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Jin PR, Ta YNN, Chen IT, Yu YN, Hsieh HT, Nguyen VAT, Hsieh SY, Hsia T, Liu H, Hsu CW, Han JL, Chen Y. Cinchona Alkaloid-Inspired Urea-Containing Autophagy Inhibitor Shows Single-Agent Anticancer Efficacy. J Med Chem 2021; 64:14513-14525. [PMID: 34558909 DOI: 10.1021/acs.jmedchem.1c01036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Autophagy is upregulated in response to metabolic stress, a hypoxic tumor microenvironment, and therapeutic stress in various cancers and mediates tumor progression and resistance to cancer therapy. Herein, we identified a cinchona alkaloid derivative containing urea (C1), which exhibited potential cytotoxicity and inhibited autophagy in hepatocellular carcinoma (HCC) cells. We showed that C1 not only induced apoptosis but also blocked autophagy in HCC cells, as indicated by the increased expression of LC3-II and p62, inhibition of autophagosome-lysosome fusion, and suppression of the Akt/mTOR/S6k pathway in the HCC cells. Finally, to improve its solubility and efficacy, we encapsulated C1 into PEGylated lipid-poly(lactic-co-glycolic acid) (PLGA) nanoscale drug carriers. Systemic administration of nanoscale C1 significantly suppressed primary tumor growth and prevented distant metastasis while maintaining a desirable safety profile. Our findings demonstrate that C1 combines autophagy modulation and apoptosis induction in a single molecule, making it a promising therapeutic option for HCC.
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Affiliation(s)
- Pei-Ru Jin
- Institute of Biomedical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yen-Nhi Ngoc Ta
- Institute of Biomedical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - I-Ting Chen
- Department of Chemistry, National Chung Hsing University, 145 Xingda Rd., South District, Taichung City 40227, Taiwan
| | - Yan-Ning Yu
- Institute of Biomedical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Hsin Tzu Hsieh
- Institute of Biomedical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Van-Anh Thi Nguyen
- Institute of Biomedical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Shang-Ying Hsieh
- Institute of Biomedical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Tiffaney Hsia
- Institute of Biomedical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan.,Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
| | - Hao Liu
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, United States
| | - Chan-Wei Hsu
- Department of Chemistry, Chung Yuan Christian University, Taoyuan City 320314, Taiwan
| | - Jeng-Liang Han
- Department of Chemistry, National Chung Hsing University, 145 Xingda Rd., South District, Taichung City 40227, Taiwan.,Department of Chemistry, Chung Yuan Christian University, Taoyuan City 320314, Taiwan
| | - Yunching Chen
- Institute of Biomedical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
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Abstract
The gene of caspase-activated DNase (CAD), the key enzyme for nucleosome cleavage during apoptosis, is mapped at chromosome 1p36, a region usually associated with hemizygous deletions in human cancers, particularly in hepatoma (HCC). It is tempting to speculate that CAD plays a tumour-suppressive role in hepatocarcinogenesis. To address this, we examined the CAD transcripts in six human HCC cell lines, one liver tissue from a non-HCC subject, and peripheral blood leukocytes (PBL) from three healthy individuals. Alternatively spliced CAD transcripts with fusion of exon 1 to exon 7 were isolated in most of the examined samples including HCC cells and normal controls. However, relatively abundant alternatively spliced CAD transcripts with fusion of exon 2 to exon 6 or 7, in which the corresponding domain directing CAD interaction with ICAD was preserved, were found only in poorly differentiated Mahlavu and SK-Hep1 cells. Interestingly, an abnormal CAD transcript with its exon 3 replaced by a truncated transposable Alu repeat was isolated in Hep3B cells, indicative of the implication of an Alu-mediated genomic mutation. Moreover, mis-sense mutations in the CAD genes were identified in all six HCC cell lines. Upon UV-induced apoptosis, DNA fragmentation efficiency was found to be intact, partially reduced and remarkably reduced in Huh7 and J328, Hep3B and HepG2, and Mahlavu cells, respectively. That mutations and aberrantly spliced transcripts for the CAD gene are frequently present in human HCC cells, especially in poorly differentiated HCC cells, suggests a significant role of CAD in human hepatocarcinogenesis.
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Affiliation(s)
- S Y Hsieh
- Liver Research Unit, Chang Gung Memorial Hospital, Taipei, Taiwan.
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Lin CH, Hsieh SY, Sheen IS, Lee WC, Chen TC, Shyu WC, Liaw YF. Genome-wide hypomethylation in hepatocellular carcinogenesis. Cancer Res 2001; 61:4238-43. [PMID: 11358850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Aberrant genome-wide hypomethylation has been thought to be related to tumorigenesis. However, its mechanism and implications in hepatocellular carcinogenesis remain to be elucidated. Samples of hepatoma (hepatocellular carcinoma, HCC) and paired non-HCC liver tissues were obtained from 17 HCC patients. Normal liver tissues obtained from three individuals were used as controls. Compared with the paired non-HCC liver tissues, genome-wide 5-methylcytosine content in HCC was reduced in all of the tested HCC samples (P < 0.001). Conversely, genome-wide 5-methylcytosine content did not significantly differ among normal, noncirrhotic, and cirrhotic liver tissues. Moreover, the degree of reduced DNA methylation was related to late histopathological HCC grade (P = 0.005) and large tumor size (P = 0.079). Compared with the paired non-HCC liver tissues, expression of DNA methyltransferases DNMT-1, DNMT-3A, and DNMT-3B and the DNA methyltransferase-like gene, DNMT-2, was up-regulated in 53, 41, 59, and 47% of the HCC samples, respectively. Surprisingly, small amounts of LINE-1 retrotransposon transcripts were detected in HCC and non-HCC as well as normal liver tissues, and the expression levels were not significantly different in HCC compared with the paired non-HCC or normal liver tissues. Of interest, the 3' ends of these LINE-1 transcripts were truncated. Our findings suggest that genome-wide hypomethylation in HCC is a continuing process that persists throughout the lifetime of the tumor cells rather than a historical event occurring in precancer stages or in cell origins for HCC. Up-regulation of DNA methyltransferases might simply be a result of increased cell proliferation in cancer. In addition, our results did not support the hypothesis of activation of transposable elements in HCC via genome-wide hypomethylation.
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Affiliation(s)
- C H Lin
- Liver Research Unit, Chang Gung Memorial Hospital, 199 Tung-Hua North Road, Taipei, Taiwan 155
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4
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Abstract
OBJECTIVES Mutations in the promoter as well as in the coding region of the bilirubin UDP-glucuronosyltransferase gene (UGT1A1) have been found to be associated with Gilbert's syndrome. However, the genetic basis of Gilbert's syndrome in our population and correlation of these mutations to fasting serum bilirubin levels in patients with Gilbert's syndrome remain to be clarified. METHODS We applied polymerase chain reaction-based direct-sequencing assays to examine mutations in UGT1A1 gene in 20 unrelated Gilbert's patients and in a family with Gilbert's syndrome. RESULTS We studied three mutations that were previously reported to be associated with Gilbert's syndrome (i.e., the TATAA-box mutation, Gly71Arg, and Pro229Gln) in 20 patients with Gilbert's syndrome. Of the patients, 16, five, and six were found to have the TATAA-box, Gly71Arg and Pro229Gln mutations, respectively. Seven patients had simultaneous mutations both in the TATAA box and in the coding region. Of note, all six patients with Pro229Gln also had the TATAA-box mutation. Localization of Pro229Gln on the allele containing the TATAA-box mutation was demonstrated in a family with Gilbert's syndrome. The patients simultaneously heterozygous for both the TATAA-box mutation and Gly71Arg usually had serum bilirubin levels similar to those found in the patients homozygous for the TATAA-box mutation, but usually higher than those found in the patients heterozygous for the TATAA-box mutation alone. On the other hand, concurrence of Pro229Gln in patients with TATAA-box mutation or with Gly71Arg did not significantly affect serum bilirubin levels. CONCLUSIONS The TATAA-box mutation and Gly71Arg are the major causes for Gilbert's syndrome in our population. Concurrence of mutations of Gly71Arg and TATAA-box usually exerts a synergistic effect on hyperbilirubinemia. Pro229Gln, which is regularly linked to the TATAA-box mutation, may not have a significant effect on serum bilirubin levels.
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Affiliation(s)
- S Y Hsieh
- Liver Research Unit, Chang Gung Memorial Hospital, and School of Medicine Chang Gung University, Taoyuan, Taiwan
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Yeh CT, Sheen IS, Chen TC, Hsieh SY, Chu CM, Liaw YF. Olone modulates the therapeutic effect of interferon to eliminate preferentially the hepatitis B virus precore stop mutant. J Hepatol 2000; 32:829-36. [PMID: 10845671 DOI: 10.1016/s0168-8278(00)80253-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND/AIMS The aim of this study was to understand the changes in the proportion of hepatitis B virus precore stop mutant during the course of prednisolone primed interferon (IFN) therapy. METHODS Three groups of patients were included: patients receiving prednisolone-primed IFN treatment (Group I, n=31), IFN treatment only (Group II, n=29), and placebo (Group III, n=25). The proportion of precore stop mutant was measured by a quantitative amplification-created restriction site method. RESULTS Distinct patterns of the progression of the proportion of mutant were found among these three groups. A steady increase in the proportion of mutant was observed only in Group III patients. In Group II patients, the presence of a higher percentage of mutant (> 25%) immediately before IFN treatment was predictive for the subsequent clearance of hepatitis B e antigen (HBeAg) (p<0.01), but not for complete anti-viral response (p>0.05). Prednisolone pretreatment resulted in an increase in the proportion of mutant in patients with initially low percentages (< or = 25%) of mutant. During the period of IFN treatment, both the relative and absolute amount of the precore stop mutant decreased significantly in Group I patients who cleared HBeAg. The presence of such a decrease in this group of patients was predictive for both HBeAg clearance and complete anti-viral response. CONCLUSIONS Our data suggest that prednisolone serves as a modulator to enhance elimination of precore stop mutant by IFN, which advocates the benefit of corticosteroid pretreatment in an area where the precore mutants are prevalent.
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Affiliation(s)
- C T Yeh
- Liver Research Unit, Chang Gung Memorial Hospital and Chang Gung University School of Medicine, Taipei, Taiwan
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Abstract
Clostridium septicum is an anaerobic, gram-positive bacillus. Infection with this organism has a known association with malignant diseases, especially colon and haematological cancers. Clostridium septicum is rarely found to be a pathogen of liver abscess. Herein, we report the case of a female choriocarcinoma patient with liver metastasis in which C. septicum infection presented as a gas-forming liver abscess. This case and previous reports indicate that once C. septicum is identified as a pathogen in liver abscess, metastatic liver tumours should be highly suspected.
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Affiliation(s)
- C H Lee
- Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital and Chang Gang University, Taipei, Taiwan
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7
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Hsieh SY, Meng XJ, Wu YH, Liu ST, Tam AW, Lin DY, Liaw YF. Identity of a novel swine hepatitis E virus in Taiwan forming a monophyletic group with Taiwan isolates of human hepatitis E virus. J Clin Microbiol 1999; 37:3828-34. [PMID: 10565892 PMCID: PMC85823 DOI: 10.1128/jcm.37.12.3828-3834.1999] [Citation(s) in RCA: 196] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recently, we found that more than 10% of the cases of acute non-A, non-B, non-C hepatitis in Taiwan were caused by a novel strain of hepatitis E virus (HEV). Since none of these patients had a history of travel to areas where HEV is endemic, the source of transmission remains unclear. The recent discovery of a swine HEV in herd pigs in the United States has led us to speculate that HEV may also circulate in herd pigs in Taiwan and may serve as a reservoir for HEV in Taiwan. Of 275 herd pigs obtained from 10 pig farms in Taiwan, 102 (37%) were seropositive for serum anti-HEV immunoglobulin G (IgG). A 185-bp genomic sequence within the ORF-2 of the HEV genome was amplified and cloned from serum samples of an anti-HEV positive pig and subsequently from serum samples of a patient with acute hepatitis E. Sequence comparison revealed that the swine and human isolates of HEV share 97.3% identity. Phylogenetic analyses further showed that the Taiwan swine and human isolates of HEV form a distinct branch divergent from all other known strains of HEV, including the U.S. swine strain. To examine the potential risk of cross-species transmission of swine HEV to humans, the seroprevalences of anti-HEV IgG in 30 swine handlers, 20 pork dealers, and 50 control subjects were assessed and were found to be 26.7, 15, and 8%, respectively (for swine handlers versus controls, P = 0.048). Our findings may help provide an understanding of the modes of HEV transmission and may also raise potential public health concerns for HEV zoonosis.
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Affiliation(s)
- S Y Hsieh
- Liver Research Unit, Chang Gung Memorial Hospital, School of Medicine, Chang Gung University, Taoyuan, Taiwan.
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8
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Hsieh SY, Wu YH, Ho YP, Tsao KC, Yeh CT, Liaw YF. High prevalence of TT virus infection in healthy children and adults and in patients with liver disease in Taiwan. J Clin Microbiol 1999; 37:1829-31. [PMID: 10325332 PMCID: PMC84962 DOI: 10.1128/jcm.37.6.1829-1831.1999] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A newly identified DNA virus, named TT virus (TTV), was found to be related to transfusion-associated hepatitis. We conducted the following experiments to evaluate its pathogenic role in liver disease and potential modes of transmission. We used PCR to detect TTV DNA in serum. The rates of TTV viremia in 13 patients with idiopathic acute hepatitis, 14 patients with idiopathic fulminant hepatitis, 22 patients with chronic hepatitis, and 19 patients with cirrhosis of the liver were 46, 64, 55, and 63%, respectively, and were not significantly different from those in 50 healthy control subjects (53%). PCR products derived from seven patients with liver disease and three healthy controls were cloned and then subjected to phylogenetic analyses, which failed to link a virulent strain of TTV to severe liver disease. TTV infection was further assessed in an additional 148 subjects with normal liver biochemical tests, including 30 newborns (sera collected from the umbilical cord), 23 infants, 16 preschool children, 21 individuals of an age prior to that of sexual experience (aged 6 to 15 years), 15 young adults (aged under 30 years), and 43 individuals older than 30 years. The rates of TTV viremia were 0, 17, 25, 33, 47, and 54%, respectively. These findings suggest that TTV is transmitted mainly via nonparenteral daily contact and frequently occurs very early in life and that TTV infection does not have a significant effect on liver disease.
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Affiliation(s)
- S Y Hsieh
- Liver Research Unit, Chang Gung Memorial Hospital, Taipei, Republic of Taiwan.
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9
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Chu CM, Lin SM, Hsieh SY, Yeh CT, Lin DY, Sheen IS, Liaw YF. Etiology of sporadic acute viral hepatitis in Taiwan: the role of hepatitis C virus, hepatitis E virus and GB virus-C/hepatitis G virus in an endemic area of hepatitis A and B. J Med Virol 1999; 58:154-9. [PMID: 10335863 DOI: 10.1002/(sici)1096-9071(199906)58:2<154::aid-jmv9>3.0.co;2-e] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The etiology of sporadic acute hepatitis was studied in 334 consecutive patients from Taiwan (237 men and 97 women, aged 16-81 years), with emphasis on the role of hepatitis C virus (HCV), hepatitis E virus (HEV), and GB virus-C/hepatitis G virus (GBV-C/HGV) in acute non-A, non-B (NANB) hepatitis and in HBsAg carriers with superimposed acute hepatitis. According to the conventional diagnostic criteria, there were 12 cases (3.6%) of acute hepatitis A, 17 cases (5.1%) of acute hepatitis B, 128 cases (38.3%) of acute NANB hepatitis, and 177 cases (53.0%) of acute hepatitis in HBsAg carriers (those who were HBsAg positive but IgM anti-HBc negative). Among 128 cases of acute NANB hepatitis, 70 (54.7%) had acute hepatitis C (HCV RNA positive), 5 (3.9%) had acute hepatitis E (IgM anti-HEV positive), and the other 53 (41.4%) were presumably acute hepatitis non-A-E. The prevalence of acute hepatitis A, B, E, and non-A-E showed no significant sex difference, whereas acute hepatitis C was significantly more prevalent in females. The prevalence of acute hepatitis A and B decreased and that of acute hepatitis C increased significantly with increasing age. In contrast, acute hepatitis E and non-A-E showed no significant age predominance. Of 177 HBsAg carriers with acute hepatitis, 64 (36.1%) demonstrated non-B hepatotropic virus superinfection, with HCV being the most common (60.9%), followed by hepatitis D, E, and A viruses, and the other 55 (31.1%) and 58 (32.8%) were presumed to have acute exacerbation of chronic hepatitis B or superimposed acute hepatitis non-A-E, respectively. Serum GBV-C/HGV RNA was detected in 3-4% of acute hepatitis non-A-E cases, suggesting its limited role in these cases.
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Affiliation(s)
- C M Chu
- Liver Research Unit, Chang Gung Memorial Hospital, Chang Gung University, Taipei, Taiwan.
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Tsai MH, Chien RN, Hsieh SY, Hung CF, Chen TC, Sheen IS. Primary hepatic angiosarcoma: report of a case involving environmental arsenic exposure. Changgeng Yi Xue Za Zhi 1998; 21:469-74. [PMID: 10074736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Hepatic angiosarcoma is a rare malignant tumor with a rapidly fatal course. It has become a subject of interest because of its intimate relationship with environmental carcinogens, such as thorium dioxide (Thorotrast), vinyl chloride monomer, and arsenic. We describe a case of a chronic hepatitis B surface antigen carrier, with a 20-year history of environmental exposure to arsenical-containing agricultural herbicides and bactericides, who developed a hepatic angiosarcoma. He died due to rupture of the hepatic angiosarcoma with acute hemoperitoneum 9 weeks after initial diagnosis. This is a rare case of primary hepatic sarcoma, especially in Taiwan where hepatocellular carcinoma is endemic. This case not only serves to give more evidence of the relationship between hepatic angiosarcoma and arsenical exposure, but also demonstrates the key point in the differential diagnosis of liver tumors. Increased familiarity with this disease will facilitate correct diagnosis and help to improve management of the condition in the future.
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Affiliation(s)
- M H Tsai
- Department of Radiology, Chang Gung Memorial Hospital, Taipei, Taiwan, R.O.C
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11
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Tang JH, Yeh CT, Chen TC, Hsieh SY, Chu CM, Liaw YF. Emergence of an S gene mutant during thymosin alpha1 therapy in a patient with chronic hepatitis B. J Infect Dis 1998; 178:866-9. [PMID: 9728561 DOI: 10.1086/515345] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The presence of a hepatitis B virus S gene mutant was investigated in a patient being treated with thymosin alpha1. He was seropositive for hepatitis B e antigen throughout therapy but was intermittently seronegative for hepatitis B surface antigen (HBsAg) by an RIA. Sequence analysis revealed an S gene mutant in HBsAg-seronegative serum with two consecutive amino acid substitutions: threonine115-to-isoleucine and threonine116-to-asparagine, whereas no amino acid substitution or deletion was found in the pre-S region. A site-directed mutagenesis experiment confirmed that these mutations were responsible for the failure to detect HBsAg. In summary, an S gene mutant was identified in an HBsAg-seronegative patient. The mutations were located outside the putative "a" determinant. The emergence of an S gene mutant during thymosin alpha1 treatment suggests that enhanced host immunity against HBsAg may play a role in its antiviral activity.
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Affiliation(s)
- J H Tang
- Department of Pathology, Chang Gung Memorial Hospital and University, Taipei, Taiwan
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12
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Abstract
Hepatitis caused by the hepatitis E virus (HEV) is a self-limited disease and occurs most frequently as epidemic or sporadic hepatitis in developing countries. The role of HEV in sporadic acute hepatitis in areas without a history of hepatitis E epidemics is obscure. Recently, it was found that more than 10% of the patients with acute non-A, non-B, non-C hepatitis in Taiwan were associated with an acute HEV infection. Nucleotide sequences of the regions within the first open reading frame of HEV were determined in four cases and were 96.7-100% identical to each other. As compared to the isolates from China, Pakistan, Burma, India, Africa, and Mexico, the similarities were, however, only 71.7-79.3%. Phylogenetic analysis revealed that the four Taiwan isolates were categorized as a novel HEV group (the Taiwan strain), which was distinct from all of the strains isolated from other parts of the world. In addition, the isolates from China, Burma, India, and Pakistan were catalogued as the second genotype of HEV (the Asian strain), and the Mexican isolate as the third (the Mexican strain). The African isolate was more related to the Asian type and might be a subtype of the Asian strain. A simple genotyping method by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) is described. The findings also support the hypothesis that HEV may be responsible for some sporadic acute non-A, non-B, non-C hepatitis in other developed countries.
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Affiliation(s)
- S Y Hsieh
- Liver Research Unit, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan
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Abstract
Purified colicin E7 was analyzed by CD spectrum and gel filtration chromatography in a mimicking membrane-translocation phase. It was found that the CD spectra of colicin E7 at pH 7 and pH 2.5 were similar. Although the melting temperature of the protein shifted from 54.5 degrees C to 34 degrees C at low pH, the thermal denaturation curves of colicin E7 at different pH conditions still fit a two-state model. These experimental results imply that a minor structural change, triggered by acidic pH, for instance, may reduce the energy required for protein melting. In contrast to the minor change in secondary structure at different pH conditions, we observed that, in vitro, all monomeric colicin E7s converted into multimer-like conformations after recovering from the partial unfolding process. This multimeric form of colicin can only be dissociated by formamide and guanidine hydrochloride, indicating that this protein complex is indeed formed by aggregation of the monomeric colicins. Most interestingly, the aggregated colicins still perform in vivo bacteriocidal activity. We suggest that in a partial unfolding state the colicin is prepared for binding to the specific targets for translocation through the membrane. However, in the absence of specific targets in vitro these unfold intermediates may therefore aggregate into the multimeric form of colicins.
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Affiliation(s)
- K F Chak
- Institute of Biochemistry, National Yang Ming University, Taipei, Taiwan, ROC.
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14
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Liaw YF, Tsai SL, Sheen IS, Chao M, Yeh CT, Hsieh SY, Chu CM. Clinical and virological course of chronic hepatitis B virus infection with hepatitis C and D virus markers. Am J Gastroenterol 1998; 93:354-9. [PMID: 9517639 DOI: 10.1111/j.1572-0241.1998.00354.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Hepatitis B, C, and delta virus (HBV, HCV, HDV) share similar transmission routes; thus, dual or triple infections may occur and even persist in the same patient. However, little is known about the presentations and course of chronic HBV infection with HCV and HDV markers, which this study examined. METHODS Antibodies against HCV (anti-HCV) and HDV (anti-HDV) were assayed as appropriate in patients with HBV infection. The clinical, pathological, and virological presentations as well as the course of the disease in patients with HBV/HDV/HCV triple infection markers were then reviewed. RESULTS A total of 60 patients, 51 men and nine women, age 19-67 yr (mean 45.9+/-1.6 yr) were identified. Of these 60 patients, five (8.3%) were HBeAg positive and 10 (16.7%) cirrhotic at entry, 30 (50%) presented with acute superinfection (HCV or HDV, or both) and the remaining 30 presented with chronic liver disease. On presentation, 16 (53.3%) of the 30 patients with acute superinfection showed hepatic decompensation and eight (26.7%) died. In contrast, only one of the patients with "chronic liver disease" presented with hepatic decompensation. Of the 42 patients followed up for 1-15 (mean, 4.7+/-0.6) yr, 45.2% showed remission and 19% showed HBsAg seroclearance, whereas 12.5% of the 32 noncirrhotics developed cirrhosis and three of the nine cirrhotics became decompensated. At the end of follow-up, 29 patients (69.9%) were still seropositive for HCV-RNA but only nine (22.5%) were seropositive for HDV-RNA and five (12.5%) were seropositive for HBV-DNA. CONCLUSIONS These results suggest that infection with HBV, HCV, and HDV triple markers is a severe disease in acute superinfection stage but that the course is relatively benign, slowly progressive, and usually dominated by HCV.
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Affiliation(s)
- Y F Liaw
- Liver Research Unit, Chang Gung Memorial Hospital and University, Taipei, Taiwan
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15
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Liu CM, Chen YK, Yang TH, Hsieh SY, Hung MH, Lin ET. High-performance liquid chromatographic determination of clindamycin in human plasma or serum: application to the bioequivalency study of clindamycin phosphate injections. J Chromatogr B Biomed Sci Appl 1997; 696:298-302. [PMID: 9323551 DOI: 10.1016/s0378-4347(97)00241-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This paper presents an assay of clindamycin phosphate injection in human plasma or serum. A 0.5-ml volume of plasma was used with the internal standard, propranolol. The sample was loaded onto a silica extraction column. The column was washed with deionized water and then eluted with methanol. The eluates were evaporated under nitrogen gas. The residue was reconstituted with the mobile phase and injected onto the high-performance liquid chromatographic system: a 5-micron, 25 cm X 4.6 mm I.D. ODS2 column was used with acetonitrile, tetrahydrofuran and 0.05 M phosphate buffer as the mobile phase and with ultraviolet detection at 204 nm. A limit of quantitation of 0.05 microgram/ml was found, with a coefficient of variation of 11.6% (n = 6). The linear range is between 0.05 and 20.00 micrograms/ml and gives a coefficient of determination (r2) or 0.9992. The method has been successfully applied to the bioavailability study of two commercial preparations of clindamycin phosphate injection (300 mg each) in twelve healthy adult male volunteers.
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Affiliation(s)
- C M Liu
- Department of Pharmaceutical Technology, Mithra Bioindustry Co., Ltd., Taipei, Taiwan
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16
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Hsieh SY, Yang PY, Chen HC, Liaw YF. Cloning and characterization of the extreme 5'-terminal sequences of the RNA genomes of GB virus C/hepatitis G virus. Proc Natl Acad Sci U S A 1997; 94:3206-10. [PMID: 9096371 PMCID: PMC20347 DOI: 10.1073/pnas.94.7.3206] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The extreme 5'-terminal sequences of the GB virus C/hepatitis G virus (GBV-C/HGV), containing elements essential for regulation of viral gene expression and replication, have not been determined. By using a RNA-ligase-mediated RACE (rapid amplification of the cDNA ends) procedure, we have cloned the extreme 5'-terminal sequences of the viral genome from the serum of three Taiwanese patients. Sequence analysis of the 5' noncoding region in alignment with one West African and two American isolates showed that (i) a consensus 5'-end sequence was cloned; (ii) about 97% of sequences were homologous among the three Taiwan isolates and also between the two American isolates, whereas about 90% of sequences were homologous among the isolates from the three different geographic areas; (iii) the sequence heterogeneity related to geographic separation is confined mainly to three domains; and (iv) a potential hairpin structure, resembling the hairpin structure found in the 5' end of hepatitis C virus genome, was detected in the 5' end of the noncoding region. Our data support the hypotheses that (i) the extreme 5' end of the hepatitis GBV-C/HGV viral genome has been cloned, (ii) there are different genotypes correlated with geographic separation, and (iii) the viral translation and replication mechanisms may be similar to that of hepatitis C virus and pestiviruses. Our data have not only shed light on the viral replication mechanism but also offer information for selection of optimal primer sequences for the detection and genotyping of the hepatitis GBV-C/HGV virus by PCR assays.
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Affiliation(s)
- S Y Hsieh
- Department of Microbiology and Immunology, Chang Gung College of Medicine and Technology, Taipei, Taiwan
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17
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Hsieh SY, Ko TP, Tseng MY, Ku W, Chak KF, Yuan HS. A novel role of ImmE7 in the autoregulatory expression of the ColE7 operon and identification of possible RNase active sites in the crystal structure of dimeric ImmE7. EMBO J 1997; 16:1444-54. [PMID: 9135159 PMCID: PMC1169741 DOI: 10.1093/emboj/16.6.1444] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Site-specific cleavage of mRNA has been identified in vivo for the polycistronic colicin E7 operon (ColE7), which occurs between G and A nucleotides located at the Asp52 codon (GAT) of the immunity gene (ceiE7). In vitro, this specific cleavage occurs only in the presence of the ceiE7 gene product (ImmE7). The crystal structure of dimeric ImmE7 has been determined at 1.8 A resolution by X-ray crystallographic analysis. We found that several residues located at the interface of dimeric ImmE7 bear surprising resemblance to the active sites of some RNases. These results suggest that dimeric ImmE7 may possess a novel RNase activity that cleaves its own mRNA at a specific site and thus autoregulates translational expression of the downstream celE7 gene as well as degradation of the upstream ceaE7 mRNA.
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MESH Headings
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Base Sequence
- Binding Sites/genetics
- Colicins
- Crystallography, X-Ray
- DNA Primers/genetics
- Dimerization
- Escherichia coli/chemistry
- Escherichia coli/genetics
- Gene Expression Regulation, Bacterial
- Genes, Bacterial
- Models, Molecular
- Molecular Sequence Data
- Molecular Structure
- Nucleic Acid Conformation
- Operon
- Protein Conformation
- Protein Folding
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Ribonucleases/metabolism
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Affiliation(s)
- S Y Hsieh
- Institute of Biochemistry, Center for Cellular and Molecular Biology, National Yang Ming University, Taipei, Taiwan, Republic of China
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18
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Lin DY, Wu CS, Hsieh SY. "String sign" of portal vein as precursor of portal thrombosis: color Doppler ultrasonographic study of one case. J Clin Ultrasound 1997; 25:77-81. [PMID: 9023695 DOI: 10.1002/(sici)1097-0096(199702)25:2<77::aid-jcu5>3.0.co;2-g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- D Y Lin
- Department of Gastroenterology, Chang Gung Memorial Hospital, Taipei, Taiwan, R.O.C
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19
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Chak KF, Safo MK, Ku WY, Hsieh SY, Yuan HS. The crystal structure of the immunity protein of colicin E7 suggests a possible colicin-interacting surface. Proc Natl Acad Sci U S A 1996; 93:6437-42. [PMID: 8692833 PMCID: PMC39041 DOI: 10.1073/pnas.93.13.6437] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The immunity protein of colicin E7 (ImmE7) can bind specifically to the DNase-type colicin E7 and inhibit its bactericidal activity. Here we report the 1.8-angstrom crystal structure of the ImmE7 protein. This is the first x-ray structure determined in the superfamily of colicin immunity proteins. The ImmE7 protein consists of four antiparallel alpha-helices, folded in a topology similar to the architecture of a four-helix bundle structure. A region rich in acidic residues is identified. This negatively charged area has the greatest variability within the family of DNase-type immunity proteins; thus, it seems likely that this area is involved in specific binding to colicin. Based on structural, genetic, and kinetic data, we suggest that all the DNase-type immunity proteins, as well as colicins, share a "homologous-structural framework" and that specific interaction between a colicin and its cognate immunity protein relies upon how well these two proteins' charged residues match on the interaction surface, thus leading to specific immunity of the colicin.
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Affiliation(s)
- K F Chak
- Institute of Biochemistry, National Yang-Ming University, Taipei, Taiwan, Republic of China
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20
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Abstract
To evaluate the potential implication of in vivo interferon production in the pathogenesis of different forms of acute and chronic hepatitis B virus infection, serum levels of interferon-alpha and -gamma were measured using immunoassay techniques in 20 patients with acute hepatitis B who subsequently cleared the virus (group Ia), 8 patients with acute hepatitis B who became HBsAg carriers (group Ib), 55 patients with chronic hepatitis B (group II), and 15 healthy controls. None of the controls had interferon-alpha or -gamma detectable in serum, while 15% and 100% of group Ia patients, 25% and 100% of group Ib patients, and 22% and 15% of group II patients, had raised serum levels of interferon-alpha and -gamma, respectively. Serum interferon-gamma was detected significantly more frequently in group Ia and Ib patients than in controls and in group II patients. Among patients with acute hepatitis B, serum levels of interferon-alpha and -gamma showed no significant difference between group Ia and group Ib patients. Among patients with chronic hepatitis B, interferon-alpha was detected significantly more frequently in patients with serum HBV-DNA (31.4% or 11/35) than in those without (5% or 1/20), whereas interferon-gamma was detected significantly more frequently in patients with chronic active hepatitis (28% or 7/25) than in those with chronic persistent hepatitis (3.3% or 1/30). In conclusion, in acute hepatitis B, serum levels of interferon-alpha and -gamma did not show a significant difference between patients who subsequently cleared the virus and those who became HBsAg carriers.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C M Chu
- Liver Research Unit, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan
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21
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Abstract
To elucidate the clinical entity of pseudomyxoma peritonei, nine patients (male: female = 6:3) who had been treated in Chang Gung Memorial Hospital in the past 13 years were reviewed. The male patients with original appendiceal tumour were older than the male patients with original colon cancer or indefinite tumour (70, 67 and 67 years vs 42, 27 and 50 years). In addition, the former group survived in a disease-free status for 28 months on average, while the latter group died within 2 years. Echogenic ascites and diffuse low-attenuation intra-abdominal masses with scalloping on the surface of liver detected by ultrasonography and by computerized tomography, respectively, were found in most of the patients. Elevation of the serum carcinoembryonic antigen (CEA) during recurrence of the disease was also noted. This series suggested that: (i) the pre-operative diagnosis could be made with careful physical examination in conjunction with sonography or computerized tomography; (ii) the prognosis was better in patients with tumour of appendiceal origin; and (iii) serum CEA might be valuable for early detection of recurrence.
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Affiliation(s)
- S Y Hsieh
- Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital, Taipei, Taiwan
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22
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Abstract
We have previously demonstrated that the ribozyme located 34 nucleotides downstream of the polyadenylation site on the antigenomic RNA of the hepatitis delta virus can stabilize the downstream transcript after polyadenylation. Here, we have reports on further investigations of the molecular mechanism of this stabilization effect and the potential role of the small and large delta antigens. We found that the downstream transcripts after polyadenylation were stabilized by the ribozyme independently of either the small or large delta antigen. The stabilization effect was abolished as the ribozyme activity was eliminated by mutations on either the enzyme domain or target site of the ribozyme. These findings suggested that it was the ribozyme activity rather than the RNA structure or the delta antigens that contributed to the stabilization effect.
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Affiliation(s)
- S Y Hsieh
- Liver Unit, Chang Gung Memorial Hospital, Taipei, Taiwan
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23
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Abstract
Two transcriptional start sites were identified 77 and 78 nucleotides upstream of the translation initiation codon of the colicin E7 gene (ceaE7). The guanosine nucleotide located at the fifth position of the SOS box is probably a universal transcriptional start site of all E group colicins. Major and minor transcripts of the immunity gene (cei) are initiated at the 3' end of the cea gene. Relative to the -10 sequence, CAAAAT, of the major ceiE7 promoter, the corresponding region of the cei gene of other E group colicins has an increased content of guanosine nucleotides. However the -10 sequence of the minor ceiE7 promoter, TATGAT, was found to be conserved in other colicin promoters. The results indicate that the structure of the major promoter of the ceiE7 gene is unique among the E group colicins.
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Affiliation(s)
- B W Soong
- Institute of Clinical Medicine, National Yang Ming Medical College, Shi-Pai, Taipei, Taiwan, Republic of China
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24
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Hsieh SY, Yang PY, Ou JT, Chu CM, Liaw YF. Polyadenylation of the mRNA of hepatitis delta virus is dependent on the structure of the nascent RNA and regulated by the small or large delta antigen. Nucleic Acids Res 1994; 22:391-6. [PMID: 8127676 PMCID: PMC523594 DOI: 10.1093/nar/22.3.391] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
During the hepatitis delta virus (HDV) RNA replication, synthesis of either the mRNA for the delta antigen (HDAg) or the full-length antigenomic RNA is determined by selective usage of the potent poly(A) signal on the antigenome. To elucidate the regulatory mechanism, HDV cDNA cotransfection system was used to examine the potential effect of the secondary structure of the nascent RNA and that of the HDAg on HDV polyadenylation in transfected cells. We found that when the nascent RNA species could fold itself to form the rodlike structure, the HDV polyadenylation was suppressed 3 to 5 fold by the HDAg. In addition, we observed that the small and the large HDAg exerted a similar suppressive effect on the HDV polyadenylation, though they played different roles in HDV replication. We concluded that the HDV polyadenylation could be regulated by the structure of the nascent antigenomic RNA and by either the small or large HDAg.
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Affiliation(s)
- S Y Hsieh
- Department of Microbiology and Immunology, Chang Gung College of Medicine and Technology, Taipei, Taiwan
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25
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Hsieh SY, Taylor J. Delta virus as a vector for the delivery of biologically-active RNAs: possibly a ribozyme specific for chronic hepatitis B virus infection. Adv Exp Med Biol 1992; 312:125-8. [PMID: 1514438 DOI: 10.1007/978-1-4615-3462-4_12] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- S Y Hsieh
- Fox Chase Cancer Center, Philadelphia, PA 19111
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26
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Abstract
Hepatitis delta virus (HDV) is a subviral agent with a small RNA genome that is replicated in the nucleus of an infected cell. During genome replication, there is the synthesis of a complementary RNA, known as the antigenome, and also of a smaller complementary species that is polyadenylated and acts in the cytoplasm as the mRNA for the only known HDV protein, the delta antigen. We have carried out an examination of the cis- and trans-acting elements that regulate the polyadenylation process involved in the synthesis of this mRNA for the delta antigen. Our experimental approach has been to study the processing of nascent antigenomic RNA as it occurs in transfected cells via DNA-directed RNA synthesis, in the absence of genome replication. Three conclusions have been made. (i) The polyadenylation process occurs independent of the functionality of a unique self-cleavage domain located just 3' of the polyadenylation site. (ii) RNA transcripts that proceed beyond the polyadenylation site can be stabilized by the self-cleavage reaction. Thus, a single transcription initiation event can lead not only to the mRNA species but also to at least one more stable RNA species. (iii) If the nascent RNA species can fold on itself, into the so-called rodlike structure, then the presence of the delta antigen leads to a major suppression of polyadenylation. These results are incorporated into a more detailed model of the replication of the HDV genome.
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MESH Headings
- Animals
- Base Sequence
- Blotting, Northern
- Cell Line
- Cloning, Molecular
- DNA, Viral/genetics
- Gene Expression Regulation, Viral
- Genes, Viral
- Hepatitis Delta Virus/genetics
- Models, Genetic
- Molecular Sequence Data
- Plasmids
- Poly A/genetics
- RNA/genetics
- RNA, Antisense/genetics
- RNA, Messenger
- RNA, Viral/genetics
- Transcription, Genetic
- Transfection
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Affiliation(s)
- S Y Hsieh
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111
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27
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Abstract
The only known protein of hepatitis delta virus (HDV), the delta antigen, is found both within virus particles and within the nucleus of the infected cell, where it has one or more roles essential for RNA genome replication. Others have demonstrated that the antigen has the ability, in vitro, to specifically bind HDV RNA species. We report a further examination of this phenomenon, using partially purified recombinant protein, expressed as a fusion with the staphylococcal protein A. From Northwestern (RNA-immunoblot) analyses with both complete and various subdomains of HDV genomic and antigenomic RNAs, we found that a necessary feature for specific binding was that the RNA be able to fold to some extent into the so-called rodlike structure; this structure is a predicted intramolecular partial base-pairing of the circular RNA, with about 70% of all bases involved, so as to produce an unbranched rodlike structure. Six different subregions of the HDV rodlike structure, three on the genomic RNA and three on its complement, the antigenomic RNA, were tested and found to be sufficient for antigen binding. However, features in addition to the rodlike structure may also be necessary for specific binding, because we found that a similar structure present in the RNA of the potato spindle tuber viroid did not allow binding.
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Affiliation(s)
- M Chao
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111
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28
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Abstract
The delta antigen is the only known protein encoded by hepatitis delta virus (HDV). The predicted protein is 195 amino acids in length, but for reasons that are not yet clear, there occurs during the replication of the HDV genome, a specific base change in the termination codon of this open reading frame. This leads to the synthesis of a form of the delta antigen that is 19 amino acids longer, with a total length of 214 amino acids. Studies are described which relate to the roles of these two forms of the delta antigen in genome replication and subsequent particle assembly.
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Affiliation(s)
- J Taylor
- Fox Chase Cancer Center, Philadelphia, PA 19111
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29
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Abstract
Hepatitis delta virus (HDV) replicates its genome in the nucleus of an infected cell. However, an unsolved problem has been the identification in the cytoplasm of a putative mRNA for the synthesis of the only virus-coded protein, the delta antigen. We now report the characterization of an 800-base RNA that is cytoplasmic, polyadenylated, and antigenomic and that should direct the translation of the delta antigen. This RNA was about 500 times less abundant than full-length genomic RNA. We mapped the predominant 5' terminus and also the 3' site at which the poly(A) is added. At a point 15 to 20 bases upstream of the poly(A) addition site is the sequence AAUAAA, which could have been used as a signal for the polyadenylation. When an infectious cDNA clone of the whole HDV genome was changed at this site to UUUAAA, the clone was no longer infectious and it was unable to direct the synthesis of the delta antigen. These findings provided additional evidence that the polyadenylated RNA was at least the predominant method for the expression of the delta antigen. Apparently the HDV RNA was processed as if it were a host mRNA polymerase II transcript, although this did not necessarily indicate that HDV RNA was transcribed with this enzyme.
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Affiliation(s)
- S Y Hsieh
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111
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30
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Abstract
Three independent lines of evidence showed that when an infectious clone of hepatitis delta virus of known sequence was used to initiate genome replication, up to 41% of the genomes were specifically mutated in the amber termination codon (UAG to UGG) for the open reading frame of the delta antigen, thereby increasing the length of the predicted protein from 195 to 214 amino acids. This change was detected only on molecules that participated in RNA-directed RNA synthesis.
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Affiliation(s)
- G X Luo
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111
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