The epidemiology of hepatocellular cancer: from the perspectives of public health problem to tumor biology

The monoclonal antibody CH12 enhances the sorafenib-mediated growth inhibition of hepatocellular carcinoma xenografts expressing epidermal growth factor receptor variant III

The multikinase inhibitor sorafenib is the first oral agent to show activity against human hepatocellular carcinoma (HCC). Although the clinical application of sorafenib has shown good tolerability in the studied populations, it also causes multiple human dose-limiting toxicities. Thus, there is a strong need to reduce the overall dose of sorafenib. We have reported that the epidermal growth factor receptor variant III (EGFRvIII) expression can decrease the sensitivity of HCC cells to chemotherapeutic drugs. Therefore, we sought to explore whether EGFRvIII can affect the sensitivity of HCC cells to sorafenib. In this study, we observed that EGFRvIII expression significantly decreased the sensitivity of HCC cells to sorafenib. To enhance the antitumor effect and reduce the overall dose of sorafenib, we evaluated the combined effects of CH12, a monoclonal antibody against EGFRvIII, and sorafenib on the growth of HCC cells expressing EGFRvIII in vitro and in vivo. The results showed that, when CH12 was combined with sorafenib, the tumor growth suppression effect was significantly increased, and the concentration of sorafenib required for growth inhibition was substantially reduced. Mechanistically, the combination could more noticeably downregulate the phosphorylation of constitutively active extracellular signal-regulated kinase (ERK), Akt (Thr308), and signal transducer and activator of transcription 3 (STAT3) than sorafenib alone. Collectively, these findings demonstrate that CH12 interacts additively with sorafenib to strongly inhibit the tumor growth of HCC xenografts expressing EGFRvIII by enhancing the sorafenib-mediated inhibition of the MEK/ERK, phosphoinositide 3-kinase/AKT, and STAT3 pathways.

Treatment of hepatocellular carcinoma: a systematic review

Hepatocellular carcinoma (HCC) is one of the most common malignancies, with an increasing incidence. With advances in surgical techniques and instrumentation and the development of molecular-target drugs, a number of potentially curative treatments have become available. Management of HCC patients depends on the stage of their tumor. Liver resection remains the first choice for very early-stage HCC, but it is being challenged by local ablative therapy. For early-stage HCC that meet the Milan criteria, liver transplantation still offers a better outcome; however, local ablative therapy can be a substitute when transplantation is not feasible. Local ablation is also used as a bridging therapy toward liver transplantation. HCC recurrence is the main obstacle to successful treatment, and there is currently no effective means of preventing or treating HCC recurrence. Transarterial therapy is considered suitable for intermediate-stage HCC, while sorafenib is recommended for advanced-stage HCC. This stage-based approach to therapy not only provides acceptable outcomes but also improves the quality of life of HCC patients. Because of the complexity of HCC, therapeutic approaches must be adapted according to the characteristics of each individual patient. This review discusses the current standards and trends in the treatment of HCC.

X-ray repair cross-complementing group 1 polymorphisms and hepatocellular carcinoma: A meta-analysis

AIM: To perform a systematic meta-analysis to investigate the association between X-ray repair cross-complementing group 1 (XRCC1) polymorphisms and hepatocellular carcinoma (HCC) risk.

METHODS: Relevant studies extracted from PubMed, Embase, Wanfang, VIP and the Chinese National Knowledge Infrastructure databases up to March 2012 were included in the study. Stata software, version 11.0, was used for the statistical analysis. The odds ratios (ORs) and 95% confidence interval (CI) of the XRCC1 polymorphisms in HCC patients were analyzed and compared with healthy controls. The meta-analysis was performed using fixed-effect or random-effect methods, depending on the absence or presence of significant heterogeneity.

RESULTS: Eleven studies with 2075 HCC cases and 2604 controls met our eligibility criteria (four studies, 888 cases and 938 controls for Arg194Trp, four studies, 858 cases and 880 controls for Arg280His, and nine studies, 1845 cases and 2401 controls for Arg399Gln). The meta-analysis revealed no associations between the Arg194Trp and Arg399Gln polymorphisms of the XRCC1 gene and HCC risk under all contrast models (codominant, dominant and recessive models) in the overall analysis and sensitivity analysis (the studies with controls not in the Hardy-Weinberg equilibrium were excluded). For XRCC1 Arg280His polymorphism, the overall analysis revealed the significant association between the His/His genotype and the increased risk of HCC (His/His vs Arg/Arg model, OR: 1.96, 95% CI: 1.03-3.75, P = 0.04). However, sensitivity analysis showed an altered pattern of result and non-significant association (OR: 2.06, 95% CI: 0.67-6.25, P = 0.20). The heterogeneity hypothesis test did not reveal any heterogeneity, and Begg’s and Egger’s tests did not find any obvious publication bias.

CONCLUSION: The XRCC1 Arg194Trp and Arg399Gln polymorphisms are not associated with HCC risk. More rigorous association studies are needed to verify the involvement of XRCC1 Arg280His polymorphism in HCC susceptibility.

Genetic signatures shared in embryonic liver development and liver cancer define prognostically relevant subgroups in HCC

Multiple activations of individual genes during embryonic liver and HCC development have repeatedly prompted speculations about conserved embryonic signatures driving cancer development. Recently, the emerging discussion on cancer stem cells and the appreciation that generally tumors may develop from progenitor cells of diverse stages of cellular differentiation has shed increasing light on the overlapping genetic signatures between embryonic liver development and HCC. However there is still a lack of systematic studies investigating this area. We therefore performed a comprehensive analysis of differentially regulated genetic signaling pathways in embryonic and liver cancer development and investigated their biological relevance.

Genetic signaling pathways were investigated on several publically available genome wide microarray experiments on liver development and HCC. Differentially expressed genes were investigated for pathway enrichment or underrepresentation compared to KEGG annotated pathways by Fisher exact evaluation. The comparative analysis of enrichment and under representation of differentially regulated genes in liver development and HCC demonstrated a significant overlap between multiple pathways. Most strikingly we demonstrated a significant overlap not only in pathways expected to be relevant to both conditions such as cell cycle or apoptosis but also metabolic pathways associated with carbohydrate and lipid metabolism. Furthermore, we demonstrated the clinical significance of these findings as unsupervised clustering of HCC patients on the basis of these metabolic pathways displayed significant differences in survival.

These results indicate that liver development and liver cancer share similar alterations in multiple genetic signaling pathways. Several pathways with markedly similar patterns of enrichment or underrepresentation of various regulated genes between liver development and HCC are of prognostic relevance in HCC. In particular, the metabolic pathways were identified as novel prognostically relevant players in HCC development.

Clinical and pathological progression of non-alcoholic steatohepatitis to hepatocellular carcinoma

AIM

  Non-alcoholic steatohepatitis (NASH) can progress to hepatocellular carcinoma (HCC). We aimed to examine the clinical and pathological course of how NASH progresses to HCC.

METHODS

  In this retrospective multicenter study conducted in Japan, we examined 19 patients (53% female), who had been previously diagnosed with histologically proven NASH and developed HCC during the follow-up period. The median age of the patients at the time of initial diagnosis of NASH was 65 years.

RESULTS

  NASH progressed to HCC after a median follow-up period of 3.8 years (range: 0.5-11.6 years). All patients had been identified as having HCC during screening, which included 12 patients assessed by ultrasound, four patients assessed with computerized tomography, two patients that underwent serum des-γ-carboxy prothrombin testing and one patient that underwent serum α-fetoprotein testing. The median diameter of HCC tumors was 1.8 cm (range: 0.8-3.0 cm). The majority of patients (n = 13; 68%) presented with only one HCC tumor. The stage of liver fibrosis was significantly more advanced at the time of diagnosis of HCC than at the time of initial diagnosis of NASH, whereas there were no significant differences in the degree of steatosis.

CONCLUSION

  Screening for HCC with imaging is necessary not only in NASH patients with advanced fibrosis, but also in those with less advanced forms of fibrosis, particularly if they are old men. Liver fibrosis progresses to a more advanced stage during the development of HCC in NASH patients.

The DNA damage checkpoint protein ATM promotes hepatocellular apoptosis and fibrosis in a mouse model of non-alcoholic fatty liver disease

Steatoapoptosis is a hallmark of non-alcoholic fatty liver disease (NAFLD) and is an important factor in liver disease progression. We hypothesized that increased reactive oxygen species resulting from excess dietary fat contribute to liver disease by causing DNA damage and apoptotic cell death, and tested this by investigating the effects of feeding mice high fat or standard diets for 8 weeks. High fat diet feeding resulted in increased hepatic H 2O 2, superoxide production, and expression of oxidative stress response genes, confirming that the high fat diet induced hepatic oxidative stress. High fat diet feeding also increased hepatic steatosis, hepatitis and DNA damage as exemplified by an increase in the percentage of 8-hydroxyguanosine (8-OHG) positive hepatocytes in high fat diet fed mice. Consistent with reports that the DNA damage checkpoint kinase Ataxia Telangiectasia Mutated (ATM) is activated by oxidative stress, ATM phosphorylation was induced in the livers of wild type mice following high fat diet feeding. We therefore examined the effects of high fat diet feeding in Atm-deficient mice. The prevalence of apoptosis and expression of the pro-apoptotic factor PUMA were significantly reduced in Atm-deficient mice fed the high fat diet when compared with wild type controls. Furthermore, high fat diet fed Atm (-/-) mice had significantly less hepatic fibrosis than Atm (+/+) or Atm (+/-) mice fed the same diet. Together, these data demonstrate a prominent role for the ATM pathway in the response to hepatic fat accumulation and link ATM activation to fatty liver-induced steatoapoptosis and fibrosis, key features of NAFLD progression.

CHK1 targets spleen tyrosine kinase (L) for proteolysis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies resistant to current chemotherapies or radiotherapies, which makes it urgent to identify new therapeutic targets for HCC. In this study, we found that checkpoint kinase 1 (CHK1) was frequently overexpressed and correlated with poor clinical outcome in patients with HCC. We further showed that the CHK1 inhibitor GÖ6976 was capable of sensitizing HCC cells to cisplatin, indicating that CHK1 may have oncogenic function in HCC. We found that CHK1 phosphorylated the tumor suppressor spleen tyrosine kinase (L) (SYK[L]) and identified the phosphorylation site at Ser295. Furthermore, CHK1 phosphorylation of SYK(L) promoted its subsequent proteasomal degradation. Expression of a nonphosphorylated mutant of SYK(L) was more efficient at suppressing proliferation, colony formation, mobility, and tumor growth in HCC lines. Importantly, a strong inverse correlation between the expression levels of CHK1 and SYK(L) was observed in patients with HCC. Collectively, our data demonstrate that SYK(L) is a substrate of CHK1 in tumor cells and suggest that targeting the CHK1/SYK(L) pathway may be a promising strategy for treating HCC.

A polymorphism within ErbB4 is associated with risk for hepatocellular carcinoma in Chinese population

AIM: To investigate the association between hepatocellular carcinoma (HCC) susceptibility and a 12-bp insertion/deletion polymorphism (rs6147150) in the 3’UTR of ErbB4.

METHODS: Using a case-control design, the rs6147150 genotypes in 270 patients with HCC and 270 healthy controls were determined by direct polymerase chain reaction and polyacrylamide gel electrophoresis. Logistic regression was used to analyze the association between the polymorphism and cancer risk.

RESULTS: Computational modeling suggested that rs6147150 was located in the seed region of hsa-let-7c, a potential target sequence in ErbB4 3’UTR. Logistic regression analysis showed that, compared with individuals homozygous for wild-type, heterozygotes [adjusted odds ratio (OR) = 1.48, 95% confidence interval (CI) = 1.03-2.17, P = 0.034] and individuals homozygous for 12-bp del/del (OR = 2.50, 95% CI = 1.37-4.56, P = 0.001) were at significantly higher risk of HCC. Carriers of the “del” allele of rs6147150 had a 1.59-fold increased risk for HCC (95% CI = 1.22-2.07, P = 0.003).

CONCLUSION: rs6147150 may be associated with HCC risk, in part through let-7c-mediated regulation, and may be involved in the pathogenesis of HCC in Chinese populations.

A polymorphism at the miR-502 binding site in the 3'-untranslated region of the histone methyltransferase SET8 is associated with hepatocellular carcinoma outcome

MicroRNAs (miRNAs) can bind to the 3'-untranslated regions (UTRs) of messenger RNAs, where they interfere with translation and thereby regulate cell differentiation, apoptosis and tumorigenesis. Genetic polymorphisms in the 3'-UTRs targeted by miRNAs alter the strength of miRNA binding in a manner that affects the behavior of individual miRNAs. The histone methyltransferase SET8 has been reported to methylate TP53 and regulate genomic stability. We analyzed a single-nucleotide polymorphism (rs16917496) within the miR-502 miRNA seed region for the 3'-UTR of SET8 in Chinese patients with hepatocellular carcinoma (HCC). The SET8 CC genotype was independently associated with longer postoperative survival in patients with HCC by multivariate analysis (relative risk, 0.175; 95% CI = 0.053-0.577; p = 0.004). The SET8 CC genotype was associated with reduced SET8 protein levels based on the immunostaining of 51 HCC tissue samples. We also found that the low SET8 levels were associated with longer HCC survival. Our data suggest that SET8 modifies HCC outcome by altering its expression, which depends, at least in part, on its binding affinity with miR-502. The analysis of genetic polymorphisms in miRNA binding sites can help to identify patient subgroups that are at high risk for poor disease outcomes.

Hepatocellular carcinoma in non-alcoholic steatohepatitis: Growing evidence of an epidemic?

The incidence of hepatocellular carcinoma in non-viral-related chronic liver disease has gradually increased in Japan. Obesity and diabetes mellitus type 2 have been established as a significant risk factor for hepatocellular carcinoma (HCC) by epidemiologic observations and experimental studies. The risks of these factors for HCC are likely conferred by two factors: the increased risk for development of non-alcoholic steatohepatitis (NASH) and the carcinogenic potential of themselves. Hepatocellular carcinoma in NASH is difficult to evaluate because histological diagnosis is required for diagnosis of NASH, which can lead selection bias. Furthermore, end-stage NASH is in effect "burned-out" NASH, for which the diagnosis of NASH cannot be made any more. At all events, previous studies on the etiology of Japanese HCC showed that non-alcoholic fatty liver disease accounts for 1-5% of all HCC (male predominant, median age 72 years). They have high prevalences of obesity and/or diabetes mellitus type 2 and 10-75% of the HCC arose from non-cirrhotic livers. HCC in NASH may be of multicentric origin, similar to HCC based on viral hepatitis. Regular screening for HCC is extremely important especially in cirrhotic NASH patients and recurrence should be warned. In western and Asian countries, the prevalence of non-alcoholic fatty liver disease in the general population is increasing dramatically. Therefore, there is an urgent need to elucidate pathogenesis and clinical features of HCC in NASH. In this review we summarize current concepts for HCC in NASH.

Circulating tumor cells measurements in hepatocellular carcinoma

Liver cancer is the fifth most common cancer in men and the seventh in women. During the past 20 years, the incidence of HCC has tripled while the 5-year survival rate has remained below 12%. The presence of circulating tumor cells (CTC) reflects the aggressiveness nature of a tumor. Many attempts have been made to develop assays that reliably detect and enumerate the CTC during the development of the HCC. In this case, the challenges are (1) there are few markers specific to the HCC (tumor cells versus nontumor cells) and (2) they can be used to quantify the number of CTC in the bloodstream. Another technical challenge consists of finding few CTC mixed with million leukocytes and billion erythrocytes. CTC detection and identification can be used to estimate prognosis and may serve as an early marker to assess antitumor activity of treatment. CTC can also be used to predict progression-free survival and overall survival. CTC are an interesting source of biological information in order to understand dissemination, drug resistance, and treatment-induced cell death. Our aim is to review and analyze the different new methods existing to detect, enumerate, and characterize the CTC in the peripheral circulation of patients with HCC.

Mitochondrial DNA haplogroup M is associated with late onset of hepatocellular carcinoma

The accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) has been associated with various types of cancer. The association of SNPs with cancer risk and disease outcome has been exhaustively studied. In this study, we investigated the association of age-at-onset and SNPs in the mitochondrial D-loop using a population-based series of hepatocellular carcinoma (HCC) patients. Haplogroup M (489C) and allele 235G were identified for their association with the late onset of HCC by the log-rank test. In an overall multivariate analysis, haplogroup M (489C) was identified as an independent predictive factor for the age-at-onset of HCC at borderline significant levels [relative risk, 1.736; 95% confidence interval (CI), 0.967-3.115; p=0.065]. Genetic polymorphisms in the D-loop are predictive markers for age-at-onset in HCC patients. Accordingly, the analysis of genetic polymorphisms in the mitochondrial D-loop may help to identify HCC patient subgroups at high risk of early onset of the disease.

Hepatocellular carcinoma within a noncirrhotic, nonfibrotic, seronegative liver: surgical approaches and outcomes

BACKGROUND

Hepatocellular carcinoma (HCC) most commonly arises in patients with chronic liver disease. Data on outcomes after liver resection in patients with noncirrhotic, nonfibrotic, seronegative, referred to as a "normal" liver are limited. We aimed to investigate differences in prognostic factors and outcomes between patients presenting with HCC arising in "normal" liver (NLHCC) and that arising in "diseased" liver (DLHCC).

STUDY DESIGN

All patients undergoing resection for HCC between 1994 and 2008 were assessed. Multivariable analysis of clincopathologic data from the NLHCC group was performed by comparing them with data from the group who had surgery for DLHCC during this period.

RESULTS

During the 15-year study period, 142 patients underwent liver resection for HCC: 81 for NLHCC and 61 for DLHCC. NLHCCs were more often solitary but were larger and required more major resections. There was no significant difference in survival outcomes between patients who had NLHCC or DLHCC, with overall and recurrence-free 5-year survivals of 60% and 51% in NLHCC and 55% and 33% in DLHCC, respectively. In patients with NLHCC, significant factors predicting overall survival were blood transfusion requirement (p = 0.003) and age (p = 0.009), and the only significant factor at predicting recurrence-free survival was presence of multiple tumors (p = 0.025). In contrast, in DLHCC, the only significant prognostic variables were a preoperative tumor biopsy (p = 0.017) or a high neutrophil-to-lymphocyte ratio (p = 0.001), both of which predicted a poorer recurrence-free survival.

CONCLUSIONS

HCC presenting in patients with a normal background liver parenchyma appears to present a different spectrum of the disease. However, excellent outcomes can be achieved after liver resection, although this often requires the use of advanced techniques due to late presentation.

Comparison of entecavir and lamivudine in preventing hepatitis B reactivation in lymphoma patients during chemotherapy

During chemotherapy for lymphoma, the administration of cytotoxic agents and rituximab often results in hepatitis B reactivation (incidence, 14-72%). This study was designed to compare the efficacy of entecavir and lamivudine in preventing hepatitis B reactivation in lymphoma patients. Between January 2007 and February 2009, patients treated in four hospitals in China were screened to identify those most appropriate for analysis. These patients received either entecavir or lamivudine during chemotherapy and for 6 months after completion of chemotherapy. A total of 34 patients received entecavir and 89 patients received lamivudine. Compared with the lamivudine group, the entecavir group had significantly lower rates of hepatitis (5.9 vs 27.0%, P = 0.007), hepatitis B reactivation (0 vs 12.4%, P = 0.024) and disruption of chemotherapy (5.9 vs 20.2%, P = 0.042). All patients with hepatitis B reactivation had B-cell non-Hodgkin's lymphoma (stage III-IV). In lymphoma patients under chemotherapy treatment, entecavir is more effective than lamivudine in preventing hepatitis B reactivation. For patients with advanced stage disease, entecavir should be considered the primary preventive therapy.

Interaction of occupational and personal risk factors in workforce health and safety

Most diseases, injuries, and other health conditions experienced by working people are multifactorial, especially as the workforce ages. Evidence supporting the role of work and personal risk factors in the health of working people is frequently underused in developing interventions. Achieving a longer, healthy working life requires a comprehensive preventive approach. To help develop such an approach, we evaluated the influence of both occupational and personal risk factors on workforce health. We present 32 examples illustrating 4 combinatorial models of occupational hazards and personal risk factors (genetics, age, gender, chronic disease, obesity, smoking, alcohol use, prescription drug use). Models that address occupational and personal risk factors and their interactions can improve our understanding of health hazards and guide research and interventions.

Induction of apoptosis by cinobufacini preparation through mitochondria- and Fas-mediated caspase-dependent pathways in human hepatocellular carcinoma cells

Cinobufacini (Huachansu), an aqueous extract from the skins of Bufo bufo gargarizans Cantor, is a well-known traditional Chinese medicine widely used in clinical cancer therapy in China. However, the precise mechanisms induced by cinobufacini in human hepatocellular carcinoma (HCC) cells are still not very clear. The aim of present study was to investigate possible apoptotic mechanisms induced by cinobufacini in HCC cell lines HepG(2) and Bel-7402. We found that cinobufacini treatment resulted in a significant decrease in cell proliferation and induced apoptotic cell death with the increase of treatment time. It indicated that cinobufacini-induced apoptosis was associated with mitochondria-mediated pathway including the loss of mitochondrial membrane potential (Δψm), the increase of Bax/Bcl-2 ratio, cytochrome c release, caspase-9 and caspase-3 activation, and poly(ADP-ribose) polymerase (PARP) degradation. Additionally, cinobufacini also activated Fas-mediated apoptosis pathway obviously as evident by an increase in Fas expression, and caspase-8 and caspase-10 activation. Moreover, the BH3-only protein Bid was cleaved into a truncated Bid (tBid) after cinobufacini treatment. Taken together, these data suggested cinobufacini could induce apoptosis of HCC cells through mitochondria- and Fas-mediated caspase-dependent pathways with the increase of treatment time, which might provide an experimental evidence for cinobufacini treatment of HCC.

Inactivation of PTEN is responsible for the survival of Hep G2 cells in response to etoposide-induced damage

The chemo-resistance character of human hepatocellular carcinoma cells is well known but the anomalies associated with such resistance character are not completely understood. In this study, etoposide-induced signaling events in human hepatocellular carcinoma cell line, Hep G2 has been compared with Chang Liver cells, a normal human liver cell line. Hep G2 cells are resistant to etoposide when compared with Chang Liver cells. Etoposide-induced γH2AX foci in Hep G2 cells are persisted for a longer time without affecting cell cycle, indicating that Hep G2 cells are able to maintain its growth with damaged DNA. Further, Akt signaling pathway is deregulated in Hep G2 cells. The upstream negative regulator of Akt, PTEN remains inactive, as it is hyperphosphorylated in Hep G2 cells. Inhibition of PI-3K pathway by wortmannin partially reverses the etoposide-resistance character of Hep G2 cells. Either Hep G2 or Chang Liver cells when transfected with plasmid carrying active Akt (myr-Akt) become resistance towards etoposide compared to the cells transfected with empty vectors or kinase defective Akt. Transient transfection of wild type PTEN in Hep G2 cells does not change its response towards etoposide whereas Chang Liver cells become sensitive after transfection with same plasmid. These results suggest that inactivation of PTEN, which renders activation of Akt, may contribute largely for the etoposide-resistance character of Hep G2 cells.

Notch signaling inhibits hepatocellular carcinoma following inactivation of the RB pathway

Mice lacking all three Rb genes in the liver develop tumors resembling specific subgroups of human hepatocellular carcinomas, and Notch activity appears to suppress the growth and progression of these tumors.

Hepatocellular carcinoma (HCC) is the third cancer killer worldwide with >600,000 deaths every year. Although the major risk factors are known, therapeutic options in patients remain limited in part because of our incomplete understanding of the cellular and molecular mechanisms influencing HCC development. Evidence indicates that the retinoblastoma (RB) pathway is functionally inactivated in most cases of HCC by genetic, epigenetic, and/or viral mechanisms. To investigate the functional relevance of this observation, we inactivated the RB pathway in the liver of adult mice by deleting the three members of the Rb (Rb1) gene family: Rb, p107, and p130. Rb family triple knockout mice develop liver tumors with histopathological features and gene expression profiles similar to human HCC. In this mouse model, cancer initiation is associated with the specific expansion of populations of liver stem/progenitor cells, indicating that the RB pathway may prevent HCC development by maintaining the quiescence of adult liver progenitor cells. In addition, we show that during tumor progression, activation of the Notch pathway via E2F transcription factors serves as a negative feedback mechanism to slow HCC growth. The level of Notch activity is also able to predict survival of HCC patients, suggesting novel means to diagnose and treat HCC.

An insertion/deletion polymorphism in the 3' untranslated region of type I collagen a2 (COL1A2) is associated with susceptibility for hepatocellular carcinoma in a Chinese population

Hepatocellular carcinoma (HCC) is one of the most common and severe diseases in the world. Besides the influence of environmental factors, such as viral infection, an increasing number of novel genetic components identified by genome-wide association studies have been associated with predisposition to HCC. Thus, studies focusing on functional variants in these findings are indispensable. In the present study, based on in-silico analysis, we carried out a case-control study in a Chinese population (207 cases and 245 controls) to investigate the association between HCC susceptibility with a 7 base pair (bp) insertion/deletion polymorphism (rs3917) in the 3'UTR of COL1A2. Our results showed that the ins/del + del/del genotype had an odds ratio of 1.76 (95% C.I.=1.03-3.01; P=0.028) for developing HCC compared to the ins/ins genotype. Carriers for the "del" allele of rs3917 were associated with a 1.73-fold increased risk for HCC (95% C.I.=1.06-2.84; P(trend)=0.02). Computational modeling suggests that this polymorphism is located in the hsa-let-7 g potential target sequence in the COL1A2 3' untranslated region. Our data suggest that most likely, common genetic changes in COL1A2 may influence HCC risk, at least in part by let-7 g-mediated regulation, which is possibly involved in the pathogenesis of HCC. The replication of our studies in other populations will further strengthen our understanding of this association.

Molecular characteristics of non-cancerous liver tissue in non-B non-C hepatocellular carcinoma

Although chronic infection with hepatitis B virus (HBV) and/or hepatitis C virus (HCV) are the most important risk factors for the development of hepatocellular carcinoma (HCC) worldwide, the proportion of HCC patients negative for the hepatitis B surface antigen and hepatitis C antibody, so-called "non-B non-C HCC", is rapidly increasing, especially in Japan. The background liver diseases of non-B non-C HCC patients can be multifactorial, including occult HBV infection and non-alcoholic steatohepatitis. It is reasonable to investigate the non-cancerous liver tissues to identify the potential molecular mechanisms responsible for the processes of hepatocarcinogenesis of non-B non-C HCC. However, to date, only a few studies have focused on this research concept based on the idea of "field cancerization". This review highlights the potential importance of the molecular analysis of non-cancerous liver tissues to clarify the molecular characteristics in patients with non-B non-C HCC. A better understanding of the molecular mechanisms underlying the individual predisposition to non-B non-C HCC will lead to improvements in the prevention, early diagnosis and treatment of this neoplastic disease.

High prevalence of hepatitis C virus infection in Airin district, Osaka, Japan: A hospital-based study of 1162 patients

AIM

  The Airin district, located in Nishinari-ku, Osaka, is known as Japan's largest slum area, and has the largest concentration of day laborers in the country. We conducted a large hospital-based study to determine the prevalence of hepatitis C virus (HCV) infection in the district.

METHODS

  The subjects were 1162 men (mean age, 57 ± 9 years) admitted to the Osaka Socio-Medical Center Hospital between April 2005 and March 2008. Their case records were retrospectively reviewed.

RESULTS

  Anti-HCV antibodies were found in 218 (18.8%) patients; in contrast, only 24 (2.1%) patients had hepatitis B surface antigen. The prevalence of anti-HCV antibodies was 59% among the 122 patients admitted for liver diseases and 14% among the 1040 patients with other diseases. Among 927 patients with normal alanine aminotransferase levels (≤40 IU/L), 128 (13.8%) had anti-HCV antibodies. The prevalence of anti-HCV antibodies increased with age significantly (P < 0.001). At least 33 of the 218 (15%) patients with anti-HCV antibodies admitted to having a history of injection drug use. Interferon therapy was initiated in 26 patients (11 with genotype 1, 14 with genotype 2 and one unclassifiable), but only six completed their scheduled regimens. Hepatocellular carcinoma was diagnosed in 20 patients, but only seven had early-stage disease in which curative treatment, such as surgical hepatectomy or percutaneous ablation, was indicated.

CONCLUSION

  The prevalence of HCV infection in the Airin district is extremely higher than that in the Japanese general population. Patient education and strict action against illegal drug use are indispensable to prevent the spread of HCV infection from the district.

The uptake transporter OATP8 expression decreases during multistep hepatocarcinogenesis: correlation with gadoxetic acid enhanced MR imaging

OBJECTIVES

To clarify the changes in organic anion-transporting polypeptide 8 (OATP8) expression and enhancement ratio on gadoxetic acid-enhanced MR imaging in hepatocellular nodules during multistep hepatocarcinogenesis.

METHODS

In imaging analysis, we focused on 71 surgically resected hepatocellular carcinomas (well, moderately and poorly differentiated HCCs) and 1 dysplastic nodule (DN). We examined the enhancement ratio in the hepatobiliary phase of gadoxetic acid enhanced MR imaging [(1/postcontrast T1 value-1/precontrast T1 value)/(1/precontrast T1 value)], then analysed the correlation among the enhancement ratio, tumour differentiation grade and intensity of immunohistochemical OATP8 expression. In pathological analysis, we focused on surgically resected 190 hepatocellular nodules: low-grade DNs, high-grade DNs, early HCCs, well-differentiated, moderately differentiated and poorly differentiated HCCs, including cases without gadoxetic acid-enhanced MR imaging. We evaluated the correlation between the immunohistochemical OATP8 expression and the tumour differentiation grade.

RESULTS

The enhancement ratio of HCCs decreased in accordance with the decline in tumour differentiation (P < 0.0001, R = 0.28) and with the decline of OATP8 expression (P < 0.0001, R = 0.81). The immunohistochemical OATP8 expression decreased from low-grade DNs to poorly differentiated HCCs (P < 0.0001, R = 0.15).

CONCLUSIONS

The immunohistochemical expression of OATP8 significantly decreases during multistep hepatocarcinogenesis, which may explain the decrease in enhancement ratio on gadoxetic acid-enhanced MR imaging.

Expression of T-cell lymphoma invasion and metastasis 2 (TIAM2) promotes proliferation and invasion of liver cancer

The T-cell lymphoma invasion and metastasis 2 (TIAM2) gene is the homolog of human TIAM1, a Rac-specific guanine nucleotide exchange factor that plays important roles in neuron development and human malignancies. Although the role of TIAM1 is well characterized, the physiological and pathological functions of TIAM2 remain unknown. In our study, human cDNA and protein panels were evaluated for endogenous expression of TIAM2. Four hepatocellular carcinoma (HCC) cell lines and 91 HCC samples were used to demonstrate expression of TIAM2S (the short form of TIAM2) in cancer cells. In addition, HepG2 cells stably expressing TIAM2S were used for tumorigenic assays in both cellular and mouse models. We demonstrate that endogenous TIAM2S was induced in several human cancers including HCC. TIAM2S expression was undetectable in normal human liver but was induced in all HCC cell lines and in 86% (78/91) of HCC biopsies. TIAM2S expression was positively associated with TIAM1 expression, hepatitis B virus (HBV) infection and metastatic phenotype. Expression of recombinant TIAM2S in HepG2 cells promoted growth and invasiveness. In vivo study using a xenografted mouse model demonstrated that induced endogenous expression of TIAM2S converted non-invasive human HCC cells into highly aggressive vascular tumors. Further examination revealed that TIAM2S expression resulted in up-regulation of N-cadherin and vimentin, and in redistribution of E-cadherin. These findings show, for the first time, that human TIAM2S is involved in HCC pathogenesis, and that increased expression of TIAM2S promotes epithelial-to-mesenchymal transition and results in proliferation and invasion in liver cancer cells.

Functional interactions between retinoblastoma and c-MYC in a mouse model of hepatocellular carcinoma

Inactivation of the RB tumor suppressor and activation of the MYC family of oncogenes are frequent events in a large spectrum of human cancers. Loss of RB function and MYC activation are thought to control both overlapping and distinct cellular processes during cell cycle progression. However, how these two major cancer genes functionally interact during tumorigenesis is still unclear. Here, we sought to test whether loss of RB function would affect cancer development in a mouse model of c-MYC-induced hepatocellular carcinoma (HCC), a deadly cancer type in which RB is frequently inactivated and c-MYC often activated. We found that RB inactivation has minimal effects on the cell cycle, cell death, and differentiation features of liver tumors driven by increased levels of c-MYC. However, combined loss of RB and activation of c-MYC led to an increase in polyploidy in mature hepatocytes before the development of tumors. There was a trend for decreased survival in double mutant animals compared to mice developing c-MYC-induced tumors. Thus, loss of RB function does not provide a proliferative advantage to c-MYC-expressing HCC cells but the RB and c-MYC pathways may cooperate to control the polyploidy of mature hepatocytes.

Characteristics of patients with nonalcoholic steatohepatitis who develop hepatocellular carcinoma

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) can progress to hepatocellular carcinoma (HCC). We aimed to characterize the clinical features of NASH patients with HCC.

METHODS

In a cross-sectional multicenter study in Japan, we examined 87 patients (median age, 72 years; 62% male) with histologically proven NASH who developed HCC. The clinical data were collected at the time HCC was diagnosed.

RESULTS

Obesity (body mass index ≥25 kg/m(2)), diabetes, dyslipidemia, and hypertension were present in 54 (62%), 51 (59%), 24 (28%), and 47 (55%) patients, respectively. In nontumor liver tissues, the degree of fibrosis was stage 1 in 10 patients (11%), stage 2 in 15 (17%), stage 3 in 18 (21%), and stage 4 (ie, liver cirrhosis) in 44 (51%). The prevalence of cirrhosis was significantly lower among male patients (21 of 54, 39%) compared with female patients (23 of 33, 70%) (P = .008).

CONCLUSIONS

Most patients with NASH who develop HCC are men; the patients have high rates of obesity, diabetes, and hypertension. Male patients appear to develop HCC at a less advanced stage of liver fibrosis than female patients.

The role of oncogenic viruses in the pathogenesis of hepatocellular carcinoma

HBV and HCV have major roles in hepatocarcinogenesis. More than 500 million people are infected with hepatitis viruses and, therefore, HCC is highly prevalent, especially in those countries endemic for HBV and HCV. Viral and host factors contribute to the development of HCC. The main viral factors include the circulating load of HBV DNA or HCV RNA and specific genotypes. Various mechanisms are involved in the host-viral interactions that lead to HCC development, among which are genetic instability, self-sufficiency in growth signals, insensitivity to antigrowth signals, evasion of apoptosis, limitless replicative potential, sustained angiogenesis, and tissue invasiveness. Prevention of HBV by vaccination, as well as antiviral therapy against HBV and for HCV seem able to inhibit the development of HCC.

Sequence polymorphisms of mitochondrial D-loop and hepatocellular carcinoma outcome

Accumulation of mutations and single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) might be associated with cancer risk and disease outcome. We investigated the prediction power of D-loop SNPs in hepatocellular carcinoma (HCC) patients. No mutation in these HCC patients has prediction power for post-operational survival, whereas two SNP sites (nucleotides 146 T/C and 150 C/T) were identified by the log-rank test for statistically significant prediction of HCC survival. In an overall multivariate analysis, allele 146 was identified as an independent predictor of HCC outcome. The length of survival of patients with allele 146C was significantly shorter than that of patients with allele 146T (relative risk, 2.781; 95% CI, 1.127-6.859; p=0.026). The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify patient subgroups at high risk of a poor disease outcome.

Targeting oxidative stress in cancer

IMPORTANCE OF THE FIELD

Reactive oxygen species (ROS) occur as natural by-products of oxygen metabolism and have important cellular functions. Normally, the cell is able to maintain an adequate balance between the formation and removal of ROS either via anti-oxidants or through the use specific enzymatic pathways. However, if this balance is disturbed, oxidative stress may occur in the cell, a situation linked to the pathogenesis of many diseases, including cancer.

AREAS COVERED IN THIS REVIEW

HDACs are important regulators of many oxidative stress pathways including those involved with both sensing and coordinating the cellular response to oxidative stress. In particular aberrant regulation of these pathways by histone deacetylases may play critical roles in cancer progression.

WHAT THE READER WILL GAIN

In this review we discuss the notion that targeting HDACs may be a useful therapeutic avenue in the treatment of oxidative stress in cancer, using chronic obstructive pulmonary disease (COPD), NSCLC and hepatocellular carcinoma (HCC) as examples to illustrate this possibility.

TAKE HOME MESSAGE

Epigenetic mechanisms may be an important new therapeutic avenue for targeting oxidative stress in cancer.

Oxidative stress and antioxidants in hepatic pathogenesis

Long term hepatitis B virus (HBV) infection is a major risk factor in pathogenesis of chronic liver diseases, including hepatocellular carcinoma (HCC). The HBV encoded proteins, hepatitis B virus X protein and preS, appear to contribute importantly to the pathogenesis of HCC. Both are associated with oxidative stress, which can damage cellular molecules like lipids, proteins, and DNA during chronic infection. Chronic alcohol use is another important factor that contributes to oxidative stress in the liver. Previous studies reported that treatment with antioxidants, such as curcumin, silymarin, green tea, and vitamins C and E, can protect DNA from damage and regulate liver pathogenesis-related cascades by reducing reactive oxygen species. This review summarizes some of the relationships between oxidative stress and liver pathogenesis, focusing upon HBV and alcohol, and suggests antioxidant therapeutic approaches.

MicroRNA binding site polymorphisms as biomarkers of cancer risk

MicroRNAs (miRNAs) are well established as global gene regulators and thus, slight alterations in miRNA levels as well as their ability to regulate their targets may cause important cellular changes leading to cancer risk. 3´ untranslated region (UTR) miRNA binding site single nucleotide polymorphisms (SNPs) have added another layer of possible genetic variation involved in the complex process of oncogenesis. Identifying these key genetically inherited effectors of miRNA functioning has improved our understanding of the complexity of disease. Interest in the field has grown rapidly in only the last 5 years, with several studies reporting on the role of 3´UTR binding site SNPs as genetic markers of increased cancer susceptibility, as well as biomarkers of cancer type, outcome and response to therapy. Currently, there are numerous known miRNA binding site SNPs associated with multiple cancer subtypes.

Viral factors induce Hedgehog pathway activation in humans with viral hepatitis, cirrhosis, and hepatocellular carcinoma

Hedgehog (Hh) pathway activation promotes many processes that occur during fibrogenic liver repair. Whether the Hh pathway modulates the outcomes of virally mediated liver injury has never been examined. Gene-profiling studies of human hepatocellular carcinomas (HCCs) demonstrate Hh pathway activation in HCCs related to chronic infection with hepatitis B virus (HBV) or hepatitis C virus (HCV). Because most HCCs develop in cirrhotic livers, we hypothesized that Hh pathway activation occurs during fibrogenic repair of liver damage due to chronic viral hepatitis, and that Hh-responsive cells mediate disease progression and hepatocarciongenesis in chronic viral hepatitis. Immunohistochemistry and qRT-PCR analysis were used to analyze Hh pathway activation and identify Hh-responsive cell types in liver biopsies from 45 patients with chronic HBV or HCV. Hh signaling was then manipulated in cultured liver cells to directly assess the impact of Hh activity in relevant cell types. We found increased hepatic expression of Hh ligands in all patients with chronic viral hepatitis, and demonstrated that infection with HCV stimulated cultured hepatocytes to produce Hh ligands. The major cell populations that expanded during cirrhosis and HCC (ie, liver myofibroblasts, activated endothelial cells, and progenitors expressing markers of tumor stem/initiating cells) were Hh responsive, and higher levels of Hh pathway activity associated with cirrhosis and HCC. Inhibiting pathway activity in Hh-responsive target cells reduced fibrogenesis, angiogenesis, and growth. In conclusion, HBV/HCV infection increases hepatocyte production of Hh ligands and expands the types of Hh-responsive cells that promote liver fibrosis and cancer.

The liver tissue bank and clinical database in China

To develop a standardized and well-rounded material available for hepatology research, the National Liver Tissue Bank (NLTB) Project began in 2008 in China to make well-characterized and optimally preserved liver tumor tissue and clinical database. From Dec 2008 to Jun 2010, over 3000 individuals have been enrolled as liver tumor donors to the NLTB, including 2317 cases of newly diagnosed hepatocellular carcinoma (HCC) and about 1000 cases of diagnosed benign or malignant liver tumors. The clinical database and sample store can be managed easily and correctly with the data management platform used. We believe that the high-quality samples with detailed information database will become the cornerstone of hepatology research especially in studies exploring the diagnosis and new treatments for HCC and other liver diseases.

Prolonged recurrence-free survival following OK432-stimulated dendritic cell transfer into hepatocellular carcinoma during transarterial embolization

Despite curative locoregional treatments for hepatocellular carcinoma (HCC), tumour recurrence rates remain high. The current study was designed to assess the safety and bioactivity of infusion of dendritic cells (DCs) stimulated with OK432, a streptococcus-derived anti-cancer immunotherapeutic agent, into tumour tissues following transcatheter hepatic arterial embolization (TAE) treatment in patients with HCC. DCs were derived from peripheral blood monocytes of patients with hepatitis C virus-related cirrhosis and HCC in the presence of interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor and stimulated with 0·1 KE/ml OK432 for 2 days. Thirteen patients were administered with 5 × 10⁶ of DCs through arterial catheter during the procedures of TAE treatment on day 7. The immunomodulatory effects and clinical responses were evaluated in comparison with a group of 22 historical controls treated with TAE but without DC transfer. OK432 stimulation of immature DCs promoted their maturation towards cells with activated phenotypes, high expression of a homing receptor, fairly well-preserved phagocytic capacity, greatly enhanced cytokine production and effective tumoricidal activity. Administration of OK432-stimulated DCs to patients was found to be feasible and safe. Kaplan-Meier analysis revealed prolonged recurrence-free survival of patients treated in this manner compared with the historical controls (P = 0·046, log-rank test). The bioactivity of the transferred DCs was reflected in higher serum concentrations of the cytokines IL-9, IL-15 and tumour necrosis factor-α and the chemokines CCL4 and CCL11. Collectively, this study suggests that a DC-based, active immunotherapeutic strategy in combination with locoregional treatments exerts beneficial anti-tumour effects against liver cancer.

Identification of sequence polymorphism in the D-Loop region of mitochondrial DNA as a risk factor for hepatocellular carcinoma with distinct etiology

Background

Hepatocellular carcinoma (HCC) is frequently preceded by hepatitis virus infection or alcohol abuse. Genetic backgrounds may increase susceptibility to HCC from these exposures.

Methods

Mitochondrial DNA (mtDNA) of peripheral blood, tumor, and/or adjacent non-tumor tissue from 49 hepatitis B virus-related and 11 alcohol-related HCC patients, and from 38 controls without HCC were examined for single nucleotide polymorphisms (SNPs) and mutations in the D-Loop region.

Results

Single nucleotide polymorphisms (SNPs) in the D-loop region of mt DNA were examined in HCC patients. Individual SNPs, namely the 16266C/T, 16293A/G, 16299A/G, 16303G/A, 242C/T, 368A/G, and 462C/T minor alleles, were associated with increased risk for alcohol- HCC, and the 523A/del was associated with increased risks of both HCC types. The mitochondrial haplotypes under the M haplogroup with a defining 489C polymorphism were detected in 27 (55.1%) of HBV-HCCand 8 (72.7%) of alcohol- HCC patients, and in 15 (39.5%) of controls. Frequencies of the 489T/152T, 489T/523A, and 489T/525C haplotypes were significantly reduced in HBV-HCC patients compared with controls. In contrast, the haplotypes of 489C with 152T, 249A, 309C, 523Del, or 525Del associated significantly with increase of alcohol-HCC risk. Mutations in the D-Loop region were detected in 5 adjacent non-tumor tissues and increased in cancer stage (21 of 49 HBV-HCC and 4 of 11 alcohol- HCC, p < 0.002).

Conclusions

In sum, mitochondrial haplotypes may differentially predispose patients to HBV-HCC and alcohol-HCC. Mutations of the mitochondrial D-Loop sequence may relate to HCC development.

Vitamin D binding protein-macrophage activating factor inhibits HCC in SCID mice

BACKGROUND

A high incidence of recurrence after treatment is the most serious problem in hepatocellular carcinoma (HCC). Therefore, a new strategy for the treatment of the disease is needed. The aim of the present study was to investigate whether vitamin D binding protein-macrophage activating factor (DBP-maf) is able to inhibit the growth of HCC.

METHODS

The effects of DBP-maf on endothelial cells and macrophage were evaluated by WST-1 assay and phagocytosis assay, respectively. Human HCC cells (HepG2) were implanted into the dorsum of severe combined immunodeficiency (SCID) mice. These mice were divided into control and DBP-maf treatment groups (n = 10/group). The mice in the treatment group received 40 ng/kg/d of DBP-maf for 21 d.

RESULTS

DBP-maf showed anti-proliferative activity against endothelial cells and also activated phagocytosis by macrophages. DBP-maf inhibited the growth of HCC cells (treatment group: 126 ± 18mm(3), untreated group: 1691.5 ± 546.9mm(3), P = 0.0077). Histologic examinations of the tumors revealed the microvessel density was reduced and more macrophage infiltration was demonstrated in the tumor of mice in the treatment group.

CONCLUSION

DBP-maf has at least two novel functions, namely, an anti-angiogenic activity and tumor killing activity through the activation of macrophages. DBP-maf may therefore represent a new strategy for the treatment of HCC.

Prospective study of hepatocellular carcinoma in nonalcoholic steatohepatitis in comparison with hepatocellular carcinoma caused by chronic hepatitis C

BACKGROUND

This study was performed to clarify the outcomes and recurrence of hepatocellular carcinoma (HCC) in nonalcoholic steatohepatitis (NASH) in comparison with the data for HCC caused by hepatitis C virus (HCV) infection.

METHODS

Data for 34 NASH patients with HCC (NASH-HCC) were analyzed prospectively, and data for 56 age- and sex-matched patients with HCC due to HCV chronic liver disease (HCV-HCC) were collected retrospectively. After the initial treatment for HCC, patients were followed regularly at least every 4 months by performing clinical examinations, serum liver function tests, monitoring alpha-fetoprotein and des-gamma-carboxy prothrombin, and utilizing various imaging modalities.

RESULTS

The five-year survival rate was 55.2% and the cumulative recurrence of HCC at 5 years was 69.8% in treated cases of NASH-HCC. The NASH-HCC and HCV-HCC groups showed similar survival and recurrence rates. Of the 16 NASH-HCC patients curatively treated, recurrence was detected more than 2 years after the initial treatment in 9. Three patients showed intrahepatic recurrences away from the initial HCC, and 3 patients showed a change in tumor marker production after treatment of the initial HCC. The size of the HCC and the stage of fibrosis were significant risk factors for HCC recurrence in NASH-HCC.

CONCLUSIONS

HCC recurrence was very high in NASH, and the HCC may be of multicentric origin, similar to HCC based on viral hepatitis. Regular screening for HCC is extremely important for NASH patients with HCC, even after curative treatment. This study confirmed that NASH-HCC has a similar course to that of HCV-HCC.

Nonalcoholic fatty liver disease and hepatocellular carcinoma: a weighty connection

Hepatocellular carcinoma (HCC) is a common and deadly malignancy that is increasing in incidence in developed countries. The emergence of hepatitis C virus (HCV) accounts for about half of this increase in HCC, although the etiology of HCC in 15%-50% of new HCC cases remains unclear. The most common form of chronic liver disease in developed countries is nonalcoholic fatty liver disease (NAFLD), which encompasses a broad spectrum of histopathology. The prevalence of NAFLD, including the more aggressive nonalcoholic steatohepatitis (NASH), is increasing with the growing epidemics of diabetes and obesity. NASH can progress to cirrhosis and its related complications. Growing evidence suggests that NASH accounts for a large proportion of idiopathic or cryptogenic cirrhosis, which is associated with the typical risk factors for NASH. HCC is a rare, although important complication of NAFLD. Diabetes and obesity have been established as independent risk factors for the development of HCC. New evidence also suggests that hepatic iron deposition increases the risk of HCC in NASH-derived cirrhosis. Multiple case reports and case reviews of HCC in the setting of NASH support the associations of diabetes and obesity with the risk of HCC, as well as suggest age and advanced fibrosis as significant risks. Insulin resistance and its subsequent inflammatory cascade that is associated with the development of NASH appear to play a significant role in the carcinogenesis of HCC. The complications of NASH, including cirrhosis and HCC, are expected to increase with the growing epidemic of diabetes and obesity.

Viral hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer death worldwide. Despite recent advances in the diagnosis and treatment of HCC, its prognosis remains dismal. Infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) are the major risk factors for HCC. Although both are hepatotropic viral infections, there are important differences between the oncogenic mechanisms of these two viruses. In addition to the oncogenic potential of its viral proteins, HBV, as a DNA virus, can integrate into host DNA and directly transform hepatocytes. In contrast, HCV, an RNA virus, is unable to integrate into the host genome, and viral protein expression has a more critical function in hepatocarcinogenesis. Both HBV and HCV proteins have been implicated in disrupting cellular signal transduction pathways that lead to unchecked cell growth. Most HCC develops in the cirrhotic liver, but the linkage between cirrhosis and HCC is likely multifactorial. In this review, we summarize current knowledge regarding the pathogenetic mechanisms of viral HCC.

Gene expression in nontumoral liver tissue and recurrence-free survival in hepatitis C virus-positive hepatocellular carcinoma

Background

The goal of this study was to understand gene expression signatures of hepatocellular carcinoma (HCC) recurrence in subjects with hepatitis C virus (HCV) infection. Recurrence-free survival (RFS) following curative resection of HCC in subjects with HCV is highly variable. Traditional clinico-pathological endpoints are recognized as weak predictors of RFS. It has been suggested that gene expression profiling of HCC and nontumoral liver tissue may improve prediction of RFS, aid in understanding of the underlying liver disease, and guide individualized patient management. Frozen samples of the tumors and nontumoral liver were obtained from 47 subjects with HCV-associated HCC. Additional nontumoral liver samples were obtained from HCV-free subjects with metastatic liver tumors. Gene expression profiling data was used to determine the molecular signature of HCV-associated HCC and to develop a predictor of RFS.

Results

The molecular profile of the HCV-associated HCC confirmed central roles for MYC and TGFβ1 in liver tumor development. Gene expression in tumors was found to have poor predictive power with regards to RFS, but analysis of nontumoral tissues yielded a strong predictor for RFS in late-recurring (>1 year) subjects. Importantly, nontumoral tissue-derived gene expression predictor of RFS was highly significant in both univariable and multivariable Cox proportional hazard model analyses.

Conclusions

Microarray analysis of the nontumoral tissues from subjects with HCV-associated HCC delivers novel molecular signatures of RFS, especially among the late-recurrence subjects. The gene expression predictor may hold important insights into the pathobiology of HCC recurrence and de novo tumor formation in cirrhotic patients.

Overexpression of eukaryotic initiation factor 5A2 enhances cell motility and promotes tumor metastasis in hepatocellular carcinoma

A high incidence of tumor recurrence and metastasis has been reported in hepatocellular carcinoma (HCC) patients; however, the underlying molecular mechanisms are largely unknown. In the present study a novel metastasis-related gene, eukaryotic initiation factor 5A2 (EIF5A2), was characterized for its role in HCC metastasis and underlying molecular mechanisms. Overexpression of EIF5A2 messenger RNA (mRNA) was detected in 50/81 (61.7%) of HCCs, which was significantly higher than those in nontumorous liver tissues. Compared with matched primary HCC, higher expression of EIF5A2 protein was observed in 25/47 (53.2%) of metastatic tumors. Functional studies found that ectopic expression of EIF5A2 could enhance cancer cell migration and invasion in vitro and tumor metastasis in vivo in an experimental mouse model. Moreover, inhibition of EIF5A by small interfering RNA (siRNA) or deoxyhypusine synthase (DHPS) inhibitor GC7, which inhibits EIF5A2 maturation, could effectively decrease cell motility. Further study found that EIF5A2 was able to induce epithelial-mesenchymal transition (EMT), a key event in tumor invasion and metastasis, characterized by down-regulation of epithelial markers (E-cadherin and beta-catenin) and up-regulation of mesenchymal markers (fibronectin, N-cadherin, alpha-SMA, and vimentin). In addition, EIF5A2 could also activate RhoA/Rac1 to stimulate the formation of stress fiber and lamellipodia.

CONCLUSION

EIF5A2 plays an important role in HCC invasion and metastasis by inducing EMT, as well as stimulating cytoskeleton rearrangement through activation of RhoA and Rac1.

Alpha-fetoprotein and tumour size are associated with microvascular invasion in explanted livers of patients undergoing transplantation with hepatocellular carcinoma

BACKGROUND

To determine factors associated with outcomes and microvascular invasion (MVI) in patients undergoing liver transplantation (LT) for hepatocellular carcinoma (HCC).

METHODS

Between July 1996 and August 2008 at the Universities of Kentucky or Tennessee, LT recipients were retrospectively analysed.

RESULTS

One hundred and one patients had HCC in the explanted liver; one patient was excluded because of fibrolamellar histology. Seventy-nine (79%) were male and 81 (81%) were older than 50. HCC was incidental in 32 patients (32%). Median follow-up was 31 months. Ten patients (10%) developed recurrence, which was associated with poor survival (P= 0.006). Overall 1-, 3-, and 5-year survival rates were 87%, 69% and 62%, respectively. Excluding patients with lymph node metastasis (LNM) or MVI yielded 91%, 81% and 75% survival at the same time points. MVI was independently associated with recurrence (OR 28.40, 95% CI 1.77-456.48, P= 0.018) and decreased survival (OR 4.70, 95% CI 1.24-17.80, P= 0.023), and LNM with decreased survival (OR 6.05, 95% CI 1.23-29.71, P= 0.027). Tumour size (OR 4.1, 95% CI 1.2-13.5, P= 0.013) and alpha-fetoprotein (AFP) > 100 (OR 5.0, 95% CI 1.4-18.1, P= 0.006) were associated with MVI.

CONCLUSIONS

MVI greatly increases the risk of recurrence and death after LT for HCC, and is strongly associated with tumour size and AFP > 100.