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Liu J, Tan X, Li L, Cao L, Zhou Y, Li H, Peng T. Protein expression of nucleolar protein 12 in the retina and its implication in protection of retina from UV irradiation damage. Cell Death Discov 2024; 10:130. [PMID: 38467618 PMCID: PMC10928217 DOI: 10.1038/s41420-024-01902-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 01/28/2024] [Accepted: 02/29/2024] [Indexed: 03/13/2024] Open
Abstract
Nucleolar protein 12 (NOL12), one of the nucleolar proteins which are primarily expressed in the nucleolus and play key roles in RNA metabolism, cell proliferation, cell cycle, and cell survival, is widely expressed in various species and multiple organs. Although it has been reported that the mRNA of Drosophila NOL12 homolog viriato is expressed in the eyes of Drosophila, the protein expression of NOL12 in mammalian eyes remains to be elucidated. In this study, we showed through immunohistochemistry that NOL12 was present in the rat retina, with predominant distribution in the cytoplasm of the retinal neuronal cells. In the human retinoblastoma cell line WERI-Rb1, we found that altering NOL12 expression led to a change in WERI-Rb1 cell viability. Knocking down NOL12 expression decreased cell viability. In contrast, overexpressing NOL12 increased cell viability. Furthermore, increasing NOL12 expression inhibited ultraviolet (UV)-induced apoptosis. These findings demonstrated that NOL12 may play an important protective role in retinal cells. In the WERI-Rb1 cells exposed to UV irradiation, we detected that NOL12 was degraded, but this degradation could be attenuated by a pan-Caspase inhibitor. Notably, the inhibitory effect of NOL12 against UV-induced apoptosis could be restrained by increasing the expression of ATR serine/threonine kinase (ATR), a kinase that, when activated by severe DNA damage, can result in apoptosis. We also found that upregulating NOL12 inhibited the activation of ATR caused by UV irradiation. Additionally, inhibiting ATR activity reduced apoptosis resulting from both silencing NOL12 expression and UV exposure. Thus, NOL12 may protect against UV irradiation-induced retinal damage by inhibiting ATR activity.
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Affiliation(s)
- Jingtao Liu
- Department of Histology and Embryology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
- Department of Histology and Embryology, Hubei University of Medicine, Shiyan, 442000, People's Republic of China
| | - Xiaomei Tan
- Department of Histology and Embryology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Li Li
- Department of Critical Care Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071, People's Republic of China
| | - Liying Cao
- Department of Histology and Embryology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Yan Zhou
- Department of Histology and Embryology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - He Li
- Department of Histology and Embryology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
- Department of Histology and Embryology, Hubei University of Medicine, Shiyan, 442000, People's Republic of China.
- Department of Histology and Embryology, School of Medicine, Yunnan University, Kunming, 650091, People's Republic of China.
| | - Ting Peng
- Department of Histology and Embryology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
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Xu X, Zhang L, Ye G, Shi J, Peng Y, Xin F, Lin Y, Wu Q, Lin X, Chen W. Hepatitis B doubly spliced protein (HBDSP) promotes hepatocellular carcinoma cell apoptosis via ETS1/GATA2/YY1-mediated p53 transcription. J Virol 2023; 97:e0108723. [PMID: 37929990 PMCID: PMC10688342 DOI: 10.1128/jvi.01087-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/26/2023] [Indexed: 11/07/2023] Open
Abstract
IMPORTANCE Hepatitis B virus (HBV) spliced variants are associated with viral persistence or pathogenicity. Hepatitis B doubly spliced protein (HBDSP), which has been previously reported as a pleiotropic transactivator protein, can potentially serve as an HBV virulence factor. However, the underlying mechanisms of HBDSP in HBV-associated liver diseases remain to be elucidated. In this study, we revealed that HBDSP promotes cellular apoptosis and induces wt-p53-dependent apoptotic signaling pathway in wt-p53 hepatocellular cells by transactivating p53 transcription, and increases the release of HBV progeny. Therefore, HBDSP may promote the HBV particles release through wt-p53-dependent hepatocellular apoptosis. Our findings suggest that blocking HBDSP-induced wt-p53-dependent apoptosis might have therapeutic values for chronic hepatitis B.
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Affiliation(s)
- Xiazhen Xu
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Lu Zhang
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Guiying Ye
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Jiajian Shi
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Yibin Peng
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Fan Xin
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Yi Lin
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Qiong Wu
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Xu Lin
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Wannan Chen
- Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
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Li Y, Gan L, Lu M, Zhang X, Tong X, Qi D, Zhao Y, Ye X. HBx downregulated decorin and decorin-derived peptides inhibit the proliferation and tumorigenicity of hepatocellular carcinoma cells. FASEB J 2023; 37:e22871. [PMID: 36929160 DOI: 10.1096/fj.202200999rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 02/03/2023] [Accepted: 03/01/2023] [Indexed: 03/18/2023]
Abstract
Hepatitis B virus (HBV) is one of the important risk factors in inducing the occurrence and development of liver cancer, while the mechanism has not been fully clarified. In this study, we found decorin (DCN) was significantly reduced in HBV transgenic cell line HepG2-4D14 compared to HepG2. The data from hepatocellular carcinoma (HCC) patients indicated that the level of DCN mRNA was significantly lower in tumor tissues than healthy control and positively correlated with the survival of HCC patients. We revealed that HBV HBx can inhibit the transcription of DCN by blocking p53 activity. Functional analysis demonstrated that overexpression of DCN substantially inhibits the proliferation of HCC cells, while knockdown of DCN enhances the proliferation of HCC cells. It is known that DCN could competitively bind to c-Met to inhibit HGF/c-Met signaling pathway to inhibit the development of HCC. Therefore, we screened the novel antitumor peptides derived from DCN based on the sequence of DCN and the complex structure of HGF/c-Met with virtual screening and identified a set of DCN-derived peptides (DCN-Ps) which may competitively bind to c-Met. We found that 5 of peptides can reduce the proliferation and migration of HepG2 cells significantly. Among them, DCN-P#3 can inhibit the growth of HCC cells both in vitro and in vivo. In conclusion, we discovered that HBV HBx downregulates the expression of DCN, which in turn promotes the proliferation of hepatocytes and the development of HCC. We identified DCN-derived antitumor peptides which provides the candidates for developing novel drugs against HCC.
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Affiliation(s)
- Yong Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Lipeng Gan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Min Lu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaodan Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaomei Tong
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
| | - Dandan Qi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
| | - Yan Zhao
- Department of General Surgery, Strategic Support Force Medical Center, Beijing, China
| | - Xin Ye
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
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Duan Y, Zhang W, Chen X, Wang M, Zhong L, Liu J, Bian W, Zhang S. Genome-wide identification and expression analysis of mitogen-activated protein kinase (MAPK) genes in response to salinity stress in channel catfish (Ictalurus punctatus). JOURNAL OF FISH BIOLOGY 2022; 101:972-984. [PMID: 35818162 DOI: 10.1111/jfb.15158] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
The mitogen-activated protein kinase (MAPK) gene family has been systematically described in several fish species, but less so in channel catfish (Ictalurus punctatus), which is an important global aquaculture species. In this study, 16 MAPK genes were identified in the channel catfish genome and classified into three subfamilies based on phylogenetic analysis, including six extracellular signal regulated kinase (ERK) genes, six p38-MAPK genes and four C-Jun N-terminal kinase (JNK) genes. All MAPK genes were distributed unevenly across 10 chromosomes, of which three (IpMAPK8, IpMAPK12 and IpMAPK14) underwent teleost-specific whole genome duplication during evolution. Gene expression profiles in channel catfish during salinity stress were analysed using transcriptome sequencing and qRT-PCR (quantitative reverse transcription PCR). Results from reads per kilobase million (RPKM) analysis showed IpMAPK13, IpMAPK14a and IpMAPK14b genes were differentially expressed when compared with other genes between treatment and control groups. Furthermore, three of these genes were validated by qRT-PCR, of which IpMAPK14a expression levels were significantly upregulated in treatment groups (high and low salinity) when compared with the control group, with the highest expression levels in the low salinity group (P < 0.05). Therefore, IpMAPK14a may have important response roles to salinity stress in channel catfish.
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Affiliation(s)
- Yongqiang Duan
- National Genetic Breeding Center of Channel Catfish, Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Wenping Zhang
- College of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, China
| | - Xiaohui Chen
- National Genetic Breeding Center of Channel Catfish, Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, China
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Nanjing, China
| | - Minghua Wang
- National Genetic Breeding Center of Channel Catfish, Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, China
- The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Nanjing, China
| | - Liqiang Zhong
- National Genetic Breeding Center of Channel Catfish, Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, China
- The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Nanjing, China
| | - Ju Liu
- National Genetic Breeding Center of Channel Catfish, Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, China
| | - Wenji Bian
- National Genetic Breeding Center of Channel Catfish, Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, China
- College of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, China
- The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Nanjing, China
| | - Shiyong Zhang
- National Genetic Breeding Center of Channel Catfish, Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, China
- The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Nanjing, China
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Detoxification II Prescription Suppresses the Th-17/IL-17 Inflammatory Axis to Improve the Liver Function of ACLF-Rats via Inactivating the P38MAPK Pathway. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:7563383. [PMID: 34900202 PMCID: PMC8664511 DOI: 10.1155/2021/7563383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 10/28/2021] [Accepted: 11/02/2021] [Indexed: 11/17/2022]
Abstract
Hepatitis is a metabolic system disease which is a serious challenge to the medical and healthcare system of the world. This study attempted to investigate the therapeutic effect and illustrate the regulation pharmacological mechanism of Detoxification II Prescription on ACLF. In this study, the rats were injected with D-galactosamine to establish ACLF-rat models, and the levels of cholinesterase (CHE), alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB), and total bilirubin (TBiL) were measured with the related kits to reflect the liver functions of the rats. The levels of IL-17, IL-6, and IFN-γ in the serums of the rats were detected by qRT-PCR, and the percentages of Th-17 cells in CD4+ cells of the rats were measured by flow cytometry assay. In the results, the increased ALT, AST, TBiL, IL-6, IL-17, IFN-γ, and percentage of Th-17 cells in CD4+ and decreased ALB and CHE were found in the serums of the ACLF-rats, while Detoxification II Prescription could partly reverse those indexes of the ACLF-rats. Moreover, it was also found that Detoxification II Prescription could inhibit the expression of P38MAPK, and P38MAPK downregulation obviously improved the liver function indexes of the ACLF-rats including the levels of ALT, AST, TBiL, IL-6, IL-17, IFN-γ, and percentage of Th-17 cells in CD4+ cells. In conclusion, this study suggested that Detoxification II Prescription could suppress the Th-17/IL-17 inflammatory axis to improve the liver function of ACLF-rats via inhibiting the activity of the P38MAPK pathway.
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Wei L, Ploss A. Mechanism of Hepatitis B Virus cccDNA Formation. Viruses 2021; 13:v13081463. [PMID: 34452329 PMCID: PMC8402782 DOI: 10.3390/v13081463] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/14/2021] [Accepted: 07/21/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV) remains a major medical problem affecting at least 257 million chronically infected patients who are at risk of developing serious, frequently fatal liver diseases. HBV is a small, partially double-stranded DNA virus that goes through an intricate replication cycle in its native cellular environment: human hepatocytes. A critical step in the viral life-cycle is the conversion of relaxed circular DNA (rcDNA) into covalently closed circular DNA (cccDNA), the latter being the major template for HBV gene transcription. For this conversion, HBV relies on multiple host factors, as enzymes capable of catalyzing the relevant reactions are not encoded in the viral genome. Combinations of genetic and biochemical approaches have produced findings that provide a more holistic picture of the complex mechanism of HBV cccDNA formation. Here, we review some of these studies that have helped to provide a comprehensive picture of rcDNA to cccDNA conversion. Mechanistic insights into this critical step for HBV persistence hold the key for devising new therapies that will lead not only to viral suppression but to a cure.
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Abstract
Viral infections lead to the death of more than a million people each year around the world, both directly and indirectly. Viruses interfere with many cell functions, particularly critical pathways for cell death, by affecting various intracellular mediators. MicroRNAs (miRNAs) are a major example of these mediators because they are involved in many (if not most) cellular mechanisms. Virus-regulated miRNAs have been implicated in three cell death pathways, namely, apoptosis, autophagy, and anoikis. Several molecules (e.g., BECN1 and B cell lymphoma 2 [BCL2] family members) are involved in both apoptosis and autophagy, while activation of anoikis leads to cell death similar to apoptosis. These mechanistic similarities suggest that common regulators, including some miRNAs (e.g., miR-21 and miR-192), are involved in different cell death pathways. Because the balance between cell proliferation and cell death is pivotal to the homeostasis of the human body, miRNAs that regulate cell death pathways have drawn much attention from researchers. miR-21 is regulated by several viruses and can affect both apoptosis and anoikis via modulating various targets, such as PDCD4, PTEN, interleukin (IL)-12, Maspin, and Fas-L. miR-34 can be downregulated by viral infection and has different effects on apoptosis, depending on the type of virus and/or host cell. The present review summarizes the existing knowledge on virus-regulated miRNAs involved in the modulation of cell death pathways. Understanding the mechanisms for virus-mediated regulation of cell death pathways could provide valuable information to improve the diagnosis and treatment of many viral diseases.
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Bhukya PL, C VK, Lole KS. Transcriptome analysis of hepatoma cells transfected with Basal Core Promoter (BCP) and Pre-Core (PC) mutant hepatitis B virus full genome construct. J Gen Virol 2021; 102. [PMID: 33595430 DOI: 10.1099/jgv.0.001568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Infections with Basal Core Promoter (BCP) (A1762T/G1764A) and Pre-Core (PC) (G1896A) hepatitis B virus HBeAg mutants are associated with severe liver injury. We analysed host cell responses in HepG2/C3A, hepatoma cells transfected with infectious clones developed from genotype D wild type (WT) and BCP/PC mutant (MT) viruses isolated from an acute resolved and an acute liver failure hepatitis B case respectively. Cells transfected with MT virus construct showed ~55 % apoptosis and with WT ~30 % apoptosis at 72 h. To determine possible roles of HBe and HBx proteins in apoptosis, we cloned these genes and co-transfected cells with WT+HBe/HBx or MT+HBe/HBx constructs. Co-expression of HBe protein improved cell viability significantly in both WT and MT virus constructs, indicating an important role of HBe in protecting cells. RNA sequencing analysis carried out at 12 and 72 h post-transfection with WT virus construct showed enrichment of innate/adaptive immune response-activating signal transduction, cell survival and amino acid/nucleic acid biosynthetic pathways at 12 and 72 h. By contrast, MT virus construct showed enrichment in host defence pathways and some biosynthetic pathways at the early time point (12 h), and inflammatory response, secretary granule, regulation of membrane potential and stress response regulatory pathways at the late time point (72 h). There was a significant down-regulation of genes involved in endoplasmic reticulum and mitochondrial functions and metabolism with MT construct and this possibly led to induction of apoptosis in cells. Considering rapid apoptotic changes in cells transfected with MT construct, it can be speculated that HBeAg plays a crucial role in cell survival. It enhances induction of metabolic and synthetic pathways and facilitates management of cellular stress that is induced due to hepatitis B virus infection/replication.
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Meier T, Timm M, Montani M, Wilkens L. Gene networks and transcriptional regulators associated with liver cancer development and progression. BMC Med Genomics 2021; 14:41. [PMID: 33541355 PMCID: PMC7863452 DOI: 10.1186/s12920-021-00883-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 01/24/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Treatment options for hepatocellular carcinoma (HCC) are limited, and overall survival is poor. Despite the high frequency of this malignoma, its basic disease mechanisms are poorly understood. Therefore, the aim of this study was to use different methodological approaches and combine the results to improve our knowledge on the development and progression of HCC. METHODS Twenty-three HCC samples were characterized by histological, morphometric and cytogenetic analyses, as well as comparative genomic hybridization (aCGH) and genome-wide gene expression followed by a bioinformatic search for potential transcriptional regulators and master regulatory molecules of gene networks. RESULTS Histological evaluation revealed low, intermediate and high-grade HCCs, and gene expression analysis split them into two main sets: GE1-HCC and GE2-HCC, with a low and high proliferation gene expression signature, respectively. Array-based comparative genomic hybridization demonstrated a high level of chromosomal instability, with recurrent chromosomal gains of 1q, 6p, 7q, 8q, 11q, 17q, 19p/q and 20q in both HCC groups and losses of 1p, 4q, 6q, 13q and 18q characteristic for GE2-HCC. Gene expression and bioinformatics analyses revealed that different genes and gene regulatory networks underlie the distinct biological features observed in GE1-HCC and GE2-HCC. Besides previously reported dysregulated genes, the current study identified new candidate genes with a putative role in liver cancer, e.g. C1orf35, PAFAH1B3, ZNF219 and others. CONCLUSION Analysis of our findings, in accordance with the available published data, argues in favour of the notion that the activated E2F1 signalling pathway, which can be responsible for both inappropriate cell proliferation and initial chromosomal instability, plays a pivotal role in HCC development and progression. A dedifferentiation switch that manifests in exaggerated gene expression changes might be due to turning on transcriptional co-regulators with broad impact on gene expression, e.g. POU2F1 (OCT1) and NFY, as a response to accumulating cell stress during malignant development. Our findings point towards the necessity of different approaches for the treatment of HCC forms with low and high proliferation signatures and provide new candidates for developing appropriate HCC therapies.
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Affiliation(s)
- Tatiana Meier
- Institute of Pathology, Nordstadtkrankenhaus, Hanover, Germany.
| | - Max Timm
- Institute of Pathology, Nordstadtkrankenhaus, Hanover, Germany
- Clinic for Laryngology, Rhinology and Otology, Medical School Hanover, Hanover, Germany
| | - Matteo Montani
- Institute of Pathology, University of Bern, Bern, Switzerland
| | - Ludwig Wilkens
- Institute of Pathology, Nordstadtkrankenhaus, Hanover, Germany
- Institute of Human Genetics, Medical School Hanover, Hanover, Germany
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Iriana S, Asha K, Repak M, Sharma-Walia N. Hedgehog Signaling: Implications in Cancers and Viral Infections. Int J Mol Sci 2021; 22:1042. [PMID: 33494284 PMCID: PMC7864517 DOI: 10.3390/ijms22031042] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/11/2021] [Accepted: 01/14/2021] [Indexed: 12/14/2022] Open
Abstract
The hedgehog (SHH) signaling pathway is primarily involved in embryonic gut development, smooth muscle differentiation, cell proliferation, adult tissue homeostasis, tissue repair following injury, and tissue polarity during the development of vertebrate and invertebrate organisms. GLIoma-associated oncogene homolog (GLI) family of zinc-finger transcription factors and smoothened (SMO) are the signal transducers of the SHH pathway. Both SHH ligand-dependent and independent mechanisms activate GLI proteins. Various transcriptional mechanisms, posttranslational modifications (phosphorylation, ubiquitination, proteolytic processing, SUMOylation, and acetylation), and nuclear-cytoplasmic shuttling control the activity of SHH signaling pathway proteins. The dysregulated SHH pathway is associated with bone and soft tissue sarcomas, GLIomas, medulloblastomas, leukemias, and tumors of breast, lung, skin, prostate, brain, gastric, and pancreas. While extensively studied in development and sarcomas, GLI family proteins play an essential role in many host-pathogen interactions, including bacterial and viral infections and their associated cancers. Viruses hijack host GLI family transcription factors and their downstream signaling cascades to enhance the viral gene transcription required for replication and pathogenesis. In this review, we discuss a distinct role(s) of GLI proteins in the process of tumorigenesis and host-pathogen interactions in the context of viral infection-associated malignancies and cancers due to other causes. Here, we emphasize the potential of the Hedgehog (HH) pathway targeting as a potential anti-cancer therapeutic approach, which in the future could also be tested in infection-associated fatalities.
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Luo D, Li H, Hu J, Zhang M, Zhang S, Wu L, Han B. Development and Validation of Nomograms Based on Gamma-Glutamyl Transpeptidase to Platelet Ratio for Hepatocellular Carcinoma Patients Reveal Novel Prognostic Value and the Ratio Is Negatively Correlated With P38MAPK Expression. Front Oncol 2020; 10:548744. [PMID: 33344225 PMCID: PMC7744698 DOI: 10.3389/fonc.2020.548744] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 10/30/2020] [Indexed: 12/15/2022] Open
Abstract
Background Early prediction of recurrence and death risks is significant to the treatment of hepatocellular carcinoma (HCC) patients. We aimed to develop and validate prognosis nomogram models based on the gamma-glutamyl transpeptidase (GGT)-to-platelet (PLT) ratio (GPR) for HCC and to explore the relationship between the GPR and inflammation-related signaling pathways. Methods All data were obtained from 2000 to 2012 in the Affiliated Hospital of Qingdao University. In the training cohort, factors included in the nomograms were determined by univariate and multivariate analyses. In the training and validation cohorts, the concordance index (C-index) and calibration curves were used to assess predictive accuracy, and receiver operating characteristic curves were used to assess discriminative ability. Clinical utility was evaluated using decision curve analysis. Moreover, improvement of the predictive accuracy of the nomograms was evaluated by calculating the decision curve analysis, the integrated discrimination improvement, and the net reclassification improvement. Finally, the relationship between the GPR and inflammation-related signaling pathways was evaluated using the independent-samples t-test. Results A larger tumor size and higher GPR were common independent risk factors for both disease-free survival (DFS) and overall survival (OS) in HCC (P < 0.05). Good agreement between our nomogram models' predictions and actual observations was detected by the C-index and calibration curves. Our nomogram models showed significantly better performance in predicting the HCC prognosis compared to other models (P < 0.05). Online webserver and scoring system tables were built based on the proposed nomogram for convenient clinical use. Notably, including the GPR greatly improved the predictive ability of our nomogram models (P < 0.05). In the validation cohort, p38 mitogen-activated protein kinase (P38MAPK) expression was significantly negatively correlated with the GPR (P < 0.01) and GGT (P = 0.039), but was not correlated with PLT levels (P = 0.063). And we found that P38MAPK can regulate the expression of GGT by quantitative real-time PCR and Western blotting experiments. Conclusions The dynamic nomogram based on the GPR provides accurate and effective prognostic predictions for HCC, and P38MAPK-GGT may be a suitable therapeutic target to improve the prognosis of HCC patients.
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Affiliation(s)
- Dingan Luo
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Haoran Li
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jie Hu
- Department of General Surgery, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Mao Zhang
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Shun Zhang
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Liqun Wu
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Bing Han
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
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12
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Abstract
Hepatitis B virus (HBV) chronically infects hundreds of millions of people and remains a major cause of viral hepatitis, cirrhosis, and liver cancer. HBV persistence is sustained by a viral nuclear episome that directs all viral gene expression needed to support viral replication. The episome is converted from an incomplete DNA precursor in viral particles in an ill-understood process. We report here that the incomplete DNA precursor is recognized by the host cell in a way similar to the sensing of damaged cellular DNA for subsequent repair to form the nuclear episome. Intense efforts are ongoing to develop novel antiviral strategies to eliminate CCC DNA so as to cure chronic HBV infection. Our results here provide novel insights into, and suggest novel ways of perturbing, the process of episome formation. Furthermore, our results inform mechanisms of cellular DNA damage recognition and repair, processes essential for normal cell growth. The covalently closed circular (CCC) DNA of hepatitis B virus (HBV) functions as the only viral transcriptional template capable of producing all viral RNA species and is essential to initiate and sustain viral replication. CCC DNA is converted from a relaxed circular (RC) DNA, in which neither of the two DNA strands is covalently closed. As RC DNA mimics damaged cellular DNA, the host cell DNA damage repair (DDR) system is thought to be responsible for HBV CCC DNA formation. The potential role of two major cellular DDR pathways, the ataxia telangiectasia mutated (ATM) pathway and the ATM and Rad3-related (ATR) pathway, in HBV CCC DNA formation was thus investigated. Inhibition, or expression knockdown, of ATR and its downstream signaling factor CHK1, but not of ATM, decreased CCC DNA formation during de novo HBV infection, as well as intracellular CCC DNA amplification, when RC DNA from extracellular virions and intracellular nucleocapsids, respectively, is converted to CCC DNA. Furthermore, a novel RC DNA processing product with 5′ truncated minus strands was detected when the ATR-CHK1 pathway was inhibited, further indicating that this pathway controls RC DNA processing during its conversion to CCC DNA. These results provide new insights into how host cells recognize and process HBV RC DNA in order to produce CCC DNA and have implications for potential means to block CCC DNA production.
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13
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Abstract
Liver cancer is a particularly aggressive group of malignancies with historically low survival rates. Despite advancements in cancer treatments in general in the last few decades, incidence and mortality have not changed. Even though some phase 1 and 2 studies have shown promising results, many medication have failed to reach a sustainable level of efficacy to move into the clinical setting. Immunotherapy drugs have shown impressive results in the treatment of specific immunogenic cancers, prompting the possibility of their use in liver cancers. Immunotherapy medications approved for other cancers have received FDA accelerated approval for treatment of hepatocellular carcinoma. But, these approvals are contingent upon verification and description of clinical benefit in confirmatory trials. With more treatments in development involving cancer vaccines and natural killer cell-mediated therapy, liver cancer treatment is being reinvigorated with a broad array of new treatment angles. In this review article, we discuss these treatments, focusing on mechanism of action and clinical trials. Much needed advancements in treating late- and early-stage liver cancers will require new and innovative immunotherapeutic treatments.
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Affiliation(s)
- Christoffer Briggs Lambring
- Graduate School of Biomedical Sciences, The University of North Texas Health Science Center, Fort Worth, Texas
| | | | | | - Riyaz Basha
- Graduate School of Biomedical Sciences, The University of North Texas Health Science Center, Fort Worth, Texas
- Department of Pediatrics and Women’s Health, Texas College of Osteopathic Medicine, The University of North Texas Health Science Center, Fort Worth, Texas
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14
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Jeong H, Cha S, Jang KL. HBx natural variants containing Ser-101 instead of Pro-101 evade ubiquitin-dependent proteasomal degradation by activating proteasomal activator 28 gamma expression. J Gen Virol 2019; 100:1554-1566. [PMID: 31596196 DOI: 10.1099/jgv.0.001337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Proteasomal activator 28 gamma (PA28γ) is frequently overexpressed in hepatocellular carcinoma; however, its underlying mechanism and role in hepatitis B virus (HBV) replication are largely unknown. Here, we found that HBV X protein (HBx) natural variants containing Ser-101 instead of Pro-101 increase reactive oxygen species levels in the mitochondria and activate the ataxia telangiectasia mutated/checkpoint kinase 2 pathway in the nucleus, resulting in the phosphorylation of p53 at Ser-15 and Ser-20 and the subsequent upregulation of its protein levels. Therefore, HBx variants containing Ser-101 induced p53-dependent activation of PA28γ expression in human hepatoma cells. The elevated PA28γ levels upregulated HBx levels through the inhibition of seven in absentia homologue 1-dependent proteasomal degradation. The self-amplifying ability of HBx variants containing Ser-101 via a positive feedback loop involving p53 and PA28γ was accurately reproduced in both a 1.2-mer HBV replicon and in vitro HBV infection systems, which also provided evidence for the stimulation of HBV replication by these HBx variants. In conclusion, the ability of HBx to upregulate PA28γ levels via p53 activation, in a Ser-101-dependent pathway, is critical for the stimulation of HBV replication.
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Affiliation(s)
- Hyerin Jeong
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
| | - Sungkyung Cha
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
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15
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Manne V, Gochanour E, Kowdley KV. Current perspectives into the evaluation and management of hepatitis B: a review. Hepatobiliary Surg Nutr 2019; 8:361-369. [PMID: 31489305 DOI: 10.21037/hbsn.2019.02.09] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Hepatitis B is a widespread disease which affects millions of people worldwide. Chronic hepatitis B (CHB) can lead to significant morbidity and mortality due to complications such as cirrhosis and hepatocellular carcinoma. The pathophysiology of hepatitis is critical to diagnosing CHB. Deciding which patients with CHB should be treated is an important decision as treatment can often lead to better outcomes in the appropriate patient population. The nucleos(t)ide analog inhibitors entecavir and tenofovir are currently the mainstay of treatment as they are able to successfully suppress the virus and lead to fewer complications. Novel therapies are currently being developed which may offer a potential cure for this disease in the future.
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Affiliation(s)
- Vignan Manne
- Liver Care Network, Swedish Medical Center, Seattle, WA, USA
| | - Eric Gochanour
- Liver Care Network, Swedish Medical Center, Seattle, WA, USA
| | - Kris V Kowdley
- Liver Care Network, Swedish Medical Center, Seattle, WA, USA
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16
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Sun YW, Qiu HC, Ou MC, Chen RL, Liang G. Saponins isolated from Schizocapsa plantaginea inhibit human hepatocellular carcinoma cell growth in vivo and in vitro via mitogen-activated protein kinase signaling. Chin J Nat Med 2018; 16:29-40. [PMID: 29425588 DOI: 10.1016/s1875-5364(18)30027-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Indexed: 12/21/2022]
Abstract
The underground cane of Schizocapsa plantaginea (Hance) has long been used by Chinese ethnic minority as a constituent of anti-cancer formulae. Saponins are abundant secondary metabolic products located in the underground cane of this plant. The potential therapeutic effects of total saponins isolated from Schizocapsa plantaginea (Hance) (SSPH) on human hepatocellular carcinoma (HCC) were tested in vitro in human liver cancer cell lines, SMMC-7721 and Bel-7404. Apoptosis and cell cycle arrest were determined using flow cytometry, caspase activation was determined by ELISA, and PARP, cleaved PARP, mitogen-activated protein kinase (MAPK) expression and phosphorylation were measured using Western blotting analysis. In vivo anti-HCC effects of SSPH were verified in nude mouse xenograft model. SSPH exerted markedly inhibitory effect on HCC cell proliferation in time- and concentration-dependent manner. Moreover, SSPH significantly induced apoptosis through caspase-dependent signaling and arrested cell cycle at G2/M phase. These anti-proliferation effects of SSPH were associated with up-regulated phosphorylation of extracellular signal-regulated kinase-1/2 (Erk1/2) and c-jun-NH2-kinase-1/2 (JNK1/2) and reduced phosphorylation of p38MAPK. Furthermore, inhibitors of ERK, UO126, and JNK, SP600125 inhibited the anti-proliferation effects by SSPH, suggesting that Erk and JNK were the effector molecules in SSPH induced anti-proliferative action. During in vivo experiments, SSPH was found to inhibit xenograft tumor growth in nude mice, with a similar mechanism in vitro. Our study confirmed that SSPH exerted antagonistic effects on human liver cancer cells both in vitro and in vivo. Molecular mechanisms underlying SSPH action might be closely associated with MAPK signaling pathways. These results indicated that SSPH has potential therapeutic effects on HCC.
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Affiliation(s)
- Yue-Wen Sun
- College of Pharmacy, Guangxi Medical University, Nanning 530022, China
| | - Han-Chen Qiu
- College of Pharmacy, Guangxi Medical University, Nanning 530022, China
| | - Ming-Chun Ou
- College of Pharmacy, Guangxi Medical University, Nanning 530022, China
| | - Run-Li Chen
- College of Pharmacy, Guangxi Medical University, Nanning 530022, China
| | - Gang Liang
- College of Pharmacy, Guangxi Medical University, Nanning 530022, China.
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17
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Yeom S, Jeong H, Kim SS, Jang KL. Hepatitis B virus X protein activates proteasomal activator 28 gamma expression via upregulation of p53 levels to stimulate virus replication. J Gen Virol 2018; 99:655-666. [DOI: 10.1099/jgv.0.001054] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Sujeong Yeom
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
| | - Hyerin Jeong
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
| | - Soo Shin Kim
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
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18
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Yao JH, Liu ZJ, Yi JH, Wang J, Liu YN. Hepatitis B Virus X Protein Upregulates Intracellular Calcium Signaling by Binding C-terminal of Orail Protein. Curr Med Sci 2018; 38:26-34. [PMID: 30074148 DOI: 10.1007/s11596-018-1843-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 01/15/2018] [Indexed: 12/15/2022]
Abstract
Hepatitis B virus X (HBx) protein plays a pivotal role in the development of hepatitis B virus (HBV)-associated hepatocellular carcinoma. Although regulation of cytosolic calcium is essential for HBV replication and is mediated by HBx protein, the mechanism of HBx protein regulating intracellular calcium level remains poorly understood. The present study examined whether HBx protein elevated the intracellular calcium through interacting with storeoperated calcium entry (SOCE) components, Orail and stromal interaction molecule 1, and then identified the targets of HBx protein, with an attempt to understand the mechanism of HBx protein upsetting intracellular calcium homeostasis. By employing co-immunoprecipitation and GST-pull-down assay, we found that Orail protein interacted with HBx protein, and the C-terminus of Orail was implicated in the interaction. Confocal microscopy also revealed that HBx protein could co-localize with full-length Orail protein in HEK293 cells. Moreover, live cell calcium imaging exhibited that HBx protein elevated intracellular calcium, possibly by binding to SOCE components. Our results suggest that HBx protein binds to STIM1-Orail complexes to positively regulate the activity of plasma membrane store-operated calcium channels.
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Affiliation(s)
- Jing-Hong Yao
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zi-Jian Liu
- Department of Anatomy, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Jian-Hua Yi
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jun Wang
- Department of Gastroenterology, the Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430014, China
| | - Ya-Nan Liu
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
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19
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Role of HBx in hepatitis B virus persistence and its therapeutic implications. Curr Opin Virol 2018; 30:32-38. [PMID: 29454995 DOI: 10.1016/j.coviro.2018.01.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/17/2018] [Accepted: 01/24/2018] [Indexed: 12/12/2022]
Abstract
Chronic hepatitis B virus infection is a significant risk factor for cirrhosis and hepatocellular carcinoma. The HBx protein is required for virus replication, but the lack of robust infection models has hindered our understanding of HBx functions that could be targeted for antiviral purposes. We briefly review three properties of HBx: its binding to DDB1 and its regulation of cell survival and metabolism, to illustrate how a single viral protein can have multiple effects in a cell. We propose that different functions of HBx are needed, depending on the changing hepatocyte environment encountered during a chronic virus infection, and that these functions might serve as novel therapeutic targets for inhibiting hepatitis B virus replication and the development of associated diseases.
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20
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Wang SN, Wang LT, Sun DP, Chai CY, Hsi E, Kuo HT, Yokoyama KK, Hsu SH. Intestine-specific homeobox (ISX) upregulates E2F1 expression and related oncogenic activities in HCC. Oncotarget 2018; 7:36924-36939. [PMID: 27175585 PMCID: PMC5095049 DOI: 10.18632/oncotarget.9228] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 04/16/2016] [Indexed: 01/29/2023] Open
Abstract
Intestine-specific homeobox (ISX), a newly identified proto-oncogene, is involved in cell proliferation and progression of hepatocellular carcinoma (HCC). However, the underlying mechanisms linking gene expression and tumor formation remain unclear. In this study, we found that ISX transcriptionally activated E2F transcription factor 1 (E2F1) and associated oncogenic activity by directly binding to the E2 site of its promoter. Forced expression of ISX increased the expression of and phosphorylated the serine residue at position 332 of E2F1, which may be translocated into the nucleus to form the E2F1–DP-1 complex, suggesting that the promotion of oncogenic activities of the ISX–E2F1 axis plays a critical role in hepatoma cells. Coexpression of ISX and E2F1 significantly promoted p53 and RB-mediated cell proliferation and anti-apoptosis, and repressed apoptosis and autophagy. In contrast, short hairpin RNAi-mediated attenuation of ISX and E2F1 decreased cell proliferation and malignant transformation, respectively, in hepatoma cells in vitro and in vivo. The mRNA expression of E2F1 and ISX in 238 paired specimens from human HCC patients, and the adjacent, normal tissues exhibited a tumor-specific expression pattern which was highly correlated with disease pathogenesis, patient survival time, progression stage, and poor prognosis. Therefore, our results indicate that E2F1 is an important downstream gene of ISX in hepatoma progression.
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Affiliation(s)
- Shen-Nien Wang
- Division of Hepatobiliary Surgery, Department of Surgery, Faculty of Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Li-Ting Wang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ding-Ping Sun
- Division of General Surgery, Department of Surgery, Chi-Mei Medical Center, Tainan, Taiwan.,Department of Food Science and Technology, Chia Nan University of Pharmacy and Science, Tainan, Taiwan
| | - Chee-Yin Chai
- Department of Pathology, Faculty of Medicine, College of Medicine, Kaohsiung, Taiwan
| | - Edward Hsi
- Department of Genome Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hsing-Tao Kuo
- Department of Internal Medicine, Division of Hepatogastroenterology, Chi-Mei Medical Center, Tainan, Taiwan.,Department of Senior Citizen Service Management, Chia Nan University of Pharmacy & Science, Tainan, Taiwan
| | - Kazunari K Yokoyama
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Research Center for Stem Cell Research, Kaohsiung Medical University, Kaohsiung, Taiwan.,Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Molecular Preventive Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Faculty of Science and Engineering, Tokushima Bunri University, Sanuki, Japan.,Center of Infectious Disease and Cancer Research, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shih-Hsien Hsu
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Center of Infectious Disease and Cancer Research, Kaohsiung Medical University, Kaohsiung, Taiwan
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21
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Choi JH, Jeong H, Jang KL. Hepatitis B virus X protein suppresses all-trans retinoic acid-induced apoptosis in human hepatocytes by repressing p14 expression via DNA methylation. J Gen Virol 2017; 98:2786-2798. [PMID: 29068287 DOI: 10.1099/jgv.0.000958] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
All-trans retinoic acid (ATRA), the most biologically active metabolite of vitamin A, is known to activate p14 expression via promoter hypermethylation to induce p53-dependent apoptosis in human hepatocytes. In this study, we found that the oncogenic hepatitis B virus (HBV) X protein (HBx) of HBV, derived from both overexpression and 1.2-mer replicon systems, suppresses ATRA-induced apoptosis in p53-positive human hepatocytes. For this effect, HBx upregulated both protein and enzyme activity levels of DNA methyltransferase 1, 3a and 3b, in the presence of ATRA and thereby inhibited p14 expression via promoter hypermethylation, resulting in inactivation of the p14-mouse double minute 2 pathway and subsequent downregulation of p53 levels. As a result, HBx was able to impair the potential of ATRA to activate apoptosis-related molecules, including Bax, p53-upregulated modulator of apoptosis, caspase-9, caspase-3 and poly (ADP-ribose) polymerase. In conclusion, the present study provides a new oncogenic action mechanism of HBx, namely by suppressing the anticancer potential of ATRA to induce p53-dependent apoptosis in HBV-infected hepatocytes.
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Affiliation(s)
- Jung-Hye Choi
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Hyerin Jeong
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
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22
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Gómez-Moreno A, Garaigorta U. Hepatitis B Virus and DNA Damage Response: Interactions and Consequences for the Infection. Viruses 2017; 9:v9100304. [PMID: 29048354 PMCID: PMC5691655 DOI: 10.3390/v9100304] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 10/13/2017] [Accepted: 10/18/2017] [Indexed: 12/12/2022] Open
Abstract
Hepatitis B virus (HBV) is a major etiologic agent of acute and chronic hepatitis, and end-stage liver disease. Establishment of HBV infection, progression to persistency and pathogenesis are determined by viral and cellular factors, some of which remain still undefined. Key steps of HBV life cycle e.g., transformation of genomic viral DNA into transcriptionally active episomal DNA (cccDNA) or transcription of viral mRNAs from cccDNA, take place in the nucleus of infected cells and strongly depend on enzymatic activities provided by cellular proteins. In this regard, DNA damage response (DDR) pathways and some DDR proteins are being recognized as important factors regulating the infection. On one hand, HBV highjacks specific DDR proteins to successfully complete some of the steps of its life cycle. On the other hand, HBV subverts DDR pathways to presumably create a cellular environment that favours its replication. Direct consequences of these interactions are: HBV DNA integration into host chromosomal DNA, and accumulation of mutations in host chromosomal DNA that could eventually trigger carcinogenic processes, which would explain in part the incidence of hepatocellular carcinoma in chronically infected patients. Unravelling the interactions that HBV establishes with DDR pathways might help identify new molecular targets for therapeutic intervention.
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Affiliation(s)
- Andoni Gómez-Moreno
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Darwin 3, 28049 Madrid, Spain.
| | - Urtzi Garaigorta
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Darwin 3, 28049 Madrid, Spain.
- Centro de Investigación Biomédica en Red (CIBER) de Enfermedades Hepáticas y Digestivas (CIBERehd), 28029 Madrid, Spain.
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23
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Yeom S, Kim SS, Jeong H, Jang KL. Hepatitis B virus X protein activates E3 ubiquitin ligase Siah-1 to control virus propagation via a negative feedback loop. J Gen Virol 2017; 98:1774-1784. [PMID: 28714848 DOI: 10.1099/jgv.0.000856] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The seven in absentia homologue 1 (Siah-1) protein is an E3 ubiquitin ligase that induces ubiquitin-dependent proteasomal degradation of HBx, the principal regulatory protein of hepatitis B virus (HBV); however, its role in HBV propagation remains unknown. Here, we found that HBx upregulates Siah-1 levels in HepG2 but not in Hep3B cells, in which p53 is absent. For this effect, HBx sequentially activated ataxia telangiectasia mutated kinase and checkpoint kinase 2 via phosphorylation at the Ser-1981 and Thr-68 residues, respectively, which led to the activation of p53 via phosphorylation at the Ser-15 and Ser-20 residues. As a result, HBx was heavily ubiquitinated by Siah-1 and degraded by the ubiquitin-proteasome system in HepG2 cells, whereas this effect was marginal or undetectable in Hep3B cells. Knock-down of p53 in HepG2 cells downregulated Siah-1 levels and subsequently upregulated HBx levels, whereas ectopic p53 expression in Hep3B cells upregulated Siah-1 levels and subsequently downregulated HBx levels. In addition, Siah-1 knock-down impaired the ubiquitination and proteasomal degradation of HBx in HepG2 cells, whereas ectopic Siah-1 expression induced ubiquitin-dependent proteasomal degradation of HBx in Hep3B cells. The effects of HBx on p53 and Siah-1 were exactly reproduced in a 1.2-mer HBV replicon system, mimicking the natural course of HBV infection. In particular, Siah-1 knock-down upregulated the levels of HBx derived from the HBV replicon, resulting in an increase in HBV production. In conclusion, HBx modulates its own protein level via a negative feedback loop involving p53 and Siah-1 to control HBV propagation.
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Affiliation(s)
- Sujeong Yeom
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
| | - Soo Shin Kim
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
| | - Hyerin Jeong
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Science, Pusan National University, Busan 46241, Republic of Korea
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24
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Ghouri YA, Mian I, Rowe JH. Review of hepatocellular carcinoma: Epidemiology, etiology, and carcinogenesis. J Carcinog 2017; 16:1. [PMID: 28694740 PMCID: PMC5490340 DOI: 10.4103/jcar.jcar_9_16] [Citation(s) in RCA: 505] [Impact Index Per Article: 72.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/11/2017] [Indexed: 02/06/2023] Open
Abstract
Since the 1970s, the epidemic of hepatocellular carcinoma (HCC) has spread beyond the Eastern Asian predominance and has been increasing in Northern hemisphere, especially in the United States (US) and Western Europe. It occurs more commonly in males in the fourth and fifth decades of life. Among all cancers, HCC is one of the fastest growing causes of death in the US and poses a significant economic burden on healthcare. Chronic liver disease due to hepatitis B virus or hepatitis C virus and alcohol accounts for the majority of HCC cases. Incidence of nonalcoholic fatty liver disease has been on the risem and it has also been associated with the development of HCC. Its pathogenesis varies based on the underlying etiological factor although majority of cases develop in the setting of background cirrhosis. Carcinogenesis of HCC includes angiogenesis, chronic inflammation, and tumor macroenvironment and microenvironment. There is a significant role of both intrinsic genetic risk factors and extrinsic influences such as alcohol or viral infections that lead to the development of HCC. Understanding its etiopathogenesis helps select appropriate diagnostic tests and treatments.
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Affiliation(s)
- Yezaz Ahmed Ghouri
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Idrees Mian
- Department of Hematology and Oncology, National Institute of Health, Bethesda, Maryland, USA
| | - Julie H Rowe
- Department of Internal Medicine, Division of Oncology, University of Texas Health Science Center, McGovern Medical School, Houston, Texas, USA
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25
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Li H, Sheng C, Wang S, Yang L, Liang Y, Huang Y, Liu H, Li P, Yang C, Yang X, Jia L, Xie J, Wang L, Hao R, Du X, Xu D, Zhou J, Li M, Sun Y, Tong Y, Li Q, Qiu S, Song H. Removal of Integrated Hepatitis B Virus DNA Using CRISPR-Cas9. Front Cell Infect Microbiol 2017; 7:91. [PMID: 28382278 PMCID: PMC5360708 DOI: 10.3389/fcimb.2017.00091] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/07/2017] [Indexed: 12/12/2022] Open
Abstract
The presence of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and the permanent integration of HBV DNA into the host genome confers the risk of viral reactivation and hepatocellular carcinoma. Nucleoside/nucleotide analogs alone have little or no capacity to eliminate replicative HBV templates consisting of cccDNA or integrated HBV DNA. Recently, CRISPR/Cas9 technology has been widely applied as a promising genome-editing tool, and HBV-specific CRISPR-Cas9 systems were shown to effectively mediate HBV cccDNA disruption. However, the integrated HBV DNA fragments are considered as important pro-oncogenic properties and it serves as an important template for viral replication and expression in stable HBV cell line. In this study, we completely excised a full-length 3,175-bp integrated HBV DNA fragment and disrupted HBV cccDNA in a stable HBV cell line. In HBV-excised cell line, the HBV cccDNA inside cells, supernatant HBV DNA, HBsAg, and HBeAg remained below the negative critical values for more than 10 months. Besides, by whole genome sequencing, we analyzed off-target effects and excluded cell contamination. It is the first time that the HBV infection has been fully eradicated in a stable HBV cell line. These findings demonstrate that the CRISPR-Cas9 system is a potentially powerful tool capable of promoting a radical or “sterile” HBV cure.
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Affiliation(s)
- Hao Li
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Chunyu Sheng
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Shan Wang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Lang Yang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Yuan Liang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Yong Huang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology Beijing, China
| | - Hongbo Liu
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Peng Li
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Chaojie Yang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Xiaoxia Yang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Leili Jia
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Jing Xie
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Ligui Wang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Rongzhang Hao
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Xinying Du
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Dongping Xu
- Research Centre for Liver Failure, Beijing 302nd Hospital Beijing, China
| | - Jianjun Zhou
- Research Center for Translational Medicine, Cancer Stem Cell Institute, East Hospital, Tongji University School of MedicineShanghai, China; Gladcan Consulting CompanyBeijing, China
| | - Mingzhen Li
- Research and Development Department, Beijing Center for Physical and Chemical Analysis Beijing, China
| | - Yansong Sun
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Yigang Tong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology Beijing, China
| | - Qiao Li
- Department of Surgery, University of Michigan Ann Arbor, MI, USA
| | - Shaofu Qiu
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Hongbin Song
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
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Chen WS, Yen CJ, Chen YJ, Chen JY, Wang LY, Chiu SJ, Shih WL, Ho CY, Wei TT, Pan HL, Chien PH, Hung MC, Chen CC, Huang WC. miRNA-7/21/107 contribute to HBx-induced hepatocellular carcinoma progression through suppression of maspin. Oncotarget 2016; 6:25962-74. [PMID: 26296971 PMCID: PMC4694878 DOI: 10.18632/oncotarget.4504] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 07/06/2015] [Indexed: 02/07/2023] Open
Abstract
Maspin suppresses tumor progression by promoting cell adhesion and apoptosis and by inhibiting cell motility. However, its role in tumorigenesis of hepatocellular carcinoma (HCC) remains unclear. The gene regulation of maspin and its relationship with HCC patient prognosis were investigated in this study. Maspin expression was specifically reduced in HBV-associated patients and correlated with their poor prognosis. Maspin downregulation in HCC cells was induced by HBx to promote their motility and resistance to anoikis and chemotherapy. HBx-dependent induction of microRNA-7, -107, and -21 was further demonstrated to directly target maspin mRNA, leading to its protein downregulation. Higher expressions of these microRNAs also correlated with maspin downregulation in HBV-associated patients, and were associated with their poor overall survival. These data not only provided new insights into the molecular mechanisms of maspin deficiency by HBx, but also indicated that downregulation of maspin by microRNAs confers HBx-mediated aggressiveness and chemoresistance in HCC.
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Affiliation(s)
- Wen-Shu Chen
- Department of Pharmacology, National Taiwan University, Taipei, Taiwan.,Center for Molecular Medicine, China Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan
| | - Chia-Jui Yen
- Internal Medicine, National Cheng-Kung University, Tainan, Taiwan
| | - Yun-Ju Chen
- Department of Medical Research, E-Da Hospital, Kaohsiung, Taiwan.,Department of Biological Science and Technology, I-Shou University, Kaohsiung, Taiwan
| | - Jhen-Yu Chen
- Center for Molecular Medicine, China Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan.,The Ph.D. Program for Cancer Biology and Drug Discovery, China Medical University, Taichung, Taiwan
| | - Li-Yun Wang
- Center for Molecular Medicine, China Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan
| | - Shu-Jun Chiu
- Department of Life Sciences, Tzu Chi University, Hualien, Taiwan.,Institute of Radiation Sciences, Tzu Chi Technology College, Hualien, Taiwan
| | - Wen-Ling Shih
- Department of Biological Science and Technology, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Chien-Yi Ho
- Department of Family Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Tzu-Tang Wei
- Department of Pharmacology, National Taiwan University, Taipei, Taiwan
| | - Hsiao-Lin Pan
- Department of Medical Research, E-Da Hospital, Kaohsiung, Taiwan
| | - Pei-Hsuan Chien
- Department of Medical Research, E-Da Hospital, Kaohsiung, Taiwan
| | - Mien-Chie Hung
- Center for Molecular Medicine, China Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan.,Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ching-Chow Chen
- Department of Pharmacology, National Taiwan University, Taipei, Taiwan
| | - Wei-Chien Huang
- Center for Molecular Medicine, China Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan.,The Ph.D. Program for Cancer Biology and Drug Discovery, China Medical University, Taichung, Taiwan.,Department of Biotechnology, Asia University, Taichung, Taiwan
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27
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Karavias D, Maroulis I, Papadaki H, Gogos C, Kakkos S, Karavias D, Bravou V. Overexpression of CDT1 Is a Predictor of Poor Survival in Patients with Hepatocellular Carcinoma. J Gastrointest Surg 2016; 20:568-79. [PMID: 26408331 DOI: 10.1007/s11605-015-2960-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 09/16/2015] [Indexed: 01/31/2023]
Abstract
BACKGROUND Genomic instability is a common feature in hepatocellular carcinoma. Deregulation of replication licensing factors has been shown to trigger DNA damage response contributing to genomic instability. Overexpression of DNA replication licensing factors chromatin licensing and DNA replication factor 1 (CDT1) and minichromosome maintenance complex component 7 (MCM7) has been previously reported in several human cancers. The aim of the present study was to evaluate the expression and prognostic significance of CDT1 and MCM7 in association with DNA damage response markers and p53 in patients with hepatocellular carcinoma. METHODS Expression of CDT1, MCM7, p-H2A histone family member X (H2AX), phospho-ataxia telangiectasia-mutated (ATM)/ataxia telangiectasia rad3-related (ATR) substrate, and p53 was evaluated by immunohistochemistry on formalin-fixed paraffin-embedded surgical specimens from 111 patients who underwent hepatectomy for hepatocellular carcinoma. Statistical analysis was performed to evaluate associations between the studied proteins, clinicopathological parameters, and patient survival. RESULTS CDT1 expression correlated with p-H2AX (p = 0.038), while MCM7 correlated with p-H2AX and phospho-ATM/ATR substrate (p < 0.001). Increased CDT1 expression was associated with higher tumor grade (p = 0.006) and tumor-node-metastasis (TNM) stage (p = 0.033). High CDT1 expression correlated significantly with reduced overall survival (60.8 and 26.5 % vs 82.8 and 53.0 %, for low CDT1 expression, at 2 and 5 years, respectively, p = 0.012) and was identified by multivariate analysis as an independent predictor of poor overall survival (p = 0.049). CONCLUSIONS Overexpression of CDT1 and MCM7 in hepatocellular carcinoma correlates with DNA damage response, and CDT1 overexpression is a significant prognostic biomarker in hepatocellular carcinoma.
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Affiliation(s)
- Dimitrios Karavias
- Department of Surgery, University Hospital of Patras, Rio, 26500, Greece.
| | - Ioannis Maroulis
- Department of Surgery, University Hospital of Patras, Rio, 26500, Greece
| | - Helen Papadaki
- Department of Anatomy, Histology and Embryology, School of Medicine, University of Patras, Rio, Greece
| | - Charalambos Gogos
- Department of Internal Medicine, University Hospital of Patras, Rio, Greece
| | - Stavros Kakkos
- Department of Vascular Surgery, University Hospital of Patras, Rio, Greece
| | | | - Vasiliki Bravou
- Department of Anatomy, Histology and Embryology, School of Medicine, University of Patras, Rio, Greece
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28
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Slagle BL, Bouchard MJ. Hepatitis B Virus X and Regulation of Viral Gene Expression. Cold Spring Harb Perspect Med 2016; 6:a021402. [PMID: 26747833 DOI: 10.1101/cshperspect.a021402] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The efficient replication of hepatitis B virus (HBV) requires the HBV regulatory hepatitis B virus X (HBx) protein. The exact contributions of HBx are not fully understood, in part because of the limitations of the assays used for its study. When HBV replication is driven from a plasmid DNA, the contribution of HBx is modest. However, there is an absolute requirement for HBx in assays that recapitulate the infectious virus life cycle. There is much evidence that HBx can contribute directly to HBV replication by acting on viral promoters embedded within protein coding sequences. In addition, HBx may also contribute indirectly by modulating cellular pathways to benefit virus replication. Understanding the mechanism(s) of HBx action during virus replication may provide insight into novel ways to disrupt chronic HBV replication.
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Affiliation(s)
- Betty L Slagle
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030
| | - Michael J Bouchard
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
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29
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Nagahashi M, Matsuda Y, Moro K, Tsuchida J, Soma D, Hirose Y, Kobayashi T, Kosugi SI, Takabe K, Komatsu M, Wakai T. DNA damage response and sphingolipid signaling in liver diseases. Surg Today 2015; 46:995-1005. [PMID: 26514817 DOI: 10.1007/s00595-015-1270-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 10/04/2015] [Indexed: 02/06/2023]
Abstract
Patients with unresectable hepatocellular carcinoma (HCC) cannot generally be cured by systemic chemotherapy or radiotherapy due to their poor response to conventional therapeutic agents. The development of novel and efficient targeted therapies to increase their treatment options depends on the elucidation of the molecular mechanisms that underlie the pathogenesis of HCC. The DNA damage response (DDR) is a network of cell-signaling events that are triggered by DNA damage. Its dysregulation is thought to be one of the key mechanisms underlying the generation of HCC. Sphingosine-1-phosphate (S1P), a lipid mediator, has emerged as an important signaling molecule that has been found to be involved in many cellular functions. In the liver, the alteration of S1P signaling potentially affects the DDR pathways. In this review, we explore the role of the DDR in hepatocarcinogenesis of various etiologies, including hepatitis B and C infection and non-alcoholic steatohepatitis. Furthermore, we discuss the metabolism and functions of S1P that may affect the hepatic DDR. The elucidation of the pathogenic role of S1P may create new avenues of research into therapeutic strategies for patients with HCC.
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Affiliation(s)
- Masayuki Nagahashi
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
| | - Yasunobu Matsuda
- Department of Medical Technology, Niigata University Graduate School of Health Sciences, 2-746 Asahimachi-dori, Chuo-ku, Niigata, 951-8518, Japan
| | - Kazuki Moro
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Junko Tsuchida
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Daiki Soma
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Yuki Hirose
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Takashi Kobayashi
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Shin-Ichi Kosugi
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Kazuaki Takabe
- Division of Surgical Oncology, Department of Surgery, Virginia Commonwealth University School of Medicine and the Massey Cancer Center, West Hospital 7-402, 1200 East Broad Street, Richmond, VA, 23298-0011, USA
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Toshifumi Wakai
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
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30
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Zhao W, Lu M, Zhang Q. Chloride intracellular channel 1 regulates migration and invasion in gastric cancer by triggering the ROS-mediated p38 MAPK signaling pathway. Mol Med Rep 2015; 12:8041-7. [PMID: 26497050 PMCID: PMC4758331 DOI: 10.3892/mmr.2015.4459] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 09/24/2015] [Indexed: 01/10/2023] Open
Abstract
Chloride intracellular channel 1 (CLIC1) has been demonstrated to be overexpressed in gastric cancer, and elevated CLIC1 expression levels are markedly associated with the processes of tumor cell migration and invasion. However, the regulatory mechanism and signaling pathway underlying these processes have remained to be elucidated. The present study examined the impact of N-acetyl cysteine (NAC), indanyloxyacetic acid (IAA)-94 and SB203580, inhibitors of reactive oxygen species (ROS), as well as CLIC1 and p38 mitogen-activated protein kinase (MAPK) on the migration and invasion of SGC-7901 gastric cancer cells in a hypoxia-reoxygenation (H-R) microenvironment. The results demonstrated that intracellular ROS and CLIC1 levels were increased under H-R conditions, and that functional inhibition of CLIC1 significantly decreased the H-R-elevated ROS generation and p-p38 MAPK levels in SGC-7901 cells, as well as inhibited the migration and invasion of SGC-7901 cells. In addition, the expression levels of MMP-2 and MMP-9 were inhibited by NAC, IAA-94 and SB203580. These results indicated that CLIC1 regulates gastric cancer-cell migration and invasion via the ROS-mediated p38 MAPK signaling pathway.
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Affiliation(s)
- Wei Zhao
- Department of General Surgery, People's Hospital of Laiwu, Laiwu, Shandong 271100, P.R. China
| | - Mingshu Lu
- Department of General Surgery, People's Hospital of Laiwu, Laiwu, Shandong 271100, P.R. China
| | - Qiwen Zhang
- Department of General Surgery, People's Hospital of Laiwu, Laiwu, Shandong 271100, P.R. China
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31
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Modulation of DNA damage and repair pathways by human tumour viruses. Viruses 2015; 7:2542-91. [PMID: 26008701 PMCID: PMC4452920 DOI: 10.3390/v7052542] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/12/2015] [Indexed: 02/07/2023] Open
Abstract
With between 10% and 15% of human cancers attributable to viral infection, there is great interest, from both a scientific and clinical viewpoint, as to how these pathogens modulate host cell functions. Seven human tumour viruses have been identified as being involved in the development of specific malignancies. It has long been known that the introduction of chromosomal aberrations is a common feature of viral infections. Intensive research over the past two decades has subsequently revealed that viruses specifically interact with cellular mechanisms responsible for the recognition and repair of DNA lesions, collectively known as the DNA damage response (DDR). These interactions can involve activation and deactivation of individual DDR pathways as well as the recruitment of specific proteins to sites of viral replication. Since the DDR has evolved to protect the genome from the accumulation of deleterious mutations, deregulation is inevitably associated with an increased risk of tumour formation. This review summarises the current literature regarding the complex relationship between known human tumour viruses and the DDR and aims to shed light on how these interactions can contribute to genomic instability and ultimately the development of human cancers.
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32
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Hepatitis B virus HBx protein interactions with the ubiquitin proteasome system. Viruses 2014; 6:4683-702. [PMID: 25421893 PMCID: PMC4246244 DOI: 10.3390/v6114683] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/16/2014] [Accepted: 11/20/2014] [Indexed: 01/04/2023] Open
Abstract
The hepatitis B virus (HBV) causes acute and chronic hepatitis, and the latter is a major risk factor for the development of hepatocellular carcinoma (HCC). HBV encodes a 17-kDa regulatory protein, HBx, which is required for virus replication. Although the precise contribution(s) of HBx to virus replication is unknown, many viruses target cellular pathways to create an environment favorable for virus replication. The ubiquitin proteasome system (UPS) is a major conserved cellular pathway that controls several critical processes in the cell by regulating the levels of proteins involved in cell cycle, DNA repair, innate immunity, and other processes. We summarize here the interactions of HBx with components of the UPS, including the CUL4 adaptor DDB1, the cullin regulatory complex CSN, and the 26S proteasome. Understanding how these protein interactions benefit virus replication remains a challenge due to limited models in which to study HBV replication. However, studies from other viral systems that similarly target the UPS provide insight into possible strategies used by HBV.
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33
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Kim HY, Jung HU, Yoo SH, Yoo KS, Cheong J, Park BS, Yun I, Yoo YH. Sorafenib overcomes the chemoresistance in HBx-expressing hepatocellular carcinoma cells through down-regulation of HBx protein stability and suppresses HBV gene expression. Cancer Lett 2014; 355:61-9. [PMID: 25218348 DOI: 10.1016/j.canlet.2014.09.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 09/05/2014] [Accepted: 09/05/2014] [Indexed: 12/17/2022]
Abstract
Previous studies have revealed that HBx expression has anti-apoptotic effects, resulting in increased drug resistance in HCC cells. Thus, we examined if sorafenib efficiently induces apoptosis in HBx-overexpressing HCC cells. Noticeably, sorafenib efficiently induced apoptosis, even in HBx-expressing HepG2 cells, indicating that the HBx protein does not attenuate sorafenib-induced apoptosis. We next investigated if sorafenib modulates autophagy, allowing HCC cells to overcome the chemoresistance conferred by the HBx protein. Although autophagy plays a cytoprotective role against sorafenib-induced lethality, sorafenib was effective irrespective of HBx protein overexpression. We next examined if sorafenib exerts its cytotoxic effect via direct effects on the HBx protein. Importantly, sorafenib decreased HBx protein stability through a proteasome-dependent degradation pathway. Moreover, sorafenib decreased HBV gene expression and viral promoter activity. Taken together, sorafenib efficiently induces apoptotic cell death in HBx-expressing HCC cells via the downregulation of the HBx protein, a key factor in the anti-cancer drug resistance observed in HBV-induced HCC.
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Affiliation(s)
- Hye Young Kim
- Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan 602-714, South Korea
| | - Hye Uk Jung
- Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan 602-714, South Korea
| | - Seung Hee Yoo
- Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan 602-714, South Korea
| | - Ki Soo Yoo
- Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan 602-714, South Korea
| | - JaeHun Cheong
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busan 609-735, South Korea
| | - Bong Soo Park
- Department of Oral Anatomy and Cell Biology, School of Dentistry, Yangsan Campus of Pusan National University, Yangsan 626-870, South Korea
| | - Il Yun
- Departments of Dental Pharmacology and Biophysics, School of Dentistry and Research Institute for Oral Biotechnology, Yangsan Campus of Pusan National University, Yangsan 626-870, South Korea
| | - Young Hyun Yoo
- Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan 602-714, South Korea.
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34
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Lazar C, Uta M, Branza-Nichita N. Modulation of the unfolded protein response by the human hepatitis B virus. Front Microbiol 2014; 5:433. [PMID: 25191311 PMCID: PMC4137222 DOI: 10.3389/fmicb.2014.00433] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 07/31/2014] [Indexed: 12/23/2022] Open
Abstract
During productive viral infection the host cell is confronted with synthesis of a vast amount of viral proteins which must be folded, quality controlled, assembled and secreted, perturbing the normal function of the endoplasmic reticulum (ER). To counteract the ER stress, cells activate specific signaling pathways, designated as the unfolded proteins response (UPR), which essentially increase their folding capacity, arrest protein translation, and degrade the excess of misfolded proteins. This cellular defense mechanism may, in turn, affect significantly the virus life-cycle. This review highlights the current understanding of the mechanisms of the ER stress activation by Human Hepatitis B virus (HBV), a deadly pathogen affecting more than 350 million people worldwide. Further discussion addresses the latest discoveries regarding the adaptive strategies developed by HBV to manipulate the UPR for its own benefits, the controversies in the field and future perspectives.
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Affiliation(s)
- Catalin Lazar
- Department of Viral Glycoproteins, Institute of Biochemistry of the Romanian Academy Bucharest, Romania
| | - Mihaela Uta
- Department of Viral Glycoproteins, Institute of Biochemistry of the Romanian Academy Bucharest, Romania
| | - Norica Branza-Nichita
- Department of Viral Glycoproteins, Institute of Biochemistry of the Romanian Academy Bucharest, Romania
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35
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A novel function of HER2/Neu in the activation of G2/M checkpoint in response to γ-irradiation. Oncogene 2014; 34:2215-26. [PMID: 24909175 DOI: 10.1038/onc.2014.167] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 04/21/2014] [Accepted: 05/06/2014] [Indexed: 12/13/2022]
Abstract
In response to γ-irradiation (IR)-induced DNA damage, activation of cell cycle checkpoints results in cell cycle arrest, allowing time for DNA repair before cell cycle re-entry. Human cells contain G1 and G2 cell cycle checkpoints. While G1 checkpoint is defective in most cancer cells, commonly due to mutations and/or alterations in the key regulators of G1 checkpoint (for example, p53, cyclin D), G2 checkpoint is rarely impaired in cancer cells, which is important for cancer cell survival. G2 checkpoint activation involves activation of ataxia telangiectasia-mutated (ATM)/ATM- and rad3-related (ATR) signalings, which leads to the inhibition of Cdc2 kinase and subsequent G2/M cell cycle arrest. Previous studies from our laboratory show that G2 checkpoint activation following IR exposure of MCF-7 breast cancer cells is dependent on the activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) signaling. As HER receptor tyrosine kinases (RTKs), which have important roles in cell proliferation and survival, have been shown to activate ERK1/2 signaling in response to various stimuli, we investigated the role of HER RTKs in IR-induced G2/M checkpoint response in breast cancer cells. Results of the present studies indicate that IR exposure resulted in a striking increase in the phosphorylation of HER1, HER2, HER3 and HER4 in MCF-7 cells, indicative of activation of these proteins. Furthermore, specific inhibition of HER2 using an inhibitor, short hairpin RNA and dominant-negative mutant HER2 abolished IR-induced activation of ATM/ATR signaling, phosphorylation of Cdc2-Y15 and subsequent induction of G2/M arrest. Moreover, the inhibition of HER2 also abrogated IR-induced ERK1/2 phosphorylation. In contrast, inhibition of HER1 using specific inhibitors or decreasing expression of HER3 or HER4 using short hairpin RNAs did not block the induction of G2/M arrest following IR. These results suggest an important role of HER2 in the activation of G2/M checkpoint response following IR.
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36
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Involvement of DNA damage response pathways in hepatocellular carcinoma. BIOMED RESEARCH INTERNATIONAL 2014; 2014:153867. [PMID: 24877058 PMCID: PMC4022277 DOI: 10.1155/2014/153867] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/23/2014] [Accepted: 03/25/2014] [Indexed: 12/16/2022]
Abstract
Hepatocellular carcinoma (HCC) has been known as one of the most lethal human malignancies, due to the difficulty of early detection, chemoresistance, and radioresistance, and is characterized by active angiogenesis and metastasis, which account for rapid recurrence and poor survival. Its development has been closely associated with multiple risk factors, including hepatitis B and C virus infection, alcohol consumption, obesity, and diet contamination. Genetic alterations and genomic instability, probably resulted from unrepaired DNA lesions, are increasingly recognized as a common feature of human HCC. Dysregulation of DNA damage repair and signaling to cell cycle checkpoints, known as the DNA damage response (DDR), is associated with a predisposition to cancer and affects responses to DNA-damaging anticancer therapy. It has been demonstrated that various HCC-associated risk factors are able to promote DNA damages, formation of DNA adducts, and chromosomal aberrations. Hence, alterations in the DDR pathways may accumulate these lesions to trigger hepatocarcinogenesis and also to facilitate advanced HCC progression. This review collects some of the most known information about the link between HCC-associated risk factors and DDR pathways in HCC. Hopefully, the review will remind the researchers and clinicians of further characterizing and validating the roles of these DDR pathways in HCC.
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37
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Takahashi K. Influence of bacteria on epigenetic gene control. Cell Mol Life Sci 2014; 71:1045-54. [PMID: 24132510 PMCID: PMC11113846 DOI: 10.1007/s00018-013-1487-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/25/2013] [Accepted: 09/26/2013] [Indexed: 01/26/2023]
Abstract
Cellular information is inherited by daughter cells through epigenetic routes in addition to genetic routes. Epigenetics, which is primarily mediated by inheritable DNA methylation and histone post-translational modifications, involves changes in the chromatin structure important for regulating gene expression. It is widely known that epigenetic control of gene expression plays an essential role in cell differentiation processes in vertebrates. Furthermore, because epigenetic changes can occur reversibly depending on environmental factors in differentiated cells, they have recently attracted considerable attention as targets for disease prevention and treatment. These environmental factors include diet, exposure to bacteria or viruses, and air pollution, of which this review focuses on the influence of bacteria on epigenetic gene control in a host. Host-bacterial interactions not only occur upon pathogenic bacterial infection but also continuously exist between commensal bacteria and the host. These bacterial stimuli play an essential role in various biological responses involving external stimuli and in maintaining physiological homeostasis by altering epigenetic markers and machinery.
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Affiliation(s)
- Kyoko Takahashi
- Food and Physiological Functions Laboratory, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa-shi, Kanagawa, 252-0880, Japan,
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38
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Wu HC, Tsai HW, Teng CF, Hsieh WC, Lin YJ, Wang LHC, Yuan Q, Su IJ. Ground-glass hepatocytes co-expressing hepatitis B virus X protein and surface antigens exhibit enhanced oncogenic effects and tumorigenesis. Hum Pathol 2014; 45:1294-301. [PMID: 24767856 DOI: 10.1016/j.humpath.2013.10.039] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 10/14/2013] [Accepted: 10/16/2013] [Indexed: 12/11/2022]
Abstract
Hepatitis B virus (HBV) X protein (HBx) and pre-S2 deletion mutant large surface antigens are oncoproteins that induce hepatocellular carcinoma (HCC). The interaction of these two oncoproteins in hepatocytes and its significance in tumorigenesis remain to be elucidated. In this study, we observed the co-expression of HBx with surface antigens in ground-glass hepatocytes in 5 of 20 hepatitis B surface antigen-positive livers. In vitro, hepatocytes co-expressing HBx and a pre-S2 mutant showed enhanced expression of vascular endothelial growth factor-A, phosphorylated Akt 1/2/3, phosphorylated extracellular signal-regulated kinase 1/2, and phosphorylated mammalian target of rapamycin signals. Transgenic mice harboring both HBx and pre-S2 mutant construct plasmids developed HCCs at an average of 15.1 months, earlier than animals carrying either HBx (16.9 months) or pre-S2 mutant (24.5 months) alone. The oncogenic signals of vascular endothelial growth factor-A, phosphorylated Akt 1/2/3, phosphorylated extracellular signal-regulated kinase 1/2, and phosphorylated mammalian target of rapamycin were sequentially and differentially activated at different stages in tumorigenesis. Phosphorylated mTOR was consistently activated in transgenic and human HCCs. We conclude that ground-glass hepatocytes co-expressing HBx and surface antigens exhibit enhanced oncogenic effects and tumorigenesis in chronic HBV infections. The mTOR signal cascade may be the key regulator in HBV tumorigenesis and may be useful targets in the design of HCC therapy.
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Affiliation(s)
- Han-Chieh Wu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan 70456, Taiwan
| | - Hung-Wen Tsai
- Department of Pathology, National Cheng Kung University Hospital, Tainan 70403, Taiwan
| | - Chiao-Fang Teng
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan 70456, Taiwan
| | - Wen-Chuan Hsieh
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan 70456, Taiwan
| | - Yih-Jyh Lin
- Department of Surgery, National Cheng Kung University Hospital, Tainan 70403, Taiwan
| | - Lily Hui-Ching Wang
- Institute of Molecular and Cellular Biology and Department of Medical Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Quan Yuan
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen 361102, China
| | - Ih-Jen Su
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan 70456, Taiwan; Department of Pathology, National Cheng Kung University Hospital, Tainan 70403, Taiwan; Department of Surgery, National Cheng Kung University Hospital, Tainan 70403, Taiwan.
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Bharadwaj M, Roy G, Dutta K, Misbah M, Husain M, Hussain S. Tackling hepatitis B virus-associated hepatocellular carcinoma--the future is now. Cancer Metastasis Rev 2013; 32:229-68. [PMID: 23114844 DOI: 10.1007/s10555-012-9412-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatocellular carcinoma (HCC) is one of the most lethal and prevalent cancers in many developing countries including India. Among the various etiological factors being implicated in the cause of HCC, the most important cause, however, is hepatitis B virus (HBV) infection. Among all HBV genes, HBx is the most critical carcinogenic component, the molecular mechanisms of which have not been completely elucidated. Despite its clinical significance, there exists a very elemental understanding of the molecular, cellular, and environmental mechanisms that drive disease pathogenesis in HCC infected with HBV. Furthermore, there are only limited therapeutic options, the clinical benefits of which are insignificant. Therefore, the quest for novel and effective therapeutic regimen against HBV-related HCC is of paramount importance. This review attempts to epitomize the current state of knowledge of this most common and dreaded liver neoplasm, highlighting the putative treatment avenues and therapeutic research strategies that need to be implemented with immediate effect for tackling HBV-related HCC that has plagued the medical and scientific fraternity for decades. Additionally, this review proposes a novel "five-point" management algorithm for HBV-related HCC apart from portraying the unmet needs, principal challenges, and scientific perspectives that are relevant to controlling this accelerating global health crisis.
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Affiliation(s)
- Mausumi Bharadwaj
- Division of Molecular Genetics & Biochemistry, Institute of Cytology & Preventive Oncology (ICMR), Noida, India.
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DNA damage sensor γ -H2AX is increased in preneoplastic lesions of hepatocellular carcinoma. ScientificWorldJournal 2013; 2013:597095. [PMID: 23533353 PMCID: PMC3603670 DOI: 10.1155/2013/597095] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 02/05/2013] [Indexed: 02/06/2023] Open
Abstract
Background. Phosphorylated histone H2AX (γ-H2AX) is a potential regulator of DNA repair and is a useful tool for detecting DNA damage. To evaluate the clinical usefulness of γ-H2AX in hepatocellular carcinoma (HCC), we measured the level of γ-H2AX in HCC, dysplastic nodule, and nontumorous liver diseases. Methods. The level of γ-H2AX was measured by immunohistochemistry in fifty-eight HCC, 18 chronic hepatitis, 22 liver cirrhosis, and 19 dysplastic nodules. Appropriate cases were also examined by fluorescence analysis and western blotting. Results. All cases with chronic liver disease showed increased levels of γ-H2AX expression. In 40 (69.9%) of 58 cases with HCC, the labeling index (LI) of γ-H2AX was above 50% and was inversely correlated with the histological grade. Mean γ-H2AX LI was the highest in dysplastic nodule (74.1 ± 22.1%), which was significantly higher than HCC (P < 0.005). Moreover, γ-H2AX was significantly increased in nontumorous tissues of HCC as compared with liver cirrhosis without HCC (62.5 ± 24.7%, from 5.1 to 96.0%, P < 0.005). Conclusions. γ-H2AX was increased in the preneoplastic lesions of HCC and might be a useful biomarker for predicting the risk of HCC.
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Tang J, Zhang ZH, Liu GL. A systematic analysis of the predicted human La protein targets identified a hepatitis B virus infection signature. J Viral Hepat 2013; 20:12-23. [PMID: 23231080 DOI: 10.1111/j.1365-2893.2012.01626.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The human La (hLa) protein functions in RNA metabolism and is activated by casein kinase 2 (CK2) phosphorylation. Hepatitis B virus (HBV) can exploit hLa to stabilize its RNA and promote its pathogenesis. To enhance our knowledge of host molecular pathways involved in HBV pathogenesis, a bioinformatic approach was used to generate an expression profile of all predicted target genes of CK2-activated hLa in HBV-infected cells. A computerized literature search was performed to identify English language studies of HBV-, hLa- and CK2-related molecules. The data were pooled and the genes were classified in three functional groups by gene ontology (GO) analysis. HBV, hLa and CK2 targets were predicted, respectively, by a computational method, followed by screening for matching gene symbols in the NCBI human sequences, GO, pathway and network analyses. hLa targets and respective networks in the viral mechanisms of HBV were obtained by the final integrative analysis. Thirty-seven hub genes were identified by overlap calculation, suggesting that hLa may play an important role in the development and progression of HBV through cytokine-cytokine receptor interaction, hematopoietic cell lineage, cell adhesion molecules (CAMs), antigen processing and presentation, Jak-STAT signalling pathway, natural killer cell-mediated cytotoxicity, apoptosis, T-cell receptor signalling pathway, complement and coagulation cascades, protein export and other pathways. Our data may help researchers to predict the molecular mechanisms of hLa in the development and progression of HBV through CK2 comprehensively. Moreover, the present data indicate that hLa targets may be a series of promising candidates for HBV.
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Affiliation(s)
- J Tang
- Department of Pharmacy, First People's Hospital Affiliated to Shanghai JiaoTong University, Shanghai, China
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42
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Rawat S, Clippinger AJ, Bouchard MJ. Modulation of apoptotic signaling by the hepatitis B virus X protein. Viruses 2012; 4:2945-72. [PMID: 23202511 PMCID: PMC3509679 DOI: 10.3390/v4112945] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/23/2012] [Accepted: 10/31/2012] [Indexed: 12/18/2022] Open
Abstract
Worldwide, an estimated 350 million people are chronically infected with the Hepatitis B Virus (HBV); chronic infection with HBV is associated with the development of severe liver diseases including hepatitis and cirrhosis. Individuals who are chronically infected with HBV also have a significantly higher risk of developing hepatocellular carcinoma (HCC) than uninfected individuals. The HBV X protein (HBx) is a key regulatory HBV protein that is important for HBV replication, and likely plays a cofactor role in the development of HCC in chronically HBV-infected individuals. Although some of the functions of HBx that may contribute to the development of HCC have been characterized, many HBx activities, and their putative roles during the development of HBV-associated HCC, remain incompletely understood. HBx is a multifunctional protein that localizes to the cytoplasm, nucleus, and mitochondria of HBV‑infected hepatocytes. HBx regulates numerous cellular signal transduction pathways and transcription factors as well as cell cycle progression and apoptosis. In this review, we will summarize reports in which the impact of HBx expression on cellular apoptotic pathways has been analyzed. Although various effects of HBx on apoptotic pathways have been observed in different model systems, studies of HBx activities in biologically relevant hepatocyte systems have begun to clarify apoptotic effects of HBx and suggest mechanisms that could link HBx modulation of apoptotic pathways to the development of HBV-associated HCC.
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Affiliation(s)
- Siddhartha Rawat
- Graduate Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, PA 19102, USA;
| | - Amy J. Clippinger
- Department of Cancer Biology, Abramson Family Cancer Research Institute, School of Medicine, University of Pennsylvania Philadelphia, PA 19104, USA;
| | - Michael J. Bouchard
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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Studach LL, Menne S, Cairo S, Buendia MA, Hullinger RL, Lefrançois L, Merle P, Andrisani OM. Subset of Suz12/PRC2 target genes is activated during hepatitis B virus replication and liver carcinogenesis associated with HBV X protein. Hepatology 2012; 56:1240-51. [PMID: 22505317 PMCID: PMC3417088 DOI: 10.1002/hep.25781] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UNLABELLED Chronic hepatitis B virus (HBV) infection is a major risk factor for developing liver cancer, and the HBV X protein (pX) has been implicated as a cofactor in hepatocyte transformation. We have shown that HBV replication as well as in vitro transformation by pX are associated with induction of the mitotic polo-like kinase 1 (Plk1) and down-regulation of the chromatin remodeling components Suz12 and Znf198. Herein, we demonstrate the same inverse relationship between Plk1 and Suz12/Znf198 in liver tumors from X/c-myc bitransgenic mice and woodchuck hepatitis virus (WHV)-infected woodchucks. Employing these animal models and the HBV replicating HepAD38 cells we examined the effect of Suz12/Znf198 down-regulation on gene expression. Genes analyzed include hepatic cancer stem cell markers BAMBI, DKK1,2, DLK1, EpCAM, MYC, and proliferation genes CCNA1, CCND2, IGFII, MCM4-6, PLK1, RPA2, and TYMS. Suz12 occupancy at the promoters of BAMBI, CCND2, DKK2, DLK1, EpCAM, and IGFII was demonstrated by chromatin immunoprecipitation in untransformed hepatocytes, but was markedly reduced in pX-transformed and Suz12 knockdown cells. Accordingly, we refer to these genes as "Suz12 repressed" genes in untransformed hepatocytes. The Suz12 repressed genes and proliferation genes were induced in HBV-replicating HepAD38 cells and, interestingly, they exhibited distinct expression profiles during hepatocellular carcinoma (HCC) progression in X/c-myc bitransgenics. Specifically, CCND2, EpCAM, and IGFII expression was elevated at the proliferative and preneoplastic stages in X/c-myc bitransgenic livers, whereas BAMBI and PLK1 were overexpressed in hepatic tumors from X/c-myc bitransgenics and WHV-infected woodchucks. Importantly, most of these genes were selectively up-regulated in HBV-induced HCCs. CONCLUSION The distinct expression profile of the identified Suz12 repressed genes in combination with the proliferation genes hold promise as biomarkers for progression of chronic HBV infection to HCC.
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MESH Headings
- Animals
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/virology
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/metabolism
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/pathology
- Cells, Cultured
- Disease Models, Animal
- Down-Regulation
- Gene Expression Regulation, Viral
- Hepatitis B virus/genetics
- Hepatitis B, Chronic/genetics
- Hepatitis B, Chronic/physiopathology
- Hepatocytes/pathology
- Liver Neoplasms/genetics
- Liver Neoplasms/virology
- Marmota
- Mice
- Mice, Transgenic
- Polycomb Repressive Complex 2/genetics
- Polycomb Repressive Complex 2/metabolism
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Random Allocation
- Sensitivity and Specificity
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcriptional Activation
- Viral Regulatory and Accessory Proteins
- Virus Replication/genetics
- Polo-Like Kinase 1
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Affiliation(s)
- Leo L. Studach
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
| | - Stephan Menne
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, USA
| | - Stefano Cairo
- XenTech, Research and Development Department, Genopole Campus 3 Evry, France
| | - Marie Annick Buendia
- Inserm U785 Unit, Hepatobiliary Center, Paul Brousse Hospital, Villejuif, France
| | - Ronald L. Hullinger
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
| | - Lydie Lefrançois
- Inserm U1052, Centre de Recherche en Cancérologie de Lyon, Hepatocarcinogenesis and Viral Infection, Lyon Cedex 03 France
| | - Philippe Merle
- Inserm U1052, Centre de Recherche en Cancérologie de Lyon, Hepatocarcinogenesis and Viral Infection, Lyon Cedex 03 France
| | - Ourania M. Andrisani
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
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Shi XY, Zhang YY, Zhou XW, Lu JS, Guo ZK, Huang PT. Hepatitis B virus X protein regulates the mEZH2 promoter via the E2F1-binding site in AML12 cells. CHINESE JOURNAL OF CANCER 2012; 30:273-9. [PMID: 21439249 PMCID: PMC4013354 DOI: 10.5732/cjc.010.10437] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Histone lysine methyltransferase EZH2 has been reported to be frequently overexpressed in hepatocellular carcinoma (HCC) tissues and associated with hepatocarcinogenesis. However, the exact mechanism of EZH2 up-regulation in HCC has not been determined. In this study, we used murine hepatocyte AML12 cells to investigate the role of hepatitis B virus X protein (HBx) in regulating the expression of mEZH2. Western blot analysis demonstrated that the expression level of mEZH2 protein in AML12 cells was up-regulated by HBx in a dose-dependent manner. To further investigate the mechanism of mEZH2 overexpression, the 2500 bp regulatory sequence upstream from the first exon of the mEZH2 gene was amplified from AML12 genomic DNA and constructed into a luciferase reporter plasmid. The luciferase activity of the mEZH2 promoter significantly increased in AML12 cells co-transfected with HBx plasmid, and deleting the −486/−214 promoter region decreased HBx-induced mEZH2 promoter activation by nearly 50%. The −486/−214 region was then analyzed in the TRANSFAC 6.0 database and a typical E2F1-binding site was found. Mutation of this E2F1-binding site or knockdown of E2F1 expression by RNAi led to a dramatic decrease in HBx-induced activation of the mEZH2 promoter and mEZH2 overexpression in AML12 cells. These results provide evidence that HBx up-regulates mEZH2 expression by transactivating the mEZH2 promoter through E2F1 transcription factor, thereby providing new epigenetic evidence for the carcinogenic effect of HBx.
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Affiliation(s)
- Xiao-Yan Shi
- Beijing Institute of Biotechnology, Beijing 100071, P. R. China
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45
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Du Y, Kong G, You X, Zhang S, Zhang T, Gao Y, Ye L, Zhang X. Elevation of highly up-regulated in liver cancer (HULC) by hepatitis B virus X protein promotes hepatoma cell proliferation via down-regulating p18. J Biol Chem 2012; 287:26302-11. [PMID: 22685290 DOI: 10.1074/jbc.m112.342113] [Citation(s) in RCA: 310] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Long noncoding RNAs (lncRNAs) play crucial roles in human cancers. It has been reported that lncRNA highly up-regulated in liver cancer (HULC) is dramatically up-regulated in hepatocellular carcinoma (HCC). Hepatitis B virus X protein (HBx) contributes importantly to the development of HCC. However, the function of HULC in HCC mediated by HBx remains unclear. Here, we report that HULC is involved in HBx-mediated hepatocarcinogenesis. We found that the expression levels of HULC were positively correlated with those of HBx in clinical HCC tissues. Moreover, we revealed that HBx up-regulated HULC in human immortalized normal liver L-O2 cells and hepatoma HepG2 cells. Luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) assay showed that HBx activated the HULC promoter via cAMP-responsive element-binding protein. We further demonstrated that HULC promoted cell proliferation by methyl thiazolyl tetrazolium, 5-ethynyl-2'-deoxyuridine, colony formation assay, and tumorigenicity assay. Next, we hypothesized that HULC might function through regulating a tumor suppressor gene p18 located near HULC in the same chromosome. We found that the mRNA levels of p18 were inversely correlated with those of HULC in the above clinical HCC specimens. Then, we validated that HULC down-regulated p18, which was involved in the HULC-enhanced cell proliferation in vitro and in vivo. Furthermore, we observed that knockdown of HULC could abolish the HBx-enhanced cell proliferation through up-regulating p18. Thus, we conclude that the up-regulated HULC by HBx promotes proliferation of hepatoma cells through suppressing p18. This finding provides new insight into the roles of lncRNAs in HBx-related hepatocarcinogenesis.
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Affiliation(s)
- Yumei Du
- Department of Cancer Research, Key Laboratory of Molecular Microbiology and Technology of Ministry of Education, Institute for Molecular Biology, Nankai University, Tianjin 300071, China
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Liu YP, Yang XN, Jazag A, Pan JS, Hu TH, Liu JJ, Guleng B, Ren JL. HBsAg inhibits the translocation of JTB into mitochondria in HepG2 cells and potentially plays a role in HCC progression. PLoS One 2012; 7:e36914. [PMID: 22615844 PMCID: PMC3352868 DOI: 10.1371/journal.pone.0036914] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 04/10/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND AIMS The expression of the jumping translocation breakpoint (JTB) gene is upregulated in malignant liver tissues; however, JTB is associated with unbalanced translocations in many other types of cancer that suppress JTB expression. No comprehensive analysis on its function in human hepatocellular carcinoma (HCC) has been performed to date. We aimed to define the biological consequences for interaction between JTB and HBsAg in HCC cell lines. METHODS We employed the stable transfection to establish small HBsAg expressing HepG2 cell line, and stably silenced the JTB expression using short hairpin RNA in HepG2 cell line. The effects of JTB and small HBsAg in vitro were determined by assessing cell apoptosis and motility. RESULTS Silencing of JTB expression promoted cancer cell motility and reduced cell apoptosis, which was significantly enhanced by HBs expression. Expression of HBsAg inhibited the translocation of JTB to the mitochondria. Furthermore, silencing of the JTB resulted in an increase in the phosphorylation of p65 in HepG2 cells and HepG2-HBs cells, whereas HBsAg expression decreased the phosphorylation of p65. The silencing of JTB in HepG2-HBs cells conferred increased advantages in cell motility and anti-apoptosis. CONCLUSION HBsAg inhibited the translocation of JTB to the mitochondria and decreased the phosphorylation of p65 through the interaction with JTB, After JTB knockdown, HBsAg exhibited a stronger potential to promote tumor progression. Our data suggested that JTB act as a tumor suppressor gene in regards to HBV infection and its activation might be applied as a therapeutic strategy for in control of HBV related HCC development.
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Affiliation(s)
- Yun-Peng Liu
- Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, Fujian Province, China
| | - Xiao-Ning Yang
- Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, Fujian Province, China
| | - Amarsanaa Jazag
- National Institute of Medical Research, 3rd General Hospital, Ulaanbaatar, Mongolia
| | - Jin-Shui Pan
- Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, Fujian Province, China
| | - Tian-Hui Hu
- Medical College of Xiamen University, Xiamen, Fujian Province, China
| | - Jing-Jing Liu
- Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, Fujian Province, China
| | - Bayasi Guleng
- Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, Fujian Province, China
- Medical College of Xiamen University, Xiamen, Fujian Province, China
| | - Jian-Lin Ren
- Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, Fujian Province, China
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Yan Y, Greer PM, Cao PT, Kolb RH, Cowan KH. RAC1 GTPase plays an important role in γ-irradiation induced G2/M checkpoint activation. Breast Cancer Res 2012; 14:R60. [PMID: 22494620 PMCID: PMC3446395 DOI: 10.1186/bcr3164] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 12/25/2011] [Accepted: 04/11/2012] [Indexed: 01/06/2023] Open
Abstract
Introduction In response to gamma-irradiation (IR)-induced double-strand DNA breaks, cells undergo cell-cycle arrest, allowing time for DNA repair before reentering the cell cycle. G2/M checkpoint activation involves activation of ataxia telangiectasia mutated (ATM)/ATM- and rad3-related (ATR) kinases and inhibition of Cdc25 phosphatases, resulting in inhibition of Cdc2 kinase and subsequent G2/M cell-cycle arrest. Previous studies from our laboratory showed that the G2/M checkpoint activation after IR exposure of MCF-7 breast cancer cells is dependent on the activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) signaling. In the present studies, we investigated the role of Ras-related C3 botulinum toxin substrate 1 (Rac1) guanosine triphosphatase (GTPase) in IR-induced G2/M checkpoint response and ERK1/2 activation, as well as in cell survival after IR. Methods With Rac1-specific inhibitor, dominant negative mutant Rac1 (N17Rac1) and specific small interfering RNA, the effect of Rac1 on IR-induced G2/M checkpoint response and ERK1/2 activation was examined in human breast cancer cells. In addition, the effect of Rac1 on cell survival after irradiation was assessed by using Rac1-specific inhibitor. Results IR exposure of MCF-7 breast cancer cells was associated with a marked activation of Rac1 GTPase. Furthermore, inhibition of Rac1 by using specific inhibitor, dominant-negative Rac1 mutant, or specific siRNA resulted in attenuation of IR-induced G2/M arrest and concomitant diminution of IR-induced activation of ATM, ATR, Chk1, and Chk2 kinases, as well as phosphorylation of Cdc2-Tyr15. Moreover, Rac1 inhibition or decreased Rac1 expression also abrogated IR-induced phosphorylation of mitogen-activated protein kinase kinase 1 and 2 (MEK1/2) and ERK1/2. Ultimately, inhibition of Rac1 markedly increased cellular sensitivity to IR exposure, which involves induction of apoptosis. Conclusion Studies in this report suggest that Rac1 GTPase plays an essential role in the activation of IR-induced ERK1/2 signaling and subsequent G2/M checkpoint response. Furthermore, results also support a role for Rac1 in promoting cell survival after irradiation treatment.
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Affiliation(s)
- Ying Yan
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE, USA.
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48
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E2F-1 is overexpressed and pro-apoptotic in human hepatocellular carcinoma. Virchows Arch 2012; 460:439-46. [PMID: 22450712 DOI: 10.1007/s00428-012-1220-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2011] [Revised: 01/30/2012] [Accepted: 02/27/2012] [Indexed: 12/18/2022]
Abstract
E2F-1 is a transcription factor involved in DNA synthesis and repair, cell proliferation, and apoptosis. Hyposphorylated pRb represses E2F-1 action in early G1 phase, while in late G1, pRb hyperphosphorylation leads to E2F-1 release and activation. In vitro studies have shown that E2F-1 may act either as oncogene or as tumor suppressor gene. We evaluated immunohistochemical expression of E2F-1 protein in chronic viral liver disease and hepatocellular carcinoma (HCC) and correlated this with clinicopathological parameters, cell proliferation, apoptosis, and the expression of E2F-1-regulators, pRb, and phospho-pRb (Ser795). In liver biopsies from 30 patients with chronic viral hepatitis, including 22 with cirrhosis without HCC, and 57 with cirrhosis with HCC, E2F-1 expression was assessed by immunohistochemistry. In chronic hepatitis and cirrhosis, hepatocytes and cholangiocytes demonstrated mild cytoplasmic and/or nuclear membrane E2F-1 immunostaining. In contrast, all HCC (100 %) showed strong nuclear E2F-1 immunostaining, with or without membrane accentuation, while a minority demonstrated additional moderate cytoplasmic immunostaining. Abnormally low pRb and phospho-pRb expression was seen in 70 % and 67.9 % of HCC, respectively. In HCC, nuclear E2F-1 expression was inversely correlated with phospho-pRb expression (p = 0.001) and positively related to tumor apoptotic index (p = 0.025). No significant correlation was found between E2F-1 expression and patient demographics, HCC etiology, tumor grade, pRb, p53 expression, or cell proliferation. In conclusion, we show that the increased expression of E2F-1 protein in human HCC is correlated with enhanced tumor cell apoptosis supporting a pro-apoptotic role of E2F-1 in human HCC.
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Abstract
The DNA damage response (DDR) has emerged as a critical tumour suppressor pathway responding to cellular DNA replicative stress downstream of aberrant oncogene over-expression. Recent studies have now implicated the DDR as a sensor of oncogenic virus infection. In this review, we discuss the mechanisms by which tumour viruses activate and also suppress the host DDR. The mechanism of tumour virus induction of the DDR is intrinsically linked to the need for these viruses to promote an S-phase environment to replicate their nucleic acid during infection. However, inappropriate expression of viral oncoproteins can also activate the DDR through various mechanisms including replicative stress, direct interaction with DDR components and induction of reactive oxygen species. Given the growth-suppressive consequences of activating the DDR, tumour viruses have also evolved mechanisms to attenuate these pathways. Aberrant expression of viral oncoproteins may therefore promote tumourigenesis through increased somatic mutation and aneuploidy due to DDR inactivation. This review will focus on the interplay between oncogenic viruses and the DDR with respect to cellular checkpoint control and transformation.
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Affiliation(s)
- P A Nikitin
- Department of Molecular Genetics and Microbiology, Center for Virology, Duke University Medical Center, 213 Research Dr., CARL 424, DUMC 3054, Durham, NC 27710, USA
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50
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Ye P, Yang B, Wu XL, Jiang MD. P38 MAPK signaling pathway: biological functions, roles in the pathogenesis of liver fibrosis and common research methods. Shijie Huaren Xiaohua Zazhi 2011; 19:3353-3358. [DOI: 10.11569/wcjd.v19.i32.3353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The activation and proliferation of hepatic stellate cells (HSC) are the key events in hepatic fibrogenesis. Now the research about the mechanisms of action of HSC-related signal transduction has become a hot topic. This article reviews the biological functions of the p38 MAPK signaling pathway and its roles in the pathogenesis of liver fibrosis and summarizes common research methods for this signaling pathway.
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