54 research outputs found

    OncoDB.HCC: an integrated oncogenomic database of hepatocellular carcinoma revealed aberrant cancer target genes and loci

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    The OncoDB.HCC () is based on physical maps of rodent and human genomes containing quantitative trait loci of rodent HCC models and various human HCC somatic aberrations including chromosomal data from loss of heterozygosity and comparative genome hybridization analyses, altered expression of genes from microarray and proteomic studies, and finally experimental data of published HCC genes. Comprehensive integration of HCC genomic aberration data avoids potential pitfalls of data inconsistency from single genomic approach and provides lines of evidence to reveal somatic aberrations from levels of DNA, RNA to protein. Twenty-nine of 30 (96.7%) novel HCC genes with significant altered expressions in compared between tumor and adjacent normal tissues were validated by RT–PCR in 45 pairs of HCC tissues and by matching expression profiles in 57 HCC patients of re-analyzed Stanford HCC microarray data. Comparative mapping of HCC loci in between human aberrant chromosomal regions and QTLs of rodent HCC models revealed 12 syntenic HCC regions with 2 loci effectively narrowed down to 2 Mb. Together, OncoDB.HCC graphically presents comprehensive HCC data integration, reveals important HCC genes and loci for positional cloning and functional studies, and discloses potential molecular targets for improving HCC diagnosis and therapy

    ICTV Virus Taxonomy Profile:Coronaviridae 2023

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    The family Coronaviridae includes viruses with positive-sense RNA genomes of 22-36 kb that are expressed through a nested set of 3' co-terminal subgenomic mRNAs. Members of the subfamily Orthocoronavirinae are characterized by 80-160 nm diameter, enveloped virions with spike projections. The orthocoronaviruses, severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome-related coronavirus are extremely pathogenic for humans and in the last two decades have been responsible for the SARS and MERS epidemics. Another orthocoronavirus, severe acute respiratory syndrome coronavirus 2, was responsible for the recent global COVID-19 pandemic. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Coronaviridae which is available at www.ictv.global/report/coronaviridae.</p

    Microbiologic Characteristics, Serologic Responses, and Clinical Manifestations in Severe Acute Respiratory Syndrome, Taiwan1

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    The genome of one Taiwanese severe acute respiratory syndrome-associated coronavirus (SARS-CoV) strain (TW1) was 29,729 nt in length. Viral RNA may persist for some time in patients who seroconvert, and some patients may lack an antibody response (immunoglobulin G) to SARS-CoV >21 days after illness onset. An upsurge of antibody response was associated with the aggravation of respiratory failure

    Associations Between Hepatitis B Virus Genotype and Mutants and the Risk of Hepatocellular Carcinoma

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    Background The risk of hepatocellular carcinoma (HCC) increases with increasing level of hepatitis B virus (HBV) in serum (viral load). However , it is unclear whether genetic characteristics of HBV, including HBV genotype and specific genetic mutations, contribute to the risk of HCC. We examined the HCC risk associated with HBV genotypes and common variants in the precore and basal core promoter (BCP) regions. Methods From January 5, 1991, to December 21, 1992 , baseline blood samples were collected from 2762 Taiwanese men and women who were seropositive for HBV surface antigen but had not been diagnosed with HCC; the samples were tested for HBV viral load by real-time polymerase chain reaction and genotyped by melting curve analysis. Participants who had a baseline serum HBV DNA level greater than 101 copies/ mL (n = 1526) were tested for the precore G 1896A and BCP A 1762T/G1764A mutants by direct sequencing. Incident cases of HCC were ascertained through follow-up examinations and computerized linkage to the National Cancer Registry and death certification profiles. A Cox proportional hazards model was used to estimate the risk of HCC associated with HBV genotype and precore and BCP mutants after adjustment for other risk factors. All statistical tests were two-sided . Results A total of 153 HCC cases occurred during 33847 person-years of follow-up. The HCC incidence rates per 100000 person-years for participants infected with HBV genotype B or C were 305.6 (95% confidence interval [CI] = 236.9 to 388.1) and 785.8 (95% CI = 626.8 to 972.9), respectively. Among participants with a baseline HBV DNA level of at least 10(4) copies/mL, HCC incidence per 100000 person-years was higher for those with the precore G1896 ( wild-type) variant than for those with the G1896A variant ( 955.5 [95% CI = 749.0 to 1201.4] vs 269.4 [95% CI = 172.6 to 400.9]) and for those with the BCP A1762T/G1764A double mutant than for those with BCP A1762/G1764 (wild-type) variant (1149.2 [95% CI = 872.6 to 1485.6] vs 358.7 [95% Cl = 255.1 to 490.4]). The multivariable-adjusted hazard ratio of developing HCC was 1.76 (95% CI = 1.19 to 2.61) for genotype C vs genotype B, 0.34 (95% CI = 0.21 to 0.57) for precore G1896A vs wild type, and 1.73 (95% CI = 1.13 to 2.67 ) for BCP A1762T/G1764A vs wild type. Risk was highest among participants infected with genotype C HBV and wild type for the precore 1896 variant and mutant for the BCP 1762/1764 variant ( adjusted hazard ratio = 2.99, 95% CI = 1.57 to 5.70 , P<.001). Conclusions HBV genotype C and specific alleles of BCP and precore were associated with risk of HCC. These associations were independent of serum HBV DNA level

    Hepatitis B Virus Quantification and Detection of Ymdd Mutants in a Single Reaction by Real-Time Pcr and Annealing Curve Analysis

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    BACKGROUND: Long-term antiviral therapy, although effective for treatment of hepatitis B, might select the emergence of drug-resistant hepatitis B virus (HBV) mutants. Detection of HBV mutants and determination of viral titre are two crucial parameters for monitoring treatment response and occurrence of mutants. In this study, we take lamivudine resistance as an example to develop a method that can determine both parameters in a single -tube PCR reaction. METHODS: The method contained two consecutive steps: in the first step, real-time PCR was used for quantification; in the second step, a novel annealing curve analysis was used for detecting YMDD mutants. For accurate quantification, PCR primers and hybridization probes were chosen from highly conserved regions to ensure the equivalent amplification of all HBV genotypes. Within the sensor probe, there were signature nucleotide polymorphisms that could effectively differentiate YMDD mutants from wild type by distinct melting temperatures (Tm) values. The clinical applicability of the assay was tested in serial samples from 90 patients receiving lamivudine treatment. RESULTS: This assay could readily differentiate YMDD, YIDD and YVDD mutants by their distinct Tm values. The quantification results showed great consistency in a linear range from 10(3) to 10(11) copies/ml . Moreover, this assay could detect YMDD mutants accounting for < or = 10% of the total viral population. Its clinical feasibility has been verified in primary specimens. CONCLUSIONS: The newly designed YMDD detection method is simple, sensitive, cost- effective, time-saving and provides a useful tool for follow-up of patients treated with lamivudine or other antiviral drugs

    Allelic Loss on Chromosomes 4q and 16q in Hepatocellular Carinoma-- Association with Elevated α-Fetoprotein

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    Background & Aims: In human hepatocellular carcinoma, restriction fragment length polymorphism analysis has shown frequent allelic loss on chromosomes 4q and 16q. To better define the commonly affected region for further positional cloning of the putative tumor-suppressor genes contained in these two chromosome arms, microsatellite polymorphism analysis was conducted to analyze extensively the allelic loss on both chromosome loci. Methods: DNA from 42 pairs of large hepatocellular carcinoma (>5 cm) and corresponding nonneoplastic liver tissues were prepared. Allelic loss on chromosome 4q and 16q was investigated by 13 or 12 sets of microsatellite polymorphic markers. Results: The frequency of allelic loss on chromosome 16q was 70%, and the common region was mapped to 16q22-23. An even higher frequency (77% ) was found on chromosome 4q with the common region mapped to 4ql2-23. The allelic loss of chromosome 4 q was significantly associated with hepatocellular carcinoma of elevated serum α-fetoprotein but not with those of normal level (91% vs. 30%; Fisher's Exact Test, two-tailed P = 1.12 x 10-4). Conclusions: The results form the basis for further positional cloning of putative tumor- suppressor genes on chromosome 4q and 16q. Moreover, the one on chromosome 4q might shed light on the mechanism of α- fetoprotein expression in hepatocellular carcinoma

    Viral Hepatocarcinogenesis: From Infection to Cancer

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    Hepatocellular carcinoma (HCC) is a worldwide health issue that has started receiving attention but is still poorly understood. However, the hepatitis B virus (HBV) and the hepatitis C virus (HCV) are known to be two major causative agents of HCC. They differ in their modes of infection , their treatment options, their genomes and their carcinogenic abilities. However, both share a link with HCC through alterations of the host genome. In order to continue in our search for the mechanisms behind viral hepatocarcinogenesis, the individual entities (HBV, HCV, HCC and host), their natural history, treatment options and genomic properties must be further understood. Additionally, an understanding of the genomics, the link between the entities, is crucial for the success of the ongoing search for therapeutic options for HCC. Similar to most types of cancer, hepatocarcinogenesis is a multistep process involving different genetic alterations that ultimately lead to malignant transformation of the hepatocyte. As technology advances and research continues, the genetic changes and influences among these entities will prove essential to improved diagnostic and therapeutic options. It remains a challenge to provide a clear picture of the connection between virus and cancer. We review (i) the epidemiological link between HBV/HCV infection to HCC; (ii) prevention and control of chronic hepatitis B or C in reducing HCC risk; and (iii) genetic characters of viruses and hosts and the mechanisms associated with HCC susceptibilities, with the intention of providing a direction for future research and treatment
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