Primary hepatocellular carcinoma

Characterization of CD40+ leukocytes in flounder (Paralichthys olivaceus) and its response after Hirame novirhabdovirus infection and immunization

CD40 is a crucial signal mediating factor in T-dependent B cell responses and involved in many aspects of cellular and humoral immunity. In this paper, recombinant protein of CD40 in flounder (Paralichthys olivaceus) and its antibodies (Abs) were produced, native CD40 molecules in flounder tissues were identified, then the CD40⁺ leukocytes in T/B lymphocytes were characterized, and the variations of CD40⁺ leukocytes in flounder after Hirame novirhabdovirus (HIRRV) infection and immunization were investigated, respectively. The results showed that the Abs could specifically recognize native flounder CD40 molecule at 32 kDa. The proportions of CD40⁺ leukocytes were varied by flounder tissues. CD40⁺/IgM⁺ B lymphocytes, CD40⁺/CD4-1⁺ T lymphocytes, CD40⁺/CD4-2⁺ T lymphocytes and CD40⁺/CD8⁺ T lymphocytes in peripheral blood leukocytes (PBLs) were 1.18 ± 0.27%, 0.69 ± 0.17%, 0.75 ± 0.14% and 0.25 ± 0.14%; were 2.80 ± 0.32%, 0.71 ± 0.19%, 0.88 ± 0.23% and 0.33 ± 0.17% in spleen; 4.11 ± 0.47%, 0.92 ± 0.18%, 1.09 ± 0.17% and 0.9 ± 0.17% in head kidney; 1.92 ± 0.39%, 1.02 ± 0.23%, 1.33 ± 0.38% and 0.67 ± 0.24% in intestine; 1.24 ± 0.36%, 1.21 ± 0.24%, 1.70 ± 0.3% and 0.97 ± 0.21% in gill, respectively. The percentages of CD40⁺ leukocytes in PBLs were significantly increased in both HIRRV infection and immunization groups, and reached their peak levels at 3rd day with 5.70 ± 0.16% and 6.40 ± 0.13%, respectively. Concluded with our previous study, these data first reported that CD40 molecules were expressed on both B and T lymphocytes in teleost, and had a coordination with T and B lymphocytes in immune responses.

Identification and characterization of CD40 from humphead snapper (Lutjanus sanguineus)

CD40 is known as "master switch" in immune response to pathogen infection in mammals. However, limited information of CD40 is known in lower vertebrates. In this study, a novel CD40 homolog (Ls-CD40) was cloned and characterized from humphead snapper, Lutjanus sanguineus. The Ls-CD40 cDNA composed of 2073 bp with a 69 bp of 5'-UTR, a 1020 bp of 3'-UTR and an open reading frame (ORF) of 984 bp, encoding 327 amino acid residues. Sequence analysis showed that Ls-CD40 contained a single peptide, a transmembrane domain and four cysteine-rich domains. The deduced amino acid sequence of Ls-CD40 shared 40%-53% identities with other known fish CD40. The qRT-PCR showed that Ls-CD40 gene expressed in all examined tissues with the most abundant in spleen and lowest level in intestine. After V. harveyi and poly I:C stimulation, the expression of CD40 were significantly induced in spleen. Moreover, Ls-CD40 could interact with Ls-TRAF3 in vitro. These data indicate that Ls-CD40 might play a regulatory role in immune response of L. sanguineus.

Hepatic vena cava syndrome: New concept of pathogenesis

Hepatic vena cava syndrome, also known as membranous obstruction of inferior vena cava (IVC), was considered a rare congenital disease and classified under Budd-Chiari syndrome. It is now recognized as a bacterial infection-induced disease related to poor hygiene. Localized thrombophlebitis of the IVC at the site close to hepatic vein outlets is the initial lesion which converts on resolution into stenosis or complete obstruction, the circulatory equilibrium being maintained by development of cavo-caval collateral anastomosis. These changes persist for the rest of the patient's life. The patient remains asymptomatic for a variable period until acute exacerbations occur, precipitated by bacterial infection, resulting in deposition of thrombi at the site of the lesion and endophlebitis in intrahepatic veins. Large thrombus close to hepatic vein outlets results in ascites from hepatic venous outflow obstruction, which is followed by development of venocentric cirrhosis. Endophlebitis of intrahepatic veins results in ischemic liver damage and development of segmental stenosis or membrane. Acute exacerbations are recognized clinically as intermittent jaundice and/or elevation of aminotransferase or ascites associated with neutrophil leukocytosis and elevation of C-reactive protein; sonologically, they are recognized as the presence of thrombi of different ages in IVC and thrombosis of intrahepatic veins. Development of liver cirrhosis and hepatocellular carcinoma is related to severity or frequency of acute exacerbations and not to duration or type of caval obstruction. Hepatic vena cava syndrome is a common co-morbid condition with other liver diseases in developing countries and it should be considered in differential diagnosis in patient with intermittent elevation serum bilirubin and or aminotransferase or development of ascites and cirrhosis.

Hepatic resection for predominantly large size hepatocellular carcinoma: Early and long-term results from a tertiary care center in India

BACKGROUND AND AIM

There are no large series on hepatic resection for hepatocellular carcinoma (HCC) from India. We present the results of consecutive patients of HCC treated with hepatic resection at a tertiary care center in India.

METHODS

The records of all patients who underwent hepatic resection for HCC in the Department of Gastrointestinal Surgery, All India Institute of Medical Sciences (New Delhi), were reviewed. The relevant perioperative and follow up data were extracted from a prospectively maintained database.

RESULTS

Between January 1987 and December 2013, 81 patients [71 males; mean age: 49.2 ± 15.6 years] underwent hepatic resection for HCC. Of these, 23 (28 %) were cirrhotic and 36 (49 %) had hepatitis B. Hepatitis B was significantly more common in cirrhotic (77 % vs. 37 %; p = 0.001). Most patients had locally advanced disease at presentation [tumor size ≥10 cm in 61 (75 %); vascular tumor thrombus in 10 (12 %)]. Anatomical resection was done in 61 (75 %) including 56 major hepatic resections (≥3 segments). Overall in-hospital mortality was 13 (16 %) [cirrhotic 5 (22 %) vs. noncirrhotic 8 (14 %), p = 0.503]. Grade III-V complications (modified Clavien-Dindo classification) occurred in 25 (31 %) patients (cirrhotic 48 % vs. noncirrhotic 24 %; p = 0.037). Follow up information was available for 51 (75 %) patients. The median time to recurrence was 12 months, and most (86 %) occurred within 1 year. The recurrence-free survival at 1, 3, and 5 years was 48 %, 40 %, and 36 %, respectively. Positive resection margin and vascular invasion were significantly associated with very poor prognosis.

CONCLUSION

Majority of Indian HCC patients present with locally advanced disease. Despite this, surgical resection provides a chance for long-term recurrence-free survival in a third of them.

Serum Dickkopf-1 as a Biomarker for the Diagnosis of Hepatocellular Carcinoma

PURPOSE

Dickkopf-1 (DKK-1) is a Wnt/β-catenin signaling pathway inhibitor. We investigated whether DKK-1 is related to progression in hepatocellular carcinoma (HCC) cells and HCC patients.

MATERIALS AND METHODS

In vitro reverse-transcription polymerase chain reaction (RT-PCR), wound healing assays, invasion assays, and ELISAs of patient serum samples were employed. The diagnostic accuracy of the serum DKK-1 ELISA was assessed using receiver operating characteristic (ROC) curves and area under ROC (AUC) analyses.

RESULTS

RT-PCR showed high DKK-1 expression in Hep3B and low in 293 cells. Similarly, the secreted DKK-1 concentration in the culture media was high in Hep3B and low in 293 cells. Wound healing and invasion assays using 293, Huh7, and Hep3B cells showed that DKK-1 overexpression promoted cell migration and invasion, whereas DKK-1 knock-down inhibited them. When serum DKK-1 levels were assessed in 370 participants (217 with HCC and 153 without), it was significantly higher in HCC patients than in control groups (median 1.48 ng/mL vs. 0.90 ng/mL, p<0.001). The optimum DKK-1 cutoff level was 1.01 ng/mL (AUC=0.829; sensitivity 90.7%; specificity 62.0%). Although DKK-1 had a higher AUC than alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) (AUC=0.829 vs. 0.794 and 0.815, respectively), they were statistically similar (all p>0.05). When three biomarkers were combined (DKK-1 plus AFP plus DCP), they showed significantly higher AUC (AUC=0.952) than single marker, DKK-1 plus AFP, or DKK-1 plus DCP (all p<0.001).

CONCLUSION

DKK-1 might be a key regulator in HCC progression and a potential therapeutic target in HCC. Serum DKK-1 could complement the diagnostic accuracy of AFP and DCP.

Harnessing the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated Cas9 system to disrupt the hepatitis B virus

The current therapies to treat hepatitis B virus (HBV) infection are limited. Recently, clustered regularly interspaced short palindromic repeat (CRISPR) systems, originally identified in bacteria and archaea, have been found to consist of an RNA-based adaptive immune system that degrades complimentary sequences of invading plasmids and viruses. Here, we studied the effects of the CRISPR/CRISPR-associated Cas9 system that was targeted to the surface antigen (HBsAg)-encoding region of HBV, both in a cell culture system and in vivo. The HBsAg levels in the media of the cells and in the sera of mice were analyzed by a quantitative enzyme-linked immunosorbent assay. The HBV DNA levels were assessed by quantitative PCR and HBsAg expression in mouse livers was assessed by an immunohistochemical assay. The amount of HBsAg secreted in the cell culture and mouse serum was reduced by CRISPR/Cas9 treatment. Immunohistochemistry analyses showed almost no HBsAg-positive cells in the liver tissue of CRISPR/Cas9-S1+X3-treated mice. The CRISPR/Cas9 system efficiently produced mutations in HBV DNA. Thus, CRISPR/Cas9 inhibits HBV replication and expression in vitro and in vivo and may constitute a new therapeutic strategy for HBV infection.

Profile of hepatocellular carcinoma in a tertiary care hospital in Punjab in northern India

PURPOSE/AIM

Hepatocellular carcinoma (HCC) is a major cause of morbidity and mortality in all parts of the world. We analyzed the clinical presentation, etiology, and tumor characteristics of HCC presenting to our hospital.

METHODS

All patients diagnosed to have HCC from September 2007 to August 2010 were prospectively enrolled. HCC was diagnosed according to EASL criteria-USG/CT/MRI of the abdomen and/or serum alpha-fetoprotein and/or histology (where indicated). Detailed clinical and laboratory parameters were noted. Barcelona Clinic Liver Cancer (BCLC) staging was done.

RESULTS

One hundred and twenty-eight patients (22 females, mean ± SD; age, 49.8 ± 10.2 years) were diagnosed to have HCC. Underlying cirrhosis was present in 99.2 %. Hepatitis C virus infection, alone (21.9 %) or with alcohol (22.9 %) was the most common etiological factor, followed by alcohol alone; 33.6 % of the patients had more than one etiological factor. Most patients (83.5 %) presented with features of decompensated cirrhosis. HCC leading to decompensation of cirrhosis was the first presentation of the liver disease in nearly one third of the cases. Serum alpha-fetoprotein was >200 ng/mL in 67.2 % of the patients, while it was normal in 18.7 % of the patients. The mean ± SD size of HCC was 5.3 ± 2.9 cm. HCC was multicentric in 57 %, and portal vein thrombosis was present in 34.4 %. About 66 % of the patients belonged to BCLC stage C or D.

CONCLUSIONS

Hepatitis C virus infection was the most common cause of HCC in Punjab. One-third of the patients had multiple etiological factors and almost all had underlying cirrhosis and presented at advanced stage.

Short hairpin RNAs with a 2- or 3-base mismatch inhibit HBV expression and replication in HepG2 cells

PURPOSE

To assess the functions of mismatched short hairpin RNAs (shRNAs) that inhibit replication and the expression of hepatitis B virus (HBV), two shRNAs possessing a 2- or 3-base mismatch that targeted HBV were studied.

METHODS

shRNAs and pHY106-HBV were cotransfected into HepG2 cells. The culture supernatants were collected and used in hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) assays. The levels of HBsAg and HBcAg mRNA were detected by reverse-transcriptase PCR (RT-PCR). HBV DNA replication intermediates were extracted for Southern blot hybridization.

RESULTS

The results demonstrate that mismatched shRNA-458 and shRNA-635 can significantly inhibit HBsAg and HBeAg protein expression, and the maximal inhibition ratio for both proteins was found at 72 h after cotransfection: 80 and 50 %, respectively. Similar inhibitory effects were found on HBsAg and HBcAg mRNA levels and HBV DNA replication intermediates at 72 h after cotransfection, and the inhibition ratio was found to be approximately 70 and 90 %, respectively.

CONCLUSIONS

Despite the 2- or 3-base mismatch between the shRNAs and the HBV target sequences, shRNA-458 and shRNA-635 exerted a significant inhibitory effect on HBsAg and HBeAg expression and HBV replication. This indicates that mismatched shRNAs could be a promising therapy for HBV.

Necrotic hepatocellular carcinoma occurring within an inflammatory pseudotumor-like nodule

Hepatocellular carcinoma (HCC) and inflammatory pseudotumor of the liver (IPL) are often difficult to differentiate before surgery. To date, colocalization of IPL and HCC has not been reported. We experienced a case of necrotic HCC surrounded by IPL-like tissue. The raised levels of alpha-fetoprotein and PIVKA-II declined to within the normal ranges after resection of the tumor. The IPL-like nodule most likely developed as a process of an inflammatory reaction such as abscess formation after the spontaneous destruction of the HCC. Our case is a warning that the presence of a 'pseudotumor' does not rule out the possible simultaneous presence of carcinoma.

Multi-stage delivery nano-particle systems for therapeutic applications

BACKGROUND

The daunting task for drug molecules to reach pathological lesions has fueled rapid advances in Nanomedicine. The progressive evolution of nanovectors has led to the development of multi-stage delivery systems aimed at overcoming the numerous obstacles encountered by nanovectors on their journey to the target site.

SCOPE OF REVIEW

This review summarizes major findings with respect to silicon-based drug delivery vectors for cancer therapeutics and imaging. Based on rational design, well-established silicon technologies have been adapted for the fabrication of nanovectors with specific shapes, sizes, and porosities. These vectors are part of a multi-stage delivery system that contains multiple nano-components, each designed to achieve a specific task with the common goal of site-directed delivery of therapeutics.

MAJOR CONCLUSIONS

Quasi-hemispherical and discoidal silicon microparticles are superior to spherical particles with respect to margination in the blood, with particles of different shapes and sizes having unique distributions in vivo. Cellular adhesion and internalization of silicon microparticles is influenced by microparticle shape and surface charge, with the latter dictating binding of serum opsonins. Based on in vitro cell studies, the internalization of porous silicon microparticles by endothelial cells and macrophages is compatible with cellular morphology, intracellular trafficking, mitosis, cell cycle progression, cytokine release, and cell viability. In vivo studies support superior therapeutic efficacy of liposomal encapsulated siRNA when delivered in multi-stage systems compared to free nanoparticles. This article is part of a Special Issue entitled Nanotechnologies - Emerging Applications in Biomedicine.

Aflatoxin B1 albumin adducts in plasma and aflatoxin M1 in urine are associated with plasma concentrations of vitamins A and E

BACKGROUND

Although aflatoxin exposure has been associated with micronutrient deficiency in animals, there are few investigations on the effects of aflatoxin exposure on micronutrient metabolism in humans.

OBJECTIVE

To examine the relationship between aflatoxin B1 (AFB1) albumin adducts (AF-ALB) in plasma and the aflatoxin M1 (AFM1) metabolite in urine and plasma concentrations of retinol (vitamin A) and alpha-tocopherol (vitamin E) in Ghanaians.

METHODS

A cross-sectional study of 147 adult participants was conducted. Blood and urine samples were tested for aflatoxin and vitamins A and E levels.

RESULTS

Multivariable analysis showed that participants with high AF-ALB (>or=0.80 pmol/mg albumin) had increased odds of having vitamin A deficiency compared to those with lower AF-ALB [Odds Ratio (OR)=2.61; CI=1.03-6.58; p=0.04]. Participants with high AF-ALB also showed increased odds of having vitamin E deficiency but this was not statistically significant (OR=2.4; CI=0.96-6.05; p=0.06). Conversely, those with higher AFM1 values had a statistically nonsignificant reduced odds of having vitamin A deficiency (OR=0.31; CI=0.09-1.02; p=0.05) and a statistically significant reduced odds of having vitamin E deficiency (OR=0.31; CI=0.10-0.97; p=0.04). Participants with high AF-ALB or high AFM1 (>or=437.95 pg/dL creatinine) were almost 6 times more likely to be hepatitis B virus surface antigen (HBsAg)-positive (OR=5.88; CI=1.71-20.14; p=0.005) and (OR=5.84; CI=1.15-29.54; p=0.03) respectively.

CONCLUSIONS

These data indicate that aflatoxin may modify plasma micronutrient status. Thus, preventing aflatoxin exposure may reduce vitamin A and E deficiencies.

Liver cirrhosis and hepatocellular carcinoma in hepatic vena cava disease, a liver disease caused by obstruction of inferior vena cava

PURPOSE

Hepatic vena cava disease (HVD), a form of Budd-Chiari syndrome, is caused by the obstruction of hepatic portion of the inferior vena cava. It is a chronic disease characterized by the development of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). As HVD occurred in areas with high incidence of hepatitis B virus (HBV) infection and some patients tested HBsAg positive, it was thought to be the cause of LC and HCC. To assess the pathogenesis of LC or HCC in HVD, a long-term follow-up study was done.

METHOD

Fifty-six patients with HVD diagnosed by ultrasound (US) and confirmed by cavography in 31 and liver biopsy in 34 were followed up for an average of 14.8 +/- 9 years. The occurrence of LC was diagnosed by US and/or liver biopsy and that of HCC by US, elevated level of alpha-fetoprotein, and liver biopsy or fine-needle aspiration cytology, or computed tomographic scan. Other risk factors for LC/HCC such as alcohol use and HBV and hepatitis C virus (HCV) infections were assayed.

RESULTS

Forty-four (78.5%) and 6 (10.7%) patients developed cirrhosis and HCC, respectively. LC/HCC occurred more frequently among those who had severe or frequent acute exacerbations (P = 0.017), but it was not related to alcohol use or HBV and HCV infections.

CONCLUSION

HVD is independent risk factors for LC and HCC. Severe and/or recurrent loss of hepatocytes caused by hepatic venous outflow obstruction and/or thrombotic obstruction of small radicals of hepatic and portal veins that occurred during acute exacerbations was considered important in the pathogenesis of LC and HCC in HVD.

Multifunctional micellar nanomedicine for cancer therapy

Polymeric micelles are supramolecular, core-shell nanoparticles that offer considerable advantages for cancer diagnosis and therapy. Their relatively small size (10-100 nm), ability to solubilize hydrophobic drugs as well as imaging agents, and improved pharmacokinetics provide a useful bioengineering platform for cancer applications. Several polymeric micelle formulations are currently undergoing phase I/II clinical trials, which have shown improved antitumor efficacy and reduced systemic toxicity. This minireview will focus on recent advancements in the multifunctional design of micellar nanomedicine with tumor targeting, stimulated drug release, and cancer imaging capabilities. Such functionalization strategies result in enhanced micellar accumulation at tumor sites, higher drug bioavailability, as well as improved tumor diagnosis and visualization of therapy. Ultimately, integrated nanotherapeutic systems (e.g., theranostic nanomedicine) may prove essential to address the challenges of tumor heterogeneity and adaptive resistance to achieve efficacious treatment of cancer.

siRNA pool targeting different sites of human hepatitis B surface antigen efficiently inhibits HBV infection

The main objective was to determine whether a pool of small interfering RNAs (siRNAs) targeting different regions of hepatitis B virus surface antigen (HBsAg) efficiently inhibits hepatitis B virus (HBV) infection. siRNAs targeting different regions of HBsAg were transfected into HBV-producing HepG2.2.15 cells and at 72 h post-transfection, the culture medium was collected for ELISA to determine HBsAg, while total RNA was isolated from the cells for real-time PCR. Three siRNA sequences that efficiently inhibited HBV infection were converted into small hairpin RNAs (shRNAs) and then cloned into a single plasmid psiSTRIKE driven by a single U6 promoter. These shRNA expressing plasmids were tested for HBsAg gene silencing in HepG2.2.15 cells. A pool of siRNAs targeting HBsAg efficiently inhibited HBV replication and antigen expression when transfected into HepG2.2.15 cells, compared with the use of single siRNA. Similarly, the plasmid encoding three different shRNAs driven by a single U6 promoter was more effective in silencing HBsAg at DNA, mRNA and protein levels compared with the plasmid encoding single shRNA. No apoptotic change was observed in the cells when the plasmid was transfected at a dose of 0.5-2 microg/1 x 10(6) cells after complex formation with Lipofectamine LTX. Furthermore, transfection with siRNA or shRNA did not increase interferon-gamma (IFNs-gamma) release, suggesting no induction of IFN response. In conclusion, a pool of chemically synthesised siRNAs as well as the shRNA expression plasmid encoding multiple shRNAs targeting different regions of HBsAg showed high gene silencing in HepG2.2.15 cells.

RNAi for treating hepatitis B viral infection

Chronic hepatitis B virus (HBV) infection is one of the leading causes of liver cirrhosis and hepatocellular carcinoma (HCC). Current treatment strategies of HBV infection including the use of interferon (IFN)-α and nucleotide analogues such as lamivudine and adefovir have met with only partial success. Therefore, it is necessary to develop more effective antiviral therapies that can clear HBV infection with fewer side effects. RNA interference (RNAi), by which a small interfering RNA (siRNA) induces the gene silence at a post-transcriptional level, has the potential of treating HBV infection. The successful use of chemically synthesized siRNA, endogenous expression of small hairpin RNA (shRNA) or microRNA (miRNA) to silence the target gene make this technology towards a potentially rational therapeutics for HBV infection. However, several challenges including poor siRNA stability, inefficient cellular uptake, widespread biodistribution and non-specific effects need to be overcome. In this review, we discuss several strategies for improving the anti-HBV therapeutic efficacy of siRNAs, while avoiding their off-target effects and immunostimulation. There is an in-depth discussion on the (1) mechanisms of RNAi, (2) methods for siRNA/shRNA production, (3) barriers to RNAi-based therapies, and (4) delivery strategies of siRNA for treating HBV infection.

Functionalized micellar systems for cancer targeted drug delivery

Polymer micelles are rapidly becoming a powerful nanomedicine platform for cancer therapeutic applications due to their small size (10-100 nm), in vivo stability, ability to solubilize water insoluble anticancer drugs, and prolonged blood circulation times. Recent data from clinical trials with three micelle formulations have highlighted these and other pharmacokinetic advantages with reduced systemic toxicity and patient morbidity compared to conventional drug formulation. While the initial anti-tumor efficacy of these systems seems promising, a strong research impetus has been placed on micelle functionalization in order to achieve tumor targeting and site-specific drug release, with the hope of reaching a more pronounced tumor response. Hence, the purpose of this review is to draw attention to the new developments of multi-functional polymer micelles for cancer therapy with special focus on tumor targeting and controlled drug release strategies.

Treatment of hepatitis C virus infection in thalassemia

Treatment of hepatitis C virus (HCV) in the general population has improved over the last decade. Patients treated with peginterferon alfa (PegIFN) and ribavirin (RBV) combination therapy demonstrate overall 50-55% sustained viral response (SVR) with rates as high as 80% in patients with genotypes 2 and 3. Because RBV induces hemolysis and subsequently increases blood transfusion requirements, combination therapy has been considered contraindicated for hemoglobinopathies. This report reviews the response to interferon alfa and RBV (IFN/RBV) and PegIFN/RBV combination therapies in patients treated in the Northern California Comprehensive Thalassemia Center. A total of six thalassemia major patients were treated with IFN/RBV (n = 5; age: 4-38 years) or with PegIFN/RBV (n = 1; age: 26 years). Quantitative HCV RNA polymerase chain reaction and liver iron level assessment were completed. Transfusion volumes were obtained from patients' medical records. On IFN/RBV combination, four of five patients demonstrated SVR. The one patient on PegIFN/RBV showed end-treatment viral response after 6 months of therapy (genotype 3), but subsequently relapsed. Liver iron pretreatment level ranged from 0.2 to 22 mg/g dry weight, with a mean +/- SD of 7.9 +/- 7.7. Transfusion requirement increased by a median of 43.5% (range: 32-137%). Five of the six patients had liver iron measurements within 1 year following completion of treatment, with quantitative liver iron increasing in two patients by 2.5 mg/g dry weight, decreasing in two patients by 3 and 14 mg/g dry weight, and remaining unchanged in one patient. All patients were able to complete combination therapy, although dose reductions were required. Patients with thalassemia and high iron overload can obtain SVR after combination therapy with rates similar to those in the general population and without significant complications. Although transfusion requirements increased in most patients, iron burden was not necessarily increased.

Therapeutic short hairpin RNA expression in the liver: viral targets and vectors

Over 500 million people worldwide are infected with one or more different and unrelated types of human hepatitis virus. Such individuals are at a high risk of developing acute or chronic hepatic disease, and ultimately dying from sequelae. Although a vaccine is available for hepatitis A and B virus, treatment options for chronically infected patients are limited, and particularly ineffective in case of hepatitis C virus (HCV) infection. A promising new avenue currently being explored is to harness the power of RNA interference for development of an antiviral therapy. The timing to pursue this particular approach is excellent, with the first in vivo animal models for HCV infection becoming available, and the technology for liver-specific expression of short hairpin RNAs advancing at a rapid pace. Here, we critically review these important current developments, and discuss the next steps to bring this novel approach into the clinics.

Therapeutic inhibition of hepatitis B virus surface antigen expression by RNA interference

RNA interference (RNAi) mediated inhibition of virus-specific genes has emerged as a potential therapeutic strategy against virus induced diseases. Human hepatitis B virus (HBV) surface antigen (HBsAg) has proven to be a significant risk factor in HBV induced liver diseases, and an increasing number of mutations in HBsAg are known to enhance the difficulty in therapeutic interventions. The key challenge for achieving effective gene silencing in particular for the purpose of the therapeutics is primarily based on the effectiveness and specificity of the RNAi targeting sequence. To explore the therapeutic potential of RNAi on HBV induced diseases in particular resulted from aberrant or persistent expression of HBsAg, we have especially screened and identified the most potent and specific RNAi targeting sequence that directly mediated inhibition of the HBsAg expression. Using an effective DNA vector-based shRNA expression system, we have screened 10 RNAi targeting sequences (HBsAg-1 to 10) that were chosen from HBsAg coding region, in particular the major S region, and have identified four targeting sequences that could mediate sequence specific inhibition of the HBsAg expression. Among these four shRNAs, an extremely potent and highly sequence specific HBsAg-3 shRNA was found to inhibit HBsAg expression in mouse HBV model. The inhibition was not only preventive in cotransfection experiments, but also had therapeutic effect as assessed by post-treatment protocols. Moreover, this HBsAg-3 shRNA also exhibited a great potency of inhibition in transgenic mice that constitutively expressed HBsAg. These results indicate that HBsAg-3 shRNA can be considered as a powerful therapeutic agent on HBsAg induced diseases.

Review article: the changing epidemiology of hepatocellular carcinoma in Canada

The aim of this study was to examine the incidence of and mortality caused by hepatocellular carcinoma over the last 20 years in Canada, including the associated risk factors hepatitis C, diabetes and obesity. Databases from the Surveillance & Risk Assessment Division of Health Canada & Statistics Canada were analysed for trends in both age-adjusted incidence of and mortality due to hepatocellular carcinoma from 1984 to 2001. The epidemiological impact of hepatitis C, diabetes and obesity on hepatocellular carcinoma was also assessed. The incidence of hepatocellular carcinoma increased from 4.0 per 100,000 in 1984 to 5.5 in 2,000 for males, and from 1.6 per 100,000 in 1984 to 2.2 in 2,000 for females. Mortality rates showed a 48% increase in males and 39% increase in females. The incidence of hepatitis C increased sharply in 1995 and remained elevated until 2,000 with an average value of 85.4 per 100,000 in males and 45.4 per 100,000 in females. This increase is likely due to the widespread testing for hepatitis C. The prevalence of obesity and diabetes has increased in recent years and probably contributes to the increased incidence of hepatocellular carcinoma. The incidence of hepatocellular carcinoma in Canada has increased in the past 20 years and is associated with a rise in the incidence of hepatitis C, obesity and diabetes.

[Hepatitis B and C virus infection and the hepatocellular carcinoma in the East Amazon, Brazil]

In order to contribute to a better understanding of the possible role of hepatits B and C in the etiopathogenis of HCC in the East Amazon, there were studied 36 patients in Belém/PA. Serological hepatitis markers were evaluated and polymerase chain reaction assays were used to detect HBV-DNA and HCV-RNA. Alcohol abuse was observed in 33.3% and cirrhosis in 83.3%. In 88.9% of the sample, one or more hepatitis B markers were positive. Also, 8.3% those patients had anti-HCV simultaneously positive. The HBsAg serological test was positive in 58.3%; anti-HBc in 86%; anti-HBe in 85.7%; anti-HBe in 9.5%; IgM anti-HBc in 57.1%. The HBV DNA was found in 37.7% and in 65% of the HBsAg positive. The HCV RNA was detected in 8.5% and in 100% of the patients positive to anti-HCV. The AFP was above the normal value in 88.9% of patients, with levels up to 400ng/ml in 75% of them. In conclusion, hepatitis B virus infection seems to be important in the etiology of HCC and improving measures such immunization and screening in the risk population should be emphasyzed.

Fiber-modified adenoviral vector expressing the tumor necrosis factor-related apoptosis-inducing ligand gene from the human telomerase reverse transcriptase promoter induces apoptosis in human hepatocellular carcinoma cells

AIM: Because of a major resistance to chemotherapy, prognosis of hepatocellular carcinoma (HCC) is still poor. New treatments are required and gene therapy may be an option. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in multiple malignant tumors, and using adenoviral vectors has shown a targeted tumor-specific therapy. However, repeated administration of adenoviral vectors can lead to cell resistance, which may be caused by the initial coxsackie-adenovirus receptor (CAR). One technique to overcome resistance is the use of modified adenoviral vectors containing an Arg-Gly-Asp (RGD) sequence. In this study we constructed an adenoviral vector (designated Ad/TRAIL-F/RGD) with RGD-modified fibers, expressing the TRAIL gene from the human telomerase reverse transcriptase (hTERT) promoter, and evaluated its antitumor activity in HCC cell lines.

METHODS: To investigate the effects of Ad/TRAIL-F/RGD in human HCC cell lines Hep G2 and Hep 3b, cells were infected with Ad/CMV-GFP (vector control), Ad/gTRAIL (positive control), and Ad/TRAIL-F/RGD. Phosphate-buffered saline (PBS) was used as control. Cell viability was determined by proliferation assay (XTT), and apoptosis induction by fluorescence activated cell sorting (FACS).

RESULTS: Cells treated with Ad/TRAIL-F/RGD and Ad/gTRAIL showed a significantly reduced cell viability in comparison to PBS and Ad/CMV-GFP treatment in both cell lines. Whereas, treatment with PBS and Ad/CMV-GFP had no cell-killing effect. The reduced cell viability was caused by induction of apoptosis as shown by FACS analysis. The amount of apoptotic cells was similar after incubation with Ad/gTRAIL and Ad/TRAIL-F/RGD.

CONCLUSION: The new RGD modified vector Ad/TRAIL-F/RGD could become a potent therapeutic agent for the treatment of HCC, adenovirus resistant tumors, and CAR low or negative cancer cells.

Oligomer synthesis by priming deficient polymerase in hepatitis B virus core particle

Hepadnavirus DNA polymerase functions in DNA synthesis and encapsidation, and acts as a primer for minus-strand DNA synthesis. Through protein priming reaction, a short DNA oligomer synthesized from the bulge of epsilon as template is covalently attached to the Tyr residue in the terminal protein (TP) domain of DNA polymerase. Using endogenous polymerase assays and native agarose gel analysis, we detected endogenous polymerase activity in priming-deficient mutant core particles, but not in reverse transcriptase (RT) reaction- or P protein-deficient mutant core particles. In addition, priming-deficient mutant core particles incorporated radiolabeled (32)P-dATP, (32)P-TTP, and (32)P-dGTP, but not (32)P-dCTP. Our results suggest that the priming-deficient mutant P protein has the ability to synthesize oligomers (presumably nascent minus-strand DNA) in the absence of covalent linkage between TP and the first deoxynucleotide. We propose that the priming-deficient mutant may be defective in minus-strand DNA translocation to direct repeat (DR) 1 at the 3' end of pregenomic RNA (pgRNA) that leads to the elongation of minus-strand DNA.

Laparoscopic staging and tumor ablation for hepatocellular carcinoma in Child C cirrhotics evaluated for orthotopic liver transplantation

BACKGROUND

Surgical resection and liver transplantation remain the only treatments that offer cure for hepatoma, but are limited to those with early stage disease. Prelisting radiological staging is not always definitive. In this study, we sought to delineate the role of laparoscopy for clarification of staging in advanced cirrhotic patients when radiological assessment during evaluation for orthotopic liver transplants (OLTx) is equivocal.

METHODS

Over a 3-year period, 18 patients with advanced liver insufficiency being evaluated for OLTx listing underwent laparoscopic staging when the following criteria were met: (1) lesion(s) with indeterminate size/borders, (2) an indeterminate number of lesions, or (3) lesion(s) and alpha-fero protein (AFP) less than 100 ng/ml. Patients underwent exploratory laparoscopy and laparoscopic ultrasound with biopsy, with or without ablation of lesion(s).

RESULTS

Laparoscopic staging was initiated in 18 patients; four of the first six patients were converted to open procedures. Twelve patients were restaged as a result of the procedure: six down-staged and six up-staged. Stage changes were based on laparoscopic visualization of advanced disease in two, ultrasonographic clarification of tumor size/number in seven, and biopsy in three. Twelve of the 14 laparoscopic procedures included laparoscopic radiofrequency ablation while one received ethanol ablation. One patient required 2 units of red blood cells. One patient died on postoperative day 7 because of gastrointestinal bleeding. Four of the six down-staged patients underwent liver transplant, and pathological staging of the explants agreed with laparoscopic staging in all cases.

CONCLUSION

Laparoscopic staging for HCC in advanced cirrhosis can clearly characterize tumor burden when preoperative radiological assessment is equivocal.

p73β inhibits transcriptional activities of enhancer I and X promoter in hepatitis B virus more efficiently than p73α

AIM: p73, as a novel member of a family of p53-related transcription factors, shares redundant functions with p53, such as the abilities of inducing apoptosis and suppressing growth. It is well known that p53 can repress HBV expression and transcription efficiently. The aim of this paper is to investigate the transcriptional effect of p73α and p73β on hepatitis B virus (HBV) and to understand the correlation between HBV and p73.

METHODS: To construct an x-gene inactivated HBV plasmid which was cotransfected with p73α or p73β expression vectors into HepG2 cells. After transiently transfection, HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) were detected by ELISA. Viral transcripts synthesized by HBV were evaluated by Northern blotting analysis. The activities of HBV regulatory elements, including enhancer I/X promoter (ENI/Xp) and enhancer II/core promoter (ENII/Cp) were monitored by luciferase assays.

RESULTS: Both p73α and p73β could repress HBsAg and HBeAg expression by downregulating the ENI/Xp and ENII/ Cp activities. But p73β exerted stronger inhibition on the activity of ENI/Xp than p73α, resulting in much lower level of viral transcripts and the antigens expression.

CONCLUSION: p73β as a novel member of p53 family can efficiently inhibit HBV transcription mainly through downregulating the activities of the HBV ENI/Xp regulatory elements.

Hepatitis B virus X protein activates the p38 mitogen-activated protein kinase pathway in dedifferentiated hepatocytes

Hepatitis B virus X protein (pX) is implicated in hepatocarcinogenesis by an unknown mechanism. Employing a cellular model linked to pX-mediated transformation, we investigated the role of the previously reported Stat3 activation by pX in hepatocyte transformation. Our model is composed of a differentiated hepatocyte (AML12) 3pX-1 cell line that undergoes pX-dependent transformation and a dedifferentiated hepatocyte (AML12) 4pX-1 cell line that does not exhibit transformation by pX. We report that pX-dependent Stat3 activation occurs only in non-pX-transforming 4pX-1 cells and conclude that Stat3 activation is not linked to pX-mediated transformation. Maximum Stat3 transactivation requires Ser727 phosphorylation, mediated by mitogenic pathway activation. Employing dominant negative mutants and inhibitors of mitogenic pathways, we demonstrate that maximum, pX-dependent Stat3 transactivation is inhibited by the p38 mitogen-activated protein kinase (MAPK)-specific inhibitor SB 203580. Using transient-transreporter and in vitro kinase assays, we demonstrate for the first time that pX activates the p38 MAPK pathway only in 4pX-1 cells. pX-mediated Stat3 and p38 MAPK activation is Ca(2+) and c-Src dependent, in agreement with the established cellular action of pX. Importantly, pX-dependent activation of p38 MAPK inactivates Cdc25C by phosphorylation of Ser216, thus initiating activation of the G(2)/M checkpoint, resulting in 4pX-1 cell growth retardation. Interestingly, pX expression in the less differentiated hepatocyte 4pX-1 cells activates signaling pathways known to be active in regenerating hepatocytes. These results suggest that pX expression in the infected liver effects distinct mitogenic pathway activation in less differentiated versus differentiated hepatocytes.

Rapid detection of hepatitis B virus mutations using real-time PCR and melting curve analysis

Current methods of detecting hepatitis B virus (HBV) mutations are time consuming, labor intensive, and not suitable for screening large numbers of samples. In the present study, we documented the advantages of a system that exploits differences in thermal stability between perfect match and mismatch hybrids, and thereby distinguishes between wild-type and mutants. Hybridization probes were designed complementary to specific wild-type HBV sequences in surface (S), precore, and basal core promoter (BCP) regions of the HBV genome (nt 587, 1896, and 1762/1764, respectively). Two probes were designed for each mutation: anchor probes were 3' labeled with fluorescein and sensor probes, 5' labeled with LC-Red 640, and 3' phosphorylated. Temperatures for each probe melted from amplification products were then determined in a melting program. Sera from 12 patients, each containing identified HBV mutants (6 S-escape, 1 precore, 1 BCP, and 4 mixed precore and BCP), and 5 control sera from patients with wild-type virus were analyzed. Genomic sequences of mutant and wild-type viruses were confirmed by direct sequencing. Real-time polymerase chain reaction (PCR) with fluorescent hybridization probes accurately identified each mutant and wild-type genome. Melting temperatures obtained from probe-product duplexes for the 3 mutants were distinguished from wild-type (>4.0 degrees C, minimal) within 45 minutes. The sensitivity of the system was 100 copies/mL and as few as 5% of mutant among wild-type virus were detected. In conclusion, real-time PCR with fluorescent hybridization probes is a specific, sensitive, quantitative, and rapid means of detecting clinically relevant HBV mutants.

Hepatocellular Cancer Metastatic to the Zygoma: Primary Resection and Immediate Reconstruction

Hepatocellular carcinoma is common worldwide but relatively rare in the United States, where only 13,000 new cases are diagnosed each year. Metastasis to osseous structures in the head and neck are extremely rare; when they do occur, most appear as oral cavity masses secondary to mandibular and maxillary involvement. We report the case of an isolated zygomatic metastasis in a patient who had been previously treated for hepatocellular carcinoma with orthotopic liver transplantation. The patient underwent a complete excision of the mass followed by immediate reconstruction of the zygomaxillary buttress and the orbital rim and floor. To our knowledge, only one other case similar to ours has been previously reported; in that instance, the metastatic tumor was not resectable.

Adenovirus-mediated gene transfer to orthotopic hepatocellular carcinomas in athymic nude mice

Gene therapy may become an option for the treatment of malignant tumors such as hepatocellular carcinoma (HCC), once safe and efficient vector systems have been established. Due to their stability in vivo, recombinant adenoviral vectors are promising vectors for gene delivery to HCC. To study the characteristics of gene delivery into HCCs by recombinant adenoviral vectors in vivo, we established an in situ HCC model in the livers of athymic nude mice by intrahepatic injection of human HCC cells. Recombinant adenovirus vectors expressing beta-galactosidase (Ad2CMV beta gal) were injected via the tail vein of mice bearing HCC or directly into intrahepatic tumors. Levels of beta-galactosidase expression in tumor tissue and surrounding normal liver were analyzed by histochemistry or for quantification by a chemiluminescence assay in tissue homogenates. Following tail vein injection, high levels of beta-galactosidase expression were found in the liver, but virtually no gene expression could be detected in the tumor tissue. In contrast, after direct injection of Ad2CMV beta gal into intrahepatic HCCs, high levels of beta-galactosidase expression were detected in the tumor tissue. However, single transduced hepatocytes scattered throughout the normal liver could also be identified. These results indicate that barriers such as the endothelial lining of the tumor vasculature impair the efficiency of adenoviral vectors for gene delivery into HCCs by intravenous administration, which can be overcome by direct injection into the tumor tissue. However, due to the observed transduction of disseminated hepatocytes following intratumoral administration, additional HCC-specific targeting to further enhance the safety of adenoviral vectors may be required.

Hepatocellular carcinoma with lymphoid stroma: a tumour with good prognosis after liver transplantation

AIMS

Carcinomas with lymphoid stroma arising in non-liver-organs have a better prognosis than other carcinomas and may be associated with Epstein-Barr virus. We determined the frequency, characteristics and prognosis of hepatocellular carcinomas with lymphoid stroma.

METHODS AND RESULTS

Histology of the livers of 162 patients with hepatocellular carcinoma, who underwent an orthotopic liver transplantation, was reviewed independently by three pathologists. Hepatocellular carcinoma with lymphoid stroma was diagnosed when all tumour samples contained more lymphocytes than tumour cells. Epstein-Barr virus was detected by in-situ hybridization and by polymerase chain reaction. Five patients (3.6%) were classified as hepatocellular carcinomas with lymphoid stroma. All patients were males. Cirrhosis was present in four/five patients. Serum alpha-fetoprotein levels were normal. Inter-observer histological reproducibility was good. Tumour cells did not contain Epstein-Barr virus. The five patients were alive without tumour at three years, although two of them had adverse prognostic factors at the time of transplantation (more than one tumour with a diameter > or = 40 mm). Only one patient had tumour recurrence, but he survived 7.6 years post-transplantation. The 5-year survival of patients with hepatocellular carcinoma with lymphoid stroma was better than that of the patients with other types of hepatocellular carcinomas (P = 0.04).

CONCLUSIONS

Hepatocellular carcinoma with lymphoid stroma should be considered as a distinct clinicopathological and prognostic entity.

Targeting a recombinant adenovirus vector to HCC cells using a bifunctional Fab-antibody conjugate

We developed a specific adenoviral gene delivery system with monoclonal antibody (mAb) AF-20 that binds to a 180 kDa antigen highly expressed on human hepatocellular carcinoma (HCC) cells. A bifunctional Fab-antibody conjugate (2Hx-2-AF-20) was generated through AF-20 mAb crosslinkage to an anti-hexon antibody Fab fragment. Uptake of adenoviral particles and gene expression was examined in FOCUS HCC and NIH 3T3 cells by immunofluorescence; beta-galactosidase expression levels were determined following competitive inhibition of adenoviral CAR receptor by excess fibre knob protein. The chimeric complex was rapidly internalized at 37 degrees C, and enhanced levels of reporter gene expression was observed in AF-20 antigen positive HCC cells, but not in AF-20 antigen negative NIH 3T3 control cells. Targeting of recombinant adenoviral vectors to a tumor associated antigen by a bifunctional Fab-antibody conjugate is a promising approach to enhance specificity and efficiency of gene delivery to HCC.

Vaccination against hepatitis B: current challenges for Asian countries and future directions

AIMS

To review the current status of hepatitis B immunization programmes as well as future issues concerning hepatitis B immunization in Asian countries.

METHODS

Pertinent literature was identified via in-house and MEDLINE (1980-99) searches and references cited in published articles. Articles within the Proceedings of the IX Triennial International Symposium on Viral Hepatitis and Liver Disease provided valuable state-of-the-art resource data.

RESULTS

Chronic hepatitis B infection is responsible for 75-90% of primary hepatocellular carcinoma, one of the 10 most common cancers worldwide. Hepatitis B and its chronic sequelae can potentially be eradicated through vaccines that have been shown to be 95-99% efficacious in preventing development of the disease or the carrier state in immunized infants. Approximately 75% of the world's hepatitis B carriers live in Asian countries wherein wide variations in immunization strategies exist. Vaccination programmes in hyperendemic Asian countries have elicited decreases in the incidence of acute and chronic infections as well as a decrease in chronic carriers in the unvaccinated population. Decreases in the incidence of hepatocellular carcinoma have been recorded in Taiwan and Singapore after at least 10 years of universal hepatitis B immunization programmes.

CONCLUSIONS

In Asian countries currently without nationwide hepatitis B programmes, utilization of the existing vaccination infrastructure for administration of other World Health Organization Expanded Programme on Immunization vaccines will provide the most economical and efficient means of administration of the hepatitis B vaccine.

P53 tumor suppressor gene mutations in hepatocellular carcinoma patients in India

BACKGROUND

Specific mutations of the p53 tumor suppressor gene in hepatocellular carcinoma (HCC) have been reported from several parts of the world, but to the authors' knowledge to date the status of this gene has not been studied in HCC patients in India, where HCC is one of the major cancers and the frequency of chronic hepatitis B virus (HBV) as well as hepatitis C virus (HCV) infection and exposure to dietary aflatoxin B(1) is very high. The most frequent mutation of the p53 gene in HCC is an AGG(Arg) to AGT(Ser) missense mutation at codon 249 of exon 7.

METHODS

Liver biopsy specimens from 21 HCC patients and 10 healthy controls were obtained through surgery or by needle biopsy technique. Phenol-chloroform-extracted DNA specimens were employed for the detection of HBV infection and p53 gene mutations. Nucleotide mutations of exons 4-9 of the p53 gene were analyzed by polymerase chain reaction (PCR), single strand confirmation polymorphism, and direct sequencing. Third-generation sandwich enzyme-linked immunosorbent assay (ELISA) was used for the serologic detection of HBV and HCV infection.

RESULTS

Analysis of exons 4-9 of the p53 gene revealed only 3 mutations (3 of 21 specimens, 14.28%; 95% confidence interval, -0.7-29.3), 2 mutations at codon 249 showing G-->T transversions, and 1 mutation (4.7%) at codon 250 with a C-->T transition. The base substitutions at the third base of codon 249 resulted in a missense mutation leading to a change in amino acid from arginine to serine whereas at codon 250 it caused a change from proline to serine. Dot blot hybridization and PCR for HBV DNA from HCCs revealed 58.8% (10 of 17 specimens) and 90. 47% (19 of 21 specimens), positivity, respectively. ELISA for hepatitis B virus surface antigen in serum showed a positivity of 71. 42% (15 of 21 specimens), but there was only 40% positivity (8 of 20 specimens) for hepatitis B virus envelope antigen whereas 6 of 17 patients (35.29%) showed the presence of antibodies against hepatitis B virus envelope protein. No patient was found to be positive for the HCV antibody.

CONCLUSIONS

The very low frequency of p53 mutations and the extremely high frequency of HBV infection (> 90%) in HCC indicate that the mutations in the p53 gene frequently found in HCC reported from different endemic areas of the world may not play a direct role in the development of HCC in India. HBV infection and, possibly, exposure to the dietary aflatoxin B(1) appear to play major roles in the molecular pathogenesis of HCC in India.

Gene therapy of hepatocellular carcinoma in vitro and in vivo in nude mice by adenoviral transfer of the Escherichia coli purine nucleoside phosphorylase gene

Expression of viral or bacterial enzymes in tumor cells to convert nontoxic prodrugs into highly toxic metabolites is an attractive gene-therapeutic approach for the treatment of hepatocellular carcinoma (HCC). The Escherichia coli purine nucleoside phosphorylase (PNP) converts purine analogs into freely diffusible metabolites, which are highly toxic to dividing and nondividing cells. We investigated the antitumor effects of PNP in the human HCC cell lines, HepG2, Hep3B, and HuH-7, and performed a comparison with herpes simplex thymidine kinase (TK). The genes for PNP, TK, and enhanced green fluorescent protein (EGFP) were delivered to HCC cells by identical adenoviral vectors. Fludarabine and ganciclovir (GCV) served as prodrugs for PNP and TK, respectively. Expression of PNP highly sensitized HCC cells to fludarabine treatment. Fludarabine concentrations between 0.5 and 1 microg/mL killed 100% of the cells expressing PNP with no detectable toxicity in control cells expressing EGFP. Expression of PNP in as few as 10% of HCC cells induced efficient killing of most bystander cells. Expression of TK followed by GCV treatment produced a potent growth inhibition but failed to kill all TK-expressing HCC cells. More importantly, the TK system exhibited a lower degree of bystander effect. Adenoviral delivery of PNP followed by fludarabine administration prevented subcutaneous and intrahepatic tumor formation in nude mice and was also effective for the treatment of established tumors. These results demonstrate the potential of the PNP/fludarabine system for the treatment of HCC.

Does aflatoxin B1 play a role in the etiology of hepatocellular carcinoma in the United States?

Previous research showed that risk factors associated with hepatocellular carcinoma (HCC) include infection with hepatitis B (HBV) and hepatitis C (HCV) viruses, exposure to aflatoxin B1 (AFB1), and liver cirrhosis, due primarily to alcohol consumption. To determine whether AFB1 may play a role in HCC in the United States, a search for AFB1 adducts and p53 alterations, potentially induced by AFB1, was conducted in the United States in 23 HCC patients with available tissue samples. The presence of AFB1 tumor-DNA and -serum lysine adducts and mutant p53 product was determined by immunoassays and codon 249 p53 mutation by restriction enzyme analysis. HBV and HCV serology and serum HBV-DNA were also determined. Thirteen patients were positive for HBV by HBs antigen or anti-HBc antigen or by polymerase chain reaction for HBV-DNA sequences. Nine patients were free of HBV and HCV markers; 5 of 22 sera tested were anti-HCV positive. p53 Protein expression, determined by immunohistochemical staining, was present in 5 of the 23 tumor tissues, whereas p53 codon 249 mutations were not observed in the 5 cases in which tissue was available for study. AFB1 tumor-DNA adducts were present in 3 of 19 tumor tissues, and in 1 of these 3 samples p53 protein was also detected. Sera from only 5 of the patients were tested for AFB1-lysine adducts, and all were positive. In these five patients, neither p53 protein nor a mutation on codon 249 was detected. The demonstration that AFB1-DNA and -lysine adducts are present in HCC patients in the United States is intriguing but requires further substantiation because of the small number of subjects in this pilot study. To elucidate the pathogenetic significance of these findings, further investigation, including studies in larger patient cohorts and properly selected controls, is warranted.

Extraosseous metastases of hepatocellular carcinoma detection and therapeutic assessment with Tc-99m PMT SPECT

Owing to recent advances in imaging technology and radiologic intervention, survival rates in patients with hepatocellular carcinoma have improved markedly. However, such prolonged survival has resulted in an increase in extrahepatic metastases. Tc-99m (Sn)-N-pyridoxyl-5-methyltryptophan (Tc-99m PMT), developed for hepatobiliary scintigraphy, has been used to visualize extrahepatic metastases, with most related reports limited to osseous metastases. The authors report two cases of hepatocellular cancer presenting as a hypopharyngeal metastasis and intraperitoneal dissemination along the tract of a fine-needle biopsy. Lesions undetectable on planar imaging could be visualized by Tc-99m PMT SPECT.

Antisense therapy of hepatitis B virus infection

Chronic infection with the hepatitis B virus (HBV) is a major health problem worldwide. The only established therapy is interferon-a with an efficacy of only 30-40% in highly selected patients. The discovery of animal viruses closely related to the HBV has contributed to active research on antiviral therapy of chronic hepatitis B. The animal model tested and described in this article are Peking ducks infected with the duck hepatitis B virus (DHBV). Molecular therapeutic strategies aimed at blocking gene expression include antisense DNA. An antisense oligodeoxynucleotide directed against the 5'-region of the preS gene of DHBV inhibited viral replication and gene expression in vitro in primary duck hepatocytes and in vivo in Peking ducks. These results demonstrate the potential clinical use of antisense DNA as antiviral therapeutics.

Survival and recurrence after liver transplantation versus liver resection for hepatocellular carcinoma: a retrospective analysis

OBJECTIVE

This study compares the results of liver transplantation (LTx) and liver resection (LR) for hepatocellular carcinoma (HCC) to test the widespread hypothesis that LTx is the preferable approach for small HCCs.

SUMMARY BACKGROUND DATA

With respect to scarcity of donor organs and poor results, LTxs for large HCCs are obsolete. Small HCC transplantations have been reported to result in an excellent survival rate. However, the data of comparative studies are controversial.

METHODS

Patients who were treated curatively by LTx (n = 50) or LR (n = 52) for HCC were included in this retrospective study. Survival and freedom from recurrence were analyzed. Patients were stratified according to prognostic factors (pT classification, tumor size, number of tumor nodules, vascular infiltration, and cirrhosis).

RESULTS

Overall, after LTx and LR the 3-year survival rate and recurrence rate were not significantly different. In the Cox analysis, tumor size (p = 0.02) and vascular infiltration (p = 0.04) were independent variables after LTx, whereas after LR, none of the tested prognostic parameters was significant. With regards to recurrence, tumor size was the only independent factor, after both LTx and LR (p = 0.02, respectively). Directly comparing the two therapeutic approaches, a 3-year survival rate in pT 1/2, oligocentric (1-5 nodules), and oligocentric and small tumors proved to be superior after LTx. The recurrence rate after LTx was superior to LR in pT 1/2 and oligocentric tumors. Remarkably, for small (< or = 5 cm) tumors, LTx and LR resulted in a similar 3-year survival rate and freedom from recurrence.

CONCLUSIONS

According to our analysis, the oncological advantage of LTx compared with LR is questionable. This applies especially for small tumors. Superior results of LTx in early stage HCC and particularly in oligocentric tumors may be attributed to incorrect preoperative diagnosis. Nevertheless, LTx is a reasonable treatment for patients with early stage tumors if a LR is impossible because of tumor localization or poor functional hepatic capacity.

Immunological approach to hepatocellular carcinoma

A library of monoclonal antibodies (MoAbs) has been produced against a human hepatocellular carcinoma (HCC) cell line designated FOCUS in order to study the antigenic properties of transformed hepatocytes. Several monoclonal antibodies (MoAbs) were initially selected for study since they bound to antigens which were overexpressed in HCC tissues compared with the adjacent uninvolved normal liver counterpart; in addition, these MoAbs revealed low level antigen expression on other normal human tissues. Subsequently, HCC cell lines were metabolically labelled and the antigens further characterized by immunoprecipitation and Western blot analysis. If the MoAb recognized a primary linear epitope on a protein, cloning was performed using a lambda GT11 cDNA expression library prepared from the FOCUS HCC cell line. These studies characterized the HCC associated antigen(s) at the molecular level. This review illustrates the value of such an experimental approach to search for and identify HCC associated antigens and emphasizes the biological properties of novel proteins may be defined and characterized by these techniques. More important, our investigations have described unique proteins that may not only be important in the pathogenesis of HCC but also demonstrates how such antigen-antibody systems may be used to develop strategies for immunotargetting and gene therapy of HCC.