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Naturally occurring hepatitis B virus reverse transcriptase mutations related to potential antiviral drug resistance and liver disease progression

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World Journal of Gastroenterology 2018年第16期24卷 1708-1724页

作者： Yu-Min Choi So-Young Lee Bum-Joon Kim Department of Microbiology and Immunology Biomedical Sciences Liver Research Institute and Cancer Research Institute Seoul National University College of Medicine

The annual number of deaths caused by hepatitis B virus(HBV)-related disease, including cirrhosis and hepatocellular carcinoma(HCC), is estimated as 887000. The reported prevalence of HBV reverse transcriptase(RT) mutation prior to treatment is varied and the impact of preexisting mutations on the treatment of na?ve patients remains controversial, and primarily depends on geographic factors, HBV genotypes, HBe Ag serostatus, HBV viral loads, disease progression, intergenotypic recombination and co-infection with HIV. Different sensitivity of detection methodology used could also affect their prevalence results. Several genotype-dependent HBV RT positions that can affect the emergence of drug resistance have also been reported. Eight mutations in RT(rtL80I, rtD134N, rtN139K/T/H, rtY141F, rtM204I/V, rtF221Y, rtI224V, and rtM309K) are significantly associated with HCC progression. HBe Ag-negative status, low viral load, and genotype C infection are significantly related to a higher frequency and prevalence of preexisting RT mutations. Preexisting mutations are most frequently found in the A-B interdomain of RT which overlaps with the HBs Ag "a" determinant region, mutations of which can lead to simultaneous viral immune escape. In conclusion, the presence of baseline RT mutations can affect drug treatment outcomes and disease progression in HBVinfected populations via modulation of viral fitness and host-immune responses.

关键词： polymerase hepatocellular carcinoma reverse transcriptase preexisting mutations hepatitis B virus

Unique case of oligoastrocytoma with recurrence and grade progression:Exhibiting differential expression of high mobility group-A1 and human telomerase reverse transcriptase

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World Journal of Clinical Cases 2016年第9期4卷 296-301页

作者： Puneet Gandhi Richa Khare Kavita Niraj Nitin Garg Sandeep K Sorte Hanni Gulwani Department of Research Bhopal Memorial Hospital and Research Centre Department of Neurosurgery Bhopal Memorial Hospital and Research Centre and Bansal Hospital Department of Pathology Bhopal Memorial Hospital and Research Centre

Mixed gliomas, primarily oligoastrocytomas, account for about 5%-10% of all gliomas. Distinguishing oligoastrocytoma based on histological features alone has limitations in predicting the exact biological behavior, necessitating ancillary markers for greater specificity. In this case report, human telomerase reverse transcriptase(hT ERT) and high mobility group-A1(HMGA1); markers of proliferation and stemness, have been quantitatively analyzed in formalin-fixed paraffin-embedded tissue samples of a 34 years old patient with oligoastrocytoma. Customized florescence-based immunohistochemistry protocol with enhanced sensitivity and specificity is used in the study. The patient presented with a history of generalized seizures and his magnetic resonance imaging scans revealed infiltrative ill-defined mass lesion with calcified foci within the left frontal white matter, suggestive of glioma. He was surgically treated at our center for four consecutive clinical events. Histopathologically, the tumor was identified as oligoastrocytoma-grade Ⅱ followed by two recurrence events and final progression to grade Ⅲ. Overall survival of the patient without adjuvant therapy was more than 9 years. Glial fibrillary acidic protein, p53, Ki-67, nuclear atypia index, pre-operative neutrophillymphocyte ratio, are the other parameters assessed. Findings suggest that hT ERT and HMGA1 are linked to tumor recurrence and progression. Established markers can assist in defining precise histopathological grade in conjuction with conventional markers in clinical setup.

关键词： Human telomerase reverse transcriptase High mobility group-A1 Oligoastrocytoma Recurrence Tumor grade

SYBR Green I-based product-enhanced reverse transcriptase assay for quantification of retroviral PFV and detection of the divalent cation preference of PFV RT

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Virologica Sinica 2014年第5期29卷 314-317页

作者： Xiaofang Yi Yan Sun Qingmei Liu Zhi Li Wanhong Liu Xiaohua He Linjuan Zhang Yuxin Wang College of Life Sciences Shaanxi Normal University School of Medicine Wuhan University

Dear Editor,Prototype foamy virus(PFV)belongs to the genus Spumavirus in the Spumaretrovirinae subfamily of Retroviridae.Although PFV and HIV have much in common,research into PFV has lagged far behind that into HIV,as PFV appeared to be non-pathogenic both in accidentally infected humans and in experimentally infected animals.In recent decades,however,more attention has been focused on PFV because it seems to

关键词： preference transcriptase subfamily pathogenic quantification divalent belongs behind infected template

Identification and Characterization of Reverse transcriptase Fragments of Long Interspersed Nuclear Elements (LINEs) in the <i>Morus notabilis</i>Genome

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American Journal of Molecular Biology 2017年第3期7卷 138-152页

作者： Bi Ma Youchao Xin Lulu Kuang Fei Hou Ningjia He State Key Laboratory of Silkworm Genome Biology Southwest University Chongqing China

Reverse transcriptase (rt) fragments from LINE retrotransposons in the mulberry genome were analyzed in terms of heterogeneity, phylogeny, and chromosomal distribution. We amplified and characterized conserved domains of the rt using degenerate primer pairs. Sequence analyses indicated that the rt fragments were highly heterogeneous and rich in A/T bases. The sequence identity ranged from 31.8% to 99.4%. Based on sequence similarities, the rt fragments were categorized into eight groups. Furthermore, similar stop codon distribution patterns among a series of clones in the same group indicated that they underwent a similar evolutionary process. Interestingly, phylogenetic analyses of the rt fragments isolated from mulberry and 13 other plant species revealed that two distantly related taxa (mulberry and Paeonia suffruticosa) grouped together. It does not appear that this phenomenon resulted from horizontal transposable element transfer. Fluorescence in situ hybridization analysis revealed that most of the rt fragments were concentrated in the subtelomeric and pericentromeric regions of the mulberry chromosomes, but that these elements were not abundant in the mulberry genome. Future studies will focus on the potential roles of these elements in the subtelomeric and pericentromeric regions of the mulberry genome.

关键词： iMorus notabilis LINE Retrotransposons Reverse transcriptase Characterization Fluorescence in site Hybridization

Molecular Modeling of Quinoline-Based Compounds as Potential Dual Inhibitors of Reverse transcriptase and Integrase of HIV

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Computational Molecular Bioscience 2018年第3期8卷 122-148页

作者： Alberto Cabrera Leonor Huerta Hernández Daniel Chávez José L. Medina-Franco Departamento de Farmacia Facultad de Química Universidad Nacional Autónoma de México México City México Instituto de Investigaciones Biomédicas Universidad Nacional Autónoma de México México City México Centro de Graduados e Investigación en Química del Instituto Tecnológico de Tijuana Tijuana México

As follow-up of our past publication?[1], we propose that quinolones (as part of the pyridinone family) are capable to increase the number of interactions with HIV reverse transcriptase (RT) or integrase (IN) by adding a halogen in position C-8 of aromatic portion of the quinolones. This addition could help with the activity of dual inhibitors of RT and IN. In this work, we add a chlorine atom with the rationale to identify in the docking simulations a halogen interaction with the oxygen in the near aminoacids in the binding pockets of RT and IN enzymes. Our docking studies started with RT and 320 structures. Later, we took 73 structures with good results in docking with RT. The structures that we choose contain ester or acids groups in C-3 due the structural similarity with groups in charge to interact with the Mg++ ions in Elvitegravir. In conclusion, we obtained 14 structures that could occupy the allosteric pocket of RT and could inhibit the catalytic activity of IN, for this reason could be dual inhibitors. A major perspective of this work is the synthesis and testing of the potential dual inhibitors designed.

关键词： Reverse transcriptase Integrase Quinolone Dual Inhibitor Docking

Covariation of mutation pairs expressed in HIV-1 protease and reverse transcriptase genes subjected to varying treatments

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Journal of Biomedical Science and Engineering 2010年第3期3卷 291-299页

作者： David King Roger Cherry Wei Hu 不详

A previous study, focused on the correlation of muta-tion pairs of synonymous (S) and asynonymous (A) mutations, distinguished only between the treated and untreated data of protease and reverse tran-scriptase (RT) of HIV-1 subtype B. It is well known that single mutation patterns in HIV-1 are treat-ment-specific. It logically follows that covariation between mutations will also be treatment specific. Thus, our motivation is to give a more in depth study of the covariation between mutation pairs, analyzing not only treated and untreated, but what specific treatments were used, and how they affected the co-variation between the mutations differently. We in-tended to further deepen this study by analyzing the covariation of mutations in protease and RT in dif-ferent subtypes of HIV-1. We found that virus sam-ples subjected to antiretroviral Protease- and RT- inhibitors do show different patterns of mutation covariation in B-subtype protease and RT of HIV-1, while maintaining the same overall trend. covariation will tend to be higher and more distinct from and covariation after treatment. The same trend continues in protease and RT re-gardless of subtype. We also found the highly cova-ried codon positions, position pairs, and position- covariation clusters in protease, affected by different treatments. Most of them are well known major drug-resistance sites for these treatments.

关键词： HIV Covariation Synonymous Mutation Asynonymous Mutation Protease Reverse transcriptase Drug Resistance

Expression of Telomerase Reverse transcriptase during the Malignant Transformation of Cadmium-Induced Cells

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Journal of Geoscience and Environment Protection 2014年第2期2卷 129-133页

作者： Min Wang Yixiong Lei School of Public Health Guangzhou Medical University Guangzhou China

The objective of the present study was to investigate human telomerase reverse transcriptase (hTERT) mRNA and protein expressions during the cadmium chloride-induced malignant transformation of human bronchial epithelial (16HBE) cells. Fluorescence quantitative PCR (FQ-PCR) and Western blot analyses were performed to detect the hTERT mRNA and protein expressions in normal 16HBE cells, cadmium chloride-transformed 16HBE cells, and tumorigenic cells from nude mice inoculated with cadmium chloride-transformed 16HBE cells. Under the inner standard of GAPDH, the hTERT mRNA expression was significantly higher at different stages of malignant transformation (cadmium chloride-transformed 16HBE cells at passages 15 and 35 and tumorigenic cells from nude mice) than in normal 16HBE cells, and increased with the development of malignancy (P < 0.01). In addition, hTERT protein expression increased with the development of malignancy. These findings demonstrate that hTERT expression is related to cadmium chlorideinduced malignant transformation. Cadmium chloride-induced malignant transformation is involved in changes in the hTERT activity, and might be an early event in cadmium chloride-induced malignant transformation.

关键词： Cadmium Chloride Human Bronchial Epithelial Cells Malignant Transformation Telomerase Reverse transcriptase

Clinical significance of detection of human telomerase reverse transcriptase in colorectal cancer and its precancerous lesions

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China Medical Abstracts(Internal Medicine) 2014年第3期31卷 177-178页

作者：刘少平 Dept Gastroenterol Huangshi Centr HospHubei Instit Technol

Objective To evaluate the expression and clinical significance of human telomerase reverse transcriptase(h TERT)in colorectal cancer and its precancerous lesion.Methods The levels of h TERT expression were detected by immunohistochemistry in colorectal cancers(n=95),colorectal adenomatous polyposis(n=30)and normal colorectal tissues(n=30).The relationship between the expression of h TERT in colorectal cancer tissues and the pathologic features and prognosis were analyzed.Results The positive rate of h TERT

关键词： colorectal precancerous telomerase transcriptase TERT adenomatous polyposis pathologic prognosis invasion

Expression and purification of a functional human hepatitis B virus polymerase

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World Journal of Gastroenterology 2010年第45期16卷 5752-5758页

作者： Dipendra Raj Pandeya Seong-Tshool Hong Department of Microbiology and Immunology Institute of Medical ScienceChonbuk National University Medical SchoolChonjuChonbuk 561-712South Korea

AIM: To identify a method for efficient large-scale purification of functional hepatitis B virus polymerase (HBV-Pol) without addition of cellular factors. METHODS: Full-length HBV-Pol (843 amino acids) tagged with 5' end Polyhistidine was expressed at a high level in an Escherichia coli (E. coli ) system. Sodium dodecyl sulfate lysis buffer was utilized to dissolve insoluble HBV-Pol, and Ni-NTA resin affinity chromatography was utilized for HBV-Pol purification. Most recombinant HBV-Pol was eluted with 100 mmol/L imidazole in the presence of NP-40, a weak detergent that keeps HBV-Pol in solution. A reducing agent was utilized throughout the purification steps to keep soluble HBV-Pol from redundant disulfide bond formation. RESULTS: The large-scale production of functional intact human HBV-Pol was achieved in an E. coli expression system. Purified HBV-Pol showed stable reverse transcriptase activity and DNA polymerase activity. The purified protein was of high purity and had stable reverse transcriptase activity.CONCLUSION: Large-scale production of HBV-Pol in pure form should facilitate crystallization and detailed analysis of the structure and mechanism of HBV-Pol. Ability of this purification approach to obtain human HBV-Pol in an enzymatically active form should be helpful for development of drugs for treatment of chronic hepatitis B.

关键词： Hepatitis B Virus Virus polymerase Reverse transcriptase Detergent