Viral hepatocarcinogenesis: from infection to cancer

The Strategy of Conditionally Replicating Adenovirus-Mediated PreS2 Mini-Antibody Expression Has Dual Effects of Inhibiting HBV Infection and Preventing Hepatocellular Carcinoma

Aim

To investigate the inhibitory effect of hepatitis B virus (HBV) preS2 mini-antibody (mPreS2) against HBV infection, HBV-associated liver injury and HBV-associated hepatic carcinogenesis.

Methods

A recombinant adenovirus vector with the human survivin promoter and mPreS2 gene, Ad5SVP-mPreS2, was constructed. Fluorescence microscopy examination and TCID 50 analysis were utilized to determine the specific proliferation of recombinant adenovirus in liver cancer cells. Western blot analysis was used to determine the mPreS2 expression levels. Enzyme-linked immunosorbent assay (ELISA) was used to examine HBsAg levels to evaluate the inhibitory effect of mPreS2 against HBV infection. The protective effects on hepatic function and preventive effects against hepatic carcinogenesis of Ad5SVP-mPreS2 were studied in diethylnitrosamine (DEN)-treated HBV transgenic Imprinting Control Region mice.

Results

The recombinant adenovirus regulated by the human survivin promoter proliferated exclusively in liver cancer cells rather than normal liver cells. The expression levels of mPreS2 were increased in liver cancer cells compared with normal liver cells, and mPreS2 could be used to recognize liver cells from HBV transgenic mice. ELISA showed that HBsAg levels were decreased in the group treated with Ad5SVP-mPreS2. Ad5SVP-mPreS2 had a protective effect on hepatic function in a DEN-induced liver injury model because of lower serum levels of alanine transaminase and aspartate transaminase. Additionally, HBV transgenic mice treated with Ad5SVP-mPreS2 had fewer and smaller cancerous nodes after induction with DEN than untreated mice.

Conclusion

Conditionally replicating adenovirus-mediated mPreS2 expression inhibited HBV infection and had an inhibitory effect on liver injury and hepatocellular carcinogenesis in HBV transgenic mice.

Tea bioactive components prevent carcinogenesis via anti-pathogen, anti-inflammation, and cell survival pathways

Cancer seriously impairs human health and survival. Many perturbations, such as increased oxidative stress, pathogen infection, and inflammation, promote the accumulation of DNA mutations, and ultimately lead to carcinogenesis. Tea is one of the most highly consumed beverages worldwide and has been linked to improvements in human health. Tea contains many active components, including tea polyphenols, tea polysaccharides, L-theanine, tea pigments, and caffeine among other common components. Several studies have identified components in tea that can directly or indirectly reduce carcinogenesis with some being used in a clinical setting. Many previous studies, in vitro and in vivo, have focused on the mechanisms that functional components of tea utilized to protect against cancer. One particular mechanism that has been well described is an improvement in antioxidant capacity seen with tea consumption. However, other mechanisms, including anti-pathogen, anti-inflammation and alterations in cell survival pathways, are also involved. The current review focuses on these anti-cancer mechanisms. This will be beneficial for clinical utilization of tea components in preventing and treating cancer in the future.

Peptide SMIM30 promotes HCC development by inducing SRC/YES1 membrane anchoring and MAPK pathway activation

BACKGROUND & AIMS

Growing evidence shows that some non-coding RNAs (ncRNAs) contain small open reading frames (smORFs) that are translated into short peptides. Herein, we aimed to determine where and how these short peptides might promote hepatocellular carcinoma (HCC) development.

METHODS

We performed an RNA-immunoprecipitation followed by high-throughput sequencing (RIP-seq) assay with an antibody against ribosomal protein S6 (RPS6) on 4 cancer cell lines. Focusing on 1 long non-coding RNA (lncRNA), LINC00998, we used qPCR and public databases to evaluate its expression level in patients with HCC. Special vectors were constructed to confirm its coding potential. We also explored the function and mechanism of LINC00998-encoded peptide in tumor growth and metastasis.

RESULTS

We discovered that many lncRNAs bind to RPS6 in cancer cells. One of these lncRNAs, LINC00998, encoded a small endogenous peptide, termed SMIM30. SMIM30, rather than the RNA itself, promoted HCC tumorigenesis by modulating cell proliferation and migration, and its level was correlated with poor survival in patients with HCC. Furthermore, SMIM30 was transcribed by c-Myc and then drove the membrane anchoring of the non-receptor tyrosine kinases SRC/YES1. Moreover, the downstream MAPK signaling pathway was activated by SRC/YES1.

CONCLUSIONS

Our results not only unravel a new mechanism of HCC tumorigenesis promoted by ncRNA-encoded peptides, but also suggest that these peptides can serve as a new target for HCC cancer therapy and a new biomarker for HCC diagnosis and prognosis.

LAY SUMMARY

Very little is known about how peptides activate signaling pathways that play a crucial role in diseases such as cancer. Specifically, we reported on a conserved peptide encoded by LINC00998, SMIM30. This peptide promoted the tumorigenesis of hepatocellular carcinoma (HCC) by modulating cell proliferation and migration. Of note, it bound the non-receptor tyrosine kinases, SRC/YES1, to drive their membrane anchoring and phosphorylation, activating the downstream MAPK signaling pathway. Our work not only unravels a new mechanism of HCC tumorigenesis promoted by peptides, but also demonstrates how the peptide works to activate a signaling pathway.

Curcumin and Photobiomodulation in Chronic Viral Hepatitis and Hepatocellular Carcinoma

Immune modulation is a very modern medical field for targeting viral infections. In the race to develop the best immune modulator against viruses, curcumin, as a natural product, is inexpensive, without side effects, and can stimulate very well certain areas of the human immune system. As a bright yellow component of turmeric spice, curcumin has been the subject of thousands of scientific and clinical studies in recent decades to prove its powerful antioxidant properties and anticancer effects. Curcumin has been shown to influence inter- and intracellular signaling pathways, with direct effects on gene expression of the antioxidant proteins and those that regulate the immunity. Experimental studies have shown that curcumin modulates several enzyme systems, reduces nitrosative stress, increases the antioxidant capacity, and decreases the lipid peroxidation, protecting against fatty liver pathogenesis and fibrotic changes. Hepatitis B virus (HBV) affects millions of people worldwide, having sometimes a dramatic evolution to chronic aggressive infection, cirrhosis, and hepatocellular carcinoma. All up-to-date treatments are limited, there is still a gap in the scientific knowledge, and a sterilization cure may not yet be possible with the removal of both covalently closed circular DNA (cccDNA) and the embedded HBV DNA. With a maximum light absorption at 420 nm, the cytotoxicity of curcumin as photosensitizer could be expanded by the intravenous blue laser blood irradiation (IVBLBI) or photobiomodulation in patients with chronic hepatitis B infection, Hepatitis B e-antigen (HBeAg)-positive, noncirrhotic, but nonresponsive to classical therapy. Photobiomodulation increases DNA repair by the biosynthesis of complex molecules with antioxidant properties, the outset of repairing enzyme systems and new phospholipids for regenerating the cell membranes. UltraBioavailable Curcumin and blue laser photobiomodulation could suppress the virus and control better the disease by reducing inflammation/fibrosis and stopping the progression of chronic hepatitis, reversing fibrosis, and diminishing the progression of cirrhosis, and decreasing the incidence of hepatocellular carcinoma. Photodynamic therapy with blue light and curcumin opens new avenues for the effective prevention and cure of chronic liver infections and hepatocellular carcinoma. Blue laser light and UltraBioavailable Curcumin could be a new valuable alternative for medical applications in chronic B viral hepatitis and hepatocarcinoma, saving millions of lives.

miR-939-3p promotes epithelial-mesenchymal transition and may be used as a prognostic marker in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of cancer worldwide with a high morbidity and mortality rate. An increasing number of studies have demonstrated that microRNAs (miRNAs) serve an important role in HCC. The present study investigated the role of miR-939-3p in HCC. It was demonstrated that miR-939-3p was upregulated in HCC cell lines and HCC tissues compared with normal liver cell lines and paired normal tissues, respectively. It was also found that upregulation of miR-939-3p expression levels in HCC tissues was associated with a less favorable prognosis. Moreover, the overexpression of miR-939-3p in LM3 cells enhanced the metastatic capacity of these cells and promoted epithelial-mesenchymal transition (EMT). In contrast, miR-939-3p inhibition decreased the invasive capacity of HCC cells and EMT. Potential binding target of miR-939-3p to estrogen receptor 1 (ESR1) were predicted using TargetScan. The expression levels of miR-939-3p were negatively associated with ESR1 in HCC tissues based on data from The Cancer Genome Atlas. A luciferase reporter assay was used to confirm ESR1 as a direct downstream target of miR-393-3p. The miR-939-3p/ESR1 axis may be a potential novel target for the treatment of HCC.

Pathological changes of liver one year later in CHB patients with negative HBV DNA

Background

In this study, we aim to determine the hepatic pathological changes in HBV DNA-negative chronic Hepatitis B (CHB) patients after 12-month antiviral therapy.

Methods

Blood routine indicators including platelet count (PLT) and white blood cell (WBC) were determined. The coagulation function was evaluated by determining the prothrombin time (PT) and prothrombin time activity (PTA), together with the HBV DNA quantification and alpha fetoprotein (AFP). The virology data included hepatitis B surface antigen (HBsAg)/antibodies against hepatitis B surface antigen (anti-HBs), hepatitis B e antigen (HBeAg)/antibodies against hepatitis B e antigen (anti-HBe) and antibodies against hepatitis B core antigen (anti-HBc) were tested. Pathological assay was performed to the liver puncture tissues. Based on the HBV DNA data in the 12-month follow-up of the cases that received anti-viral therapy during this time, the experimental group was divided into group A (HBV DNA negative at the baseline level, HBV DNA negative after 12 months, N = 79) and group B (HBV DNA negative at the baseline level, HBV DNA turning to be positive after 12 months, N = 13). Statistical analysis was performed on the each test index of the two groups.

Results

The inflammation grade of group A showed significant improvement after 12-month treatment (P < 0.05). The pathological inflammation grade of group B was increased after one year, and the liver function indices and the PTA (P < 0.05) levels were all increased. Pathological results indicated that the proportion of disease progression in group A was decreased after 12-month follow-up while that proportion was increased in group B. Significant differences were noticed in AFP levels between the patients with progression in group A and those with progression in group B.

Conclusion

Negative HBV DNA does not mean a controlled hepatitis B. Hepatitis B patients transferred to HBV DNA positivity during the anti-viral therapy are easily to show disease progression, and then special attention should be paid to the HBV DNA monitoring. Meanwhile, close monitoring to the changes of liver function, PTA and AFP levels may help to detect changes on the disease in a timely manner.

Chemopreventive Effect of Phytosomal Curcumin on Hepatitis B Virus-Related Hepatocellular Carcinoma in A Transgenic Mouse Model

Chronic hepatitis B virus (HBV) infection is a major risk factor for the development of hepatocellular carcinoma (HCC), a leading cause of cancer mortality worldwide. Hepatitis B X protein (HBx) and pre-S2 mutant have been proposed as the two most important HBV oncoproteins that play key roles in HCC pathogenesis. Curcumin is a botanical constituent displaying potent anti-inflammatory and anti-cancer properties without toxic side effects. Phytosomal formulation of curcumin has been shown to exhibit enhanced bioavailability, improved pharmacokinetics, and excellent efficacy against many human diseases. However, effectiveness of phytosomal curcumin for HCC treatment remains to be clarified. In this study, we evaluated chemopreventive effect of phytosomal curcumin on HBV-related HCC by using a transgenic mouse model specifically expressing both HBx and pre-S2 mutant in liver. Compared with unformulated curcumin, phytosomal curcumin exhibited significantly greater effects on suppression of HCC formation, improvement of liver histopathology, decrease of lipid accumulation and leukocyte infiltration, and reduction of total tumor volume in transgenic mice. Moreover, phytosomal curcumin exerted considerably stronger effects on activation of anti-inflammatory PPARγ as well as inhibition of pro-inflammatory NF-κB than unformulated curcumin. Furthermore, phytosomal curcumin showed a comparable effect on suppression of oncogenic mTOR activation to unformulated curcumin. Our data demonstrated that phytosomal curcumin has promise for HCC chemoprevention in patients with chronic HBV infection.

Hepatitis B variants among Egyptian patients undergoing hemodialysis

Hepatitis B virus (HBV) infection is a serious nosocomial infection that affects patients undergoing hemodialysis (HD). However, certain HBV variants are not detected by routine serological tests in Egyptian dialysis units because of mutations that change important viral antigens (Ags). Of note, these mutations can result in the appearance of different HBV variants with different clinical manifestations. Thus, the present study aimed to assess different clinical forms of HBV infections and viral genotypes among patients undergoing HD in the Ismailia governorate of Egypt. To this end, serum samples were collected from 150 patients undergoing HD and screened for HBV-DNA using a nested PCR technique. Positive samples were then screened for HBV serological markers (hepatitis B core antibody [HBcAb], hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B e antigen and hepatitis B e antibody) using ELISA and the HBV viral load quantitated by qPCR. HBV genotypes were detected by direct sequencing of the partial surface (S) gene. The most common clinical form of HBV infection in our study cohort was overt HBV infection (10%); followed by seropositive occult hepatitis B infection (7.3%), most of whom had an isolated HBcAb. The least common form was the precore mutant (1.3%). All HBV isolates were genotype D. This study reveals the importance of HBcAb and PCR in screening for HBV, especially for detection of occult hepatitis B infection.

miR-21 promotes cell migration and invasion of hepatocellular carcinoma by targeting KLF5

Previous studies have reported that microRNAs regulate gene expression and transcription. miR-21 have been identified to play a role in many types of cancer. KLF5 functions as a tumor inhibitor in certain cancers. However, the role of KLF5 plays in hepatocellular carcinoma (HCC), especially concerning the relationship between miR-21 and the KLF5 gene remains to be determined. Reverse transcription-quantitative PCR (RT-qPCR), western blot analysis, as well as luciferase reporter and Transwell assays were used to determine the expression of miR-21 and KLF5 in Huh 7, SK-HEP-1, LO-2, and HCC tissues. In HCC cells and tissues, the upregulation of miR-21 was identified. HCC cell migratory and invasive abilities significantly increased because of miR-21 overexpression. KLF5 expression was inhibited by miR-21 by targeting its 3′-UTR. KLF5 overexpression alleviated the effect induced by miR-21 on the migratory and invasive ability of the Huh 7 cells. The results therefore show that, HCC cell migration and invasion is significantly suppressed by miR-21 via targeting KLF5. The newly identified miR-21/KLF5 axis provides a useful therapeutic biomarker for HCC treatment.

Vitamin D Status and Virologic Response to HCV Therapy in the HALT-C and VIRAHEP-C Trials

More than 150 million people worldwide are chronically infected with hepatitis C virus (HCV) and face higher risk of cirrhosis and hepatocellular carcinoma. Highly effective HCV treatments have recently been developed; however, they are costly and therefore poorly suited for application in resource-limited settings where HCV burden is high. Pegylated-interferon alpha (PEG-IFNα) and ribavirin (RBV) therapy is far less costly, but also less effective. Vitamin D supplementation has been proposed as an inexpensive adjuvant to treatment, however, prior epidemiological evidence on its effectiveness is inconsistent, with little data available among African Americans who naturally have lower vitamin D concentrations. We thus evaluated associations between baseline vitamin D status, measured by circulating 25-hydroxyvitamin D (25(OH)D), which is considered to be the best marker of vitamin D status in humans, and subsequent response to PEG-IFNα/RBV therapy in two large clinical trials that together included 1292 patients infected with HCV genotype 1. We used race-stratified logistic regression models to evaluate multivariable-adjusted associations of 25(OH)D with early virologic response (EVR; 2-log₁₀ HCV RNA decline at week 12) and sustained virologic response (SVR). Among African Americans, we saw no associations. Among European Americans, we saw no association with low vitamin D (≤20 ng/mL) versus sufficient concentrations (20-<30 ng/mL). However, patients with 25(OH)D ≥30 ng/mL were actually less likely to attain EVR (OR = 0.64, 95% CI = 0.43–0.94) than those with sufficient concentrations, with a similar but non-significant association observed for SVR (OR = 0.49, 95% CI = 0.20–1.17).

HBx-induced miR-21 suppresses cell apoptosis in hepatocellular carcinoma by targeting interleukin-12

Hepatitis B virus (HBV) X protein (HBx) plays a key role in the initiation and progression of HBV infection‑induced hepatocellular carcinoma (HCC). Oncogenic microRNA-21 (miR-21) can be modulated by HBx protein in HCC. However, critical regulator genes in the pathway of HBx-induced miR-21 in HCC remain unclear. This study aimed to investigate the role of HBx-induced miR-21 in the apoptosis of HCC cells. In the study, interleukin-12 (IL-12) was demonstrated as a direct target of miR-21 by dual‑luciferase report assay, and miR-21 was highly expressed in HCC cells (HepG2 and HepG2 2.2.15) compared to L02 cells, but IL-12 was weakly expressed as detected by real-time quantitative PCR (RT-qPCR). Furthermore, miR-21 mimics, inhibitor, HBx-targeted siRNA, and the HBx overexpression vector (pHBx) were used to observe the regulatory effects of HBx-induced miR-21 via IL-12, and cell apoptosis was assessed. The results showed that overexpression of HBx resulted in the inhibition of IL-12. A high level of miR-21 resulted in a significant increase in proliferation and a decrease in IL-12 expression. Inhibition of miR-21 resulted in a significant increase in apoptosis and increased IL-12 expression. The results suggest that HCC cell apoptosis was suppressed at least partially through HBx-induced miR-21 by targeting IL-12.

Hostile takeover: Manipulation of HIF-1 signaling in pathogen-associated cancers (Review)

Hypoxia-inducible factor (HIF)-1 is a central regulator in the adaptation process of cell response to hypoxia (low oxygen). Emerging evidence has demonstrated that HIF-1 plays an important role in the development and progression of many types of human diseases, including pathogen-associated cancers. In the present review, we summarize the recent understandings of how human pathogenic agents including viruses, bacteria and parasites deregulate cellular HIF-1 signaling pathway in their associated cancer cells, and highlight the common molecular mechanisms of HIF-1 signaling activated by these pathogenic infection, which could act as potential diagnostic markers and new therapeutic strategies against human infectious cancers.

The attenuated hepatocellular carcinoma-specific Listeria vaccine Lmdd-MPFG prevents tumor occurrence through immune regulation of dendritic cells

Immunotherapy is a promising treatment for liver cancer. Here, we tested the ability of the attenuated hepatocellular carcinoma-specific Listeria vaccine (Lmdd-MPFG) to treat hepatocellular carcinoma (HCC) in a mouse model. Immunization with the vaccine caused a strong anti-tumor response, especially in mice reinfused with dendritic cells (DCs). In mice that were also administered DCs, tumor suppression was accompanied by the strongest cytotoxic T lymphocyte response of all treatment groups and by induced differentiation of CD4+ T cells, especially Th17 cells. Additionally, the Lmdd-MPFG vaccine caused maturation of DCs in vitro. We demonstrated the synergistic effect of TLR4 and NLRP3 or NOD1 signaling pathways in LM-induced DC activation. These results suggest that the Lmdd-MPFG vaccine is a feasible strategy for preventing HCC.

Genetic variation in PTX3 and plasma levels associated with hepatocellular carcinoma in patients with HCV

Hepatitis C virus (HCV) is the main cause of chronic liver disease, cirrhosis and hepatocellular carcinoma (HCC) worldwide. The risk to develop HCC increases with the severity of liver inflammation and fibrosis. Long pentraxin 3 (PTX3) is a soluble pattern-recognition receptor produced by phagocytes and nonimmune cells at sites of inflammation or injury. The aim of the present study was to determine the association of PTX3 polymorphisms and its plasma levels with HCC occurrence among patients with HCV. Samples from 524 patients with chronic hepatitis C were evaluated in this study. Two polymorphisms (rs1840680 and rs2305619) in the PTX3 gene were determined by real-time PCR. PTX3 plasma levels were measured by Enzyme-linked Immunosorbent Assay (ELISA). Our data show a significant association between PTX3 polymorphisms and HCC occurrence in univariate and multivariate analysis (P = 0.024). Patients with HCC had higher PTX3 plasma levels compared to individuals with mild or severe fibrosis (P < 0.0001 and P = 0.002, respectively). In addition, PTX3 rs2305619 polymorphism and plasma levels were correlated with Child-Pugh scores B and C in HCC individuals. PTX3 seems to be a risk factor for HCC occurrence in chronic hepatitis C. This is the first study that evaluates PTX3 in the context of hepatitis C.

Hepatocellular carcinoma mouse models: Hepatitis B virus-associated hepatocarcinogenesis and haploinsufficient tumor suppressor genes

The multifactorial and multistage pathogenesis of hepatocellular carcinoma (HCC) has fascinated a wide spectrum of scientists for decades. While a number of major risk factors have been identified, their mechanistic roles in hepatocarcinogenesis still need to be elucidated. Many tumor suppressor genes (TSGs) have been identified as being involved in HCC. These TSGs can be classified into two groups depending on the situation with respect to allelic mutation/loss in the tumors: the recessive TSGs with two required mutated alleles and the haploinsufficient TSGs with one required mutated allele. Hepatitis B virus (HBV) is one of the most important risk factors associated with HCC. Although mice cannot be infected with HBV due to the narrow host range of HBV and the lack of a proper receptor, one advantage of mouse models for HBV/HCC research is the numerous and powerful genetic tools that help investigate the phenotypic effects of viral proteins and allow the dissection of the dose-dependent action of TSGs. Here, we mainly focus on the application of mouse models in relation to HBV-associated HCC and on TSGs that act either in a recessive or in a haploinsufficient manner. Discoveries obtained using mouse models will have a great impact on HCC translational medicine.

Hepatitis viruses exploitation of host DNA methyltransferases functions

Hepatitis B virus (HBV), hepatitis C virus (HCV) and Delta (HDV) infections are a global health burden. With different routes of infection and biology, HBV, HCV and HDV are capable to induce liver cirrhosis and cancer by impinging on epigenetic mechanisms altering host cell's pathways. In the present manuscript, we reviewed the published studies taking into account the relationship between the hepatitis viruses and the DNA methyltransferases proteins.

Hepatocellular carcinoma in Asia: Prevention strategy and planning

AIM: To review all of epidemiological and etiological aspects of hepatocellular carcinoma (HCC) and examined the prevention of this disease in Asia.

METHODS: We conducted a systematic review according to the PRISMA guidelines. We were chosen articles that published previously, from PubMed (MEDLINE), the Cochrane database and Scopus. The key words used in this research were as follows: HCC in Asia and the way of prevention of this disease, with no language limitations. We selected those papers published before 2014 that we considered to be most important and appropriate. All relevant articles were accessed in full text and all relevant materials was evaluated and reviewed.

RESULTS: More than 70% of all new cases of liver cancer were diagnosed in Asia, a region that 75% of all those chronically infected with hepatitis B virus (HBV) in the world. Chronic HBV infection is the main cause of HCC in Asia, where the virus is endemic and vertical transmission is common. Japan, Saudi Arabia, Egypt and Pakistan are exception because of high prevalence of HCV infection in these regions. The prevalence of this cancer is high in Eastern and South-Eastern Asia, But Middle Eastern countries are characterized as moderate prevalence rate of HCC region and Central Asia and some part of Middle Eastern countries are known as low prevalence rate of HCC. In addition of HBV and HCV the other factors such as aflatoxin, alcohol, obesity, diabetes and non-alcoholic fatty liver disease (NAFLD) might be responsible for a low prevalence of HCC in Asian countries. Currently available HCC therapies, chemotherapy, surgical are inefficient, mainly due to usually late diagnosis and high recurrence rates after surgical resection, and usually end with treatment failure. Liver transplantation also remains as a difficult strategy in patients with HCC. Thus prevention of HCC by treating and prevention HBV and HCV infection, the major causative agents of HCC, and the other risk factors such as aflatoxin, alcohol, obesity, diabetes and NAFLD is of a great medical importance.

CONCLUSION: The main challenge which still present in Asia, is the high prevalence of chronic hepatitis. So, prevention of HBV and HCV is the key strategy to reduce the incidence of HCC in Asia.

Increased DNA damage in hepatitis C virus-related hepatocellular carcinoma

One consequence of hepatitis C virus (HCV) infection is an elevated cancer risk. During chronic viral infection, deoxyribonucleic acid (DNA) damage is being induced by reactive oxygen and nitrogen species, which may play a pathogenic role in HCV-induced carcinogenesis. The study investigated DNA damage in peripheral blood lymphocytes from patients with hepatocellular carcinoma (HCC) and those with HCV infection with and without associated cirrhosis and normal controls. As a measure for genomic damage, the comet assay (single cell gel electrophoresis) was applied, which detects single- and double-strand breaks and alkali-labile sites through electrophoretic mobility of the resulting fragments. The levels of DNA damage were significantly higher in HCC and HCV-associated cirrhosis compared to HCV without cirrhosis and the control group. Patients presenting with DNA damage more than mean+two standard deviation of the controls had a 3.6-fold risk of having HCC more than those with undamaged DNA. HCV disease progression was the only discriminator predicting the extent of DNA damage. The accumulation of DNA damage is important in HCC evolution. DNA damage indicating intracellular oxidative and nitrative stress may lead to mutagenesis and consequently malignant transformation, which emphasizes the need to optimize the therapy for reducing the degree of genomic damage.

Multiple pregnancies, hepatitis C, and risk for hepatocellular carcinoma in Egyptian women

BACKGROUND

The reasons for the worldwide sex disparity in the incidence of hepatocellular carcinoma (HCC) remain elusive. We investigated the role of multiple pregnancies on the associations between viral hepatitis C (HCV) infection and HCC risk among Egyptian women.

METHODS

We used data collected from blood specimens and questionnaires administered to female HCC cases and controls in Cairo, Egypt, from 1999 through 2009. HCV infection was defined as being sero-positive for either anti-HCV antibodies or HCV-RNA. Using logistic regression models we calculated odds ratios (OR) and 95% confidence intervals (CI) to estimate the associations between being HCV positive and HCC risk, and how it is modified by the number of pregnancies, after adjustment for other factors, including hepatitis B status.

RESULTS

Among 132 confirmed female cases and 669 controls, the risk of HCV-related HCC increased with the number of pregnancies. Women infected with HCV had higher risk for HCC if they had more than five pregnancies, as compared to those who had five or fewer pregnancies (adjusted OR (95% CI): 2.33 (1.29-4.22)). The association of HCV infection with HCC risk was significantly greater among the former (21.42 (10.43-44.00)) than among the latter (6.57 (3.04-14.25)).

CONCLUSION

Having multiple pregnancies increases the risk of HCV-related HCC among Egyptian women, raising questions about the roles of estrogens and other pregnancy-related hormones in modulating HCV infection and its progression to HCC.

The emerging role of hepatitis B virus pre-S2 deletion mutant proteins in HBV tumorigenesis

Chronic hepatitis B virus (HBV) infection can cause hepatocellular carcinoma (HCC). Several hypotheses have been proposed to explain the mechanisms of HBV tumorigenesis, including inflammation and liver regeneration associated with cytotoxic immune injuries and transcriptional activators of mutant HBV gene products. The mutant viral oncoprotein-driven tumorigenesis is prevailed at the advanced stage or anti-HBe-positive phase of chronic HBV infection. Besides HBx, the pre-S2 (deletion) mutant protein represents a newly recognized oncoprotein that is accumulated in the endoplasmic reticulum (ER) and manifests as type II ground glass hepatocytes (GGH). The retention of pre-S2 mutant protein in ER can induce ER stress and initiate an ER stress-dependent VEGF/Akt/mTOR and NFκB/COX-2 signal pathway. Additionally, the pre-S2 mutant large surface protein can induce an ER stress-independent pathway to transactivate JAB-1/p27/RB/cyclin A,D pathway, leading to growth advantage of type II GGH. The pre-S2 mutant protein-induced ER stress can also cause DNA damage, centrosome overduplication, and genomic instability. In 5-10% of type II GGHs, there is co-expression of pre-S2 mutant protein and HBx antigen which exhibited enhanced oncogenic effects in transgenic mice. The mTOR signal cascade is consistently activated throughout the course of pre-S2 mutant transgenic livers and in human HCC tissues, leading to metabolic disorders and HCC tumorigenesis. Clinically, the presence of pre-S2 deletion mutants in sera frequently develop resistance to nucleoside analogues anti-virals and predict HCC development. The pre-S2 deletion mutants and type II GGHs therefore represent novel biomarkers of HBV-related HCCs. A versatile DNA array chip has been developed to detect pre-S2 mutants in serum. Overall, the presence of pre-S2 mutants in serum has implications for anti-viral treatment and can predict HCC development. Targeting at pre-S2 mutant protein-induced, ER stress-dependent, mTOR signal cascade and metabolic disorders may offer potential strategy for chemoprevention or therapy in high risk chronic HBV carriers.

Recurrence patterns and prognostic factors in patients with hepatocellular carcinoma in noncirrhotic liver: a multi-institutional analysis

BACKGROUND

Hepatocellular carcinoma (HCC) primarily affects patients with a cirrhotic liver. Reports on the characteristics of patients with HCC in noncirrhotic liver, as well as predictors of recurrence and survival, are scarce.

METHODS

Between 1992 and 2011, 334 patients treated for HCC in noncirrhotic liver were identified from three major hepatobiliary centers. Clinicopathological characteristics were analyzed and independent predictors of recurrence and overall survival were identified using Cox proportional hazards models.

RESULTS

Median patient age was 58 years and 77 % were male. Most patients had a solitary (81 %) and poorly or undifferentiated tumor (56 %); median size was 6.5 cm. The majority of patients (96 %) underwent liver resection (microscopically negative margins in 94 %), whereas a few had transarterial chemoembolization or transplantation (4 %). Median recurrence-free survival (RFS) was 2.5 years, and 1- and 5-year RFS was 71.1, and 35 %, respectively. Elevated alkaline phosphatase levels [hazards ratio (HR) = 1.82], poor tumor differentiation (HR = 1.4), macrovascular invasion (HR = 2.18), and the presence of satellite lesions (HR = 1.9), or intrahepatic metastases (HR = 2.59) were independently associated with shorter RFS; in contrast, an intact tumor capsule independently prolonged RFS (HR = 0.46). Median overall survival was 5.9 years, and 1- and 5-year overall survival was 86.9, and 54.5 %, respectively. Tumor size ≥5 cm (HR = 2.27), macrovascular (HR = 2.72) or adjacent organ invasion (HR = 3.34), and satellite lesions (HR = 2.18) were independently associated with shorter overall survival, whereas an intact tumor capsule showed a protective effect (HR = 0.51).

CONCLUSIONS

Following resection of HCC in the setting of no cirrhosis, more than one-half of patients were alive after 5 years. However, even among patients with no cirrhosis, recurrence was common. Factors associated with RFS and overall survival included tumor characteristics, such as tumor capsule, satellite lesions, and vascular invasion.

Inflammatory response of endothelial cells to hepatitis C virus recombinant envelope glycoprotein 2 protein exposure

The hepatitis C virus (HCV) encodes approximately 10 different structural and non-structural proteins, including the envelope glycoprotein 2 (E2). HCV proteins, especially the envelope proteins, bind to cell receptors and can damage tissues. Endothelial inflammation is the most important determinant of fibrosis progression and, consequently, cirrhosis. The aim of this study was to evaluate and compare the inflammatory response of endothelial cells to two recombinant forms of the HCV E2 protein produced in different expression systems (Escherichia coli and Pichia pastoris). We observed the induction of cell death and the production of nitric oxide, hydrogen peroxide, interleukin-8 and vascular endothelial growth factor A in human umbilical vein endothelial cells (HUVECs) stimulated by the two recombinant E2 proteins. The E2-induced apoptosis of HUVECs was confirmed using the molecular marker PARP. The apoptosis rescue observed when the antioxidant N-acetylcysteine was used suggests that reactive oxygen species are involved in E2-induced apoptosis. We propose that these proteins are involved in the chronic inflammation caused by HCV.

Outcomes after curative hepatectomy in patients with non-B non-C hepatocellular carcinoma and hepatitis B virus hepatocellular carcinoma from non-cirrhotic liver

BACKGROUNDS AND OBJECTIVE

There is controversy regarding liver function of non-B, non-C hepatocellular carcinoma (NBNC-HCC) patients, the biological behavior of their tumors, and the outcome after surgical treatment. The aims of the present study were to compare clinicopathologic data and long-term clinical outcomes between NBNC-HCC patients and hepatitis B virus HCC (HBV-HCC) patients from non-cirrhotic liver after curative hepatectomy.

METHODS

Data for HBV-HCC patients (n = 360) and NBNC-HCC patients (n = 103) were retrospectively reviewed.

RESULTS

The median age of patients in the NBNC group was significantly higher than that of the HBV group (63 years vs. 53 years, P < 0.001). Tumor size in the NBNC group was greater than that in the HBV group (5.1 cm vs. 3.8 cm, P < 0.001). Regarding liver histology, the grade of lobular activity, periportal activity, and fibrosis in the HBV group was higher than in the NBNC group (P < 0.001, P < 0.001, and P < 0.001, respectively). There were no statistically significant differences in disease-free survival and overall survival between the two groups (P = 0.257 and P = 0.579, respectively). Multivariate analysis showed that increased tumor size, microvascular invasion, and intrahepatic metastasis were associated with tumor recurrence after curative liver resection.

CONCLUSION

For patients with non-cirrhotic liver, clinical outcomes for NBNC-HCC were comparable to those for HBV-HCC after curative hepatectomy.

Elevated p53 promotes the processing of miR-18a to decrease estrogen receptor-α in female hepatocellular carcinoma

The estrogen pathway has long been implicated as a tumor protector in female hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Our previous study identified that estrogen receptor alpha (ERα) protein is downregulated in 60% of female HCC cases, via a miR-18a elevation mediated suppression of ERα translation. This study aims to delineate the mechanism underlying the upregulation of miR-18a in female HCC. The analysis of 77 female HCC specimens revealed that miR-18a levels were associated with pre-miR-18a rather than pri-miR-18a levels, suggesting an enhanced processing of pri- to pre-miR-18a. Among a panel of factors involved in microRNA processing, p53 was identified as a novel regulator for miR-18a maturation process. Knockdown of p53 by si-RNA decreased the level of miR-18a, whereas overexpression of either wild-type or mutant p53 increased its level. The association between the elevation of miR-18a and the accumulation of p53, mainly caused by somatic mutations, was confirmed in the clinical specimens of HBV-related female HCC. By analyzing the association with clinicopathological features, activation of this p53/miR-18a pathway mainly occurs in younger or noncirrhosis female HCC patients and associated with a trend of worse overall survival. Therefore, this study demonstrated a novel function of elevated/mutant p53 in regulating the amount of ERα protein through its promoting the biogenesis of miR-18a, which could lead to decrease the tumor-protective function of the estrogen pathway in female hepatocarcinogenesis.

Ground-glass hepatocytes co-expressing hepatitis B virus X protein and surface antigens exhibit enhanced oncogenic effects and tumorigenesis

Hepatitis B virus (HBV) X protein (HBx) and pre-S2 deletion mutant large surface antigens are oncoproteins that induce hepatocellular carcinoma (HCC). The interaction of these two oncoproteins in hepatocytes and its significance in tumorigenesis remain to be elucidated. In this study, we observed the co-expression of HBx with surface antigens in ground-glass hepatocytes in 5 of 20 hepatitis B surface antigen-positive livers. In vitro, hepatocytes co-expressing HBx and a pre-S2 mutant showed enhanced expression of vascular endothelial growth factor-A, phosphorylated Akt 1/2/3, phosphorylated extracellular signal-regulated kinase 1/2, and phosphorylated mammalian target of rapamycin signals. Transgenic mice harboring both HBx and pre-S2 mutant construct plasmids developed HCCs at an average of 15.1 months, earlier than animals carrying either HBx (16.9 months) or pre-S2 mutant (24.5 months) alone. The oncogenic signals of vascular endothelial growth factor-A, phosphorylated Akt 1/2/3, phosphorylated extracellular signal-regulated kinase 1/2, and phosphorylated mammalian target of rapamycin were sequentially and differentially activated at different stages in tumorigenesis. Phosphorylated mTOR was consistently activated in transgenic and human HCCs. We conclude that ground-glass hepatocytes co-expressing HBx and surface antigens exhibit enhanced oncogenic effects and tumorigenesis in chronic HBV infections. The mTOR signal cascade may be the key regulator in HBV tumorigenesis and may be useful targets in the design of HCC therapy.

IL-28B polymorphisms and treatment response in hepatitis C virus patients with persistently normal alanine aminotransferase

AIM: To examine the association between the interleukin 28B (IL-28B) genotype and treatment response in hepatitis C virus (HCV)-infected patients with persistently normal alanine aminotransferase (PNALT).

METHODS: We compared the treatment response of HCV-infected patients with PNALT to that of patients with non-PNALT. Between February 2010 and April 2013, 278 patients infected with HCV were enrolled in this study. All of the patients were treated with peginterferon-alpha 2a or 2b plus ribavirin. In addition, 180 μg of peginterferon alpha-2a or 1.5 μg/kg peginterferon alpha-2b per week plus weight-based ribavirin (600-1000 mg/d) were typically administered for 24 wk to HCV genotype 2-infected patients or for 48-72 wk to HCV genotype 1-infected patients. In all of the patients, the IL-28B rs8099917 genotype was determined using a TaqMan single-nucleotide polymorphism assay. HCV RNA was measured using the COBAS TaqMan HCV test.

RESULTS: Female patients were dominant in the PNALT group (P < 0.0001). Among 72 HCV genotype 1-infected patients with PNALT, the early virologic response (EVR) rates (P < 0.01) and the sustained virologic response (SVR) rates (P < 0.01) were higher in patients with the IL-28B TT genotype than in those with the IL-28B TG/GG genotype. In HCV genotype 1-infected patients with PNALT, multivariate logistic-regression analysis showed that SVR was independently predicted by the IL-28B rs8099917 TT type (P < 0.05) and having an EVR (P < 0.01). The IL-28B rs8099917 TT genotype strongly correlated with treatment response in HCV genotype 1-infected Asian patients with PNALT.

CONCLUSION: The IL-28B genotype may be useful for selecting HCV genotype 1-infected patients with PNALT who should receive interferon-based treatment.

Uracil DNA glycosylase counteracts APOBEC3G-induced hypermutation of hepatitis B viral genomes: excision repair of covalently closed circular DNA

The covalently closed circular DNA (cccDNA) of the hepatitis B virus (HBV) plays an essential role in chronic hepatitis. The cellular repair system is proposed to convert cytoplasmic nucleocapsid (NC) DNA (partially double-stranded DNA) into cccDNA in the nucleus. Recently, antiviral cytidine deaminases, AID/APOBEC proteins, were shown to generate uracil residues in the NC-DNA through deamination, resulting in cytidine-to-uracil (C-to-U) hypermutation of the viral genome. We investigated whether uracil residues in hepadnavirus DNA were excised by uracil-DNA glycosylase (UNG), a host factor for base excision repair (BER). When UNG activity was inhibited by the expression of the UNG inhibitory protein (UGI), hypermutation of NC-DNA induced by either APOBEC3G or interferon treatment was enhanced in a human hepatocyte cell line. To assess the effect of UNG on the cccDNA viral intermediate, we used the duck HBV (DHBV) replication model. Sequence analyses of DHBV DNAs showed that cccDNA accumulated G-to-A or C-to-T mutations in APOBEC3G-expressing cells, and this was extensively enhanced by UNG inhibition. The cccDNA hypermutation generated many premature stop codons in the P gene. UNG inhibition also enhanced the APOBEC3G-mediated suppression of viral replication, including reduction of NC-DNA, pre-C mRNA, and secreted viral particle-associated DNA in prolonged culture. Enhancement of APOBEC3G-mediated suppression by UNG inhibition was not observed when the catalytic site of APOBEC3G was mutated. Transfection experiments of recloned cccDNAs revealed that the combination of UNG inhibition and APOBEC3G expression reduced the replication ability of cccDNA. Taken together, these data indicate that UNG excises uracil residues from the viral genome during or after cccDNA formation in the nucleus and imply that BER pathway activities decrease the antiviral effect of APOBEC3-mediated hypermutation.

HBx-mediated miR-21 upregulation represses tumor-suppressor function of PDCD4 in hepatocellular carcinoma

The hepatitis B virus (HBV) X protein (HBx) has a key role in the molecular pathogenesis of HBV-related hepatocellular carcinoma (HCC). However, the mechanism of HBx-mediated hepatocarcinogenesis remains to be elucidated. In this study, we aimed to better understand the effects of HBx on gene-expression profiles that participate in hepatocarcinogenesis and the mechanism by which HBx regulates these genes. Differentially expressed genes between L02-HBx and L02-Vector control cells were identified by microarray and validated using quantitative real-time PCR. HBx upregulates 456 genes and downregulates 843 genes, including programmed cell death 4 (PDCD4). PDCD4 was downregulated in clinical HCC specimens and the downregulation of PDCD4 in HCC is correlated with HBx. Furthermore, overexpression experiments in HCC cells proved that PDCD4 has strong tumor-suppressive effects both in vitro and in vivo, and may induce cell apoptosis to suppress the development of HCC. HBx induces expression of DNA methyltransferases (DNMTs), but failed to change the methylation status of the PDCD4 promoter. HBx downregulates PDCD4 expression at least partially through miR-21. Taken together, this study reported for the first time that HBx downregulates PDCD4 and upregulates miR-21 expression. The overexpression of PDCD4 could suppress tumorigenicity. The deregulation of PDCD4 by HBx through miR-21 represents a potential novel mechanism of the downregulation of PDCD4 in HBV-related HCC and provides new insights into HCC development.

Expression of LAG-3 is coincident with the impaired effector function of HBV-specific CD8(+) T cell in HCC patients

Hepatitis B virus (HBV)-specific T cells play a key role in the pathogenesis of hepatocellular carcinoma (HCC), but little is known about the regulation of HBV-specific CD8(+) T cells function in HCC patients. Lymphocyte activation gene-3 (LAG-3) is an inhibitory molecule with diverse biologic effects on T cell function, including direct effects on CD8(+) T cells. In this study, we assessed the frequency and function of HBV-specific CD8(+) T cells derived from peripheral blood lymphocytes (PBLs) and tumor-infiltrating lymphocytes (TILs) of HCC patients. Our data showed that compared with PBLs, LAG-3 expression is significantly up-regulated in tumor infiltrating CD8(+) T cells of HCC patients, and a severe functional defect were detectable in tumor infiltrating HBV-specific CD8(+) T cells at the tumor site. Since LAG-3 is an inhibitory molecule that plays a down-regulatory role on T cell responses, we found the correlation between LAG-3 expression and HBV-specific CD8(+) T cells dysfunction. Taken together, these results further provide a support for the role for LAG-3 in the suppression of HBV-specific cell-mediated immunity in HCC, and also provide a contribution to the potential cancer treatment.

Acetaminophen-induced acute liver injury in HCV transgenic mice

The exact etiology of clinical cases of acute liver failure is difficult to ascertain and it is likely that various co-morbidity factors play a role. For example, epidemiological evidence suggests that coexistent hepatitis C virus (HCV) infection increased the risk of acetaminophen-induced acute liver injury, and was associated with an increased risk of progression to acute liver failure. However, little is known about possible mechanisms of enhanced acetaminophen hepatotoxicity in HCV-infected subjects. In this study, we tested a hypothesis that HCV-Tg mice may be more susceptible to acetaminophen hepatotoxicity, and also evaluated the mechanisms of acetaminophen-induced liver damage in wild type and HCV-Tg mice expressing core, E1 and E2 proteins. Male mice were treated with a single dose of acetaminophen (300 or 500 mg/kg in fed animals; or 200 mg/kg in fasted animals; i.g.) and liver and serum endpoints were evaluated at 4 and 24h after dosing. Our results suggest that in fed mice, liver toxicity in HCV-Tg mice is not markedly exaggerated as compared to the wild-type mice. In fasted mice, greater liver injury was observed in HCV-Tg mice. In fed mice dosed with 300 mg/kg acetaminophen, we observed that liver mitochondria in HCV-Tg mice exhibited signs of dysfunction showing the potential mechanism for increased susceptibility.

Telomerase-specific oncolytic adenoviral therapy for orthotopic hepatocellular carcinoma in HBx transgenic mice

The telomerase-specific replication-competent oncolytic adenovirus, Telomelysin, was developed for virus-mediated preferential lysis of tumor cells. Its selectivity is derived from a human telomerase reverse transcriptase (hTERT) promoter-driven active viral replication, which occurs in cancer cells with high telomerase activity but not in normal cells lacking such activity. Because the TERT activity is elevated in most cases of hepatocellular carcinoma (HCC), the current study aims to investigate whether Telomelysin can be used for treatment of HCC. The oncolytic effect of Telomelysin has been investigated both in vitro using cell culture and in vivo using an immunocompetent in situ orthotopic HCC model. In this model, HCC developed spontaneously in the liver of HBx transgenic mice, which is pathologically and genetically similar to human HCC. In cell culture assay, Telomelysin lyses HCC cell lines at a low multiplicity of infection (MOI), ranging 0.77-6.35 (MOI [PFU/cell]). In the orthotopic HCC model, Telomelysin showed a potent oncolytic effect on HCC but spared normal liver tissue. Dose escalation analysis identified a safety dose of 1.25 × 10(8) PFU for this model. The effect of multiple injections of Telomelysin was also evaluated in this immunocompetent HCC model. We found that the virus replicates in HCC after a second intratumoral injection despite an immune response induced by the previous injection. This preclinical study shows that Telomelysin can be used for treatment of human HCC at an appropriate dosage and that its tumor-killing activity persists after multiple injections.

Histone deacetylase inhibitor suberoylanilide hydroxamic acid suppresses the pro-oncogenic effects induced by hepatitis B virus pre-S2 mutant oncoprotein and represents a potential chemopreventive agent in high-risk chronic HBV patients

Chronic hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC). The pre-S(2) mutant large HBV surface antigen (LHBS) in type II ground glass hepatocytes (GGHs) has been recognized as an emerging viral oncoprotein; it directly interacts with the c-Jun activation domain-binding protein 1 (JAB1) and subsequently causes hyperphosphorylation of the tumor-suppressor retinoblastoma and, consequently, leads to disturbed cell cycle progression. The interaction of the pre-S(2) mutant LHBS with JAB1 could provide a potential target for chemoprevention. In this study, we found that the preneoplastic type II GGHs showed a significant decrease of the cyclin-dependent kinase inhibitor p27(Kip1), which serves as a marker for pre-S(2) mutant-JAB1 complex formation. The histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) elevated expression of the tumor-suppressor thioredoxin-binding protein 2 (TBP2), which subsequently enhanced the JAB1-TBP2 interaction and abolished the pre-S(2) mutant LHBS-induced degradation of p27(Kip1), which, in turn, recovered the normal cell cycle checkpoint. The pre-S(2) mutant LHBS-induced pro-oncogenic effects: increased cell proliferation, nuclear/cytoplasmic ratio and proliferating cell nuclear antigen expression, were all greatly ameliorated after SAHA treatments, which suggested SAHA as a promising chemopreventive agent for the pre-S(2) mutant oncoprotein-induced HCC. In conclusion, this study provides the mechanism of histone deacetylase (HDAC) inhibitor in preventing the pre-S(2) mutant-induced oncogenic phenotype. The HDAC inhibitor SAHA is therefore a potential chemopreventive agent for high-risk chronic HBV patients who may develop HCC.

Promotion of hepatocellular carcinoma by hepatitis C virus

Persistent infection with the hepatitis C virus (HCV) is a major global health problem. Around 2-3% of the world's population are chronically infected, and infected individuals are at high risk of developing steatosis, fibrosis, and liver cirrhosis. The latter is a major predisposing factor for the development of hepatocellular carcinoma (HCC). It is generally accepted that an inflammatory response triggered by persistent HCV infection leads to increased cell proliferation and fibrogenesis that in turn promotes cirrhosis and ultimately HCC development. This indirect mechanism of tumor induction would explain the long incubation period from primary HCV infection to HCC and the requirement for additional cofactors such as toxins or drugs (most notably alcohol), metabolic liver diseases, steatosis, nonalcoholic liver disease, or diabetes. With the advent of adequate cell culture systems for HCV it is, however, becoming increasingly clear that the virus also contributes directly to HCC formation. Examples are the continuous induction of stress response or the massive accumulation of intracellular lipids. Moreover, viral proteins can bind to and sequester cell cycle control factors such as the retinoblastoma protein or the tumor suppressor DDX3. Thus, HCV-associated liver cancer is most likely promoted by the combined action of long-term chronic inflammation and targeted perturbations of cellular key pathways involved in metabolic homeostasis as well as cell cycle control.

Cancer risk in patients with pyogenic liver abscess: a nationwide cohort study

BACKGROUND

There has been no large-scale population-based study on the relationship between pyogenic liver abscesses (PLA) and subsequent cancer risk.

AIM

To estimate all cancer risk following a diagnosis of PLA.

METHODS

Based on Taiwan's National Health Insurance Research Database, 1257 patients with PLA without prior cancers in the period 1996-2008 were identified and followed-up. The standard incidence ratio (SIR) of each cancer was calculated as the number of observed cancer cases arising among the PLA patients divided by the expected case number of cancer cases according to the national cancer rates.

RESULTS

Of the 1257 PLA patients identified, 598 (47.6%) had diabetes mellitus. After a median (±s.d.) follow-up of 3.33 ± 3.45 years, 186 were diagnosed with cancers, including 56 liver cancer, 22 biliary tract cancer and 40 colorectal cancer patients. Patients with PLA had a higher risk of all cancers (SIR, 3.83; 95% CI, 3.30-4.42), liver cancer (SIR, 7.87; 95% CI, 5.94-10.21), biliary tract cancer (SIR, 34.58; 95% CI, 21.67-52.36) and colorectal cancer (SIR, 5.27; 95% CI, 3.76-7.18). The highest SIRs of all cancers, liver cancer, biliary tract cancer and colorectal cancer occurred within 90 days of follow-up (360.82; 95% CI, 278.46-459.91, 257.28; 95% CI, 186.17-346.56, 1153.38; 95% CI 694.08-1801.24, and 52.63; 95% CI 25.2-96.8 respectively).

CONCLUSIONS

Pyogenic liver abscesses may herald the onset of cancer, especially hepato-biliary and colon cancer. Further surveys should be conducted for the detection of occult cancers in such patients.

Androgen pathway stimulates microRNA-216a transcription to suppress the tumor suppressor in lung cancer-1 gene in early hepatocarcinogenesis

Deregulation of microRNAs (miRNAs) is common in advanced human hepatocellular carcinoma (HCC); however, the ones involved in early carcinogenesis have not yet been investigated. By examining the expression of 22 HCC-related miRNAs between precancerous and cancerous liver tissues, we found miR-216a and miR-224 were significantly up-regulated, starting from the precancerous stage. Furthermore, the elevation of miR-216a was mainly identified in male patients. To study this gender difference, we demonstrated that pri-miR-216a is activated transcriptionally by the androgen pathway in a ligand-dependent manner and is further enhanced by the hepatitis B virus X protein. The transcription initiation site for pri-miR-216a was delineated, and one putative androgen-responsive element site was identified within its promoter region. Mutation of this site abolished the elevation of pri-miR-216a by the androgen pathway. One target of miR-216a was shown to be the tumor suppressor in lung cancer-1 gene (TSLC1) messenger RNA (mRNA) through the three target sites at its 3' untranslated region. Finally, the androgen receptor level increased in male liver tissues during hepatocarcinogenesis, starting from the precancerous stage, with a concomitant elevation of miR-216a but a decrease of TSLC1.

CONCLUSION

The current study discovered the up-regulation of miRNA-216a by the androgen pathway and a subsequent suppression of TSLC1 as a new mechanism for the androgen pathway in early hepatocarcinogenesis.

Alcoholism worsens the survival of patients with hepatitis B virus and C virus-related hepatocellular carcinoma

BACKGROUND/AIMS

Chronic hepatitis B and hepatitis C virus (HBV, HCV) infection and alcoholism are common etiologies for hepatocellular carcinoma (HCC). The characteristics and impact of alcoholism and/or HCV/HBV infection on HBV- and HCV-related HCC, respectively, are investigated in this study.

METHODS

A total of 1,888 patients were retrospectively investigated and categorized into six groups, HBV only (n = 977), HBV with alcoholism (n = 197), HCV only (n = 544), HCV with alcoholism (n = 67), dual HBV and HCV (n = 82), and dual virus with alcoholism (n = 21), to examine their interactions on the outcome.

RESULTS

Compared to their counterparts, alcoholic patients coinfected with HBV and/or HCV tended to be younger, had higher male-to-female ratios, worse performance status, more severe liver cirrhosis, advanced cancer staging, and tumor burden than patients without alcoholism. In survival analysis, patients with HBV with alcoholism had a significantly decreased survival than the HBV-only group (p = 0.001). A shortened survival was also observed in HCV with alcoholism group compared to the HCV-only group (p = 0.011). Dual virus infection with alcoholism did not significantly worsen the survival compared to the dual virus infection group. In the Cox proportional hazards model, HBV with alcoholism group [risk ratio (RR) 1.299, p = 0.032] and HCV with alcoholism (RR 1.523, p = 0.025) group were independent predictors associated with decreased survival compared to their counterpart of HBV- and HCV-only groups.

CONCLUSIONS

Alcoholism in patients with HBV or HCV infection is characterized by early development of HCC with advanced cirrhosis and cancer staging at diagnosis. Alcoholism independently predicts an increased risk of mortality in patients with HBV- and HCV-related HCC.

E2F-1 is overexpressed and pro-apoptotic in human hepatocellular carcinoma

E2F-1 is a transcription factor involved in DNA synthesis and repair, cell proliferation, and apoptosis. Hyposphorylated pRb represses E2F-1 action in early G1 phase, while in late G1, pRb hyperphosphorylation leads to E2F-1 release and activation. In vitro studies have shown that E2F-1 may act either as oncogene or as tumor suppressor gene. We evaluated immunohistochemical expression of E2F-1 protein in chronic viral liver disease and hepatocellular carcinoma (HCC) and correlated this with clinicopathological parameters, cell proliferation, apoptosis, and the expression of E2F-1-regulators, pRb, and phospho-pRb (Ser795). In liver biopsies from 30 patients with chronic viral hepatitis, including 22 with cirrhosis without HCC, and 57 with cirrhosis with HCC, E2F-1 expression was assessed by immunohistochemistry. In chronic hepatitis and cirrhosis, hepatocytes and cholangiocytes demonstrated mild cytoplasmic and/or nuclear membrane E2F-1 immunostaining. In contrast, all HCC (100 %) showed strong nuclear E2F-1 immunostaining, with or without membrane accentuation, while a minority demonstrated additional moderate cytoplasmic immunostaining. Abnormally low pRb and phospho-pRb expression was seen in 70 % and 67.9 % of HCC, respectively. In HCC, nuclear E2F-1 expression was inversely correlated with phospho-pRb expression (p = 0.001) and positively related to tumor apoptotic index (p = 0.025). No significant correlation was found between E2F-1 expression and patient demographics, HCC etiology, tumor grade, pRb, p53 expression, or cell proliferation. In conclusion, we show that the increased expression of E2F-1 protein in human HCC is correlated with enhanced tumor cell apoptosis supporting a pro-apoptotic role of E2F-1 in human HCC.

The ambiguity in immunology

In the present article, we discuss the various ambiguous aspects of the immune system that render this complex biological network so highly flexible and able to defend the host from different external invaders. This ambiguity stems mainly from the property of the immune system to be both protective and harmful. Immunity cannot be fully protective without producing a certain degree of damage (immunopathology) to the host. The balance between protection and tissue damage is, therefore, critical for the establishment of immune homeostasis and protection. In this review, we will consider as ambiguous, various immunological tactics including: (a) the opposing functions driving immune responses, immune-regulation, and contra-regulation, as well as (b) the phenomenon of chronic immune activation as a result of a continuous cross-presentation of apoptotic T cells by dendritic cells. All these plans participate principally to maintain a state of chronic low-level inflammation during persisting infections, and ultimately to favor the species survival.

Younger hepatocellular carcinoma patients have better prognosis after percutaneous radiofrequency ablation therapy

GOALS

To evaluate the impact of age on the prognosis of patients with hepatocellular carcinoma (HCC) undergoing percutaneous radiofrequency ablation (RFA).

BACKGROUND

Whether age plays an important role in the outcomes of HCC after RFA remains controversial.

STUDY

Two hundred fifty-eight consecutive treatment naive HCC patients who underwent RFA were enrolled. Patients aged ≤ 65 years (n = 100) were defined as the younger group and those aged > 65 years (n = 158) were the elderly group. Their clinicopathologic features and prognosis were compared.

RESULTS

Younger patients had a higher male-to-female ratio, higher prevalence of hepatitis B virus, and smaller tumor size than elder patients. After median follow-up of 28.5 ± 18.7 months, 45 patients died. The cumulative 5-year survival rates were 81.3% and 65.4% in younger and elder HCC patients, respectively (P = 0.008). Multivariate analysis disclosed that age > 65 years, serum albumin level ≤ 3.7 g/dL, prothrombin time international normalized ratio > 1.1, α-fetoprotein (AFP) > 20 ng/mL, and no antiviral therapy after RFA were independent risk factors associated with poor overall survival. Besides, there were 163 patients with tumor recurrence after RFA. Multivariate analysis showed that age > 65 years, platelet count ≤ 10/mm, AFP > 20 ng/mL, multinodularity, and tumor size > 2 cm were the independent risk factors predicting recurrence.

CONCLUSIONS

Both liver functional reserve (serum albumin level, prothrombin time international normalized ratio, platelet count, and antiviral therapy) and tumor factors (tumor size, number, and AFP level) were crucial in determining post-RFA prognosis in HCC patients. Moreover, younger HCC patients have better overall survival and lower recurrence rate after RFA compared with elder patients.

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.

Hepatitis C Virus nonstructural 5A protein inhibits lipopolysaccharide-mediated apoptosis of hepatocytes by decreasing expression of Toll-like receptor 4

BACKGROUND

Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) has been shown to modulate multiple cellular processes, including apoptosis. The aim of this study was to assess the effects of HCV NS5A on apoptosis induced by Toll-like receptor (TLR) 4 ligand, lipopolysaccharide (LPS).

METHODS

Apoptotic responses to TLR4 ligands and the expression of molecules involved in TLR signaling pathways in human hepatocytes were examined with or without expression of HCV NS5A.

RESULTS

HCV NS5A protected HepG2 hepatocytes against LPS-induced apoptosis, an effect linked to reduced TLR4 expression. A similar downregulation of TLR4 expression was observed in Huh-7-expressing genotype 1b and 2a. In agreement with these findings, NS5A inhibited the expression of numerous genes encoding for molecules involved in TLR4 signaling, such as CD14, MD-2, myeloid differentiation primary response gene 88, interferon regulatory factor 3, and nuclear factor-κB2. Consistent with a conferred prosurvival advantage, NS5A diminished the poly(adenosine diphosphate-ribose) polymerase cleavage and the activation of caspases 3, 7, 8, and 9 and increased the expression of anti-apoptotic molecules Bcl-2 and c-FLIP.

CONCLUSIONS

HCV NS5A downregulates TLR4 signaling and LPS-induced apoptotic pathways in human hepatocytes, suggesting that disruption of TLR4-mediated apoptosis may play a role in the pathogenesis of HCV infection.

A comparison of prognosis between patients with hepatitis B and C virus-related hepatocellular carcinoma undergoing resection surgery

BACKGROUND

The impact of viral factors on the prognosis of hepatocellular carcinoma (HCC) remains controversial because of heterogeneous populations included in previous reports. This study aims to compare clinicopathologic features and prognoses between patients with hepatitis B- and hepatitis C-related HCC who underwent resection surgery.

METHODS

We enrolled 609 patients with positive serum hepatitis B virus (HBV) surface antigen (HBsAg) and negative serum antibody against hepatitis C virus (anti-HCV) as the B-HCC group and 206 patients with negative serum HBsAg and positive anti-HCV as the C-HCC group. The overall survival rates and cumulative recurrence rates were compared between these two groups.

RESULTS

B-HCC patients were significantly younger, predominantly male, had better liver functional reserve, but more advanced tumor stage than C-HCC patients. After a median follow-up period of 40.6 months, 427 patients had died. Furthermore, 501 patients had tumor recurrence after surgery. The postoperative overall survival rates (p = 0.640) and recurrence rates (p = 0.387) of the two groups were comparable. However, the overall survival rate was higher in the B-HCC group than in the C-HCC group in the cases of transplantable HCC (p = 0.021) and Barcelona-Clinic Liver Cancer stage A HCC (p = 0.040).

CONCLUSIONS

Viral etiologies were not apparent in determining outcomes of HCC patients who underwent resection due to heterogeneous studied populations. In early-stage HCC, B-HCC patients had better outcomes than C-HCC patients did because of better liver reserve and less hepatic inflammation.

miR-338-3p suppresses invasion of liver cancer cell by targeting smoothened

MicroRNAs are involved in human carcinogenesis and cancer progression. Our previous study has shown that loss of miR-338-3p expression is associated with clinical aggressiveness of hepatocellular carcinoma (HCC). However, the exact roles and mechanisms of miR-338-3p remain unknown in HCC. To determine whether and how miR-338-3p influences liver cancer cell invasion, we studied miR-338-3p in the liver cancer cell lines, and we found that miR-338-3p is down-regulated in treated cells. Forced expression of miR-338-3p in SK-HEP-1 cells suppressed cell migration and invasion, whereas inhibition of miR-338-3p in SMMC-7721 cells induced cell migration and invasion. Furthermore, smoothened (SMO) was identified as a direct target of miR-338-3p. Forced expression of miR-338-3p down-regulated SMO and matrix metalloproteinase (MMP)-9 expression, but inhibition of miR-338-3p up-regulated SMO and MMP9 expression. However, small interfering RNA targeted SMO reversed the effects induced by blockade of miR-338-3p. SMO and MMP9 were overexpressed and associated with invasion and metastasis in HCC tissues. These data indicate that miR-338-3p suppresses cell invasion by targeting the smoothened gene in liver cancer in vitro and miR-338-3p might be a novel potential strategy for liver cancer treatment.

Risk Factors for Intrahepatic Recurrence after Resection of Hepatocellular Carcinomas in Patients with Hepatitis B Virus Infection

PURPOSE

Although surgical resection offers patients with HCC the chance of a cure, the post-resection tumor recurrence rate is high, with reported cumulative 5-year tumor recurrence rates ranging from 40 to 70%. The objective of this study was to investigate risk factors for intrahepatic recurrence after resection of hepatocellular carcinoma, especially in patients with hepatitis B virus infection.

METHODS

Between January 1999 and December 2003, 59 patients in our Hospital with hepatitis B virus infection underwent liver resection for hepatocellular carcinoma. Clinical, biological, and histopathological characteristics of these patients were collected and tested for their prognostic significance using a Chi-square test and a Student's t-test. Time to recurrence and survival rate were analyzed by the Kaplan-Meier method.

RESULTS

Of the 59 patients who underwent liver resection, 24 (41%) experienced intrahepatic recurrence. The 1-, 3-, and 5-year overall survival rates of total enrolled patients were 83%, 63%, and 42%, respectively. The 1-, 3-, and 5-year overall survival rates after recurrence were 87%, 52%, and 20%, respectively. The risk factors for early recurrence were elevated serum aspartate aminotransferase (AST) level (p=0.044) and larger tumor size (p=0.049). For late recurrence, greater tumor size (p=0.039) was the only risk factor.

CONCLUSION

Tumor size and serum aspartate aminotransferase are risk factors of intrahepatic recurrence after resection of HCC in patients with chronic hepatitis B virus infection. This finding indicates that patients who have these risk factors should be under more careful supervision and have more aggressive follow-up.

Hepatitis C virus and alcohol: same mitotic targets but different signaling pathways

BACKGROUND & AIMS

Chromosomal aberrations are frequently observed in hepatitis C virus (HCV)- and alcohol-related hepatocellular carcinomas (HCCs). The mechanisms by which chromosomal aberrations occur during hepatocarcinogenesis are still unknown. However, these aberrations are considered to be the result of deregulation of some mitotic proteins, including the alteration of Cyclin B1 and Aurora kinase A expression, and the phosphorylation of gamma-tubulin. Our study aims at investigating changes in expression of the above mentioned proteins and related intracellular pathways, in in vitro and in vivo models of both HCV- and alcohol- dependent HCCs.

METHODS

In this study, the molecular defects and the mechanisms involved in deregulation of the mitotic machinery were analyzed in human hepatoma cells, expressing HCV proteins treated or not with ethanol, and in liver tissues from control subjects (n=10) and patients with HCV- (n=10) or alcohol-related (n=10) HCCs.

RESULTS

Expression of Cyclin B1, Aurora kinase A, and tyrosine-phosphorylated gamma-tubulin was analyzed in models reproducing HCV infection and ethanol treatment in HCC cells. Interestingly, HCV and alcohol increased the expression of Cyclin B, Aurora kinase A, and tyrosine-phosphorylated gamma-tubulin also in tissues from patients with HCV- or alcohol-related HCCs. In vitro models suggest that HCV requires the expression of PKR (RNA-activated protein kinase), as well as JNK (c-Jun N-terminal kinase) and p38MAPK (p38 mitogen-activated protein kinase) proteins; while, ethanol bypasses all these pathways.

CONCLUSIONS

Our results support the idea that HCV and alcohol may promote oncogenesis by acting through the same mitotic proteins, but via different signaling pathways.

Recent advances in the research of hepatitis B virus-related hepatocellular carcinoma: epidemiologic and molecular biological aspects

Hepatocellular carcinoma (HCC) is one of the commonest cancers worldwide, and more than half of HCC patients are attributable to persistent hepatitis B virus (HBV) infections. The best and cheapest way to prevent HBV-related HCC is the implementation of universal hepatitis B vaccination program, by which the incidence rates of childhood HCC have been reduced in several countries, including Taiwan. However, there are still hundreds of millions of HBV carriers in the world that remain a global health challenge. In the past decade, several hepatitis B viral factors such as serum HBV DNA level, genotype, and naturally occurring mutants have already been identified to influence liver disease progression and HCC development in HBV carriers. Several easy-to-use scoring systems based on clinical and viral characteristics are developed to predict HCC risk in HBV carriers and may facilitate the communication between practicing physicians and patients in clinical practice. In addition, the role of nonviral factors in HBV-related HCC has also been increasingly recognized. On the basis of these emerging data, it is recommended that HBV carriers should be screened and monitored to identify those who have a higher risk of liver disease progression and require antiviral treatments. Regarding the molecular carcinogenesis of HCC development, despite some progress in the research of cell biology of HCC in the past decade, aberrant pathways involved in maintaining HCC phenotypes have not been completely elucidated yet. In the future, through comprehensive and integrated approaches to analyze the genomes of human HCC, novel target genes or pathways critically involved in hepatocarcinogenesis may hopefully be identified.