1.Lamin B1 regulates the growth of hepatocellular carcinoma cells by influencing telomerase activity.
Ruiguan WANG ; Si CHEN ; Zhijia SUN ; Shikun WANG ; Jie WANG ; Lingmei QIN ; Jiangbo LI
Chinese Journal of Biotechnology 2023;39(4):1609-1620
Lamin B1 (LMNB1) is highly expressed in liver cancer tissues, and its influence and mechanism on the proliferation of hepatocellular carcinoma cells were explored by knocking down the expression of the protein. In liver cancer cells, siRNAs were used to knock down LMNB1. Knockdown effects were detected by Western blotting. Changes in telomerase activity were detected by telomeric repeat amplification protocol assay (TRAP) experiments. Telomere length changes were detected by quantitative real-time polymerase chain reaction (qPCR). CCK8, cloning formation, transwell and wound healing were performed to detect changes in its growth, invasion and migration capabilities. The lentiviral system was used to construct HepG2 cells that steadily knocked down LMNB1. Then the changes of telomere length and telomerase activity were detected, and the cell aging status was detected by SA-β-gal senescence staining. The effects of tumorigenesis were detected by nude mouse subcutaneous tumorigenesis experiments, subsequent histification staining of tumors, SA-β-gal senescence staining, fluorescence in situ hybridization (FISH) for telomere analysis and other experiments. Finally, the method of biogenesis analysis was used to find the expression of LMNB1 in clinical liver cancer tissues, and its relationship with clinical stages and patient survival. Knockdown of LMNB1 in HepG2 and Hep3B cells significantly reduced telomerase activity, cell proliferation, migration and invasion abilities. Experiments in cells and tumor formation in nude mice had demonstrated that stable knockdown of LMNB1 reduced telomerase activity, shortened telomere length, senesced cells, reduced cell tumorigenicity and KI-67 expression. Bioinformatics analysis showed that LMNB1 was highly expressed in liver cancer tissues and correlated with tumor stage and patient survival. In conclusion, LMNB1 is overexpressed in liver cancer cells, and it is expected to become an indicator for evaluating the clinical prognosis of liver cancer patients and a target for precise treatment.
Animals
;
Mice
;
Telomerase/metabolism*
;
Carcinoma, Hepatocellular/genetics*
;
Liver Neoplasms/genetics*
;
Telomere Shortening
;
In Situ Hybridization, Fluorescence
;
Mice, Nude
;
Telomere/pathology*
;
Carcinogenesis
2.A conceptual framework for dynamics of cccDNA in hepatitis B virus.
Chinese Journal of Hepatology 2023;31(5):545-550
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*
3.Research progress of lung aging in chronic respiratory diseases.
Kai ZHOU ; Long CHEN ; Xiao-Qun QIN ; Yang XIANG ; Xiang-Ping QU ; Hui-Jun LIU ; Chi LIU
Acta Physiologica Sinica 2022;74(3):479-488
Cell aging is an extremely complex process, which is characterized by mitochondrial structural dysfunction, telomere shortening, inflammatory microenvironment, protein homeostasis imbalance, epigenetic changes, abnormal DNA damage and repair, etc. Aging is usually accompanied by structural and functional damage of tissues and organs which further induces the occurrence and development of aging-related diseases. Aging includes physiological aging caused by increased age and pathological aging induced by a variety of factors. Noteworthy, as a target organ directly contacting with the outside air, lung is more prone to various stimuli, causing pathological premature aging which is lung aging. Studies have found that there is a certain proportion of senescent cells in the lungs of most chronic respiratory diseases. However, the underlying mechanism by which these senescent cells induce lung senescence and their role in chronic respiratory diseases is still obscure. This paper focuses on the causes and classification of lung aging, the internal mechanism of lung aging involved in chronic respiratory diseases, and the application of anti-aging treatments in chronic respiratory diseases. We hope to provide new research ideas and theoretical basis for the clinical prevention and treatment in chronic respiratory diseases.
Aging/pathology*
;
Cellular Senescence
;
Humans
;
Lung/pathology*
;
Lung Diseases/pathology*
;
Respiration Disorders/pathology*
;
Telomere
;
Telomere Shortening
4.SET8 Inhibition Potentiates Radiotherapy by Suppressing DNA Damage Repair in Carcinomas.
Dong PAN ; Ya Rong DU ; Rong LI ; Ai Hua SHEN ; Xiao Dong LIU ; Chuan Yuan LI ; Bu Rong HU
Biomedical and Environmental Sciences 2022;35(3):194-205
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
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Apoptosis
;
Carcinogenesis
;
Carcinoma/radiotherapy*
;
Cell Cycle
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Cell Line, Tumor
;
DNA Damage
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DNA Replication
;
HeLa Cells
;
Histone-Lysine N-Methyltransferase
;
Humans
;
Mice
;
Radiotherapy
5.A short half-life of cccDNA offer or ignite hope for hepatitis B cure under nucleos(t)ide analogues treatment.
Lin GAO ; Tian Hao MAO ; Si Wen PENG ; Jie WANG ; Xiang Mei CHEN ; Feng Min LU
Chinese Journal of Hepatology 2022;30(1):99-102
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
6.Rational selection of virologic and immunological biomarkers and therapeutic endpoints in the clinical trials of new drugs treating chronic hepatitis B.
Chinese Journal of Hepatology 2022;30(4):429-438
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*
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Biomarkers
;
DNA, Circular
;
DNA, Viral
;
Hepatitis B/drug therapy*
;
Hepatitis B Surface Antigens
;
Hepatitis B virus/genetics*
;
Hepatitis B, Chronic
;
Humans
;
Virus Replication
7.Hsp90-associated DNA replication checkpoint protein and proteasome-subunit components are involved in the age-related macular degeneration.
Chen XING ; Xiao-Feng LIU ; Chun-Feng ZHANG ; Liu YANG
Chinese Medical Journal 2021;134(19):2322-2332
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
8.Hepatitis B core-related antigen reflects viral replication and protein production in chronic hepatitis B patients.
Jun LI ; Zhao WU ; Gui-Qiang WANG ; Hong ZHAO
Chinese Medical Journal 2021;134(10):1160-1167
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
9.Correlation of telomere length and serotonin levels with job stress and locus of control type among nurses at a private hospital in Gianyar, Indonesia
Susy Purnawati ; I Made Krisna Dinata ; Ni Made Linawati ; I G Kamasan Nyoman Arijana
Acta Medica Philippina 2021;55(6):632-639
Objectives
Telomere length and its relationship to job stress among workers in the health sector in Indonesia, especially in Bali, have never been studied. The purpose of the study was to analyze the correlation of the telomere length and serotonin levels to job stress and the type of locus of control (LOC) among nurses who were running shift work.
Internal-External Control
;
Occupational Stress
;
Serotonin
;
Telomere Shortening
10.Early Mitotic Inhibitor 1 Regulates DNA Re-replication Mediated by Human Papillomavirus Subtype 16 E7 in Response to DNA Damage.
Ya-Fei LIU ; Yan-Jun SHEN ; Yang YANG ; Lan CHAO ; Fang YANG
Acta Academiae Medicinae Sinicae 2020;42(4):485-490
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


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