Sung Hyun Ahn
Konkuk University
Drug resistanceMolecular biologyVirologyHepatitis BHepatitis B virusMedicineBiology
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Publications 22
#1Soree Park (Konkuk University)H-Index: 8
#2Eun-Sook Park (Konkuk University)H-Index: 11
Last. Jeong-Hoon Lee (SNU: Seoul National University)H-Index: 24
view all 12 authors...
BACKGROUND & AIM: Since polymerase and surface genes overlap in hepatitis B virus (HBV), an antiviral-induced mutation in the polymerase gene may alter the surface antigenicity in patients with chronic hepatitis B (CHB), but this possibility has not been clearly confirmed. This study aimed to determine the drug susceptibility and surface antigenicity of the patient-derived mutants. PATIENTS AND METHODS: Full-length HBV genomes isolated from four entecavir-resistant CHB patients were cloned and s...
1 CitationsSource
#1Eun-Sook Park (Konkuk University)H-Index: 11
#2Ah Ram Lee (Konkuk University)H-Index: 7
Last. Kyun-Hwan Kim (Konkuk University)H-Index: 22
view all 26 authors...
Background & Aims Tenofovir disoproxil fumarate (TDF) is one the most potent nucleot(s)ide analogues for treating chronic hepatitis B virus (HBV) infection. Phenotypic resistance caused by genotypic resistance to TDF has not been reported. This study aimed to characterize HBV mutations that confer tenofovir resistance. Methods Two patients with viral breakthrough during treatment with TDF-containing regimens were prospectively enrolled. The gene encoding HBV reverse transcriptase was sequenced. ...
5 CitationsSource
#1J-Y KimH-Index: 5
Last. Sung Hyun AhnH-Index: 9
view all 17 authors...
Cell-free DNA (cfDNA), as a non-invasive strategy, provides substantial benefit to overcome tumor heterogeneity. Surveillance of recurrence after standard treatment in early breast cancer (BC) using cfDNA, enables to detect minimal residual disease (MRD), also to identify genomic alterations driving recurrences. We aimed to assess the role of cfDNA in detecting MRD by investigating genomic alterations of 1)primary, recurred tumor and 2)cfDNA at time of recurrence using deep targeted sequencing. ...
#1Doo Hyun Kim (Konkuk University)H-Index: 9
#2Eun-Sook Park (Konkuk University)H-Index: 11
Last. Kyun-Hwan Kim (Konkuk University)H-Index: 22
view all 17 authors...
Cytokines are involved in early host defense against pathogen infections. In particular, tumor necrosis factor (TNF) and interferon-gamma (IFN-γ) have critical functions in non-cytopathic elimination of hepatitis B virus (HBV) in hepatocytes. However, the molecular mechanisms and mediator molecules are largely unknown. Here we show that interleukin-32 (IL-32) is induced by TNF and IFN-γ in hepatocytes, and inhibits the replication of HBV by acting intracellularly to suppress HBV transcription an...
3 CitationsSource
#1Doo Hyun KimH-Index: 9
#2Hong Seok KangH-Index: 8
Last. Kyun-Hwan Kim (Konkuk University)H-Index: 22
view all 12 authors...
Background/Aims: Direct sequencing is the gold standard for the detection of drug-resistance mutations in hepatitis B virus (HBV); however, this procedure is time-consuming, labor-intensive, and difficult to adapt to high-throughput screening. In this study, we aimed to develop a dendron-modified DNA microarray for the detection of genotypic resistance mutations and evaluate its efficiency. Methods: The specificity, sensitivity, and selectivity of dendron-modified slides for the detection of rep...
1 CitationsSource
#1Keo Heun Lim (Konkuk University)H-Index: 1
#2Eun-Sook Park (Konkuk University)H-Index: 11
Last. Kyun-Hwan Kim (Konkuk University)H-Index: 22
view all 23 authors...
Objective Interferons (IFNs) mediate direct antiviral activity. They play a crucial role in the early host immune response against viral infections. However, IFN therapy for HBV infection is less effective than for other viral infections. Design We explored the cellular targets of HBV in response to IFNs using proteome-wide screening. Results Using LC-MS/MS, we identified proteins downregulated and upregulated by IFN treatment in HBV X protein (HBx)-stable and control cells. We found several IFN...
18 CitationsSource
#1Jeong Han Kim (Konkuk University)H-Index: 14
#2Sung Hyun Ahn (Konkuk University)H-Index: 9
Last. So Young Kwon (Konkuk University)H-Index: 17
view all 6 authors...
Background/Aims: Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination.
2 CitationsSource
#1Yong Kwang Park (Konkuk University)H-Index: 11
#2Eun-Sook Park (Konkuk University)H-Index: 11
Last. Kyun-Hwan Kim (Konkuk University)H-Index: 22
view all 16 authors...
Background & Aims Cytokines are key molecules implicated in the defense against virus infection. Tumor necrosis factor-alpha (TNF-α) is well known to block the replication of hepatitis B virus (HBV). However, the molecular mechanism and the downstream effector molecules remain largely unknown. Methods In this study, we investigated the antiviral effect and mechanism of p22-FLIP (FLICE-inhibitory protein) by ectopic expression in vitro and in vivo . In addition, to provide the biological relevanc...
12 CitationsSource
#1Kyung-Sook ChungH-Index: 14
#2Beom Kyung KimH-Index: 27
Last. Sung Hyun AhnH-Index: 9
view all 18 authors...
#1Sung Hyun Ahn (Konkuk University)H-Index: 9
#2Doo Hyun Kim (Konkuk University)H-Index: 9
Last. Kyun-Hwan Kim (Konkuk University)H-Index: 22
view all 14 authors...
The emergence of compensatory mutations in the polymerase gene of drug resistant hepatitis B virus (HBV) is associated with treatment failure. We previously identified a multi-drug resistant HBV mutant, which displayed resistance towards lamivudine (LMV), clevudine (CLV), and entecavir (ETV), along with a strong replication capacity. The aim of this study was to identify the previously unknown compensatory mutations, and to determine the clinical relevance of this mutation during antiviral thera...
9 CitationsSource