Detection of hepatitis C virus NS5 protein and genome in Chinese carcinoma of the extrahepatic bile duct and its significance

HCV nonstructural protein 4 is associated with aggressiveness features of breast cancer

BACKGROUND

Hepatitis C virus (HCV) has the lymphotropic feature that is supposed to be the reason of related extrahepatic manifestation. HCV viral oncoproteins may participate in the regulation of some gene expression that has been implicated in tumorigenesis. Our aim is to evaluate the HCV-NS4 circulating levels in breast cancer (BC) and to investigate its relation with BC tumor aggressiveness.

METHODS

This study was performed among 158 Egyptian women (120 with BC and 38 with benign breast diseases). ELISA was used for detection of anti-HCV antibodies, HCV-NS4, fibronectin, and CA 15-3.

RESULTS

No association between HCV detection in this group of BC patients (27.5% in BC vs. 23.7% in breast benign diseases, P = 0.687). Among HCV-infected patients, the mean HCV-NS4 serum level in BC was significantly higher than benign group (61.7 μg/mL vs. 33.9 μg/mL, P = 0.0005). Fibronectin levels were higher (P = 0.014) in patients infected with HCV than noninfected BC patients. Elevated HCV-NS4 levels were associated with tumor severity features like large size, late stages, high grades, and infiltrated lymph nodes. The elevated levels of HCV-NS4 (> 40 μg/mL) yielded an estimated odds ratio (95% confidence intervals) of 2.5 (0.98-6.36), 1.2 (0.44-3.33), 1.9 (0.53-7.00), and 2.5 (0.87-7.33) for developing large size, late stages, high grades, and infiltrated lymph nodes, respectively. Interestingly, HCV-NS4 levels significantly correlated with other BC tumor marker like CA15-3 (r = 0.535; P = 0.0009) and fibronectin (r = 0.432; P < 0.0001).

CONCLUSIONS

HCV-NS4 appears to be associated with BC progression features. Oncologists treating such BC patients should consider HCV screening to enable the early identification and to prevent progression of the disease.

Association between hepatitis B or hepatitis C virus infection and risk of pancreatic adenocarcinoma development: a systematic review and meta-analysis

BACKGROUND

Pancreatic adenocarcinoma (PAC) is an aggressive cancer with a poor prognosis. To date, PAC causes are still largely unknown. Antigens and replicative sequences of oncogenic hepatitis B (HBV) and hepatitis C (HCV) virus were detected in different extra-hepatic tissues, including pancreas.

OBJECTIVE

a systematic review and meta-analysis of epidemiological studies assessing PAC risk in patients with HBV/HCV chronic infections.

METHODS

In September 2012, we extracted the articles published in Medline, Embase and the Cochrane Library, using the following search terms: "chronic HBV" and "HCV", "hepatitis", "PAC", "risk factors", "epidemiology". Only case/control (C/C), prospective/retrospective cohort studies (PCS/RCS) written in English were collected.

RESULTS

four hospital-based C/C studies and one PCS, in HBV-infected patients and two hospital-based C/C studies and one RCS in HCV-infected subjects met inclusion criteria. In these studies HBsAg positivity enhanced significantly PAC risk (RR = 1.18, 95% CI:1.04-1.33), whereas HBeAg positivity (RR = 1.31, 95% CI:0.85-2.02) as well as HBsAg negative/HBcAb positive/HBsAb positive pattern (RR = 1.12, 95% CI:0.78-1.59) and HBsAg negative/HBcAb positive/HBsAb negative pattern (RR = 1.30, 95% CI:0.93-1.84) did not. Relationship between PAC risk and anti-HCV positivity was not significant, although it reached a borderline value (RR = 1.160, 95% CI:0.99-1.3).

CONCLUSIONS

HBV/HCV infection may represent a risk factor for PAC, but the small number of available researches, involving mainly populations of Asian ethnicity and the substantial variation between different geographical areas in seroprevalence of HBV/HCV-antigens/antibodies and genotypes are limiting factors to present meta-analysis.

Hepatitis B and C virus infections as possible risk factor for pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PAC) is a very aggressive and lethal cancer, with a very poor prognosis, because of absence of early symptoms, advanced stage at presentation, early metastatic dissemination and lack of both specific tests to detect its growth in the initial phases and effective systemic therapies. To date, the causes of PAC still remain largely unknown, but multiple lines of evidence from epidemiological and laboratory researches suggest that about 15-20% of all cancers are linked in some way to chronic infection, in particular it has been shown that several viruses have a role in human carcinogenesis. The purpose of this report is to discuss the hypothesis that two well-known oncogenic viruses, Human B hepatitis (HBV) and Human C hepatitis (HCV) are a possible risk factor for this cancer. Therefore, with the aim to examine the potential link between these viruses and PAC, we performed a selection of observational studies evaluating this association and we hypothesized that some pathogenetic mechanisms involved in liver carcinogenesis might be in common with pancreatic cancer development in patients with serum markers of present or past HBV and HCV infections. To date the available observational studies performed are few, heterogeneous in design as well as in end-points and with not univocal results, nevertheless they might represent the starting-point for future larger and better designed clinical trials to define this hypothesized relationship. Should these further studies confirm an association between HBV/HCV infection and PAC, screening programs might be justified in patients with active or previous hepatitis B and C viral infection.

HepG2 cells support viral replication and gene expression of hepatitis C virus genotype 4 in vitro

AIM

To establish a cell culture system with long-term replication of hepatitis C virus (HCV) genome and expression of viral antigens in vitro.

METHODS

HepG2 cell line was tested for its susceptibility to HCV by incubation with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various time points during the culture. Culture supernatant was tested for its ability to infect naive cells. The presence of minus (antisense) RNA strand, and the detection of core and E1 antigens in cells were examined by RT-PCR and immunological techniques (flow cytometry and Western blot) respectively.

RESULTS

The intracellular HCV RNA was first detected on d 3 after infection and then could be consistently detected in both cells and supernatant over a period of at least three months. The fresh cells could be infected with supernatant from cultured infected cells. Flow cytometric analysis showed surface and intracellular HCV antigen expression using in house made polyclonal antibodies (anti-core, and anti-E1). Western blot analysis showed the expression of a cluster of immunogenic peptides at molecular weights extended between 31 and 45 kDa in an one month old culture of infected cells whereas this cluster was undetectable in uninfected HepG2 cells.

CONCLUSION

HepG2 cell line is not only susceptible to HCV infection but also supports its replication in vitro. Expression of HCV structural proteins can be detected in infected HepG2 cells. These cells are also capable of shedding viral particles into culture media which in turn become infectious to uninfected cells.

HepG2 cells support viral replication and gene expression of hepatitis C virus genotype 4 in vitro

AIM

To establish a cell culture system with long-term replication of hepatitis C virus (HCV) genome and expression of viral antigens in vitro.

METHODS

HepG2 cell line was tested for its susceptibility to HCV by incubation with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various time points during the culture. Culture supernatant was tested for its ability to infect naive cells. The presence of minus (antisense) RNA strand, and the detection of core and E1 antigens in cells were examined by RT-PCR and immunological techniques (flow cytometry and Western blot) respectively.

RESULTS

The intracellular HCV RNA was first detected on d 3 after infection and then could be consistently detected in both cells and supernatant over a period of at least three months. The fresh cells could be infected with supernatant from cultured infected cells. Flow cytometric analysis showed surface and intracellular HCV antigen expression using in house made polyclonal antibodies (anti-core, and anti-E1). Western blot analysis showed the expression of a cluster of immunogenic peptides at molecular weights extended between 31 and 45 kDa in an one month old culture of infected cells whereas this cluster was undetectable in uninfected HepG2 cells.

CONCLUSION

HepG2 cell line is not only susceptible to HCV infection but also supports its replication in vitro. Expression of HCV structural proteins can be detected in infected HepG2 cells. These cells are also capable of shedding viral particles into culture media which in turn become infectious to uninfected cells.

Construction and expression of chrimeid plasmid pHCV-IgFc

AIM

To construct a recombinant cherimal plasmid of HCV-Fc that can express HCV core protein and IgG Fc.

METHODS

The HCV core gene derived from the plasmid pBRTM/HCV1-3011 by using polymerase chain reaction (PCR) was inserted into the backward position of cytomegalovirus (CMV) immediate early promotor element of Fc plasmid (pIgFc), then the recombinant plasmid pHCV-IgFc was obtained.

RESULTS

The insert DNA of pHCV-IgFc was HCV core and Fc gene conformed by endonuclease, PCR and sequencing. HCV core gene and Fc gene expressed transiently with Lipofectamine 2000 coated in human hepatoblastoma 7721 cells, which was conformed by immunofluorescence.

CONCLUSION

Recombinant cherimal plasmid vector pHCV-IgFc can express HCV core and Fc gene transiently in 7721 cells. It may be useful in transfection of dendritic cells and development into dendritic cell vaccince.

Effect of HCV NS3 on proliferation and phosphorylation of MAPK in human hepatocytes

AIM: To study effects of HCV NS3 protein on proliferation and transformation of normal human liver cell line.

METHODS: QSG7701 cells were transfected with pRcHCNS3-5' pRcHCNS3-3'and pRcCMV using liposome transfecting technique and selected with G418; Expression of HCV NS3 protein was determined by immunohistochemistry; Biological characters of transfected cells were evaluated by population doubling time and soft agar assays; activation of MAPK was analyzed by western blot.

RESULTS: QSG7701 cells transfected with pRcHCNS3-5'showed strong intracellular expression of HCVNS3 protein, and the positive signal was localized in cytoplasm. The level of expressed HCVNS3 protein in pRcHCNS3-3'transfected cells was lower than that in pRcHCNS3-5'transfected cells. The population doubling time in pRcHCNS3-5'ransfected cells (12 h) was significantly shorter than that in pRcHCNS3-3'ransfected cells (24 h), pRcCMV transfected cells (26h) and normal cells (28 h) (P < 0.01). The cells transfected with pRcHCNS3-5'showed much more anchorage independent colonies than those with pRcHCNS3-3'and pRcCMV (P < 0.01). The cloning efficiencies of transfected cells with pRcHCNS3-5' pRcHCNS3-3' pRcCMV and controls were 33%, 1.33%, 1.46%, 1.11%, respectively. The level of phosphorylated MAPK in cells with pRcHCNS3-5'was much higher than those with pRcHCNS3-3'nd cell transfected with pRcCMV and normal cells (8 858 ± 877, 5 612 ± 656, 2 212 ± 245, 989 ± 188, P < 0.01).

CONCLUSION: QSG7701 is the good human liver cell line for investigating the pathogenesis of HCV NS3 protein. 5'region of the HCV genome segment encoding NS3 is involved in cell growth and cell phenotype. N-terminal peptide of HCV NS3 protein may up-regulate the activation of MAPK.

Inhibitory effect of IRES specific inhibitor RNA on HCV IRES mediated protein translation

AIM: To explore the inhibitory effect of internal ribosome entry site (IRES) specific inhibitor RNA (IRNA) on HCV IRES mediated protein translation in vivo.

METHODS: Human hepatic carcinoma cell line (HHCC) was transfected with the eukaryotic vectors of IRNA or mIRNA (pcRz-IRNA or pcRz-mIRNA), and then selected with G418 for 4 weeks. HHCC expressing IRNA or mIRNA was cotransfected with pCMVNCRluc containing HCV IRES. HHCC stably expressing pcHCVcluc was transfected with pcRz-IRNA, and pcRz-mIRNA, respectively, the luciferase activity was examined at desired time post-transfection.

RESULTS: The pCMVNCRluc was efficiently suppressed in HHCC expressing IRNA rather than the cell line expressing mIRNA. The IRES specific IRNA inhibited expression of HCV IRES mediated luc gene by 20% to 80% in pcHCVcluc expressing cell after transfection; However, no inhibitory effect of the mutant IRNA was observed.

CONCLUSION: pcHCVcluc could be expressed successfully in HHCC, and IRNA inhibited HCV IRES mediated gene expression in vivo.

Construction, package and identification of replication-deficient recombinant adenovirus expression vector of HCV C

AIM: To construct a replication-deficient recombinant adenovirus expression vector of HCV C.

METHODS: The HCV core gene was cloned at the downstream of CMV promoter of the adenoviral shuttle plasmid pAd. CMV-link. 1, and the resultant recombinant plasmid pAd. HCV-C was cotransfected into 293 cell together with plasmid pJM17 containing adenoviral genome, then the adenovirus expression vector was obtained, and identified by infecting test, electronic microscope observation and PCR co-amplification. The plasmid pAd. HCV-C was identified by endonuclease, PCR and sequencing. The expressive activity of adenovirus vector was identified by immunofluorescence and Western blot.

RESULTS: HCV core gene in the inserted DNA of pAd. HCV-C was confirmed by endonuclease, PCR and sequencing. Results of infecting test, electronic microscopic observation and PCR co-amplification showed that the adenovirus vector had been constructed successfully. Expression of HCV core antigen was proved in the HepG2 cells by immunofluorescence and Western blot.

CONCLUSION: The replication-deficient recombinant adenovirus vector can express HCV core antigen in HepG2 cells. This study established a foundation for further study on HCV vaccines and gene therapy for hepatitis C.

Detection of HBV, HCV and HBV YMDD mutants by DNA microarray

AIM: To investigate the effect of DNA microarray in detection of hepatitis B virus (HBV), hepatitis C virus (HCV) and HBV YMDD mutants.

METHODS: HBV and HCV in 40 serum samples were detected by mixed microarray and quantitative determination method as well; 20 serum samples from patients with hepatitis B treated with lamivudine were detected by microarray loaded HBV YMDD mutants gene, and were simultaneously tested with mismatched PCR and DNA sequencing for comparison.

RESULTS: The coincident rate of mixed microarray and quantitative determination of HBV DNA was 85% (34/40). The detectable rate of HBV by mixed microarray was 83% (19/23); 2 of 17 samples showed false positive reaction. The coincident rate of mixed microarray and HCV RNA quantitative determination was 85% (34/40). The detectable rate of HCV by mixed microarray was 58% (7/12). One of 28 samples showed false positive reaction. The coincident rate of HBV YMDD mutants microarray and mismatched PCR was 70% (14/20). Mixed infection of wild and mutant HBV or different mutants were detected by microarray.

CONCLUSION: Mixed microarray has high sensitivity and low non-specificity in detection of HBV, but has lower sensitivity and higher specificity in detection of HCV. Detection of HBV YMDD mutants and mixed infection with microarray had higher sensitivity and specificity.

Effects of cholesterol on the phenotype of rabbit bile duct fibroblasts

AIM: To investigate how cholesterol (Ch) can affect the phenotype of bile duct fibroblasts of New Zealand rabbits.

METHODS: 16 rabbits were divided randomly into two groups: the control group and the experiment group. The rabbits in experiment group were fed with hypercholesterol diet for 8 wk. Bile duct was dissociated from rabbits and prepared for transmission electron microscopy. The purified bile duct fibroblasts were cultured and divided randomly into there groups: control group, Ch smiddle concentration group (0.6 g/L), Ch high concentration group (1.2 g/L). After incubated for 72 h, the fibroblasts were made into specimens for transmission electron microscopy. The expression of α-actin in bile duct fibroblasts was measured by means of laser scanning confocal microscopy.

RESULTS: With the transmission electron microscopy, the normal bile duct fibroblasts were shuttle-shaped, and there were abundant rough endoplasmic reticulums (RER), but few mitochondria or microfilaments in cytoplasm. This is the typical phenotype of fibroblasts. Bile duct fibroblasts of hypercholesterolemic rabbits were observed. by the transmission electron microscopy Rough endoplasmic reticulums were significantly reduced, with a lot of microfilament bundles or stress fibers appeared in cytoplasm, especially under plasma membrane. Dense bodies were scattered within these bundles. Macula densas and discontinuous sarcolemma were found under plasma membrane. It suggested that the bile duct fibroblasts of hypercholesterolemic rabbits presented the phenotype of smooth muscle cell. The cultured bile duct fibroblasts also had typical phenotype of fibroblasts. After stimulated by middle concentration cholesterol (0.6 g/L) for 72 h, there appeared lots of microfilaments in cytoplasm, but without dense body, macula densa and discontinuous sarcolemma. Observed with confocal microscopy, there were many regular bundles of microfilaments in fibroblasts treated with middle concentration ch (0.6 g/L) and the expression of α-actin was signifiantly increased. The average fluorescence value of middle concentration group was 1628 ± 189 (P < 0.01 versus control group). Microfilaments and the expression of α-actin were greatly decreased in fibroblastes of high concentration group (1.2 g/L). The average fluorescence value of high concentration group was 1427 ± 153 (P < 0.05 vs middle concentration group). There were a lower expression of α-actin and few microfilaments in bile duct fibroblasts of control group with an average fluorescence value of 1224 ± 138.

CONCLUSION: Cholesterol can make bile duct fibroblasts have the phenotypic characteristics of smooth muscle cell both in vitro and in vivo and this effect is more significant in vivo. The effect is probably associated with some other factors besides cholesterol.

Investigation of HGV and TTV infection in sera and saliva from non-hepatitis patients with oral diseases

AIM: To determine the frequencies of HGV and TTV infections in serum and saliva samples of non-hepatitis patients with oral diseases in Hangzhou area, and to understand the correlation between detected results of HGV RNA and/or TTV DNA in sera and in saliva from the same patients.

METHODS: RT-nested PCR for HGV RNA detection and semi-nested PCR for TTV DNA detection were performed in the serum and saliva samples from 226 non-hepatitis patients with oral diseases, and nucleotide sequence analysis.

RESULTS: Twenty-seven (11.9%) and 21 (9.3%) of the 226 serum samples were only positive for HGV RNA and TTV DNA, respectively. 10 (4.4%) and 9 (3.9%) of the 226 saliva samples were only positive for HGV RNA and TTV DNA, respectively. And 7 (3.1%) of the serum samples and 2 (0.9%) of the saliva samples showed the positive amplification results for both HGV RNA and TTV DNA. 12 saliva samples from the 34 patients (35.3%) with HGV or HGV/TTV viremia and 11 saliva samples from the 28 patients (39.3%) with TTV or HGV/TTV viremia were HGV RNA detectable, respectively, including two patients positive for both HGV RNA and TTV DNA in serum and saliva samples. No saliva samples from the 226 patients were found to be HGV RNA or TTV DNA detectable while their serum samples were negative for HGV or TTV. Homologies of the nucleotide sequences of HGV and TTV amplification products from the serum and saliva samples of the two patients compared with the reported sequences were 88.65%-91.49% and 65.32%-66.67%, respectively. In comparison with the nucleotide sequences of amplification products between serum and from saliva sample from any one of the two patients, the homologies were 98.58% and 99.29% for HGV, and were 98.65% and 98.20% for TTV, respectively.

CONCLUSION: Relatively high carrying rates of HGV and/or TTV in the sera of non-hepatitis patients with oral diseases in Hangzhou area are demonstrated. Parts of the carriers are HGV and/or TTV positive in their saliva. The results of this study indicate that dentists may be one of the populations with high risk for HGV and/or TTV infection, and by way of saliva HGV and TTV may be transmitted among individuals.

Preparation of human single chain Fv antibody against hepatitis C virus E2 protein and its identification in immunohistochemistry

AIM: To screen human single chain Fv antibody (scFv) against hepatitis C virus E2 antigen and identify its application in immunohistochemistry.

METHODS: The phage antibody library was panned by HCV E2 antigen, which was coated in microtiter plate. After five rounds of biopanning, 56 phage clones were identified specific to HCV E2 antigen. The selected scFv clones were digested by Sfi I/Not I and DNA was sequenced. Then it was subcloned into the vector pCANTAB5E for expression as E-tagged soluble scFv. The liver tissue sections from normal person and patients with chronic hepatitis B and chronic hepatitis C were immunostained with HCV E2 scFv antibody.

RESULTS: The data of scFv-E2 DNA digestion and DNA sequencing showed that the scFv gene is composed of 750 bp. ELISA and immunohistochemistry demonstrated that the human single chain Fv antibody against hepatitis C E2 antigen has a specific binding character with hepatitis virus E2 antigen and paraffin-embedded tissue, but did not react with liver tissues from healthy persons or patients with chronic hepatitis B.

CONCLUSION: We have successfully screened and identified HCV E2 scFv and the scFv could be used in the immunostaining of liver tissue sections from patients with chronic hepatitis C.

Construction of HCV-core gene vector and its expression in cholangiocarcinoma

AIM: To establish an experimental model for exploring the role of hepatitis C virus (HCV) in the development of cholangiocarcinoma.

METHODS: Recombinant plasmid of HCV-core gene was constructed with molecular cloning technique and transfected into QBC939 cells with lipofection. After it was selected with G418, resistant colonies were obtained. The colonies were analysed by immunocytochemistry and Western blotting.The morphology was observed under transmission electron microscope(TEM) and microscope.

RESULTS: The recombinant plasmid was proved to carry the target gene by PCR and restriction enzymed mapping. Moreover, it could express HCV-C protein efficiently in QBC939 cells. The HCV-like particles were found in the cytoplasm by electron microscope, which were spherical with a diameter of 50 nm-80 nm possessing outer membrane.The transfected cells had lower differentiation and higher malignant degree under microscope.

CONCLUSION: Because HCV-core gene could express steadily in cholangiocarcinoma cells,the transfected tumor cells(QBC939-HCVC) could be used to study the effect of HCV in the development of cholangiocarcinoma.

Distribution of nitric oxide synthase in stomach myenteric plexus of rats

AIM: To study the distribution of nitric oxide synthase (NOS) in rat stomach myenteric plexus.

METHODS: The distribution of NOS in gastric wall was studied in quantity and location by the NADPH-diaphorase (NDP) histochemical staining method and whole mount preparation technique.

RESULTS: NOS was distributed in whole stomach wall, most of them were located in myenteric plexus, and distributed in submucosal plexus. The shape of NOS positive neurons was basically similar, most of them being round and oval in shape. But their density, size and staining intensity varied greatly in the different parts of stomach. The density was 62 ± 38 cells/mm² (antrum), 43 ± 32 cells/mm² (body), and 32 ± 28 cells/mm² (fundus), respectively. The size and staining intensity of NOS positive neurons in the fundus were basically the same, the neurons being large and dark stained, while they were obviously different in antrum. In the body of the stomach, the NOS positive neurons were in an intermediate state from fundus to antrum. There were some beadlike structures which were strung together by NOS positive varicosities in nerve fibers, some were closely adherent to the outer walls of blood vessels.

CONCLUSION: Nitric oxide might be involved in the modulation of motility, secretion and blood circulation of the stomach, and the significant difference of NOS positive neurons in different parts of stomach myenteric plexus may be related to the physiologic function of stomach.

High frequencies of HGV and TTV infections in blood donors in Hangzhou

AIM: To determine the frequencies of HGV and TTV infections in blood donors in Hangzhou.

METHODS: RT-nested PCR for HGV RNA detection and semi-nested PCR for TTV DNA detection in the sera from 203 blood donors, and nucleotide sequence analysis were performed.

RESULTS: Thirty-two (15.8%) and 30 (14.8%) of the 203 serum samples were positive for HGV RNA and TTV DNA, respectively. And 5 (2.5%) of the 203 serum samples were detectable for both HGV RNA and TTV DNA. Homology of the nucleotide sequences of HGV RT-nested PCR products and TTV semi-nested PCR products from 3 serum samples compared with the reported HGV and TTV sequences was 89.36%, 87.94%, 88.65% and 63.51%, 65.77% and 67.12%, respectively.

CONCLUSION: The infection rates of HGV and/or TTV in blood donors are relatively high, and to establish HGV and TTV examinations to screen blood donors is needed for transfusion security. The genomic heterogeneity of TTV or HGV is present in the isolates from different areas.

Hepatitis C virus infection of human hepatoma cell line 7721 in vitro

AIM: To establish a cell culture system with long-term replication of hepatitis C virus in vitro.

METHODS: Human hepatoma cell line 7721 was tested for its susceptibility to HCV by incubating with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various phases during the culturing periods. The presence of HCV RNA, the expression of HCV antigens in cells and/or supernatant were examined by RT-PCR, in situ hybridization and immunohisto-chemistry respectively.

RESULTS: The intracellular HCV RNA was first detected on d2 after infection and then could be intermittently detected in both cells and supernatant over a period of at least three months. The expression of HCV NS₃, CP₁₀ antigens could be observed in cells. The fresh cells could be infected by supernatant from cultured infected cells and the transmission of viral genome from HCV-infected 7721 cells to PBMCs was also observed.

CONCLUSION: The hepatoma line 7721 is not only susceptible to HCV but also supports its long-term replication in vitro.