Core Promoter Mutations Research Articles

Predictive Risk Factors and Scoring Systems Associated with the Development of Hepatocellular Carcinoma in Chronic Hepatitis B.

Chronic hepatitis B (CHB) infection constitutes a leading cause of hepatocellular carcinoma (HCC) development. The identification of HCC risk factors and the development of prognostic risk scores are essential for early diagnosis and prognosis. The aim of this observational, retrospective study was to evaluate baseline risk factors associated with HCC in CHB. Six hundred thirty-two consecutive adults with CHB (n = 632) [median age: 46 (IQR: 24)], attending the outpatients' Hepatology clinics between 01/1993-09/2020 were evaluated. Core promoter mutations and cirrhosis-HCC (GAG-HCC), Chinese University-HCC (CU-HCC), risk estimation for hepatocellular carcinoma in chronic hepatitis B (REACH-B), Fibrosis-4 (FIB-4), and Platelet Age Gender-HBV (PAGE-B) prognostic scores were calculated, and receiver operating curves were used to assess their prognostic performance. HCC was developed in 34 (5.38%) patients. In the multivariable Cox regression analysis, advanced age (HR: 1.086, 95% CI: 1.037-1.137), male sex (HR: 7.696, 95% CI: 1.971-30.046), alcohol abuse (HR: 2.903, 95% CI: 1.222-6.987) and cirrhosis (HR: 21.239, 95% CI: 6.001-75.167) at baseline were independently associated with the development of HCC. GAG-HCC and PAGE-B showed the highest performance with c-statistics of 0.895 (95% CI: 0.829-0.961) and 0.857 (95% CI: 0.791-0.924), respectively. In the subgroup of patients with cirrhosis, the performance of all scores declined. When treated and untreated patients were studied separately, the discriminatory ability of the scores differed. In conclusion, HCC development was independently associated with advanced age, male sex, alcohol abuse, and baseline cirrhosis among a diverse population with CHB. GAG-HCC and PAGE-B showed high discriminatory performance to assess the risk of HCC development in these patients, but these performances declined in the subgroup of patients with cirrhosis. Further research to develop scores more specific to certain CHB subgroups is needed.

Characterization of mutations in hepatitis B virus DNA isolated from Japanese HBsAg-positive blood donors in 2021 and 2022

Missense mutations in certain small envelope proteins diminish the efficacy of antibodies. Consequently, tracking the incidence and types of vaccine-escape mutations (VEMs) was crucial both before and after the introduction of universal hepatitis B vaccination in Japan in 2016. In this study, we isolated hepatitis B virus (HBV) DNA from 58 of 169 hepatitis B surface antigen (HBsAg)-positive blood samples from Japanese blood donors and determined the nucleotide sequence encoding the small envelope protein. DNA from six (10%) of the samples had VEMs, but no missense mutations, such as G145R, were detected. Complete HBV genome sequences were obtained from 29 of the 58 samples; the viral genotype was A1 in one (3%), A2 in three (10%), B1 in nine (31%), B2 in five (17%), B4 in one (3%), and C2 in 10 (34%) samples. Tenofovir-resistance mutations were detected in two (7%) samples. In addition, several core promoter mutations, such as 1762A>T and 1764G>A, and a precore nonsense mutation, 1986G>A, which are risk factors for HBV-related chronic liver disease, were detected. These findings provide a baseline for future research and highlight the importance of ongoing monitoring of VEMs and drug resistance mutations in HBV DNA from HBsAg-positive blood donors without HBV antibodies.

Precore mutation enhances viral replication to facilitate persistent infection especially in HBeAg-negative patients

Naturally occurred precore (PC, G1896A) and/or basal core promoter (BCP, A1762T/G1764A) mutations are prevalent in chronic HBV-infected patients, especially those under HBeAg-negative status. However, the replicative capacity of HBV with PC/BCP mutations remains ambiguous. Herein, meta-analysis showed that, only under HBeAg-negative status, the serum HBV DNA load in patients with PC mutation was 7.41-fold higher than those without the mutation. Both PC mutation alone and BCP ​+ ​PC mutations promoted HBV replication in cell and hydrodynamic injection mouse models. In human hepatocyte chimeric mouse model, BCP ​+ ​PC mutations led to elevated replicative capacity and intrahepatic core protein accumulation. Mechanistically, preC RNA harboring PC mutation could serve as mRNA to express core and P proteins, and such pgRNA-like function favored the maintenance of cccDNA pool under HBeAg-negative status. Additionally, BCP ​+ ​PC mutations induced more extensive and severe human hepatocyte damage as well as activated endoplasmic reticulum stress and TNF signaling pathway in livers of chimeric mice. This study indicates that HBeAg-negative patients should be monitored on HBV mutations regularly and are expected to receive early antiviral treatment to prevent disease progression.

Persistently high HBsAg levels during HBeAg-seropositive stage predict lower risk of hepatocellular carcinoma in chronic hepatitis B patients.

High hepatitis B surface antigen (HBsAg) level predicts hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients with low viral load. The role of longitudinal HBsAg levels in predicting HCC in HBeAg-positive CHB patients remains unknown. HBeAg-positive CHB participants from the REVEAL-HBV cohort with ≥2 HBsAg measurements before HBeAg seroclearance were enrolled. Group-based trajectory modelling identified distinct HBsAg trajectory groups during a median of 11 years of HBeAg-positive status. Cox regression models were applied for investigating independent predictors of HCC and estimating adjusted hazard ratio (HRadj) with a 95% confidence interval (CI). A p-value less than 0.05 was considered statistically significant. A total of 319 patients were enrolled and classified by HBsAg trajectory patterns as (A) persistently high group (n = 72): HBsAg persistently ≥104 IU/mL, and (B) non-stationary group (n = 233): low HBsAg at baseline or declining to <104 IU/mL during the follow-up. Group B had higher proportions of abnormal ALT levels, HBV genotype C and basal core mutation than group A (p < 0.05); age at entry and gender were comparable. The annual incidence of HCC in group A and group B were 0.37% and 1.16%, respectively (p = 0.03). In multivariate analysis, age >40 years (HRadj [95% CI] = 4.11 [2.26-7.48]), genotype C (HRadj [95% CI] = 4.39 [1.96-9.81]) and the non-stationary group (HRadj [95% CI] = 3.50 [1.49-8.21]) were independent predictors of HCC. Basal core promoter mutation was the only risk factor of HCC in the persistently high HBsAg group (HRadj [95% CI] = 32.75 [5.41-198.42]). Patients with persistently high HBsAg levels during HBeAg-seropositive stage represent a unique population with low risk of HCC development.

Core Promoter and Pre-Core Variants of the Hepatitis B Virus (HBV) Are Frequent in Chronic Hepatitis B HBeAg-Negative Patients Infected by Genotypes A and D.

In Brazil, hepatitis B virus endemicity is low, moderate, or high in some areas, such as Espírito Santo State in the southeast region. In this study, we intend to characterize the basal core promoter (BCP) and pre-core region (PC) variants and their association with clinical/epidemiological disease patterns in patients infected with genotypes A and D. The study included 116 chronic hepatitis B patients from Espírito Santo State, Southeast Brazil, infected with genotypes A and D. Basal core promoter (BCP) and pre-core mutations were analyzed in these patients. The frequency of BCP and PC mutations was compared with age, HBeAg status, HBV genotype and subgenotype, HBV-DNA level, clinical classification, and transmission route. HBeAg-negative status was found in 101 (87.1%) patients: 87 (75.0%) were infected with genotype A (A1 = 85; A2 = 2) and 29 (25.0%) were infected with genotype D (D3 = 24; D4 = 3; D2 = 2). BCP + PC variants altogether were more frequent (48.1%) in genotype D than in genotype A strains (6.0%) (p < 0.001). When this evaluation was performed considering the cases that presented only the A1762T and/or G1764A (BCP) mutations, it was observed that the frequency was higher in genotype A (67.5%) compared to genotype D (7.4%) (p < 0.001). On the other hand, considering the samples with mutations only in positions G1896A and/or G1899A (PC), the frequency was higher in genotype D (75.8%) than in genotype A (6.9%) (p < 0.001). Interestingly, HBV DNA was lower than 2000 IU/mL especially when both BCP/PC mutations were present (p < 0.001) or when only PC mutations were detected (p = 0.047), reinforcing their role in viral replication.

Predicting Hepatocellular Carcinoma Risk in Chronic Hepatitis B Patients Receiving Finite Periods of Antiviral Therapy

PURPOSE: Hepatocellular carcinoma (HCC) is one of the most severe complications in chronic hepatitis B virus (HBV) infection. HCC can still develop in patients with chronic HBV (CHB) infection undergoing antiviral therapy. Several effective scoring systems for the prediction of HCC risk in CHB patients have been established. However, very few of them are designed for CHB patients receiving nucleos(t)ide analogues (NAs) therapy. Furthermore, none are available for HCC risk prediction in CHB patients receiving finite periods of antiviral therapy. METHODS: This study enrolled 790 consecutive treatment-naïve patients with CHB infection who had visited our liver clinics from 2008 to 2012 for pretreatment assessment before receiving antiviral therapies. The treatments were provided at finite periods according to the National Health Insurance Policy in Taiwan. The last follow-up date was 31 December 2021. We analyzed the virological and clinical factors in these 790 CHB patients receiving finite periods of NA treatments and identified the most significant risk factors for HCC to establish a novel predictive scoring system. By using stepwise selection in a multivariate Cox proportional hazards model, we divided the patients into three risk groups. RESULTS: Our predictive scoring system included five independent variables: genotype C (adjusted HR [aHR] = 2.23), NA-withdraw-related hepatitis relapse (aHR = 6.96), male (aHR = 4.19), liver cirrhosis (aHR = 11.14), and T1768A core promoter mutation (aHR = 3.21). This model revealed significant differences in HCC incidence among the three risk groups. The 5-year cumulative HCC risk significantly differed among the three risk groups (low risk: 1.33%, moderate risk: 4.99%, and high risk: 17.46%), with log-rank test p &lt; 0.001. CONCLUSION: Our predictive scoring system is a promising tool for the prediction of HCC in CHB patients receiving finite NA treatments. Genotype C, NA-withdraw-related hepatitis relapse, male gender, liver cirrhosis, and the T1768A HBV core promoter mutation were significant independent risk factors.

Clinical isolates of hepatitis B virus genotype C have higher in vitro transmission efficiency than genotype B isolates.

Serum samples were collected from 54 hepatitis B e antigen (HBeAg)-positiveChinese patients infected with hepatitis B virus (HBV)subgenotype B2 or C2. They were compared for transmission efficiency using same volume of samples or infectivity using same genome copy number. Adding polyethylene glycol (PEG)during inoculation did not increase infectivity of fresh samples but markedly increased infectivity following prolonged sample storage. Differentiated HepaRG cells infected without PEG produced more hepatitis B surface antigen (HBsAg)and higher HBsAg/HBeAgratio than sodium taurocholate cotransporting polypeptide (NTCP)-reconstitutedHepG2 cells infected with PEG. They better supported replication of core promoter mutant in contrast to wild-type (WT)virus by HepG2/NTCP cells. Overall, subgenotype C2 samples had higher viral load than B2 samples, and in general produced more HBeAg, HBsAg, and replicative DNA following same-volume inoculation. Precore mutant was more prevalent in subgenotype B2 and had reduced transmission efficiency. When same genome copy number of viral particles was inoculated, viral signals were not necessarily higher for three WT C2 isolates than four WT B2 isolates. Using viral particles generated from cloned HBV genome, three WT C2 isolates showed slightly reduced infectivity than three B2 isolates. In conclusion, subgenotype C2 serum samples had higher transmission efficiency than B2 isolates in association with higher viral load and lower prevalence of precore mutant, but not necessarily higher infectivity. PEG-independent infection by HBV viremic serum samples is probably attributed to a labile host factor.

HBV with precore and basal core promoter mutations exhibits a high replication phenotype and causes ER stress-mediated cell death in humanized liver chimeric mice.

Mutations within the precore (PC) and basal core promoter (BCP) regions of the HBV genome are associated with fulminant hepatitis and HBV reactivation. These mutations may enhance viral replication, but little is known about whether they directly induce damage to the liver. We investigated mechanisms of direct cytopathic effects induced by the infection with PC/BCP mutants in the absence of immune response in vitro and in vivo . Mice with humanized livers and hepatocytes derived from humanized mice were infected with either wild-type or mutant-type PC/BCP HBV, and the HBV replication and human hepatocyte damage were evaluated. HBV proliferated vigorously in mice with PC/BCP-mutant infection, and the severe loss of human hepatocytes with a slight human ALT elevation subsequently occurred only in PC/BCP mutant mice. In PC/BCP mutant infection, the accumulation of HBsAg in humanized livers colocalized with the endoplasmic reticulum, leading to apoptosis through unfolded protein response in HBV-infected hepatocytes. RNA-sequencing revealed the molecular characteristics of the phenotype of PC/BCP mutant infection in a humanized mouse model. Reduced ALT elevation and higher HBV DNA levels in this model are consistent with characteristics of HBV reactivation, indicating that the hepatocyte damage in this model might mimic HBV reactivation followed by hepatocyte damage under immunosuppressive conditions. PC and BCP mutations were associated with enhanced viral replication and cell death induced by ER stress using HBV infection models. These mutations might be associated with liver damage in patients with fulminant hepatitis or HBV reactivation.

Development of hepatocellular carcinoma in treated and untreated patients with chronic hepatitis B virus infection.

Hepatitis B virus (HBV) is responsible for more than 50% of hepatocellular carcinoma (HCC) in HBV hyperendemic areas, such as the Asia-Pacific region. Several hepatitis B viral factors are involved in HBV-related hepatocarcinogenesis. Hepatitis B viral load is the most important risk factor of HCC development. In addition, HBV integration, HBV genotype C, and core-promoter mutations are also associated with a risk of HCC development. For untreated chronic hepatitis B (CHB) patients, the estimated HCC incidence rates per 100 patient-years were 0.03-0.17 in inactive carriers, 0.07-0.42 in asymptomatic carriers, 0.12-0.49 in chronic hepatitis, and 2.03-3.37 in cirrhosis. Complementary to HBV DNA, serum levels of the hepatitis B surface antigen and hepatitis B core-related antigen (HBcrAg) can predict the occurrence of HCC for untreated patients with low and intermediate viral loads, respectively. For patients receiving antiviral therapy, the risks of HCC occurrence 40-60% lower than those for untreated patients. Patients treated with residual detectable HBV DNA or intrahepatic cccDNA still have a risk of HCC. Serum levels of HBcrAg, M2BPGi and fibrosis-4 are predictive of the risk of HCC development in treated patients. Several well-developed HCC risk scores can help clinicians identify high-risk CHB patients for HCC surveillance, regardless of treatment status. These strategies can help minimize the threat of HCC and prolong survival in CHB patients.

Hepatitis B Virus Genotypes and Pre-core and Core Genes Mutations in a Sample of Iraqi Patients with Chronic Hepatitis B Infection

Background: Genomic studies of hepatitis B virus (HBV) diversity are becoming increasingly significant to understand how HBV mutations interact with a wide spectrum of clinical and pathological disorders. Objective: This study focused on identifying HBV genotypes and determining the status of pre-core (PC) and core promoter (CP) mutants. Methods: Nested polymerase chain reaction was used to identify the viral genotypes of 100 patients with chronic HBV infection. Only 30 samples out of 100 were selected to determine the prevalence of mutations in the PC and CP by Sanger sequencing. Results: Over 95% of the samples had only D genotype and mixed genotypes 5% (B+C+D) in chronic hepatitis B (CHB) patients. G1898A, G1901A, G1910A and G1915A mutations in PC gene were found in total 15 out of 30 (50%) samples, which were distributed in the following proportions: 12 out of 25 (48%) in patients with hepatitis B e antigen (HBeAg) -ve, 8 samples with mutants at G1898A, G1901A, G1910A and G1915A (four mutations), 4 samples with mutants at G1898A, G 1901A and G1910A (three mutations). In addition, 3 out of 5 (60%) in patients with HBeAg +ve, while no type of any mutation was detected in the core gene in patients with chronic hepatitis type B. Conclusion: The genotype D was predominantly prevalent among HBV in CHB patients with 95% and with 5% in mixed genotypes (B+C+D), while genotype B and C were relatively less prevalent among CHB patients than genotype D. The mutations were found in the PC gene at nucleotides G1898A, G1901A, G1910A and G1915A, while no type of mutation was detected in the core gene. Keywords: Genotypes, pre-core mutation, core mutation, HBV Citation: Hussain HT, Al-Shuwaikh AM, Ahmed AM. Hepatitis B virus genotypes and pre-core and core genes mutations in a sample of Iraqi patients with chronic hepatitis B Infection. Iraqi JMS. 2022; 20(2): 217-225. doi: 10.22578/IJMS.20.2.8

Hepatitis B virus haplotype number at baseline is a predictive marker of functional cure during antiviral therapy for patients with genotypes A and D HBeAg-positive chronic hepatitis B.

We investigated associations between hepatitis B virus (HBV) genome-length haplotype number (HN) at baseline in subjects with HBeAg-positive chronic hepatitis B (CHB), and the likelihood of achieving functional cure during direct-acting antiviral therapy METHOD: We analysed 86 HBeAg-positive baseline samples from patients with HBV genotypes A and D who were enrolled in a Phase II trial of tenofovir disoproxil fumarate (TDF) to determine if HN was a biomarker of HBsAg loss during therapy. Findings were validated using baseline samples from 181 patients with HBV genotypes A and D from an independent clinical trial utilising TDF or tenofovir alafenamide therapy in HBeAg-positive CHB. In the HBeAg-positive test cohort, patients with genotypes A or D and ≤2 haplotypes had a minimum of 21-fold higher likelihood of achieving HBsAg loss on TDF. Baseline HN (p < 0.0001) was a stronger predictor of HBsAg loss on therapy than HBsAg titre (p=0.03), HBeAg titre (p=0.0002), or the presence of HBV basal core promoter (A1762T, p=0.0379 and G1764A, p=0.0176) or G1896A precore mutations (p= 0.0218). This finding was validated in the independent validation cohort. HN was statistically higher in patients with HBV genotypes B or C infection compared to genotypes A and D. Baseline HN ≤2 predicts which patients with HBV genotypes A or D will more likely progress to functional cure on current direct-acting antiviral therapy, with greater accuracy than current biomarkers including baseline HBsAg and HBeAg titre.

Core promoter in TNBC is highly mutated with rich ethnic signature.

The core promoter plays an essential role in regulating transcription initiation by controlling the interaction between transcriptional factors and sequence motifs in the core promoter. Although mutation in core promoter sequences is expected to cause abnormal gene expression leading to pathogenic consequences, limited supporting evidence showed the involvement of core promoter mutation in diseases. Our previous study showed that the core promoter is highly polymorphic in worldwide human ethnic populations in reflecting human history and adaptation. Our recent characterization of the core promoter in triple-negative breast cancer (TNBC), a subtype of breast cancer, in a Chinese TNBC cohort revealed the wide presence of core promoter mutation in TNBC. In the current study, we analyzed the core promoter in a Thai TNBC cohort. We also observed rich core promoter mutation in the Thai TNBC patients. We compared the core promoter mutations between Chinese and Thai TNBC cohorts. We observed substantial differences of core promoter mutation in TNBC between the two cohorts, as reflected by the mutation spectrum, mutation-effected gene and functional category, and altered gene expression. Our study confirmed that the core promoter in TNBC is highly mutable, and is highly ethnic-specific.

Core promoter mutation of nucleotides A1762T and G1764A of hepatitis B virus increases core promoter transactivation by hepatocyte nuclear factor 1.

Hepatitis B virus (HBV) infection highly increases the risk for liver cirrhosis and hepatocellular carcinoma (HCC). The clinical manifestation of HBV infection is determined by the mutual interplay of the viral genotype, host genetic factors, mode of transmission, adaptive mutations, and environmental factors. Core promoter activation plays a critical role in the pre-genomic RNA transcription of HBV for HBV replication. The mutations of core promoter have been implicated in HCC development. We had obtained HBV genes from Myanmar HBV infectants and identified gene variations at the core promoter region. For measuring the relative transactivation activity on core promoter, we prepared the core-promoter reporter construct. Both of A1762T and G1764A mutation were consistently found in the HBV genes with hepatocellular carcinoma. The A1762T/G1764A mutation was corresponding to K130M/V131I of HBx protein. We prepared the core promoter-luciferase reporter construct containing the double A1762T/G1764A mutation and the K130M/V131I HBx protein expression construct. The A1762T/G1764A mutation highly was responsive to core promoter transactivation by HBx, regardless of HBx mutation. The A1762T/G1764A mutation newly created hepatocyte nuclear factor 1 (HNF1) responsive element. Ectopic expression of HNF1 largely increased the HBV core promoter containing A1762T/G1764A mutation. In addition, hepatic rich fatty acid, palmitic acid and oleic acid, increased K130M/V131I HBx level by core promoter activation. These results provide biological properties and clinical significance of specific HBV core promoter mutants related with HCC development.

A cautionary note to hepatitis B e antigen (HBeAg)-negative test results in pregnant women in an area prevalent of HBeAg-negative chronic hepatitis B.

Maternal hepatitis B e Antigen (HBeAg) positivity poses a risk for hepatitis B virus (HBV) mother-to-child transmission (MTCT). In resource-constrained settings, HBeAg testing is recommended as an alternative to HBV DNA testing to establish antiviral prophylaxis eligibility. Nevertheless, the high prevalence of HBeAg-negative chronic hepatitis B (e-CHB) in many countries should not be overlooked. We studied HBV characteristics and explored the potential MTCT risk among HBeAg-negative/HBsAg-positive expectant mothers in an area prevalent of e-CHB. Among 1348 pregnant mothers screened for HBV infection, 81 (6.0%) were HBsAg-positive. These women were examined for HBeAg, HBV DNA, and cord blood HBV DNA. Sixteen (19.8%) of the HBsAg-positive mothers were HBeAg-positive, whereas 65 (80.2%) were HBeAg-negative, including eight inactive carriers (HBsAg <100 IU/ml, HBV DNA ≤ 2000 IU/ml, and ALT < 40 IU/L). Of the remaining 57 HBeAg-negative mothers, ten revealed HBV Basal Core Promoter or Precore mutations, with three having high viremia (HBV DNA > 200 000 IU/mL), which is associated with a high MTCT risk and therefore qualifies them for antiviral prophylaxis. This pilot study provides a cautionary note to the interpretation of negative HBeAg test results when determining eligibility for MTCT antiviral prophylaxis in situations with limited resources and in regions where e-CHB is prevalent.

Characterization of the tenofovir resistance-associated mutations in the hepatitis B virus isolates across genotypes A to D

Tenofovir is wildly used to treat chronic hepatitis B (CHB) infection due to good potency and high genetic barrier to drug resistance. To date, it remains controversial whether hepatitis B virus (HBV) could be resistant to tenofovir. This study used multiple HBV isolates across genotypes A to D to characterize the reported tenofovir resistance-associated mutations identified from a few clinical case reports. Our data demonstrated that all the rtS78T, rtA194T, and CYEI (S106C, H126Y, D134E, and L269I) mutants exhibited no resistance to tenofovir in vitro. In contrast, the quadruple mutation MLVV (rtL180M, rtT184L, rtA200V, and rtM204V) decreased tenofovir susceptibility, with increased half maximal efficient concentration ranging from 3.28-fold to 5.34-fold, but it severely impaired viral fitness by reducing both replication capacity and infectivity of the mutants. Interestingly, basal core promoter (BCP) mutations A1762T/G1764A and precore (PC) mutation G1896A restored the replication capacity of the MLVV mutant to a level even higher than the wild-type virus without BCP and PC mutations. In conclusion, our data support the role of tenofovir as a first-line agent to treat CHB infection but also indicate tenofovir-resistant mutants could emerge due to multiple mutations accumulated during long-term therapy, particularly in hepatitis B e antigen-negative patients.

Review on hepatitis B virus precore/core promoter mutations and their correlation with genotypes and liver disease severity.

Of 350 million people worldwide are chronically infected with hepatitis B virus (HBV) and are at risk of developing cirrhosis and hepatocellular carcinoma (HCC) later in life. HBV is the most diverse DNA virus, and its genome is composed of four open reading frames: Presurface antigen/surface antigen gene (preS/S), precore/core gene (preC/C), polymerase gene (P), and the X gene (X). HBV produces quasispecies naturally or in response to antiviral agents because of the absence of proofreading activity amid reverse transcription and a high replication rate. The virus has 10 genotypes (A to J) with different geographical distributions. There are various HBV mutations in the HBV genome, including preC/C mutations, preS/S mutations, P gene mutations, and X gene mutations. The core promoter region plays a vital part in the replication, morphogenesis and pathogenesis of the virus. The precore region also plays a crucial role in viral replication. Both core promoter and precore mutations rescue the virus from host immune surveillance and result in the formation of mutated strains that may have altered pathogenicity. preC/C mutations are associated with liver disease progression. Precore mutations stop hepatitis B e antigen (HBeAg) production and basal core promoter mutations downregulate HBeAg production. Mutations in the basal core promoter are also associated with increased HBV replication and an increased incidence of advanced liver diseases such as cirrhosis and HCC. The emergence of antiviral-resistant mutations is the main reason for treatment failure. This review focuses mainly on preC/C promoter mutations and their correlation with genotypes and liver disease severity. Thorough perception and knowledge of HBV genetic variety and mutants could be vital to discover techniques for the prognosis and control of HBV infection.

Verification of hepatitis B-related hepatocellular carcinoma predictive models to evaluate the risk of HCC in patients with liver cirrhosis under antiviral treatment.

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The development of chronic hepatitis B (CHB)-related HCC can be attributed to continuous hepatitis B virus (HBV) infection. It is crucial to identify and monitor patients with CHB at high risk of HCC occurrence so that HCC can be detected early and the patients are able to receive effective treatment promptly to increase the survival rate and improve prognosis. This study aimed to verify hepatitis B-related hepatocellular carcinoma predictive models to evaluate the risk of HCC in patients with liver cirrhosis under antiviral treatment. Patients with HBV-related compensated cirrhosis were treated with lamivudine and adefovir randomly, and then with a combination of two drugs at different time points based on the virologic response. Patients with HCC occurrence during follow-up were categorized as HCC group, whereas others as control group. They were further divided into 2-year HCC, 2-year control, 5-year HCC, and 5-year control groups according to the observation time. The operating curves of the patients were used to verify models before and after antiviral treatment. Using the baseline as a parameter, the area under the curve (AUC) of risk estimation for hepatocellular carcinoma in chronic hepatitis B (REACH-B) after 2 and 5 years was 0.863 and 0.797, respectively. The AUC after 2 and 5 years was 0.839 and 0.747, respectively, for guide with age, gender, HBV DNA, core promoter mutations and cirrhosis (GAG-HCC) and 0.741 and 0.748, respectively, for Taiwanese HBV cohort (TW1). Using 48 weeks as the parameter, it has an optimal critical value of 8 points. The AUC of REACH-B after 2 and 5 years was 0.738 and 0.721, respectively. REACH-B can predict the risk of HCC occurrence in patients with compensated liver cirrhosis before and after antiviral treatment. GAG-HCC and TW1 could predict the risk before antiviral treatment.

Core promoter mutation contributes to abnormal gene expression in bladder cancer

BackgroundBladder cancer is one of the most mortal cancers. Bladder cancer has distinct gene expression signature, highlighting altered gene expression plays important roles in bladder cancer etiology. However, the mechanism for how the regulatory disorder causes the altered expression in bladder cancer remains elusive. Core promoter controls transcriptional initiation. We hypothesized that mutation in core promoter abnormality could cause abnormal transcriptional initiation thereby the altered gene expression in bladder cancer.MethodsIn this study, we performed a genome-wide characterization of core promoter mutation in 77 Spanish bladder cancer cases.ResultsWe identified 69 recurrent somatic mutations in 61 core promoters of 62 genes and 28 recurrent germline mutations in 20 core promoters of 21 genes, including TERT, the only gene known with core promoter mutation in bladder cancer, and many oncogenes and tumor suppressors. From the RNA-seq data from bladder cancer, we observed altered expression of the core promoter-mutated genes. We further validated the effects of core promoter mutation on gene expression by using luciferase reporter gene assay. We also identified potential drugs targeting the core promoter-mutated genes.ConclusionsData from our study highlights that core promoter mutation contributes to bladder cancer development through altering gene expression.

Combining the HBcrAg decline and HBV mutations predicts spontaneous HBeAg seroconversion in chronic hepatitis B patients during the immune clearance phase.

To assess predictive ability of hepatitis B virus (HBV) markers and genome mutations for spontaneous hepatitis B e antigen (HBeAg) seroconversion. A total of 113 chronic hepatitis B (CHB) patients were followed up for 76 weeks without antiviral treatment. Baseline basal core promoter (BCP) and precore mutations were detected and serum hepatitis B surface antigen (HBsAg), HBeAg, hepatitis B core-related antigen (HBcrAg), and HBV DNA levels were serially quantified. Eighteen patients experienced spontaneous HBeAg seroconversion (Group A), and the remaining 95 patients did not experience spontaneous HBeAg seroconversion (Group B). At Week 28, HBsAg (p = 0.03) and HBcrAg (p = 0.01) levels were significantly different between Groups A and B. Reduced HBsAg (p = 0.02) and HBcrAg (p < 0.01) levels from baseline to Week 28 were significantly different between two groups. Multivariate logistic regression showed that lower HBcrAg (odds ratio [OR] = 1.02, p = 0.03) levels at Week 28, and HBcrAg levels with sharp decrease at Week 28 (OR = 0.19, p = 0.02) were related with spontaneous HBeAg seroconversion. The areas under the receiver operating characteristic curve (AUROC) showed that reduction in HBcrAg levels from baseline to Week 28 (0.93, p = 0.001, 95% CI: 0.74-1.08) have excellent prediction value. The mutation frequencies of A1574T (51.11% vs. 18.18%, p = 0.001), G1862A (30.00% vs. 13.03%, p = 0.001), G1896A (27.22% vs. 5.45%, p = 0.001), and C1913G (32.78% vs. 12.73%, p = 0.001) in Group A were significantly higher than Group B. Baseline A1574T, G1862A, G1896A, and C1913G mutations and HBcrAg levels with a sharp decrease at Week 28 were associated with spontaneous HBeAg seroconversion.

Regulatory function of interferon-inducible 44-like for hepatitis B virus covalently closed circular DNA in primary human hepatocytes.

Curing hepatitis B virus (HBV) infection requires elimination of covalently closed circular DNA (cccDNA). Interferon (IFN)-γ has noncytolytic antiviral potential; however, elimination of cccDNA could not be achieved. To enhance the regulatory effect, we comprehensively analyzed the host factors associated with cccDNA amplification and IFN-γ and IFN-α effects using an in vitro HBV infection system showing various transcription levels. Primary human hepatocytes were infected with HBV using genomic plasmids carrying the basic core promoter mutation A1762T/G1764A and/or the precore mutation G1896A and treated with IFN-γ and IFN-α. Comprehensive and functional studies involving microarray and small interfering RNA analysis revealed the host factors related to cccDNA regulation. The HBV infection system reproduced the HBV life cycle and showed various propagation levels. Microarray analysis revealed 53 genes correlated with the cccDNA levels. Of the 53 genes, expression of IFN-induced protein 44-like (IFI44L) was significantly upregulated by IFN-γ and IFN-α. The anti-HBV effect of IFI44L is exerted regardless of IFN-γ or IFN-α by inhibiting the activation of nuclear factor-κB and signal transducer and activator of transcription 1 pathways. Using the in vitro HBV infection system, an IFN-inducible molecule, IFI44L, associated with cccDNA amplification, was identified. These results suggest an innovative molecular strategy for the regulation of HBV cccDNA by controlling a novel host factor, IFI44L.