[Metabolomics of nasal lavage fluid in patients with allergic rhinitis treated by Xiaoqinglong Decoction].

This study used nasal lavage fluid for metabolomics to explore its feasibility, and applied it to the clinical metabolomics study of Xiaoqinglong Decoction in the treatment of allergic rhinitis(AR), aiming to investigate the molecular mechanism of Xiaoqing-long Decoction in the treatment of AR through differential changes in local nasal metabolism. AR patients were selected as the research subjects, and nasal lavage fluid was collected as the sample. Metabolomics analysis using liquid chromatography-mass spectrometry was performed on normal group, AR group, and Xiaoqinglong Decoction group. The differences in metabolic profiles among the groups were compared using principal component analysis and partial least squares discriminant analysis, and differential metabolites were identified and subjected to corresponding metabolic pathway analysis. The results showed that Xiaoqinglong Decoction significantly improved the symptoms of AR patients. The metabolomics analysis revealed 20 differential metabolites between AR group and Xiaoqinglong Decoction group. The core metabolite with a trending return in comparison to normal group was trimethyladipic acid. The metabolites were involved in multiple pathways, including ß-alanine metabolism, glutathione metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis. The feasibility of applying nasal lavage fluid in nasal metabolomics was preliminarily demonstrated. Differential metabolites and enriched pathways in the treatment of AR patients with Xiaoqinglong Decoction were identified, indicating that it may improve rhinitis symptoms through the regulation of various metabolites, including antioxidant effects and correction of Th1/Th2 imbalance.

Application of bridge-link type combined fixation system in the treatment of trifocal femoral fractures.

PURPOSE: Ipsilateral combined fractures of the proximal femur, femoral shaft, and distal femur, though uncommon, present significant treatment challenges for orthopaedic surgeons. This retrospective study aims to investigate the intraoperative and long-term postoperative outcomes of this combination fracture when treated using a bridge-link type combined fixation system (BCFS). PATIENTS AND METHODS: Four individuals received treatment at a level 1 trauma centre between January 2013 and December 2017 for combined fractures of the proximal femur, femoral shaft, and distal femur. The medical records of these patients were retrospectively examined. In addition to minimally invasive percutaneous plate osteosynthesis (MIO), all patients underwent BCFS. RESULTS: The median follow-up period for each patient was 28.5 months. The median duration of the surgical procedure was 176.0 min, with intraoperative haemorrhage measured at 470.0 ml. Among the cases, three patients showed firm union of the femoral shaft fractures. However, one patient experienced nonunion 12 months after the procedure, while another patient suffered from refracture of the femoral shaft and postoperative avascular necrosis of the femoral head. At the time of the last follow-up, the Friedman-Wyman functional scores were excellent in one case, good in two cases, and fair in one case. CONCLUSIONS: Trifocal femoral fractures lack a widely approved therapeutic strategy. Nonetheless, BCFS may present itself as a viable alternative for treating this type of fracture, offering positive clinical outcomes.

Xiao-qing-long-tang ameliorates OVA-induced allergic rhinitis by inhibiting ILC2s through the IL-33/ST2 and JAK/STAT pathways.

BACKGROUND: Allergic rhinitis (AR) is a chronic inflammatory disease of the nasal mucosa that is mediated by immunoglobulin E (IgE). Xiao-qing-long-tang (XQLT) is a traditional Chinese medicine compound that is widely used to treat respiratory diseases such as AR. However, the underlying mechanism of the effect of XQLT on AR remains unclear. PURPOSE: To elucidate the effect of XQLT on ovalbumin (OVA)-induced AR and the mechanisms of action. METHODS: The therapeutic efficacy of XQLT was evaluated in a well-established OVA-induced AR mouse model. Nasal symptoms were analyzed, type 2 cytokines and OVA-sIgE levels were measured, nasal mucosa tissues were collected for histological analysis, and the changes of Group 2 innate lymphoid cells (ILC2s) and the IL-33/ST2 and JAK/STAT signaling pathways in the nasal mucosa were observed. RESULTS: XQLT significantly alleviated the nasal symptoms and histological damage to the nasal mucosa in AR mice, and reduced the levels of type 2 cytokines and OVA-sIgE. In addition, after XQLT treatment, the numbers of ILC2s in the nasal mucosa of AR mice were reduced, and the mRNA levels of the transcription factors GATA3 and ROR-α were decreased. Moreover, IL-33/ST2 signaling pathway was inhibited. The costimulatory cytokine associated JAK/STAT signaling pathway was also inhibited in ILC2s. CONCLUSION: Our study demonstrated that XQLT regulated ILC2s through the IL-33/ST2 and JAK/STAT pathways to ameliorate type 2 inflammation in OVA-induced AR. These findings suggest that XQLT might be used to treat AR.

HDAC Downregulation of Xiaoqinglong Decoction in the Treatment of Allergic Rhinitis.

INTRODUCTION: As one of the most common allergic diseases, allergic rhinitis (AR) has attracted wide attention all over the world. More appropriate treatment of AR should be explored thoroughly. In recent years, traditional Chinese medicine has attracted more attention in AR treatment. As a classical Chinese medicine prescription, Xiaoqinglong decoction (XQLD) has been commonly used in treating AR. Even though its therapeutic effect on AR has been clinically confirmed, more molecular mechanism remains to be further investigated. Our research aimed to investigate the therapeutic mechanism of XQLD for AR management. METHODS: The study was evaluated in an ovalbumin sensitized mouse model and liquid chromatography-mass spectrometry was adopted to test the stability of XQLD's effective components. RESULTS: The results confirmed the stability and safety of the effective components of XQLD. XQLD significantly downregulated the expression of HDACs (HDAC1, HDAC3, and HDAC4) and Th2 inflammatory factors (IL4, IL5, and IL13) in AR mice. XQLD and the HDAC inhibitor JNJ-26481585 promoted the expression of epithelial tight junction proteins (claudin-1 and ZO-1) and decreased the expression of mucins (Muc5ac and Muc5b) in the nasal mucosa of AR mice. CONCLUSIONS: In conclusion, our findings present the beneficial effects of XQLD on AR and recovery of the nasal epithelium. We also identify the decreased HDAC as a potential target of XQLD for AR treatment. This study provides an important experimental proof for elucidating the therapeutic mechanism of XQLD.

A novel weak acid activated probe for highly selective monitoring selenocysteine in living cells.

Selenocysteine (Sec, pKa 5.8) is genetically encoded 21st amino acid into the active site of selenoproteins, which have broad functions relevant to various diseases, tissues or organs and subcellular organelles. However, many selenoproteins involved cellular functions still remains unclear. In addition, since biothiols such as glutathione (GSH, pKa 8.3), possessing similar chemical properties with Sec, commonly exist in living systems at high levels. Thus, it is of great importance and high challenge to identify novel probes for selectively monitoring Sec over biothiols. In this paper, we proposed a smart strategy which allowed us to develop a lysosome targetable probe for specifically sensing Sec. By restricting weak acidic microenvironment, the probe shows a specific detection for Sec with 85-fold fluorescence enhancement owing to the remaining high activity of Sec at pH 5.0. Moreover, being low cytotoxicity to the cells verified by MTS assay, the probe was then successfully applied for imaging exogenous and endogenous Sec in lysosomes, indicating its potential for the biological investigation of Sec in subcellular organelles.

Prognostic role of apoptosis-related gene functional variants in advanced non-small-cell lung cancer patients treated with first-line platinum-based chemotherapy.

BACKGROUND: Single-nucleotide polymorphisms in apoptosis-related genes have been shown to play a role in the efficacy of platinum-based chemotherapy and may influence clinical outcomes. Our study aimed to evaluate the correlations of four functional single-nucleotide polymorphisms - FAS -670 A>G, FAS ligand -844 T>C, survivin -31 G>C, and survivin 9386 C>T - with drug response and clinical outcomes in advanced non-small-cell lung cancer patients who received platinum-based chemotherapy. MATERIALS AND METHODS: Polymorphisms were evaluated using the polymerase chain reaction-based restriction fragment-length polymorphism technique. RESULTS: Patients with the CC genotype of FAS -670 A>G had worse overall survival (OS) than those with the CT or TT genotype (P=0.044), with median OS values of 20.1 months, 22.8 months, and 26.0 months, respectively. Furthermore, progression-free survival was associated with the FAS -670 A>G polymorphism (P=0.032). In addition, patients with the TC and CC genotypes of survivin 9386 C>T experienced improved survival compared with patients with the TT genotype (median OS 31.4 months and 22.8 months, respectively). CONCLUSION: The functional FAS -670 A>G and survivin 9386 C>T polymorphisms are potential independent prognostic factors in advanced non-small-cell lung cancer patients treated with platinum-based chemotherapy.

The role of Moloney leukemia virus 10 in hepatitis B virus expression in hepatoma cells.

Recent studies have shown that the Moloney leukemia virus 10 (Mov10), a putative RNA helicase, has very broad and potent antiretroviral activities. Hepatitis B virus (HBV) has a reverse transcription process, but the potential role of Mov10 in HBV replication remains unknown. In this study, Mov10 was demonstrated to affect HBV expression in HepG2 and HepG2.2.15 cell lines. The data showed that the over-expression of exogenous Mov10 resulted in an increase of the HBsAg and HBeAg levels in the culture supernatant and HBV mRNA level in transfected cells at a low dose and resulted in a decrease at a high dose, but HBV DNA in culture supernatant was not affected. The knockdown of endogenous Mov10 expression through siRNA treatment could suppress levels of HBsAg, HBeAg and HBV mRNA, but had no effect on HBV DNA. Above results indicate that an appropriate level of exogenous Mov10 is responsible for HBV replication, that any perturbation in the level of Mov10 could affect HBV replication, while the endogenous Mov10 could promote HBV replication in vitro. The precise mechanisms that underlie the action of Mov10 on HBV still need further investigation.

p53 is an independent prognostic factor in operable esophageal squamous cell carcinoma: a large-scale study with a long follow-up.

The p53 protein is involved in many biological functions in cancer, such as cell cycle arrest, DNA repair, apoptosis, senescence, DNA metabolism, angiogenesis, and cellular differentiation. However, the association between p53 expression and clinicopathological findings or prognosis in esophageal squamous cell carcinoma (ESCC) is controversial. We designed a large-scale study of 830 operable ESCC patients with a long follow-up to investigate the relationship between p53 expression and the clinicopathological characteristics and prognosis of patients. Immunohistochemistry was used to detect p53 protein expression. When the patients were divided into two groups, a positive expression group and a negative expression group, p53-positive expression positively correlated with a poorer differentiation level (P = 0.044). The overexpression of p53 was associated with a more advanced clinical stage (P = 0.015). A total of 775 patients were available for survival analysis. The median OS of 160 patients who had p53-positive expression and 486 patients who had p53-negative expression were 58.8 and 46.3 months, respectively (P = 0.021); the median PFS of the two groups were 39.6 and 27.5 months, respectively (P = 0.015). Lymph node metastasis, gender, differentiation, depth of invasion, and p53 protein expression were proven to have an influence on both OS and PFS in a univariate analysis. In the multivariate analysis, p53-positive expression maintained its independent prognostic impact on OS (P = 0.048) and PFS (P = 0.039), as did lymph node metastasis, differentiation, and depth of invasion. We identified that p53 protein-positive expression can serve as an independent, unfavorable prognosis biomarker in ESCC.

Altered mRNA levels of MOV10, A3G, and IFN-α in patients with chronic hepatitis B.

To explore the relationship of the MOV10, A3G, and IFN-α mRNA levels with chronic hepatitis B virus (HBV) infection, Blood samples from 96 patients with chronic hepatitis B (CHB) and 21 healthy individuals as control were collected. HBV DNA load and aminotransferase in the serum were tested using real time PCR and velocity methods, respectively. The MOV10, A3G, and IFN-α mRNA levels in the peripheral blood mononuclear cells (PBMC) were examined through qRT-PCR. The MOV10, A3G, and IFN-α mRNA levels in CHB group was significantly lower than those in the control group (P<0.01, P<0.05, P<0.01, respectively). The A3G mRNA level in the high-HBV DNA load group was lower than that in the low-HBV DNA load group (P<0.05). However, no statistical difference was found in the MOV10 and IFN-α mRNA levels between the two HBV DNA load groups. Furthermore, the MOV10 mRNA level showed positive correlation with IFN-α in the control group. These results indicated that the expression of the innate immune factors MOV10, A3G, and IFN-α is affected by chronic HBV infection.

The impact of functional LIG4 polymorphism on platinum-based chemotherapy response and survival in non-small cell lung cancer.

DNA repair capacity is correlated with the sensitivity of cancer cells toward platinum-based chemotherapy. The aim of this study was to investigate whether single-nucleotide polymorphisms (SNPs) in DNA repair genes NBS1, LIG4, and RAD51 were correlated with tumor response in advanced non-small cell lung cancer (NSCLC) patients in a Chinese population who received platinum-based chemotherapy. The treatment outcomes of 146 advanced NSCLC patients who were treated with platinum-based chemotherapy were evaluated. The polymorphic status of three SNPs was determined by genotyping via the polymerase chain reaction-restriction fragment length polymorphism method. Forty-five patients in the group with the CC genotype (45/90) showed a good response to treatment, while only 18 patients in the CT+TT group (18/55) showed a good response, indicating a substantial differences in the chemotherapy response rate based on the LIG4 Thr9Ile polymorphism (P = 0.042). Patients with the GG genotype for the NSB1 Glu185Gln polymorphism were more sensitive to platinum-based chemotherapy compared with patients with either the CG or CC genotype (P = 0.001). Kaplan-Meier analysis of all patients showed a significant association between the LIG4 Thr9Ile CC polymorphism and superior progression-free survival and overall survival (log-rank P = 0.045 and 0.031, respectively). However, there were no significant differences in survival based on the LIG4 Thr9Ile or the RAD51 135G>C polymorphisms. Polymorphisms in the NSB1 and LIG4 genes may be a predictive marker for treatment response and for advanced NSCLC patients in stage IIIB + IV. The CC genotype of the LIG4 Thr9Ile polymorphism may also serve as an independent prognosis factor.

Successful establishment and evaluation of a new animal model for studying the hepatitis B virus YVDD mutant.

The treatment of infection with lamivudine-resistant mutants of hepatitis B virus (HBV) with mutations in the YMDD motif has become a crucial issue in the clinic. In this work, the plasmids pcDNA3.1 (+)-HBV/C-YVDD and pcDNA3.1 (+)-HBV/C-YMDD were constructed and injected into BALB/c mice using a hydrodynamics-based procedure to investigate viral replication and expression of HBV lamivudine-resistant YVDD mutants in vivo. Compared with the YMDD group, HBsAg levels were higher in sera of mice in the YVDD group, but HBeAg levels were lower on day 1 after injection. Levels of HBcAg in hepatocytes were higher in the YVDD group on day 1, whereas the HBsAg levels were lower. The levels of HBV mRNA in the liver were higher in mice in the YVDD group on day 1 after injection. The results showed that injection with these plasmids resulted in efficient initiation of replication of HBV in mice and also suggested that the combined mutations in YVDD mutants could affect the replication process.

Viral deletions among healthy young Chinese adults with occult hepatitis B virus infection.

To investigate the mechanism and prognosis of occult hepatitis B virus (HBV) infection (OBI) at a molecular level among healthy young adults, the presence of HBV DNA in 1176 sera samples collected from healthy young people after neonatal vaccination was assessed by nested polymerase chain reaction (PCR) using specific primers designed for the X and S regions of the HBV genome. Full-length HBV DNA from 9 patients with OBI (OB1-OB9) was cloned and sequenced. Deletions in the pre-S, basal core promoter (BCP), core (C) and polymerase (P) regions were observed. The data indicate that there is still a substantial risk of OBI in China despite neonatal vaccination. All deletions that were observed in the pre-S, BCP, C and P regions play a direct or indirect role in OBI. The presence of a deletion mutation in the pre-S1 region was considered to play a pivotal role in hepatocarcinogenesis and was found to increase the risk of hepatocellular carcinoma in the cohorts studied.

Differential inhibition of lamivudine-resistant hepatitis B virus by allele-specific RNAi.

Drug-resistant hepatitis B virus (HBV) is a serious problem affecting antiviral therapy. In this study, two long-term eukaryotic cell lines with full-length HBV were constructed and contained either lamivudine-resistant mutants (HBV-YIDD) or wild-type virus (HBV-wt). High levels of intracellular viral DNA replication were observed continuously after transfecting the plasmids into HepG2 cells, and HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) were secreted into the cell culture supernatant. A series of experiments showed differential inhibition of HBV gene expression and replication by four specific siRNAs, according to the principles of allele-specific RNAi technology. The results showed that the designed siRNAs with a mismatch in the sixteenth nucleotide of the guide strands could effectively discriminate the HBV-YIDD mutants from the wild-type alleles, thus providing a new insight into the development of antiviral therapy with differing or complementary patterns characteristic of lamivudine-resistant HBV.

Molecular characterization and functional analysis of occult hepatitis B virus infection in Chinese patients infected with genotype C.

Occult HBV infection is defined as the persistence of HBV DNA in individuals negative for HBV surface antigen (HBsAg), and many different mechanisms have been reported in different countries. However, in China, one of the endemic areas for HBV infection, no reports have been published on occult HBV infection. The present study investigated the virological features and the mechanism of occult HBV infection in China. Full-length HBV DNA from eight patients with occult HBV infection (S1-S8) and three HBsAg-positive cases (SWT1-SWT3) was cloned and sequenced. Additionally, four entire linear HBV genomes from occult cases were transfected transiently into HepG2 cells. The sequencing results showed two major mutations in patients with occult HBV infection as follows: deletions in the pre-S1 (S3, S4, and S7) and X (S1, S2, and S5) regions. Such deletions covered the S promoter and the basal core promoter (BCP), and function analysis of these variants also showed a decrease in DNA replication and antigen expression. Two patients with occult infection (S6 and S8) had no mutations capable of interfering with viral replication and gene expression in the major viral population. Thus, the deletions in the S promoter and the BCP regions that disable the regulatory elements may be the reason for the absence of HBsAg, and multiple mechanisms may be responsible for occult HBV infection.

Prevalence of occult hepatitis B virus infection among hepatopathy patients and healthy people in China.

OBJECTIVE: To investigate the prevalence of occult hepatitis B virus (HBV) infection among hepatopathy patients and healthy people in China. METHODS: The HBV DNA in 653 sera samples collected from cryptogenic chronic liver disease patients (159), hepatitis B surface antigen (HBsAg) negative hepatocellular carcinoma (HCC) patients (135) and HBsAg-negative healthy people (359) were tested by nested PCR using specific primers of the X region of the HBV genome. We performed real-time PCR to determine the levels of serum HBV-DNA. RESULTS: Prevalence of occult HBV infection was 28.3% (45/159), 70.4% (95/135) and 10.6% (38/359) in cryptogenic chronic liver disease patients, HBsAg-negative HCC patients and HBsAg-negative healthy people, respectively. The prevalence of occult HBV infection in IgG anti-HBc-positive subjects was 100% (45/45), 86.7% (85/98) and 33.3% (14/42) in cryptogenic chronic liver disease patients, HBsAg-negative HCC patients and HBsAg-negative healthy people, respectively. In all cases, viral loads were low (<10(4)viral copies/mL). CONCLUSION: The prevalence of occult HBV infection was significantly high among hepatopathy patients and healthy people in China. Thus, more meticulous attention should be given to prevent HBV transmission by blood transfusion or organ transplantation in endemic areas, and further studies on clinical implication and mechanism of occult HBV infection are required.

Construction and expression of eukaryotic plasmids containing lamivudine-resistant or wild-type strains of Hepatitis B Virus genotype C.

AIM: To construct eukaryotic expression plasmids of full-length Hepatitis B Virus (HBV) genotype C genome, which contain lamivudine-resistant mutants (YIDD, YVDD) or wild-type strain (YMDD), and to observe the expression of HBV DNA and antigens [hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg)] of the recombinant plasmids in HepG2 cells. METHODS: Three HBV full-length genomes were amplified from the plasmids pMD18T-HBV/YIDD, pMD18T-HBV/YVDD and pMD18T-HBV/YMDD, using PCR. Three recombinant plasmids were generated by inserting each of the PCR products into the eukaryotic expression vector pcDNA3.1 (+), between the EcoRI and HindIII sites. After being characterized by restriction endonuclease digestion, and DNA sequence analysis, the recombinant plasmids were transfected into HepG2 cells. At 48 and 72 h post-transfection, the levels of intracellular viral DNA replication were detected by real-time PCR, and the expression of HBsAg and HBeAg in the cell culture supernatant was determined by ELISA. RESULTS: Restriction endonuclease digestion and DNA sequence analysis confirmed that the three recombinant plasmids were correctly constructed. After transfecting the plasmids into HepG2 cells, high levels of intracellular viral DNA replication were observed, and HBsAg and HBeAg were secreted into the cell culture supernatant. CONCLUSION: Eukaryotic expression plasmids pcDNA3.1 (+)-HBV/YIDD, pcDNA3.1 (+)-HBV/YVDD or pcDNA3.1 (+)-HBV/YMDD, which contained HBV genotype C full-length genome, were successfully constructed. After transfection into HepG2 cells, the recombinant plasmids efficiently expressed HBV DNA, HBsAg and HBeAg. Our results provide an experimental basis for the further study of HBV lamivudine-resistant mutants.

Combination therapy of siRNAs mediates greater suppression on hepatitis B virus cccDNA in HepG2.2.15 cell.

BACKGROUND/AIMS: Hepatitis B virus (HBV) infection is a world-wide health problem. The major obstacles for current anti-HBV therapy are the low efficacy and the occurrence of drug resistant HBV mutations. Recent studies have demonstrated that combination therapy can enhance antiviral efficacy and overcome the shortcomings. Here, the inhibitory effect mediated by combination of small interfering RNAs (siRNAs) targeting different sites of HBV nuclear localization signal (NLS) was monitored in HepG2.2.15 cells. METHODOLOGY: Recombinant plasmid psil-HBV was constructed and transfected into HepG2.2.15 cells. At 48, 72 and 96 h after transfection, culture media were collected and cells were harvested for HBV replication assay. HBsAg and HBeAg in the cell culture medium were detected by enzyme-linked immunoadsorbent assay. Intracellular viral DNA and covalently closed circular DNA (cccDNA) was quantified by real-time PCR. HBV viral mRNA was reverse transcribed and quantified by reverse-transcript PCR. RESULTS: Our data demonstrated that three used siRNAs showed marked anti-HBV effects. The expression of HBsAg and the replication of HBV DNA could be specifically inhibited in a dose-dependent manner by siRNAs. Furthermore, combination of siRNAs, compared with individual use of each siRNA, exerted a stronger inhibition on antigen expression and viral replication, even though the final concentration of siRNA in the therapy was the same. More importantly, we showed that combination therapy significantly suppressed HBV cccDNA amplification. CONCLUSION: Our results revealed that combination of siRNAs mediated a stronger inhibition on viral replication and antigen expression in HepG2.2.15 cells, especially, the amplification of cccDNA.

Combination of small interfering RNA and lamivudine on inhibition of human B virus replication in HepG2.2.15 cells.

AIM: To observe the inhibition of hepatitis B virus (HBV) replication and expression by combination of siRNA and lamivudine in HepG2.2.15 cells. METHODS: Recombinant plasmid psil-HBV was constructed and transfected into HepG2.2.15 cells. The transfected cells were cultured in lamivudine-containing medium (0.05 micromol/L) and harvested at 48, 72 and 96 h. The concentration of HBeAg and HBsAg was determined using ELISA. HBV DNA replication was examined by real-time PCR and the level of HBV mRNA was measured by RT-PCR. RESULTS: In HepG2.2.15 cells treated with combination of siRNA and lamivudine, the secretion of HBeAg and HBsAg into the supernatant was found to be inhibited by 91.80% and 82.40% (2.89+/-0.48 vs 11.73+/-0.38, P<0.05; 4.59+/-0.57 vs 16.25+/-0.48, P<0.05) at 96 h, respectively; the number of HBV DNA copies within culture medium was also significantly decreased at 96 h (1.04+/-0.26 vs 8.35+/-0.33, P<0.05). Moreover, mRNA concentration in HepG2.2.15 cells treated with combination of siRNA and lamivudine was obviously lower compared to those treated either with siRNA or lamivudine (19.44+/-0.17 vs 33.27+/-0.21 or 79.9+/-0.13, P<0.05). CONCLUSION: Combination of siRNA and lamivudine is more effective in inhibiting HBV replication as compared to the single use of siRNA or lamivudine in HepG2.2.15 cells.

Inhibition of Hepatitis B virus cccDNA replication by siRNA.

The development of an effective therapy for Hepatitis B virus (HBV) infection is still a challenge. Progress in RNA interference (RNAi) has shed slight on developing a new anti-HBV strategy. Here, we present a series of experiments showing a significant reduction in HBV transcripts and replication intermediates in HepG2.2.15cells by vector-based siRNA targeted nuclear localization signal (NLS) region. More importantly, we showed that siRNA1 markedly inhibited HBV covalently closed circular DNA (cccDNA) replication. Our results indicated that HBV NLS may serve as a novel RNAi target to combat HBV infection, which can enhance anti-HBV efficacy and overcome the drawbacks of current therapies.