controls. pSmad2/3 and Smad4 show more immunopositivity, higher percentage of positive hepatocytes and stronger staining intensity in CHC with late fibrosis compared to early fibrosis. pSmad2/3 shows increase of the previous parameters in CHC with high grade activity than those with low activity. Smad4 shows increase of the previous parameters in HCC compared to CHC cases. pSmad2/3 and Smad4 can be used as diagnostic and/or prognostic markers for progression of HCV‐related fibrosis to cirrhosis and further progression to HCC.     

Clinical Significance of Serum Soluble Fas,Fas Ligand and Fas in Intrahepatic Lymphocytes in Chronic Hepatitis C

Hepatitis C Virus (HCV) is a major etiological agent of chronic hepatitis, cirrhosis and hepatocellular carcinoma. Fas-mediated apoptosis is the major cause of hepatocyte damage during liver disease. The present work was performed to study the fas system (Fas-FasL and soluble Fas) in chronic hepatitis C infection. Also, to correlate the degree of liver cell damage with the Fas system. The study was carried out on 45 patients positive for HCV RNA by nested RT-PCR in addition to 13 HCV negative control subjects. Wedge liver biopsies samples were obtained from patients and controls during abdominal operations for determination of cellular expression of Fas and Fas-L on hepatocytes and infiltrating lymphocytes respectively by flow cytometry. Histological activity index (HAI) was determined in chronic HCV patients. Also blood samples were taken from patients and controls for determination of sFas. There was statistically insignificant difference in Fas expression in hepatocytes of patients (P?=?0.34) in comparison to control. Meanwhile, there was a statistically significant decrease in FasL expression in patients compared to control (P< 0.001) and statistically significant increase in soluble Fas in patients compared to control (P < 0.001). The HAI of liver fibrosis for all patients were within mild score with mean ± SD 4 ± 0.5. From this study, we could conclude that Fas system is one of the important pathways regulating the response to HCV infection. Increased serum sFas in HCV patients is accompanied by down-regulation of Fas/Fas-L expression resulting in inhibition of apoptosis in liver cells as a process for elimination of virus infected cells and this may ultimately leads to chronicity of the disease.     

Association of genetic polymorphism of BCL-2 (rs2279115) with susceptibility to HCV-related hepatocellular carcinoma

Immunologic Research - Hepatitis C virus (HCV) infection is the main risk factor for chronic hepatitis (CHC), liver cirrhosis, and hepatocellular carcinoma (HCC). B cell lymphoma-2 (BCL-2) prevents...     

Clinical study on relationship between hepatocellular carcinoma and hepatitis C virus infection in patients with chronic liver disease]

The relationship between hepatocellular carcinoma (HCC) and hepatitis C virus (HCV) infection was investigated. Antibody to hepatitis C virus was detected in 88.8% and 87.0% of 240 patients with hepatocellular carcinoma and liver cirrhosis, respectively. A history of blood transfusion was shown in only 21.8% (21/96) of the HCV antibody positive HCC patients. Of 196 patients with chronic hepatitis type C and the HCV antibody positive liver cirrhosis, 10 developed HCC during the follow-up period of two years. A high prevalence of HCV antibody was also shown among 83 patients with alcoholic liver cirrhosis and HCC associated with alcoholic liver cirrhosis. HCV-RNA was detected in all patients with alcoholic HCC. These data support a causal association between hepatitis C virus and hepatocellular carcinoma.     

The natural history of hepatitis C virus (HCV) infection

Hepatitis C virus (HCV) is a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma, as well as the most common indication for liver transplantation in many countries. Although the incidence of hepatitis C infection has dramatically decreased during the past decade, the worldwide reservoir of chronically infected persons is estimated at 170 million, or 3% of the global population. There is much controversy surrounding the natural history of hepatitis C infection. The rate of chronic HCV infection is affected by a person's age, gender, race, and viral immune response. Approximately 75%-85% of HCV-infected persons will progress to chronic HCV infection, and are at risk for the development of extrahepatic manifestations, compensated and decompensated cirrhosis, and hepatocellular carcinoma (HCC). The rate of progression to cirrhosis is highly variable, and is influenced by several factors, including the amount of alcohol consumption, age of initial HCV infection, degree of inflammation and fibrosis on liver biopsy, HIV and HBV coinfection, and comordid conditions. An estimated 10%-15% of HCV-infected persons will advance to cirrhosis within the first 20 years. Persons with cirrhosis are at increased risk of developing HCC. An understanding of the natural history of hepatitis C is essential to effectively manage, treat, and counsel individuals with HCV infection.     

Association of interleukin-18 polymorphisms and plasma level with the outcome of chronic HCV infection

Hepatitis C virus (HCV) infection is the main cause of chronic liver disease throughout the world, and may progress to cirrhosis and hepatocellular carcinoma (HCC). Immunological factors, especially cytokines and some host genetic variations, rather than direct HCV action, seem to play an important role in the pathogenesis of HCV infection. Elevated levels of interleukin-18 (IL-18) were described previously for chronically (HCV)-infected patients. This study is aimed at investigating IL-18 promoter polymorphisms (-607C/A and -137G/C) in HCV-infected patients with different disease severities (chronic hepatitis C, liver cirrhosis and HCC) and establishing an association between these polymorphisms and IL-18 plasma concentration with the outcome of chronic HCV infection. The carriage of at least one C allele at position -607 (CC + CA) was associated with a higher risk of cirrhosis and HCC (P = 0.032). Compared with controls, HCV-infected patients had significantly higher levels of IL-18 (P = 0.0001) that correlate with disease severity (P = 0.01, P = 0.001, P = 0.0006, respectively). In conclusion, we supposed a possible implication of IL-18 promoter polymorphisms in the pathogenesis of chronic HCV infection.     

Expression of Beclin‐1, an autophagy‐related marker,in chronic hepatitis and hepatocellular carcinoma and its relation with apoptotic markers

Hepatocellular carcinoma (HCC) is one of the most frequent malignant tumors in worldwide. Multiple precancerous factors, including infection with hepatitis C virus (HCV), have been studied extensively. Autophagy is a highly regulated process, involved in the turnover of damaged organelles. The relationship between apoptosis and autophagy is still a debated topic especially in HCC. This study aimed to investigate the expression of beclin‐1 in chronic hepatitis and HCC and its relation with apoptotic markers. The study included the following: 20 chronic HCV hepatitis cases (first group), 35 HCC cases (second group), and 10 normal tissues as control (third group). All were stained for anti‐beclin‐1, Bcl‐2, Bcl‐XL, and Bax antibodies. A significant positive correlation was found between beclin‐1 and Bcl‐2 among the first group. While a significant inverse correlation was found between them in the second group. A positive correlation was found between beclin‐1 and Bcl‐XL expression in the first and the second groups. Also positive significant correlations were identified between beclin‐1 and Bax in the first and the second groups. Autophagy and apoptosis in the liver are interrelated processes. The high levels of beclin‐1 observed in hepatitis may suggest a central role that may limit liver damage and interact with progression to cancer where beclin‐1 later on becomes suppressed in aggressive HCC cases. So defective autophagy synergized with defective apoptosis may facilitate tumor progression. Knowledge of the role of autophagic molecules together with apoptotic markers in HCC could lead to improved treatment efficacy and overall prognosis.     

Fas and Fas ligand: strong co-expression in human hepatocytes surrounding hepatocellular carcinoma; can cancer induce suicide in peritumoural cells?

Fas (Apo-1, CD95), a member of the nerve growth factor/tumour necrosis factor receptor superfamily, mediates apoptosis in response to agonistic antibodies or Fas ligand (Fas-L) binding. Fas has been shown to be present on hepatocyte membranes in normal liver and in chronic hepatitis C. At the present time, very limited data are available on the expression of Fas-L. This paper describes a study of 20 cases of active chronic hepatitis of different aetiologies, 20 hepatocellular carcinomas (HCCs) and the adjacent non-tumoural liver parenchyma, and five normal livers. The immunohistochemical expression of Fas and Fas-L was determined using specific monoclonal antibodies. In normal liver, Fas was faintly expressed on membranes of hepatocytes and bile duct cells, while Fas-L was negative. In active chronic hepatitis, Fas expression in hepatocytes was enhanced, resulting in a diffuse honeycomb pattern. Fas-L showed cytoplasmic positivity in hepatocytes in areas of interface hepatitis. Strong expression of Fas as well as Fas-L in the hepatocytes immediately adjacent to HCC was a constant finding. Within the HCCs, Fas-L expression was variable, but present only in a minority of cells. Fas varied from a diffuse honeycomb pattern to focal positivity in occasional cells. There was no correlation between Fas and Fas-L expression in the tumours. In conclusion, hepatocytes can co-express Fas and Fas-L in areas of interface hepatitis and adjacent to HCC, suggesting that they have the ability to induce apoptosis in an autocrine or paracrine way. Within the tumour, the Fas-Fas-L apoptosis pathway seems to be little involved.     

c－erbB－2蛋白和表皮生长因子受体在肝脏病变中的表达

对１８４例乙型肝炎、肝硬变和肝细胞癌（ＨＣＣ）及２９例正常肝组织的标本作了ＡＢＣ法染色，观察其ｃ－ｅｒｂＢ－２蛋白和表皮生长因子受体（ＥＧＦＲ）的表达情况。３６％（４８／１３４）的慢性肝炎、肝硬变和ＨＣＣ组织中有ＥＧＦＲ表达，主要定位于血窦内皮。良、恶性病变肝组织之间在ＥＧＦＲ表达强度上无显著差别，提示ＥＧＦＲ可能与慢性肝脏病变中血窦内皮的增生有关。在正常肝，仅少数标本（５／２９）中见到ｃ－ｅｒｂＢ－２微弱表达；在ＨＢＶ相关的慢性肝脏病变，所有标本中均检测到ｃ－ｅｒｂＢ－２蛋白，主要定位于肝小多角细胞（ＳＰＬＣ）、小细胞性不典型增生（ＳＣＤ）及小管状化生（ＤＭ）的肝细胞；ＨＣＣ细胞中ｃ－ｅｒｂＢ－２蛋白阳性较弱。这提示ｃ－ｅｒｂＢ－２基因的活化与人ＨＣＣ发生有关。其作用机制可能是促进ＳＰＬＣ向ＳＣＤ的转化及促进ＳＣＤ的进展。ｃ－ｅｒｂＢ－２与ＨＢｘＡｇ表达的密切关联提示这种原癌基因的活化可能也与ＨＢＶＸ基因有关。     

Clinical implications of chemokines in acute and chronic hepatitis C virus infection

Hepatitis C virus (HCV), a non-cytopathic positive-stranded RNA virus, is one of the most common causes of chronic liver diseases such as chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Upon HCV infection, the majority of patients fail to clear the virus and progress to chronic hepatitis C. Chemokines are small chemotactic cytokines that direct the recruitment of immune cells and coordinate immune responses upon viral infection. Chemokine production during acute HCV infection contributes to the recruitment of immune cells with antiviral effector functions and subsequent viral clearance. In chronic HCV infection, however, continuous production of chemokines due to persistent viral replication might result in incessant recruitment of inflammatory cells to the liver, giving rise to persistence of chronic inflammation and liver injury. In this review, we will summarize the roles of chemokines in acute and chronic settings of HCV infection and the clinical relevance of chemokines in the treatment of hepatitis C.     

Lack of in vivo blockade of Fas- and TNFR1-mediated hepatocyte apoptosis by the hepatitis C virus

In vitro data have shown that the hepatitis C virus (HCV) core protein binds to protein members of the tumour necrosis factor receptor (TNFR) superfamily. Since this interaction could be relevant to HCV persistence and oncogenesis, this study assessed whether HCV may interfere with the apoptotic cascade in vivo. Apoptosis (by TUNEL) and Fas and TNFR1 expression (by immunohistochemistry) were scored in the liver of 60 chronic hepatitis C patients. Results were compared with the liver disease grading and staging scores and the HCV replication level in serum and liver. Apoptotic hepatocytes were stained in 29 cases. Fas was expressed in 35 cases and TNFR1 in 21, 15 patients (25%) being negative for both receptors. Overall, the numbers of TUNEL-, Fas- and TNFR-positive hepatocytes did not correlate with the extent of intrahepatic CD8+ T-lymphocyte infiltration, the grading and staging of liver disease, or the serum or liver HCV RNA levels. Furthermore, when patients expressing either Fas or TNFR1 were stratified according to serum HCV RNA levels, cases with detectable hepatocyte apoptosis had higher HCV viraemias. In conclusion, an HCV-mediated, in vivo blockade of hepatocyte apoptosis via the Fas- or TNFR1-dependent pathways seems unlikely.     

Hepatitis B and C virus-related carcinogenesis

Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are the most important causes of hepatocellular carcinoma (HCC), accounting for the majority of the cases worldwide. The geographical distribution of HCC therefore coincides with the distribution of HBV and HCV infections in those areas. Similar to nonviral liver diseases, HBV and HCV infection can cause chronic injury to the liver, with subsequent progression to severe fibrosis and cirrhosis. The presence of cirrhosis is a major risk factor for the development of HCC. However, HCC can occur in the absence of cirrhosis, suggesting that both HBV and HCV may be directly involved in hepatocarcinogenesis. Several HBV factors have been implicated in hepatocarcinogenesis, including the HBx gene, the pre-S2/S gene and the HBV spliced protein. Furthermore, HBV can be integrated into the host genome, leading to changes in genomic function or chromosomal instability. By contrast to HBV, HCV cannot integrate into the host genome. Various HCV proteins, including the core, envelope and nonstructural proteins, have been shown to have oncogenic properties. For HBV infection, antiviral therapy and vaccination have been shown to decrease the risk of HCC. Antiviral therapy for HCV can also reduce the risk of HCC.     

Induction of FAS ligand expression in a human hepatoblastoma cell line by HCV core protein

Tumour cells and virus infected cells expressing Fas ligand (FasL) can evade immune surveillance by inducing apoptosis in T cells expressing Fas. In order to characterise a possible role of hepatitis C virus (HCV) core protein in similar mechanisms during HCV infection, we investigated Fas ligand expression and activity in a human hepatoblastoma cell line (HepG2) constitutively expressing this protein.Strong FasL induction was detected by immunoblotting and flow cytometry analysis in the core expressing cell lines Hep39. In contrast, vector transfected cells or cell lines expressing HCV E1-E2 proteins did not show FasL expression. Co-cultivation experiments of Hep39 cells with a Fas-sensitive T cell line indicated that FasL induced by the core protein had apoptotic activity toward target cells. Effect of the core protein on induction of FasL promoter was further examined by co-transfection of HepG2 cells with core-bearing plasmid and a vector in which luciferase gene expression is driven by human FasL promoter. Results of the luciferase assay indicated a positive regulation of FasL promoter by the core protein. In conclusion, HCV core protein plays a role in the induction of functional FasL in hepatoblastoma cell line and apoptosis in a target T cell line expressing Fas. Similar mechanisms may contribute, in vivo, to establishment of chronic infection and development of hepatocellular carcinoma (HCC).     

In vivo hepatic endoplasmic reticulum stress in patients with chronic hepatitis C

In hepatocytes, the accumulation of unfolded proteins in the endoplasmic reticulum (ER) causes ER stress and the unfolded protein response (UPR), mediated by the ER‐resident stress sensors ATF‐6, IRE1, and PERK. UPR‐responsive genes are involved in the fate of ER‐stressed cells. Cells carrying hepatitis C virus (HCV) subgenomic replicons exhibit in vitro ER stress and suggest that HCV inhibits the UPR. Since in vivo ER homeostasis is unknown in livers with chronic HCV infection, we investigated ER stress and the UPR in liver samples from untreated patients with chronic hepatitis C (CHC), in comparison with normal livers. Electron microscopy, western blotting, and real‐time RT‐PCR were used in liver biopsy specimens. Electron microscopy identified features showing ER stress in hepatocyte samples from patients with CHC; however, ‘ER‐stressed’ hepatocytes were found in clusters (3‐5 cells) that were scattered in the liver parenchyma. Western blot analysis confirmed the existence of hepatic ER stress by showing activation of the three ER stress sensors ATF‐6, IRE1, and PERK in CHC. Real‐time RT‐PCR showed no significant induction of UPR‐responsive genes in CHC. In contrast, genes involved in the control of diffuse processes such as liver proliferation, inflammation, and apoptosis were significantly induced in CHC. In conclusion, livers from patients with untreated CHC exhibit in vivo hepatocyte ER stress and activation of the three UPR sensors without apparent induction of UPR‐responsive genes. This lack of gene induction may be explained by the inhibiting action of HCV per se (as suggested by in vitro studies) and/or by our finding of the localized nature of hepatocyte ER stress. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Concomitant diffuse large B-cell lymphoma and hepatocellular carcinoma in chronic hepatitis C virus liver disease: a study of two cases

Chronic hepatitis C virus HCV infection progresses through liver fibrosis and cirrhosis to hepatocellular carcinoma HCC. It appears to be causally related to B-cell non-Hodgkin's lymphoma since regression after antiviral therapy has been described. Two cases are described of non-Hodgkin's lymphoma and HCC arising simultaneously in two patients. The first patient did not have cirrhosis on liver biopsy. HCV had been undetectable in plasma following successful therapy with interferon and ribavirin treatment 7 years earlier. The second patient developed an aggressive form of hepatocellular carcinoma HCC within weeks of stopping treatment with interferon and ribavirin. Therapy had induced complete viral suppression for over 40 weeks. The two cases suggest that non-Hodgkin's lymphoma and HCC can develop in the absence of detectable hepatitis C viremia and argues for continued surveillance even after sustained virological response to treatment.     

Expression of tumour necrosis factor-related apoptosis-inducing ligand and caspase-3 in relation to grade of inflammation and stage of fibrosis in chronic hepatitis C

AIM: To assess whether the distribution of the recently described proapoptotic ligand, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), and the apoptosis effector, caspase-3 alters with the degree of inflammation and fibrosis present in liver biopsy specimens from patients with chronic hepatitis C virus infection. METHODS AND RESULTS: Expression of TRAIL and caspase-3 was assessed immunohistochemically in liver biopsy specimens obtained from 89 adults with chronic hepatitis C. Expression of TRAIL in hepatocytes correlated inversely with stage of fibrosis (P = 0.001), classified according to the Scheuer score; expression of caspase-3 in hepatocytes correlated with grade of inflammation (P = 0.012). Expression of TRAIL in hepatocytes was not correlated with grade of inflammation (P > 0.05); expression of caspase-3 was not correlated with stage of fibrosis (P > 0.05). Maximum expression of proapoptotic TRAIL protein was observed in cases with low grade inflammation (G0) and low stage fibrosis (S1). Maximum expression of caspase-3 in hepatocytes was observed in cases with high grade inflammation (G3-4) and high stage fibrosis (S3), but not with liver cirrhosis (S4). CONCLUSIONS: There is a significant decrease in TRAIL expression with increasing grade of inflammation, whereas caspase-3 expression is significantly increased with advanced fibrosis, short of cirrhosis.