Bile detection of squamous cell carcinoma antigen (SCCA) in extrahepatic cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CCA) is a rare biliary tract tumor with poor prognosis that often is challenging to diagnose and the majority of patients present with advanced stage. Squamous cell carcinoma antigen 1 (SCCA1) overexpression has been found in different tumors associated with poor prognosis and chemoresistance. AIMS: To assess the presence and possible prognostic role of SCCA1/2 isoforms in bile and serum of patients with CCA. METHODS: Forty seven surgical patients (36 with CCA and 11 with benign diseases) were prospectively included in the study. Serum and bile specimens were collected at the time of surgery and free and IgM-complexed SCCA was quantified by ELISA (Xeptagen, srl). RESULTS: Free or IgM linked SCCA was rarely found in serum, while SCCA was detectable in bile samples of patients with CCA, especially in those with extrahepatic form (43% vs 17%, p = 0.008), but not in controls. Despite similar tumor stage, these positive patients presented a trend toward a higher percentage of portal invasion (27% vs 15%) and of tumor recurrence than negative cases (62% vs 40%), although the difference was not statistically significant. CONCLUSION: These preliminary results indicate that bile testing for SCCA is a specific marker of extrahepatic CCA, with potential prognostic value.

Au(iii)-Proline derivatives exhibiting selective antiproliferative activity against HepG2/SB3 apoptosis-resistant cancer cells.

This paper deals with the combination of a proline-based moiety with biologically active gold centers in the oxidation states +1 and +3. In particular, six Au(i)/(iii)-proline dithiocarbamato (DTC) complexes with general formulae [Au(DTC)2] and [AuIIIX2(DTC)] (X = Cl, Br) are reported here. After the synthesis of the ligand and the complexes, all derivatives were characterized via several techniques and tested for their stability in DMSO/water media. This study was focused on the demonstration of a peculiar behavior of Au(iii)-DTC species in solution. Finally, the complexes were screened for their antiproliferative activity against 2 human cancer cell lines, namely HepG2 and HepG2/SB3, taken as models of hepatocellular carcinoma. The latter, chosen for its aggressiveness due to the upregulation of the anti-apoptotic protein SerpinB3, was selectively inhibited in terms of growth by some Au(iii)-DTC complexes.

Synthesis, chemical characterization and cancer cell growth-inhibitory activities of Cu(ii) and Ru(iii) aliphatic and aromatic dithiocarbamato complexes.

In this paper, we focused on the analysis of the effects mediated by different cyclic dithiocarbamic ligands (DTC) on three classes of antiproliferative coordination compounds, namely, Ru(iii) complexes with the general formulae [Ru(DTC)3] and [Ru2(DTC)5]Cl, and the neutral Cu(ii) derivatives of the type [Cu(DTC)2]. In particular, we present the synthesis and characterization of a library of total 23 coordination compounds containing Ru(iii) or Cu(ii) as the biologically-active metal center and two or more dithiocarbamato (DTC) ligands derived from cyclic amines (aliphatic or aromatic). Several techniques including elemental analysis, X-ray crystallography, ESI-MS, 1H-NMR spectroscopy, FT-IR and UV-Vis spectrophotometry were used to characterize the compounds, which highlighted the different electronic behaviors generated by the substituents within the DTC moiety. Moreover, the synthesized compounds were tested for their stability in order to investigate their antiproliferative activity against 3 human cancer cell lines, namely, HeLa, HepG2 and HepG2/SB3. In particular, HepG2/SB3 was chosen for its aggressiveness due to upregulation of the anti-apoptotic protein SerpinB3. Finally, the most promising compounds are studied in terms of log P. Overall, the results reveal the drug-likeness of some of the derivatives of copper(ii) and ruthenium(iii).

HCV genotype 3 and squamous cell carcinoma antigen (SCCA)-IgM are independently associated with histological features of NASH in HCV-infected patients.

Nonalcoholic steatohepatitis (NASH) enhances the risk of progressive liver disease. In chronic hepatitis C (CHC), liver steatosis is frequent, especially in genotype 3, but its clinical significance is debated. As squamous cell carcinoma antigen (SCCA)-IgM has been associated with advanced liver disease and risk of tumour development, we evaluated its occurrence in CHC and the possible relation with NASH at liver biopsy. Using a validated ELISA, serum SCCA-IgM was measured in 91 patients with CHC at the time of liver biopsy performed before antiviral treatment, at the end of treatment and 6 months thereafter, and in 93 HCV-negative patients with histological diagnosis of nonalcoholic fatty liver disease, as controls. SCCA-IgM was detected in 33% of CHC patients and in 4% of controls. This biomarker was found more elevated in CHC patients with histological NASH, and at multivariate analysis, SCCA-IgM and HCV genotype 3 were independently associated with NASH [OR (95% CI): 6.94 (1.21-40) and 27.02 (4.44-166.6)]. As predictors of NASH, HCV genotype 3 and SCCA-IgM had a specificity and a sensitivity of 97% and 44%, and of 95% and 27%, respectively. PPV and NPV were 80% and 86% for HCV genotype 3 vs 73% and 72% for SCCA-IgM. In patients with sustained virologic response to therapy, SCCA-IgM levels decreased significantly, while these remained unchanged in nonresponders. In conclusion, SCCA-IgM is detectable in one-third of patients with CHC and significantly correlates with histological NASH.

SERPINB3 is associated with TGF-ß1 and cytoplasmic ß-catenin expression in hepatocellular carcinomas with poor prognosis.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most important sanitary problems for its prevalence and poor prognosis. To date, no information is available on the prognostic value of the ov-serpin SERPINB3, detected in primary liver cancer but not in normal liver. The aim of the study was to analyse SERPINB3 expression in liver cancer in relation with molecular signatures of poor prognosis and with clinical outcome. METHODS: Liver tumours of 97 patients were analysed in parallel for SERPINB3, TGF-ß and ß-catenin. In a subgroup of 67 patients with adequate clinical follow-up, the correlation of molecular findings with clinical outcome was also carried out. RESULTS: High SERPINB3 levels were detectable in 22% of the patients. A significant correlation of this serpin with TGF-ß at transcription and protein level was observed, whereas for ß-catenin a strong correlation was found only at post-transcription level. These findings were in agreement with transcriptome data meta-analysis, showing accumulation of SERPINB3 in the poor-prognosis subclass (S1). High levels of this serpin were significantly associated with early tumour recurrence and high SERPINB3 was the only variable significantly associated with time to recurrence at multivariate analysis. CONCLUSIONS: SERPINB3 is overexpressed in the subset of the most aggressive HCCs.

Squamous cell carcinoma antigen-1 (SERPINB3) polymorphism in chronic liver disease.

BACKGROUND: The serpin squamous cell carcinoma antigen (SCCA, SERPINB3) has been found over-expressed in primary liver cancer and at lower extent in cirrhosis and chronic hepatitis. A novel SCCA-1 variant (SCCA-PD), presenting a single mutation in the reactive centre (Gly351Ala), has been recently identified (rs3180227). AIM: To explore SCCA-1 polymorphism in patients with HCV infection as single etiologic factor and different extent of liver disease. METHODS: One hundred and fourty-eight patients with chronic HCV infection (45 chronic hepatitis, 53 cirrhosis, 50 HCC) and 50 controls were evaluated. SCCA-1 polymorphism was studied by restriction fragment length polymorphism and confirmed randomly by direct sequencing. Circulating SCCA-IgM complex was determined by ELISA. RESULTS: SCCA-PD was detected with higher frequency in cirrhotic patients (45.3%, odds ratio=2.62; 95%CI 1.13-6.10, p=0.038) than in patients with chronic hepatitis or in controls (24.4% and 24%, respectively). Intermediate figures were found in hepatocarcinoma (36.0%). SCCA-IgM in serum was lower in patients carrying SCCA-PD than in wild type patients and the difference was statistically significant in cirrhotic patients (mean+/-S.D.=117.45+/-54.45 U/ml vs. 268.52+/-341.27 U/ml, p=0.026). CONCLUSIONS: The newly identified SCCA-PD variant was more frequently found in liver cirrhosis, suggesting that patients carrying this polymorphism are more prone to develop progressive liver fibrosis.

Tumour-specific induction of immune complexes: DCP-IgM in hepatocellular carcinoma.

BACKGROUND: In the sera of liver, colorectal and prostate cancer patients, several biomarkers may be detected as IgM immune complexes. To determine whether the presence of immune complexes was correlated to an increase of IgMs, we measured the IgM content in the sera of patients with hepatocellular carcinoma (HCC) and cirrhosis, and evaluated the occurrence of des-gamma-carboxy prothrombin (DCP) as immune complexes (DCP-IgM) compared to the levels of DCP and alpha-fetoprotein (AFP). PATIENTS AND METHODS: Serum samples from 31 patients with cirrhosis, 33 untreated HCC patients diagnosed by ultrasound, computed tomography and/or magnetic resonance and confirmed by histopathology, when indicated, and 30 healthy controls were analysed. Concentrations of IgM and DCP-IgM were determined by ELISAs. RESULTS: Circulating IgM in patients with HCC (median level = 1.79 mg mL(-1)) and cirrhosis (1.09 mg mL(-1)) were not significantly different (P = 0.1376) while DCP-IgM were significantly higher in HCC patients (median level = 2171.2 AU mL(-1)) than in those with cirrhosis (1152 AU mL(-1), P = 0.0047). No correlation was found between DCP-IgM and IgM in HCC (r = 0.227) and cirrhosis patients (r = 0.475). DPC-IgM was positive in 55% (18/33) of HCC patients and in 26% (8/31) of cirrhosis patients compared to 39% and 26% for DCP and 48% and 13% for AFP. DCP-IgM, DCP and AFP tests had 100% specificity in healthy controls. CONCLUSIONS: DCP-IgM in HCC patients was not associated with an increase in IgM concentration. DCP-IgM was more frequently detected in HCC patients than DCP and AFP, strengthening the diagnostic role of IgM immune complexes for liver cancer.

Hepatotropic viruses: new insights in pathogenesis and treatment.

Hepatitis B virus (HBV) can be detected in peripheral blood mononuclear cells (PBMCs), mainly B lymphocytes and monocytes. The frequency of PBMC infection is higher in patients with ongoing HBV replication, but can persist for years after the complete resolution of an acute episode of hepatitis B. Infected PBMCs can act as reservoirs for the cell-to-cell transmission of the virus, and vertical transmission studies indicate that the HBV-infected PBMCs of mothers may act as a vector for intrauterine HBV infection. Recent data evaluated whether HBV occult infection could co-operate with HCV infection in the pathogenesis of mixed cryoglobulinemia (MC) and lymphoma and/or whether it may be implicated in the pathogenesis of MC and malignant diseases -B-cell non-Hodgkin's lymphoma (NHL) also independently from HCV. The treatment of chronic HBeAg-negative hepatitis B is intended to ensure the long-term suppression of HBV replication with the aim of halting the progression of liver damage and preventing the development of liver-related complications. This can be done by means of short-term "curative" treatment or long-term "suppressive" therapy. The first approach requires a 48-week course of peginterferon, which controls viral replication (HBV DNA <10.000 copies/ml) in 20-30% of patients; the second requires the long-term (possibly lifetime) administration of nucleoside and/or nucleotide analogues. As none of the currently available drugs alone suppresses viral replication (HBV DNA <200 copies/ml) for five years in all patients, some require a rescue therapy based on the addition of a non-cross-resistant drug, which should be given as early as possible ("on demand" combination therapy). However, the currently available anti-HBV analogues can easily suppress HBV replication for five years in most HBeAg-negative patients. As both strategies have their pros and cons, the best approach needs to be carefully evaluated on an individual basis.

Overexpression of squamous cell carcinoma antigen in idiopathic pulmonary fibrosis: clinicopathological correlations.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive disorder with a poor prognosis. Epithelial instability is a crucial step in the development and progression of the disease, including neoplastic transformation. Few tissue markers for epithelial instability have been reported in IPF. Squamous cell carcinoma antigen (SCCA) is a serine protease inhibitor typically expressed by dysplastic and neoplastic cells of epithelial origin, more often in squamous cell tumours. At present, no information is available on its expression in IPF. METHODS: SCCA and transforming growth factor beta (TGFbeta) expression in surgical lung biopsies from 22 patients with IPF and 20 control cases was examined. An in vitro study using A549 pneumocytes was also conducted to investigate the relationship between SCCA and TGFbeta expression. SCCA and TGFbeta epithelial expression was evaluated by immunohistochemistry and reverse transcription-PCR (RT-PCR). SCCA values were correlated with different pathological and clinical parameters. Time course analysis of TGFbeta expression in A549 pneumocytes incubated with different SCCA concentrations was assessed by real time RT-PCR. RESULTS: SCCA was expressed in many metaplastic alveolar epithelial cells in all IPF cases with a mean value of 24.9% while it was seen in only two control patients in up to 5% of metaplastic cells. In patients with IPF, SCCA correlated positively with extension of fibroblastic foci (r = 0.49, p = 0.02), expression of TGFbeta (r = 0.78, p<0.0001) and with carbon monoxide transfer factor decline after 9 months of follow-up (r = 0.59, p = 0.01). In vitro experiments showed that incubation of cultured cells with SCCA induced TGFbeta expression, with a peak at 24 h. CONCLUSION: Our findings provide for the first time a potential mechanism by which SCCA secreted from metaplastic epithelial cells may exert a profibrotic effect in IPF. SCCA could be an important biomarker in this incurable disease.

Monitoring SCCA-IgM complexes in serum predicts liver disease progression in patients with chronic hepatitis.

About 30% of the patients with chronic hepatitis develop a progressive liver disease and one of the most intriguing issues is the detection of noninvasive markers for fibrosis stage and disease progression. High levels of squamous cell carcinoma antigen (SCCA)-immunoglobulin M (IgM) are detectable in hepatocellular carcinoma and their increase in cirrhotic patients can predict tumour development. As SCCA-IgM can also be detectable at low percentages in patients with chronic hepatitis, the aim of this study was to assess SCCA-IgM complexes in relation to disease outcome in this group of patients. An ELISA assay was used to determine the presence of SCCA-IgM in 188 patients with chronic hepatitis and in 100 controls. An additional serum sample was available after a median period of 6 years in 57 untreated patients: these patients were subdivided in group A, including eight patients with a fibrosis score increase > or =2 in a second liver biopsy and group B, including 49 patients without fibrosis progression during a similar follow up. SCCA-IgM complexes were detectable in 63 of 188 (33%) patients but in none of the controls. A significant increase of SCCA-IgM levels over time was observed in patients with fibrosis progression (mean +/- SD: 117 +/- 200 U/mL/year), but not in those without histologic deterioration (mean +/- SD: -8.8 +/- 31 U/mL/year, P < 0.0001). In conclusion, monitoring SCCA-IgM levels over time appears a useful approach to identify patients with chronic hepatitis at higher risk for cirrhosis development.

Squamous cell carcinoma antigen in human liver carcinogenesis.

BACKGROUND: Squamous cell carcinoma antigen (SCCA) is a serine protease inhibitor that can be overexpressed in hepatocellular carcinoma (HCC) at both molecular and protein level, but no data are available on its expression in pre-malignant stages. AIM: To assess SCCA expression by immunohistochemistry in HCC and its nodular precursors in cirrhotic livers. METHODS: 55 nodules from 42 explanted livers were evaluated: 7 large regenerative nodules (LRNs), 7 low-grade dysplastic nodules (LG-DNs), 10 high-grade DNs (HG-DNs), and 31 HCC. SCCA expression was semiquantitatively scored on a four-tiered scale. RESULTS: SCCA hepatocyte immunostaining was always restricted to the cytoplasm, mainly exhibiting a granular pattern. Stain intensity varied, ranging from weak to very strong. Within the nodules, positive cells were unevenly distributed, either scattered or in irregular clusters. The prevalence of SCCA expression was 29% in LRNs, 100% in DNs and 93% in HCC. A significant difference emerged in both prevalence and score for LRNs versus LG-DNs (p<0.039), HG-DNs (p = 0.001), and HCC (p = 0.000). A barely significant difference (p = 0.49) was observed between LG-DNs and HG-DNs, while no difference in SCCA expression was detected between HG-DNs and HCC. Cirrhotic tissue adjacent to the nodules was positive in 96% of cases, with a significant difference in the score (p = 0.000) between hepatocytes adjacent to HCC and those surrounding LRNs. DISCUSSION: This study provides the first evidence that aberrant SCCA expression is an early event in liver cell carcinomatous transformation.

Haeme oxygenase mediates hyporeactivity to phenylephrine in the mesenteric vessels of cirrhotic rats with ascites.

BACKGROUND AND AIMS: Haeme oxygenase could play a role in the pathogenesis of arterial vasodilation in cirrhosis. The aim of this study was to verify the role of haeme oxygenase in the hyporesponsiveness to phenylephrine of small mesenteric arteries in rats with CCl(4) induced cirrhosis, with and without ascites. METHODS: Pressurised small resistance mesenteric arteries were challenged with increasing doses of phenylephrine. Dose-response curves were evaluated under basal conditions, after inhibition of haeme oxygenase with chromium-mesoporphyrin, after inhibition of nitric oxide synthase (NOS) with N(G)-nitro-L-arginine-methyl-ester (L-NAME), and then after inhibition of both NOS and haeme oxygenase. Haeme oxygenase protein expression was also analysed. RESULTS: Twenty six control rats and 35 rats with cirrhosis (17 with and 18 without ascites) were studied. Response to phenylephrine was lower in non-ascitic and ascitic cirrhosis than in controls. Chromium-mesoporphyrin increased the response to phenylephrine only in ascitic cirrhosis (p<0.001). L-NAME increased the response to phenylephrine in controls (p<0.001) and in ascitic and non-ascitic cirrhosis (p = 0.002, p<0.001, respectively) but the final response in non-ascitic cirrhosis was similar to that of control rats while it remained impaired in ascitic cirrhosis. Addition of chromium-mesoporphyrin to L-NAME improved the response to phenylephrine in ascitic cirrhosis (p<0.01), with final values not different from those of the other two groups. Protein expression of the inducible isoform of haeme oxygenase was increased in the mesenteric vessels of cirrhotic rats. CONCLUSION: Haeme oxygenase mediates hyporeactivity to phenylephrine in the mesenteric vessels of experimental cirrhosis with ascites. NOS plays a major role only in the first stage of the disease.

Extracellular matrix-enriched polymeric scaffolds as a substrate for hepatocyte cultures: in vitro and in vivo studies.

Tissue engineering is a promising approach to developing hepatic tissue suitable for the functional replacement of a failing liver. The aim of the present study was to investigate whether an extracellular cell matrix obtained from fibroblasts-cultured within scaffolds of hyaluronic acid (HYAFF) could influence the proliferation rate and survival of rat hepatocytes both during long-term culture and after in vivo transplantation. Cultures were evaluated by histological and morphological analysis, a proliferation assay and metabolic activity (albumin secretion). Hepatocytes cultured in extracellular matrix-enriched scaffolds exhibited a round cellular morphology and re-established cell-cell contacts, growing into aggregates of several cells along and/or among fibers in the fabric. Hepatocytes were able to secrete albumin up to 14 days in culture. In vivo results demonstrated the biocompatibility of HYAFF-11 implanted in nude mice, in which hepatocytes maintained small well-organised aggregates until the 35th day. In conclusion, the presence of a fibroblast-secreted extracellular matrix improved the biological properties of the hyaluronan scaffold, favoring the survival and morphological integrity of hepatocytes in vitro and in vivo.

Improvement of liver cancer detection with simultaneous assessment of circulating levels of free alpha-fetoprotein (AFP) and AFP-IgM complexes.

We assessed the presence of alpha-fetoprotein (AFP) complexed with IgM (AFP-IgM IC) in serum of patients affected by hepatocellular carcinoma (HCC), cirrhosis and chronic hepatitis as well as in healthy subjects by means of a dedicated ELISA assay. The amount of AFP-IgM IC was expressed in arbitrary units (AU) on a reference standard curve. Free AFP (FAFP) levels were determined in parallel in each sample by means of an automated immunoassay system. The mean serum concentration of AFP-IgM IC was significantly higher in HCC patients (mean +/- SD: 1378.3 +/- 2935.7 AU/mL) than in cirrhotic patients (129.8 +/- 261.4 AU/mL) and in patients with chronic hepatitis (80.9 +/- 168.9 AU/mL) (p < 0.01). HCC patients had FAFP values above the 20 ng/mL cutoff in 44% of cases (22/50) and AFP-IgM IC values above the 120 AU/mL cutoff in 60% of cases (30/50). The occurrence of the free and IgM-complexed form of circulating AFP did not overlap, and 82% of patients (41/50) were positive for at least one marker. The results indicate that AFP-IgM IC is a complementary serological marker to FAFP and that the combination of these biomarkers may be useful in the diagnosis of liver cancer.

Surface expression of squamous cell carcinoma antigen (SCCA) can be increased by the preS1(21-47) sequence of hepatitis B virus.

A variant of the serpin squamous cell carcinoma antigen (SCCA) has been identified as a hepatitis B virus binding protein and high expression of SCCA has recently been found in hepatocarcinoma. Since HBV is involved in liver carcinogenesis, experiments were carried out to examine the effect of HBV preS1 envelope protein on SCCA expression. Surface and intracellular staining for SCCA was assessed by FACS analysis. Preincubation of HepG2 cells and primary human hepatocytes with preS1 protein or with preS1(21-47) tetrameric peptide significantly increased the surface expression of SCCA, without modification of its overall cellular burden, suggesting a surface redistribution of the serpin. An increase in HBV binding and internalization was observed after pre-incubation of the cells with preS1 preparations, compared to cells preincubated with medium alone. Pretreatment of cells with DMSO, while not influencing SCCA basal expression, was responsible for an increase in the efficiency of HBV internalization and this effect was additive to that obtained after incubation with preS1 preparations. In conclusion, the HBV preS1(21-47) sequence is able to induce overexpression of SCCA at the cell surface facilitating virus internalization, while the increased efficiency of HBV entry following DMSO addition is not mediated by SCCA.

Overexpression of squamous cell carcinoma antigen variants in hepatocellular carcinoma.

Pathogenetic mechanisms of hepatocellular carcinoma (HCC) are still unclear and new tools for diagnostic and therapeutic purposes are ongoing. We have assessed whether squamous cell carcinoma antigen (SCCA), a serpin overexpressed in neoplastic cells of epithelial origin, is also expressed in liver cancer. Squamous cell carcinoma antigen was evaluated by immunohistochemistry in 65 HCCs of different aetiology and in 20 normal livers. Proliferative activity was assessed using MIB-1 antibody. In 18 surgical samples, tumour and nontumour liver tissue was available for SCCA cDNA amplification and sequencing. Squamous cell carcinoma antigen was detected in 55 out of 65 (85%) tumour specimens, but in none of the 20 controls. In the majority of the cases, the positive signal was found in the cytoplasm of more than 50% of the hepatocytes. Low or undetectable SCCA (scoreor=2 (mean+/-s.d.: 2%+/-2.4 vs 7.5%+/-10.3, P<0.05). Squamous cell carcinoma antigen mRNA could be directly sequenced in 14 out of 18 liver tumours but in none of the corresponding nontumour samples. From sequence alignment, a novel SCCA1 variant (G(351) to A) was identified in five cases, while SCCA1 was revealed in six cases and SCCA2 in three cases. In conclusion, SCCA variants are overexpressed in HCC, independently of tumour aetiology. A novel SCCA1 variant has been identified in one third of liver tumours.

Hepatitis C virus quasispecies in the natural course of HCV-related disease in patients with haemophilia.

Patients with haemophilia show high prevalence of hepatitis C infection but low rate of progressive liver disease when they are not co-infected with HIV. The balance between host immune system and hepatitis C virus (HCV) variability seems to play a major role in the evolution of the HCV-related disease. To address this point we have studied, in a group of selected patients with haemophilia, the composition and in some cases the evolution, of the highest variable envelope gene within the hypervariable region 1 (HVR1) of the HCV, which is the region more directly exposed to the host immune response. Five of 12 patients show a very high homogeneity of the HVR1 and four of those had severe progressive liver disease. These results seem to confirm the major role of the immunity in driving the variability of the HCV rather than the high degree of different HCV strains to which haemophiliacs have been in touch with, during their long-term replacement therapy. Our results seem in keeping with other studies on different type of patients, where a low degree of quasispecies variability has been demonstrated in relationship with the progression and the severity of their liver disease.

High levels of soluble tumor necrosis factor superfamily receptors in patients with hepatitis C virus infection and lymphoproliferative disorders.

BACKGROUND: Chronic hepatitis C virus (HCV) infection is associated with a variety of extrahepatic disorders that may relate to direct or indirect effects of virus infection. Increased levels of soluble forms of tumor necrosis factor (TNF) receptors I and II, found in lymphoproliferative and infectious diseases, can interfere with TNF induced apoptotic cell death. The aim of the present study was to evaluate soluble TNF family receptors levels in lymphoproliferative disorders associated with HCV infection. METHODS: One hundred and forty-nine subjects were studied, including 120 anti-HCV positive patients (60 without lymphoproliferative manifestations, 47 with type II cryoglobulinemia and 13 with low-grade B-cell non-Hodgkin's lymphoma (B-NHL)) and 29 anti-HCV negative subjects (19 with low-grade B-NHLs and ten normal controls). RESULTS: Soluble forms of TNF receptor I, TNF receptor II and Fas were significantly higher in HCV positive patients compared with normal controls. The highest levels were found in patients affected by type II cryoglobulinemia or HCV positive lymphoplasmacytoid lymphomas (LP-NHLs), while HCV positive patients without type II cryoglobulinemia or with other B-NHLs had lower values (P < 0.01). CONCLUSIONS: Among HCV infected individuals, very high levels of soluble TNF receptors are significantly associated with type II cryoglobulinemia and LP-NHLs, suggesting that they may be involved in these proliferative disorders.

Cloning and expression of a novel hepatitis B virus-binding protein from HepG2 cells.

A direct involvement of the hepatitis B virus (HBV) preS1-(21-47) sequence in virus attachment to cell membrane receptor(s) and the presence on the plasma membranes of HepG2 cells of protein(s) with receptor activity for HBV have been suggested by many previous experiments. In this study, by using a tetravalent derivative of the preS1-(21-47) sequence, we have isolated by affinity chromatography from detergent-solubilized HepG2 plasma membranes a 44-kDa protein (HBV-binding protein; HBV-BP), which was found to closely correspond to the human squamous cell carcinoma antigen 1 (SCCA1), a member of the ovalbumin family of serine protease inhibitors. Comparison of SCCA1 sequence with the sequence of the corresponding HBV-BP cDNA, cloned by polymerase chain reaction starting from RNA poly(A)(+) fractions extracted from HepG2 cells, indicated the presence of only four nucleotide substitutions in the coding region, leading to three amino acid changes. Intact recombinant HBV-BP lacked inhibitory activity for serine proteases such as alpha-chymotrypsin and trypsin but inhibited with high potency cysteine proteases such as papain and cathepsin L. Direct binding experiments confirmed the interaction of recombinant HBV-BP with the HBV preS1 domain. HepG2 cells overexpressing HBV-BP after transfection of corresponding cDNA showed a virus binding capacity increased by 2 orders of magnitude compared with untransfected cells, while Chinese hamster ovary cells, which normally do not bind to HBV, acquired susceptibility to HBV binding after transfection. Native HBV particle entry was enhanced in transfected cells. Both recombinant HBV-BP and antibodies to recombinant HBV-BP blocked virus binding and internalization in transfected cells as well as in primary human hepatocytes in a dose-dependent manner. Our findings suggest that this protein plays a major role in HBV infection.