Changes in rodent abundance and weather conditions potentially drive hemorrhagic fever with renal syndrome outbreaks in Xi'an, China, 2005-2012.

BACKGROUND: Increased risks for hemorrhagic fever with renal syndrome (HFRS) caused by Hantaan virus have been observed since 2005, in Xi'an, China. Despite increased vigilance and preparedness, HFRS outbreaks in 2010, 2011, and 2012 were larger than ever, with a total of 3,938 confirmed HFRS cases and 88 deaths in 2010 and 2011. METHODS AND FINDINGS: Data on HFRS cases and weather were collected monthly from 2005 to 2012, along with active rodent monitoring. Wavelet analyses were performed to assess the temporal relationship between HFRS incidence, rodent density and climatic factors over the study period. Results showed that HFRS cases correlated to rodent density, rainfall, and temperature with 2, 3 and 4-month lags, respectively. Using a Bayesian time-series Poisson adjusted model, we fitted the HFRS outbreaks among humans for risk assessment in Xi'an. The best models included seasonality, autocorrelation, rodent density 2 months previously, and rainfall 2 to 3 months previously. Our models well reflected the epidemic characteristics by one step ahead prediction, out-of-sample. CONCLUSIONS: In addition to a strong seasonal pattern, HFRS incidence was correlated with rodent density and rainfall, indicating that they potentially drive the HFRS outbreaks. Future work should aim to determine the mechanism underlying the seasonal pattern and autocorrelation. However, this model can be useful in risk management to provide early warning of potential outbreaks of this disease.

Hepatic angiomyolipoma mimicking hepatocellular carcinoma: magnetic resonance imaging and clinical pathological characteristics in 9 cases.

Hepatic angiomyolipoma (HAML) is a rare mesenchymal tumor of the liver with marked histological diversity. The present study was to review the magnetic resonance imaging (MRI) and clinical pathological features of HAML resembling hepatocellular carcinoma (HCC). Nine patients who underwent surgical resection and had pathological diagnosis of HAML were retrospectively analyzed. All of 9 patients (5 males and 4 females) had a solitary hepatic mass with a median size of 4 cm (from 1.4 cm to 15.3 cm). Seven cases were identified as incidental liver tumors during health screening and 2 patients were diagnosed for hepatic mass when visited hospitals with unspecific abdominal discomfort. Before resection, 6 cases were diagnosed as HCC on MRI. MRI on chemical shift imagings showed a large amount of lipids in 5 cases. The enhancement pattern of MRI was classified into 2 types: in 2 cases, lesions with small or no vessels that demonstrated prolonged enhancement (1 mixed subtype and 1 myomatous subtype) and in 7 cases, lesions with abundant central vessels that show rapid washout (3 mixed subtypes and 4 myomatous subtypes) in the portal venous/delayed phase. All patients underwent resection of hepatic tumor and no recurrence was observed during follow-up (range: 2-24 months) of median 10 months. By immunohistochemistry, the tumor cells demonstrated positive immunostaining for human melanoma black-45, smooth muscle actin, and CD34. In conclusion, all of 9 patients with HAML presented with none or nonspecific clinical manifestations. The diagnosis of HAML relies on disease and immunohistochemistry, but not MRI due to its resemblance to HCC.

Hypomethylation of long interspersed nuclear element-1 promoter is associated with poor outcomes for curative resected hepatocellular carcinoma.

BACKGROUND: Epigenetic alterations are well documented in hepatocarcinogenesis. However, hypomethylation of long interspersed nuclear element 1(LINE-1) promoter and its relationship with clinicopathological features in hepatocellular carcinoma(HCC) remain unknown. METHODS: The bisulfite-specific PCR and DNA sequencing analysis was performed to assess the methylation status of LINE-1 promoter in a pilot cohort of 71 patients with HCC. Additionally,methylation levels of two hot CpG sites of LINE-1 promoter, site 7 and 18 were measured by real-time PCR and compared with clinicopathological parameters in a cohort of 172 HCC. All the patients included were in BCLC stage A or B. RESULTS: Most patients with HCC (87.3%) showed hypomethylation of LINE-1 promoter compared with HBV-related cirrhosis and normal controls (P < 0.001). The HCC patients with LINE-1 promoter hypomethylation had a median tumour-free survival (TFS) and overall survival (OS)post-resection of 22.0 (95% CI: 13.3­30.7) months and 35.0 (95% CI: 24.0­46.1) months, respectively, compared with 40 months and ~60 months for those with LINE-1 promoter hypermethylation (P < 0.05). Multivariate analyses showed that the hypomethylation level at CpG site 7 and 18 of LINE-1 promoter, along with tumour size and tumour differentiation, was independently associated with both TFS and OS for patients with HCC after resection. CONCLUSION: Promoter hypomethylation of LINE-1, especially at the CpG site 7 and 18, was associated with a poor prognosis in HCC.

Long interspersed nuclear element ORF-1 protein promotes proliferation and resistance to chemotherapy in hepatocellular carcinoma.

AIM: To clarify the specific roles and mechanisms of long interspersed nuclear element-1 ORF-1 protein [human long interspersed nuclear element-1 (LINE-1), ORF-1p] in chemotherapeutic drug resistance and cell proliferation regulation in hepatocellular carcinoma (HCC) cells. METHODS: MTT assays were performed to identify the effect of the chemotherapeutic drug toxicity on HepG2 cells. Cell proliferation inhibition and the IC50 were calculated by the Origin 8.0 software. Western blotting assays were performed to investigate whether LINE-1 ORF-1p modulates the expression of some important genes, including p53, p27, p15, Bcl-2, mdr, and p-gp. To corroborate the proliferation and anchor-independent growth results, the HepG2 cells were analyzed by flow cytometry to investigate the effect of LINE-1 ORF-1p on the apoptosis regulation. RESULTS: LINE-1 ORF-1p contributed to the resistance to several chemotherapeutic drugs (cisplatin and epirubicin) in HepG2 cells. The IC50 of the epirubicin and cisplatin increased from 36.04 nmol/L to 59.11 nmol/L or from 37.94 nmol/L to 119.32 nmol/L. Repression of LINE-1 ORF-1p expression by the siRNA could markedly enhance the response of HepG2 cells to the epirubicin and cisplatin. The IC50 correspondingly decreased from 28.06 nmol/L to 3.83 nmol/L or from 32.04 nmol/L to 2.89 nmol/L. Interestingly, down-regulation of LINE-1 ORF-1p level by siRNA could promote the response of HepG2 cells to the paclitaxel. The IC50 decreased from 35.90 nmol/L to 7.36 nmol/L. However, overexpression of LINE-1 ORF-1p did not modulate the paclitaxel toxicity in HepG2 cells. Further Western blotting revealed that LINE-1 ORF-1p enhanced mdr and p-gp gene expression. As a protein arrested in the nucleus, LINE-1 ORF-1p may function through modulating transcriptional activity of some important transcription factors. Indeed, LINE-1 ORF-1p promoted HepG2 cell proliferation, anchor-independent growth and protected the cells against apoptosis through modulating the expression of p15, p21, p53, and Bcl-2 genes. CONCLUSION: LINE-1 ORF-1p promotes HepG2 cell proliferation and plays an important role in the resistance of chemotherapeutic drugs. By establishing novel roles and defining the mechanisms of LINE-1 ORF-1p in HCC chemotherapeutic drug resistance and cell proliferation regulation, this study indicates that LINE-1 ORF-1p is a potential target for overcoming HCC chemotherapeutic resistance.

High intratumoral metastasis-associated in colon cancer-1 expression predicts poor outcomes of cryoablation therapy for advanced hepatocellular carcinoma.

BACKGROUND: Cryoablation is one of the local therapies for hepatocellular carcinoma (HCC), but its safety and effect has not been studied in patients with Child class A or B and Barcelona Clinic Liver Cancer (BCLC) stage C HCC. Metastasis-associated in colon cancer-1 (MACC1) overexpression has been associated with poor prognosis of HCC, but its predictive value to post-cryoablation outcomes remains unknown in patients with BCLC stage C HCC. METHODS: This study assessed the safety and outcomes of cryoablation measured by time to progression (TTP) and overall survival (OS), and predictive value of MACC1 mRNA and protein overexpression in tumorous tissue to post-cryoablation outcomes in 120 advanced HCC patients with child-pugh class A or B by quantitative polymerase chain reaction and immunohistochemical staining. The potenial correlation of MACC1 and c-Met expression to tumor cell proliferation and apoptosis was also analyzed. RESULTS: The cryoablation in patients with advanced unresectable HCC resulted in a median TTP and OS of 5.5 (4.2- 6.7) months and 10.5 (9.0-12.0) months, respectively and no significant complications, comparable to the historical report for RFA therapy. The MACC1 mRNA and nuclear protein expression was significantly increased in tumorous tissues in these patients than that in normal liver tissue controls. Higher expression of MACC1 mRNA and nuclear protein in tumorous tissues in these patients was associated with shorter post cryoablation median TTP and OS than that with lower MACC1 expression. CONCLUSIONS: Cryoablation is a safe and effective therapeutic option for patients with advanced HCC and Child-pugh class A or B cirrhosis; and a higher intratumoral expression of MACC1 or nuclear translocation predicts poor outcomes of cryotherapy in these patients.

Tumour seeding after percutaneous cryoablation for hepatocellular carcinoma.

AIM: To assess the rate and risk factors for tumour seeding in a large cohort of patients. METHODS: Over an 8-year period, 1436 hepatocellular carcinoma (HCC) patients with 2423 tumour nodules underwent 3015 image-guided percutaneous cryoablation sessions [1215 guided by ultrasonography and 221 by spiral computed tomography (CT)]. Follow-up CT or magnetic resonance imaging was performed every 3 mo. The detailed clinical data were recorded to analyse the risk factors for seeding. RESULTS: The median follow-up time was 18 (range 1-90) mo. Seeding was detected in 11 patients (0.76%) at 1-24 (median 6.0) mo after cryoablation. Seeding occurred along the needle tract in 10 patients and at a distant location in 1 patient. Seeded tumours usually showed similar imaging and histopathological features to the primary HCCs. Univariate analyses identified subcapsular tumour location and direct subcapsular needle insertion as risk factors for seeding. Multivariate analysis showed that only direct subcapsular needle insertion was an independent risk factor for seeding (P = 0.017; odds ratio 2.57; 95%CI: 1.47-3.65). Seeding after cryoablation occurred earlier in patients with poorly differentiated HCC than those with well or moderately differentiated HCC [1.33 ± 0.577 mo vs 11.12 ± 6.896 mo; P = 0.042; 95%CI: (-19.115)-(-0.468)]. CONCLUSION: The risk of seeding after cryoablation for HCC is small. Direct puncture of subcapsular tumours should be avoided to minimise seeding.

Overexpression of metastasis-associated in colon cancer 1 predicts a poor outcome of hepatitis B virus-related hepatocellular carcinoma.

AIM: To investigate the intratumoral expression of metastasis-associated in colon cancer 1 (MACC1) and c-Met and determine their clinical values associated with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). METHODS: A retrospective study admitted three hundred fifty-four patients with HBV-related HCC. The expression and distribution of MACC1 and c-Met were assessed by quantitative real-time polymerase chain reaction and immunohistochemistry staining. Prognostic factors influencing survival, metastasis and recurrence were assessed. RESULTS: Intratumoral MACC1 level was found to be associated with HCC disease progression. Both median tumor-free survival (TFS) and overall survival (OS) were significantly shorter in the postoperative HCC patients with high intratumoral MACC1 expression, as compared to those with low intratumoral MACC1 levels (TFS: 34 mo vs 48.0 mo, P < 0.001; OS: 40 mo vs 48 mo, P < 0.01). Multivariable analysis indicated that high MACC1 expression or co-expression with c-Met were independent predictors for HCC clinic outcome (P < 0.001). CONCLUSION: High intratumoral MACC1 expression can be associated with enhanced tumor progression and poor outcome of HBV-related HCC. MACC1 may serve as a prognostic biomarker for postoperative HCC.

[Long term epidemiological effects of vaccination on hemorrhagical fever with renal syndrome (HFRS) in Shaanxi provincial HFRS epidemic areas].

OBJECTIVE: To evaluate the protective rate and the variation of HFRS-IgG on hemorrhagical fever with renal syndrome (HFRS) vaccine. METHODS: Cluster, random sampling and cross-sectional study were used to assess the protective rate of HFRS vaccination. Level of HFRS-IgG was detected with ELISA in epidemic and non-epidemic areas of HFRS. RESULTS: Curve equation was obtained as Yprotective rate=(0.863+0.283/Xvaccination term)×100% by protective rate with vaccination term. Protective rates showed a reducing trend, 90% after 7-8 years of vaccination, 88% after 10 years, and 94% on average. Absorbance (A) value of HFRS-IgG was 4 times higher in persons with vaccination than those without, in the epidemic area. Higher antibody level could be obtained after primary vaccination, but the level of antibody had a 50% reduction after 5-10 years of vaccination, and a 60% reduction after 10 years of vaccination. CONCLUSION: HFRS antibody had a 50% reduction after 5-10 years of vaccination. The protective rate of HFRS vaccination had a 90% loss, after 7-8 years of vaccination. Booster dose was necessary after 7 years of vaccination.

Feasibility study of secure closure of gastric fundus perforation using over-the-scope clips in a dog model.

BACKGROUND AND AIM: Gastric fundus perforation is a serious complication of endoscopic mucosal resection and endoscopic submucosal dissection performed for the removal of early gastric cancers or subepithelial tumors. The novel over-the-scope clip (OTSC) has recently been found to be effective for closing gastrointestinal-tract perforations and accesses for natural orifice transluminal endoscopic surgery. However, feasibility studies of OTSCs in gastric fundus perforation are still lacking. The aim of this study was therefore to demonstrate the feasibility of endoscopic closure of gastric fundus perforation using the OTSC system in a dog model. METHODS: Gastric fundus perforations were created by needle-knife electrocautery in seven dogs. The perforations were then closed using the OTSC clipping system. Stomach distension was maintained by maximum insufflation with air and methylene blue solution (500 mL) was instilled to submerge the closed perforation. Leaks were detected laparoscopically. RESULTS: Perforations were closed in all seven cases with a mean time of 18.5 ± 6.4 min (11-28 min). Twin Grasper assistance failed to release the OTSCs in two of the seven cases (2/7, 28.6%) because of difficulties associated with the J-maneuver (retroflexion of endoscope) required for the gastric fundus procedure, and OTCS were forced into place by suction. Minor leakage was observed in one case (1/7, 14.3%). No damages related to the clip system were found during postmortem examinations. CONCLUSIONS: Despite difficulties associated with the J-maneuver of the endoscope, this small series demonstrated that sufficient closure of gastric fundus perforation could be achieved using the OTSC system.

Decrease in size of non-treated lesions after cryoablation for hepatocellular carcinoma.

We present the case of one 58-year-old man with advancd hepatocellular carcinoma and hepatitis-B virus-related liver cirrhosis who received hepatic cryoablation. Magnetic resonance imaging (MRI) showed multiple liver tumors and the diameter of the largest tumor was more than 10cm. The patient received 2 percutaneous cryoablations in December 2009 and January 2010. Ten months later, MRI showed that not only the treated areas underwent necrosis but also the non-treated area decreased. The a-fetoprotein (AFP) level and the frequency of circulated regulatory T cell (Treg) before treatment were 13,800ng/mL and 15.6%, respectively. Following the cryoablations they dropped to 436ng/mL and 7.6%, respectively, 10 months later. The patient remains in good condition until now.

[Expression and clinical significance of metastasis-associated in colon cancer 1 (MACC1) in HBV-related hepatocellular carcinoma].

OBJECTIVE: To clarify the expression and clinical significance of metastasis-associated in colon cancer 1 (MACC1) mRNA in hepatocellular carcinoma (HCC). METHODS: The expression and distribution of MACC1 were assessed by quantitative real-time polymerase chain reaction (RT-PCR) and immunohistochemical staining (IHC) in a cohort of hepatitis B virus-related HCC, including 138 in early (A), 96 in intermediate (B) and 120 in advanced stages (C). The association of MACC1 mRNA with disease progression and outcomes was analyzed by univariate and multivariate Cox analysis. RESULTS: The intratumoral expressions of MACC1 mRNA in HCC stage I (0.001 76, range: 0.000 54 - 0.002 47), stage II (0.002 49, range: 0.000 55 - 0.006 78) and stage III (0.008 35, range: 0.006 86 - 0.009 88) were about 3-, 4- and 14-fold higher than that in the normal liver tissue (0.000 59, range: 0.000 57 - 0.000 60), respectively. Intratumoral expression of MACC1 mRNA increased with disease progression from stage I to stage III. HCC clinical staging classification, age, portal vein invasion and tumor differentiation were significantly associated with intratumoral high expression of MACC1 mRNA (All P < 0.05). Immunohistochemical staining showed that there was an increased MACC1 expression in cytoplasm of HCC cells and positive nuclear staining in some cases. Increased MACC1 mRNA expression could predict poor outcome and recurrence in stage A and B HCC postoperatively. The median tumor-free survival and total survival of patients with high MACC1 mRNA expression were 34.0 and 40 months, respectively, significantly lower than that in those with low expression (48.0 and 48.0 months) (all P < 0.01). Cox analysis showed that Child-Pugh grading and high expression of MACC1 mRNA were independent predictive factors, and high expression of MACC1 was an independent predictive factor affecting the tumor-free survival. CONCLUSIONS: MACC1 mRNA up-regulation is a feature of disease progression in HCC. MACC1 mRNA expression in the HCC may become an independent predictive factor for recurrence and survival in postoperative HCC patients.

Upregulation of circulating PD-L1/PD-1 is associated with poor post-cryoablation prognosis in patients with HBV-related hepatocellular carcinoma.

BACKGROUND: The programmed cell death-1 receptor/programmed cell death-1 ligand (PD-1/PD-L1) pathway plays a crucial role in tumor evasion from host immunity. This study was designed to evaluate the association between circulating PD-L1/PD-1 and prognosis after cryoablation in patients with HBV-related hepatocellular carcinoma (HCC). METHODOLOGY/PRINCIPAL FINDINGS: In the present study, 141 HBV-related HCC patients were enrolled and of those 109 patients received cryoablation. Circulating PD-L1/PD-1 expression was tested by flow cytometry, and 23 patients were simultaneously evaluated for intratumoral PD-L1 expression by immunohistochemical staining. Circulating PD-1/PD-L1 expression was associated with severity of diseases in patients with HCC, and the circulating PD-L1 expression was closely correlated with intratumoral PD-L1 expression. Of the clinical parameters, PD-1/PD-L1 expression was associated with tumor size, blood vessel invasion and BCLC staging. Moreover, PD-1/PD-L1 expression dropped after cryoablation while being elevated at the time of tumor recurrence. Patients with higher expression of circulating PD-L1, as well as circulating PD-1, had a significantly shorter overall survival and tumor-free survival than those with lower expression. Multivariate analysis confirmed that circulating PD-L1 could serve as an independent predictor of overall survival and tumor-recurrence survival in HCC patients after cryoablation. CONCLUSIONS/SIGNIFICANCE: Upregulation of circulating PD-L1/PD-1 is associated with poor post-cryoablation prognosis in patients with HBV-related hepatocellular carcinoma.

[Hepatitis B virus X protein inhibits hepatoma cell growth in vitro through p14(ARF)-dependent and p14(ARF)-independent pathways].

OBJECTIVE: To explore the effects of hepatitis B virus X protein (HBx) on hepatoma cell growth through p14(ARF)-dependent and p14(ARF)-independent pathways. METHODS: HBx and p14(ARF) were transfected either separately or in combination into HepG2 cells containing wt-p53 but not expressing p14(ARF). The cells were divided into 4 groups, namely pcDNA3 (control), pcDNA3HBx, pcDNA3p14(ARF), and pcDNA3HBx + pcDNA3p14(ARF) groups. Flow cytometry was used to examine the apoptosis rates and cell cycle progression of HepG2 cells in different groups. The expression of p14(ARF), MDM2, p53, and p21(WAF1) proteins were investigated by detecting the activity of p21(WAF1) promoter-luciferase and using Western blotting. RESULTS: The apoptosis rates of HepG2 cells in pcDNA3HBx and pcDNA3p14(ARF) groups were significantly higher than that in the control group (14.11%, 13.72% vs 10.66%). Compared with the control group, pcDNA3HBx and pcDNA3p14(ARF) groups also showed significantly higher cell percentages arrested at G(0)/G(1) phase (63.62%, 61.75% vs 57.42%), luciferase activity of p21 promoter (1.25-/+0.05, 1.09-/+0.06 vs 0.77-/+0.03) and expressions of p53 and p21(WAF1). The cell apoptosis rate, percentage of cells in G(0)/G(1) phase and expression level of p14(ARF) were even higher in pcDNA3HBx+pcDNA3p14(ARF) group (18.61%, 66.74%, and 3.53-/+0.43, respectively) than in either p14(ARF) or HBx group. CONCLUSION: HBx induces p53 expression through p14(ARF)-dependent and independent pathways to activate p21(WAF1) promoter, leading to G(0)/G(1) arrest and apoptosis of HepG2 cells.

Comparative study on overexpression of HER2/neu and HER3 in gastric cancer.

BACKGROUND: Owing to the special importance of the HER family in tumorigenesis, the downstream signaling pathways and effectors have become the key molecules in the strategy of carcinoma-targeted therapy. Recent evidence that HER3 is responsible for tumor resistance to therapeutic agents targeting EGFR or HER2/neu, along with the new findings that HER3 is involved in the process of dedifferentiation of gastric cancer (GC) have highlighted the critical role of HER3 in cancer research. HER3 is becoming a new targeted molecule in cancer treatment. Here, we comparatively investigated the expression of HER2/neu and HER3 in gastric cancer of two pathologic types (intestinal type and diffuse type) using immunohistochemistry (IHC) and analyzed the correlation between overexpression of HER2 and HER3 and clinicopathologic parameters. METHODS: An IHC study for HER2 and HER3 was performed on 102 formalin-fixed, paraffin-embedded specimens of GC-60 intestinal and 42 diffuse types. The correlation between overexpression of HER2 and HER3 and clinicopathologic parameters was statistically analyzed. RESULTS: In the GC group, overexpression of HER2 and HER3 was detected in 19 (18.6%) and 14 (13.7%) of 102 GC patients, respectively. In a nontumorous group of 102 specimens, 5 were HER2-positive (4.9%) (18.6% vs. 4.9%, p < 0.01), and 2 were HER3-positive (2.0%) (13.7% vs. 2.0%, p < 0.01). No co-overexpression of HER2 and HER3 was observed. The intestinal type of GC exhibited a higher rate of HER2 overexpression than did the diffuse type (26.7% vs. 7.1%, p < 0.05), whereas the diffuse type of GC exhibited a significantly higher rate of HER3 overexpression than did the intestinal type (26.2% vs. 5.0%, p < 0.01). The overexpression rates of HER2 and HER3 in phase III-IV (TNM stage) disease were significantly higher than that in phase I-II disease (24.0% vs. 7.7%, p < 0.05 and 22.0% vs. 5.8%, p < 0.05, respectively). HER2 and HER3 overexpression was also correlated with a significantly worse survival (p = 0.046 and 0.024, respectively). CONCLUSIONS: The selective overexpression of HER2 and HER3 in the two histologic types of gastric cancer is strongly associated with a poor prognosis. Being an important member of the HER family, HER3 may become another candidate for molecular-targeted therapy in gastric cancer, especially for the diffuse histologic type.

Identification of genes upregulated by recombinant interferon-alpha in HepG2 cells by suppressive subtractive hybridization analysis.

BACKGROUND: Interferon-alpha (IFN-alpha) is an important cytokine with multiple functions, but the target genes transactivated by IFN-alpha remain largely unknown. A study of such genes will help to understand the mechanism of function of IFN-alpha. To isolate the gene transcripts specifically upregulated by IFN-alpha in HepG2 cells, we conducted suppressive subtractive hybridization (SSH) analysis. METHODS: SSH was used to analyze the target genes transactivated by recombinant IFN-alpha protein, and a subtractive cDNA library was constructed from HepG2 cells treated with recombinant IFN-alpha (rIFN-alpha, 2000 IU/ml) for 16 hours as tester, and cells not treated with rIFN-alpha as driver. The SSH PCR products from the library were cloned into pGEM-T easy vector and with BLASTX, the positive clones were randomly selected, sequenced and compared to the database in GenBank of the 35 differentially expressed gene fragments from the library, 6 clones showed significant homology to other known proteins. RESULTS: The subtractive cDNA library of genes upregulated by IFN-alpha was constructed successfully. rIFN-alpha upregulated the expression of the RAN binding protein 5 (RANBP5), NADH dehydrogenase, exosome component 3 (EXOSC3), zinc finger RNA binding protein, Dickkopf homolog 1 (DKK1) and acetyl-coenzyme A acetyltransferase 2 (ACAT2). CONCLUSIONS: These results suggest that rIFN-alpha can upregulate the expression of important genes to exert its functions, and provide new clues for discovering the molecular mechanisms of action of IFN-alpha.

[Screening and identification of proteins interacting with HCV NS4A via yeast double hybridization in leukocytes and gene cloning of the interacting protein].

OBJECTIVE: To screen proteins interacting with HCV NS4A protein in leukocytes by yeast-double hybridization. METHODS: The bait plasmid pGBKT7-NS4A was transformed into yeast AH109 was transformed, and the expressing of the fusion protein was identified by SDS-page. The transformed yeast was mated with yeast Y187 containing leukocytes cDNA library plasmid in 2xYPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) and synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x-alpha-gal for selecting two times and screening. After extracting and sequencing of plasmid from blue colonies, analysis was conducted by bioinformatics. And, the gene encoding the interesting protein was cloned, and back-cross was performed. RESULTS: Forty-five colonies were sequenced, among them, 29 colonies were human calcium modulating cyclophilin ligand (CAML). The gene encoding CAML was cloned, and the interaction between NS4A and CAML was ensured. CONCLUSION: Seven kinds of proteins interacting with NS4A in leukocytes were successfully screened and the results brought some new clues for studying the pathogenesis of HCV.

Effects of hepatitis B virus on p53 expression in hepatoma cell line SMMU-7721.

AIM: To investigate the contribution of HBV in the development of hepatocarcinoma by examining the effects of HBV on p53 function in SMMU-7721 cell line. METHODS: Plasmid pCMVp53 was transfected or cotransfected with pCMVHBVa (wild-type HBV) or PCMVHBVb (mutation type HBV) into the hepatoma cell line SMMU-7721 by lipofectamine. Apoptosis cells were labeled with annexin V-FITC and confirmed by flow cytometry. Reporter plasmid PG13-CAT or p21-luc was cotransfected, respectively, into each group to determine the transactivation activity of p53 and its effect on p21 promoter. Western blot was performed to observe p53 expression in hepatoma cell line of each group. RESULTS: The group transfected with pCMVp53 alone exhibited higher luciferase activity and higher apoptosis rate, otherwise, the p53 expression and reporter activity of PG13-CAT or P21-luc as well as cell apoptosis rate were obviously higher in the group cotransfected of pCMVp53 with pCMVHBVa, but not in the other cotransfected group. CONCLUSION: Transient transfection of HBV into the SMMU-7721 cell line can enhance p53 expression and its effects on development of hepatocarcinoma.

[Study of the down-regulating effect of hepatitis C virus NS5A protein on NACA promoter].

OBJECTIVE: To investigate the effect of hepatitis C virus (HCV) non-structure protein NS5A on the activity of calcium-regulating protein alpha subunit of nascent polypeptide-associated complex (NACA) promoter. METHODS: HepG2 cell plasmid pCAT3-NACA, containing NACA promoter, was transfected alone or cotransfected with pcDNA3.1(-)-NS5A, and chloramphenicol acetyl transferase (CAT) enzyme activity was assayed by enzyme-linked immunoassay (ELISA). RESULTS: The CAT activity in the pcDNA3.1(-)-NS5A cotransfection group was 20.7% of the CAT activity in the pCAT3-NACA group. CONCLUSION: HCV non-structural protein NS5A has a down-regulating effect on the promoter of NACA gene.