The resolution of the hepatitis C issue has raised expectations for a chronic hepatitis B cure, driving the industry to expand investment in research and development efforts to strengthen functional cure strategies. These strategies have a wide variety of types, and the published research findings are heterogeneous. The theoretical analysis of these strategies is of great significance for determining prioritized research orientations as well as sensibly allocating research and development resources. However, due to a paucity of necessary conceptual models, current theoretical analysis has not been able to unify various therapeutic strategies into a proper theoretical framework. In view of the fact that the decrease in the quantity of cccDNA is an inevitable core event accompanied by the process of functional cure, this paper intends to analyze several chronic hepatitis B cure strategies using cccDNA dynamics as a framework. Furthermore, there are currently few studies on the dynamics of the cccDNA field, hoping that this article can promote recognition and research in this field.
Humans ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/drug therapy* ; Antiviral Agents/therapeutic use* ; Virus Replication ; DNA, Circular/therapeutic use* ; DNA, Viral/genetics* ; Hepatitis B/drug therapy*

Objective: SET8 is a member of the SET domain-containing family and the only known lysine methyltransferase (KMT) that monomethylates lysine 20 of histone H4 (H4K20me1). SET8 has been implicated in many essential cellular processes, including cell cycle regulation, DNA replication, DNA damage response, and carcinogenesis. There is no conclusive evidence, however, regarding the effect of SET8 on radiotherapy. In the current study we determined the efficacy of SET8 inhibition on radiotherapy of tumors and the underlying mechanism. Methods: First, we explored the radiotherapy benefit of the SET8 expression signature by analyzing clinical data. Then, we measured a series of biological endpoints, including the xenograft tumor growth in mice and apoptosis, frequency of micronuclei, and foci of 53BP1 and γ-H2AX in cells to detect the SET8 effects on radiosensitivity. RNA sequencing and subsequent experiments were exploited to verify the mechanism underlying the SET8 effects on radiotherapy. Results: Low expression of SET8 predicted a better benefit to radiotherapy in lung adenocarcinoma (LUAD) and invasive breast carcinoma (BRCA) patients. Furthermore, genetic deletion of SET8 significantly enhanced radiation treatment efficacy in a murine tumor model, and A549 and MCF7 cells; SET8 overexpression decreased the radiosensitivity. SET8 inhibition induced more apoptosis, the frequency of micronuclei, and blocked the kinetics process of DNA damage repair as 53BP1 and γ-H2AX foci remained in cells. Moreover, RNF8 was positively correlated with the SET8 impact on DNA damage repair. Conclusion Our results demonstrated that SET8 inhibition enhanced radiosensitivity by suppressing DNA damage repair, thus suggesting that SET8 potentiated radiotherapy of carcinomas. As new inhibitors of SET8 are synthesized and tested in preclinical and clinical settings, combining SET8 inhibitors with radiation warrants consideration for precise radiotherapy.
Animals ; Apoptosis ; Carcinogenesis ; Carcinoma/radiotherapy* ; Cell Cycle ; Cell Line, Tumor ; DNA Damage ; DNA Replication ; HeLa Cells ; Histone-Lysine N-Methyltransferase ; Humans ; Mice ; Radiotherapy

Hepatitis B virus (HBV) infection remains to be the major cause of chronic liver diseases in China. Since the nucleos(t)ide analogues and pegylated interferon-alpha do not directly target the covalently closed circular DNA (cccDNA) in the nuclei of HBV-infected hepatocytes, those standard-of-care medications cannot efficiently cure the infected hepatocytes and rarely achieve the functional cure of chronic hepatitis B (CHB). Therefore, new antiviral drugs targeting distinct steps of HBV replication and immunotherapeutics reinvigorating antiviral immune responses are urgently needed for the functional cure of CHB. Based on the extensive discussion of the biological and clinical significance of new virologic biomarkers and distinct mechanism of drug candidates currently in clinical development, we propose that the selection of virologic and immunological biomarkers for evaluation of therapeutic efficacy as well as setting the therapeutic endpoints in the clinical trials should be based on the mode of action of investigational drugs. In addition, due to the complexity of CHB pathogenesis, selection of specific subpopulation of CHB patients for the clinical trials of drugs with a specific mode of action should also be considered.
Antiviral Agents/therapeutic use* ; Biomarkers ; DNA, Circular ; DNA, Viral ; Hepatitis B/drug therapy* ; Hepatitis B Surface Antigens ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic ; Humans ; Virus Replication

Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is the template for HBV replication. Currently, there is a lack of therapeutic drugs that directly target cccDNA. Therefore, blocking cccDNA supplements as fast as possible and reducing the existing cccDNA is the key to achieving a complete cure of chronic hepatitis B. Previous studies have suggested that cccDNA had a long half-life, but a recent study showed that it only took a few months to update cycle of cccDNA pool, and its number was much less than previously predicted. In the future, with the advent of new antiviral drugs that can completely inhibit HBV replication, it is expected that the cccDNA pool will be completely cleared due to its supplement complete blockade, so as to achieve virological cure of chronic hepatitis B.
Antiviral Agents/therapeutic use* ; DNA, Circular/genetics* ; DNA, Viral ; Half-Life ; Hepatitis B/drug therapy* ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/drug therapy* ; Humans ; Virus Replication

BACKGROUND: Hepatitis B core-related antigen (HBcrAg) is a promising disease-monitoring marker for chronic hepatitis B (CHB). We investigated correlations between HBcrAg with antiviral efficacy and virological and histological variables. METHODS: One hundred and forty-five CHB patients from the mainland of China between August 2013 and September 2016 who underwent liver biopsy received entecavir therapy and had paired liver biopsy at 78 weeks. We analyzed correlations between HBcrAg and virological and histological variables in hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients. We also explored the predictors of HBeAg loss after 78 weeks of antiviral therapy. Pearson correlation analysis and logistic forward stepwise regression were the main statistic methods. RESULTS: HBeAg-positive patients (n = 93) had higher baseline HBcrAg (median 7.4 vs. 5.3 log10 U/mL P < 0.001) and greater HBcrAg declines (median 1.6 vs. 0.9 log10 U/mL P = 0.007) than HBeAg-negative patients after 78 weeks of therapy. At baseline, HBcrAg correlated with hepatitis B virus (HBV) DNA in both HBeAg-positive (r = 0.641, P < 0.001) and -negative patients (r = 0.616, P < 0.001), with hepatitis B surface antigen (HBsAg) in HBeAg-positive patients (r = 0.495, P < 0.001), but not with anti-hepatitis B virus core antibody (anti-HBc). Weak correlations existed between HBcrAg, histology activity index (HAI; r = 0.232, P = 0.025), and Ishak fibrosis score (r = -0.292, P = 0.005) in HBeAg-positive patients. At 78 weeks, significant correlations existed only between HBcrAg and anti-HBc in HBeAg-positive (r = -0.263, P = 0.014) and HBeAg-negative patients (r = -0.291, P = 0.045). Decreased HBcrAg significantly correlated with reduced HBV DNA (r = 0.366, P = 0.001; r = 0.626, P < 0.001) and HBsAg (r = 0.526, P = 0.001; r = 0.289, P = 0.044) in HBeAg-positive and -negative patients, respectively, and with reduced HAI in HBeAg-positive patients (r = 0.329, P = 0.001). Patients with HBeAg loss (n = 29) showed a larger reduction in HBcrAg than those without (median 2.3 vs. 1.3 log10 U/mL, P = 0.001). In multivariate analysis, decreased HBcrAg was an independent predictor of HBeAg loss (P = 0.005). CONCLUSIONS: HBcrAg reflects viral replication and protein production. Decreased HBcrAg could predict HBeAg loss after antiviral therapy. TRIAL REGISTRATION Clinical Trials.gov: NCT01962155; https://www.clinicaltrials.gov/ct2/show/NCT01962155?term=NCT01962155&draw=2&rank=1.
Antiviral Agents/therapeutic use* ; Biomarkers ; China ; DNA, Viral ; Hepatitis B Core Antigens/therapeutic use* ; Hepatitis B Surface Antigens ; Hepatitis B e Antigens ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/drug therapy* ; Humans ; Virus Replication

BACKGROUND: Age-related macular degeneration (AMD) is the leading cause of vision loss worldwide. However, the mechanisms involved in the development and progression of AMD are poorly delineated. We aimed to explore the critical genes involved in the progression of AMD. METHODS: The differentially expressed genes (DEGs) in AMD retinal pigment epithelial (RPE)/choroid tissues were identified using the microarray datasets GSE99248 and GSE125564, which were downloaded from the gene expression omnibus database. The overlapping DEGs from the two datasets were screened to identify DEG-related biological pathways using gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. The hub genes were identified from these DEGs through protein-protein interaction network analyses. The expression levels of hub genes were evaluated by quantitative real-time polymerase chain reaction following the induction of senescence in ARPE-19 with FK866. Following the identification of AMD-related key genes, the potential small molecule compounds targeting the key genes were predicted by PharmacoDB. Finally, a microRNA-gene interaction network was constructed. RESULTS: Microarray analyses identified 174 DEGs in the AMD RPE compared to the healthy RPE samples. These DEGs were primarily enriched in the pathways involved in the regulation of DNA replication, cell cycle, and proteasome-mediated protein polyubiquitination. Among the top ten hub genes, HSP90AA1, CHEK1, PSMA4, PSMD4, and PSMD8 were upregulated in the senescent ARPE-19 cells. Additionally, the drugs targeting HSP90AA1, CHEK1, and PSMA4 were identified. We hypothesize that Hsa-miR-16-5p might target four out of the five key DEGs in the AMD RPE. CONCLUSIONS Based on our findings, HSP90AA1 is likely to be a central gene controlling the DNA replication and proteasome-mediated polyubiquitination during the RPE senescence observed in the progression of AMD. Targeting HSP90AA1, CHEK1, PSMA4, PSMD4, and/or PSMD8 genes through specific miRNAs or small molecules might potentially alleviate the progression of AMD through attenuating RPE senescence.
DNA Replication ; Gene Expression Profiling ; Gene Ontology ; Humans ; Macular Degeneration/genetics* ; Proteasome Endopeptidase Complex

To explore the molecular mechanism of human papillomavirus subtype 16(HPV-16)E7 oncogene-induced DNA re-replication in response to DNA damage. Flow cytometry was performed to examine the cell cycle changes in RPE1 E7 cells stably expressing HPV-16 E7 and its control cell RPE1 Vector after DNA damage.Immunoblotting assay was used to evaluate the early mitotic inhibitor 1(Emi1)expression in RPE1 E7 and RPE1 Vector cells with or without DNA damage.The changes of the proportion of polyploidy was detected by flow cytometry in DNA-damaged RPE1 E7 cells interfered by Emi1 small interfering RNA. Compared with the control cells,the proportion of polyploids in RPE1 E7 cells was significantly increased in response to DNA damage(=6.397,=0.0031).Emi1 protein expression was significantly increased in DNA damaged RPE1 E7 cells(=8.241,=0.0012).The polyploid ratio of RPE1 E7 cells was significantly reduced after Emi1 was interfered by two independent small interfering RNAs(=2.916,=0.0434;=3.452,=0.0260). In response to DNA damage,Emi1 promoted DNA re-replication caused by HPV-16 E7.
DNA Damage ; DNA Replication ; Human papillomavirus 16 ; Mitosis ; Oncogene Proteins, Viral

Human parvovirus B19 (B19 virus) is one of the two parvoviruses that cause human diseases. As an important pathogen to humans, it causes infectious erythema in children, acute aplastic anemia, fetal edema and death. In this review, we focus on the recent advances in the molecular virology of B19V, such as viral genotypes, viral receptor, genomic features and viral replication, viral transcription and post-transcription regulation, viral nonstructural and structural protein features and functions, viral diagnosis and antiviral agents, to provide reference for further study of B19 pathogenesis mechanisms, treatment and diagnostic strategies.
Antiviral Agents ; DNA, Viral ; genetics ; Erythema Infectiosum ; diagnosis ; virology ; Genotype ; Humans ; Parvovirus B19, Human ; genetics ; Virology ; trends ; Virus Replication

OBJECTIVE: To study the correlation of Mycoplasma pneumoniae DNA (MP-DNA) replication level in throat swab and bronchoalveolar lavage fluid (BALF) with disease severity in children with severe Mycoplasma pneumoniae pneumonia (SMPP). METHODS: A total of 44 children with SMPP who underwent bronchoalveolar lavage were enrolled as subjects. The serum levels of cytokines and MP-DNA replication times in throat swab were measured in the acute stage and the recovery stage, and the levels of interleukin (IL)-8 and MP-DNA replication times in BALF were measured in the acute stage. According to whether mechanical ventilation was needed for respiratory failure, the children were divided into a mechanical ventilation group (n=19) and a non-mechanical ventilation group (n=25), and the two groups were compared in MP-DNA replication times in BALF. RESULTS: For the children with SMPP, serum levels of C-reactive protein, erythrocyte sedimentation rate, lactate dehydrogenase, IL-1, IL-6, IL-8, and IL-18 in the acute stage were significantly higher than those in the recovery stage (P<0.05). In the acute stage, MP-DNA replication times in throat swab were positively correlated with those in BALF (r=0.613, P<0.05), and MP-DNA replication times in BALF were positively correlated with IL-18 levels in peripheral blood and BALF (r=0.613 and 0.41 respectively, P<0.05). Compared with the non-mechanical ventilation group, the mechanical ventilation group had significantly higher MP-DNA replication times in BALF, a significantly longer duration of systemic hormone treatment, significantly higher serum levels of lactate dehydrogenase and IL-18, and significantly higher white blood cell count and IL-18 level in BALF (P<0.05). CONCLUSIONS In children with SMPP, MP-DNA replication level in throat swab and BALF can be used as a reference index for the assessment of disease severity.
Bronchoalveolar Lavage Fluid ; Child ; Cytokines ; DNA Replication ; DNA, Bacterial ; Humans ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma

Baller-Gerold syndrome is a rare autosomal recessive disorder characterized by premature fusion of the cranial sutures and malformation of the upper limb extremities at birth. Although the pathogenesis of Baller-Gerold Syndrome is not fully understood, it is mainly caused by mutations in the RecQ like helicase 4 (RECQL4) gene located on chromosome 8q24.3, which encodes the RECQL4 protein involved in normal DNA replication and repair. This study reports the case of a female premature infant with craniosynostosis of bilateral coronal sutures, resulting in a dysmorphic face and hypoplastic thumbs on both hands at birth, which are consistent with the core characteristics of Baller-Gerold syndrome. Diagnostic whole exome sequencing of the patient revealed a homozygous deletion from exon 13 to 18 in the RECQL4 gene. To the best of my knowledge, this is the first reported case of Baller-Gerold syndrome with RECQL4 gene mutation confirmed by diagnostic whole exome sequencing in Korea.
Cranial Sutures ; Craniosynostoses ; DNA Replication ; Exome ; Exons ; Extremities ; Female ; Hand ; Hand Deformities ; Humans ; Infant, Newborn ; Infant, Premature ; Korea ; Parturition ; Sutures ; Thumb ; Upper Extremity