Yeun-Jun Chung

Prof. Yeun-Jun Chung

1. Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul 03083, Korea
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Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 August 2022 in Nature Communications
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Journal Article
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SJSeungHyun Jung
SeungHyun Jung
BHByung-Hee Hwang
Byung-Hee Hwang
SSSun Shin
Sun Shin
EPEun-Hye Park
Eun-Hye Park
SPSin-Hee Park
Sin-Hee Park
Yeun-Jun ChungYeun-Jun Chung
Yeun-Jun Chung
Heart failure (HF) is a frequent consequence of myocardial infarction (MI). Identification of the precise, time-dependent composition of inflammatory cells may provide clues for the establishment of new biomarkers and therapeutic approaches targeting post-MI HF. Here, we investigate the spatiotemporal dynamics of MI-associated immune cells in a mouse model of MI using spatial transcriptomics and single-cell RNA-sequencing (scRNA-seq). We identify twelve major immune cell populations; their proportions dynamically change after MI. Macrophages are the most abundant population at all-time points (>60%), except for day 1 post-MI. Trajectory inference analysis shows upregulation of Trem2 expression in macrophages during the late phase post-MI. In vivo injection of soluble Trem2 leads to significant functional and structural improvements in infarcted hearts. Our data contribute to a better understanding of MI-driven immune responses and further investigation to determine the regulatory factors of the Trem2 signaling pathway will aid the development of novel therapeutic strategies for post-MI HF.

30 September 2015 in Clinical Cancer Research
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TKTae-Min Kim
Tae-Min Kim
SJSeung-Hyun Jung
Seung-Hyun Jung
CAChang Hyeok An
Chang Hyeok An
SLSung Hak Lee
Sung Hak Lee
IBIn-Pyo Baek
In-Pyo Baek
Yeun-Jun ChungYeun-Jun Chung
Yeun-Jun Chung
Purpose: The intratumoral heterogeneity (ITH) and the evolution of genomic architectures associated with the development of distant metastases are not well understood in colorectal cancers. Experimental Design: We performed multiregion biopsies of primary and liver metastatic regions from five colorectal cancers with whole-exome sequencing and copy number profiling. Results: In addition to a substantial level of genetic ITH, multiregion genetic profiling identifies the subclonal mutational architecture, leading to the region-based or spatial categorization of somatic mutations and the inference of intratumoral evolutionary history of cancers. The universal mutations (those observed in all the regional biopsies) are enriched in known cancer genes such as APC and TP53 with distinct mutational spectra compared with biopsy- or region-specific mutations, suggesting that major operative mutational mechanisms and their selective pressures are not constant across the metastatic progression. The phylogenies inferred from genomic data show branching evolutionary patterns where some primary biopsies are often segregated with metastastic lesions. Our analyses also revealed that copy number changes such as the chromosomal gains of c-MYC and chromothripsis can be region specific and the potential source of genetic ITH. Conclusions: Our data show that the genetic ITH is prevalent in colorectal cancer serving as a potential driving force to generate metastasis-initiating clones and also as a means to infer the intratumoral evolutionary history of cancers. The paucity of recurrent metastasis-clonal events suggests that colorectal cancer distant metastases may not follow a uniform course of genomic evolution, which should be considered in the genetic diagnosis and the selection of therapeutic targets for the advanced colorectal cancer. Clin Cancer Res; 21(19); 4461–72. ©2015 AACR.

28 August 2015 in Arthritis & Rheumatology
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JLJi Yeon Lee
Ji Yeon Lee
NVNadimuthu Vinayagamoorthy
Nadimuthu Vinayagamoorthy
KHKyungdo Han
Kyungdo Han
SKSeung Ki Kwok
Seung Ki Kwok
JJJi Hyeon Ju
Ji Hyeon Ju
SPSung-Hwan Park
Sung-Hwan Park
Objective: To evaluate associations of genetic polymorphisms in cytochrome P450 (CYP) isoforms 2D6, 3A5, and 3A4 with blood concentrations of hydroxychloroquine (HCQ) and its metabolite, N‐desethyl HCQ (DHCQ), in patients with systemic lupus erythematosus (SLE).Methods: SLE patients taking HCQ for >3 months were recruited and were genotyped for 4 single‐nucleotide polymorphisms in CYP2D6*10, CYP3A5*3, and CYP3A4*18B. Blood HCQ and DHCQ concentrations ([HCQ] and [DHCQ]) were measured and their association with corresponding genotypes was investigated.Results: A total of 194 patients were included in the analysis. CYP2D6*10 polymorphisms (rs1065852 and rs1135840) were significantly associated with the [DHCQ]:[HCQ] ratio after adjustment for age, sex, dose per weight per day, and SLE Disease Activity Index score (P = 0.03 and P < 0.01, respectively). In adjusted models, the [DHCQ]:[HCQ] ratio was highest in patients with the G/G genotype of the CYP2D6*10 (rs1065852) polymorphism and lowest in those with the A/A genotype (P = 0.03). Similarly, the [DHCQ]:[HCQ] ratio was highest in patients with the C/C genotype of the CYP2D6*10 (rs1135840) polymorphism and lowest in those with the G/G genotype (P < 0.01). The CYP2D6*10 (rs1065852) polymorphism was significantly related to the [DHCQ] (P = 0.01). However, the polymorphisms of CYP3A5*3 and CYP3A4*18B did not show any significant association with the [HCQ], [DHCQ], or [DHCQ]:[HCQ] ratio.Conclusion: Our study showed that the [DHCQ]:[HCQ] ratio was related to CYP2D6 polymorphisms in Korean lupus patients taking oral HCQ. CYP polymorphisms may explain why there is wide variation in blood HCQ concentrations. The role of an individual's CYP polymorphisms should be considered when prescribing oral HCQ.

7 August 2018 in Experimental & Molecular Medicine
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YCYunsik Choi
Yunsik Choi
SLSanghyuk Lee
Sanghyuk Lee
KKKapyoul Kim
Kapyoul Kim
SKSoo-Hyun Kim
Soo-Hyun Kim
Yeun-Jun ChungYeun-Jun Chung
Yeun-Jun Chung
CLCharles Lee
Charles Lee
Cancer immunotherapy is a promising way to eliminate tumor cells by using the patient’s own immune system. Selecting the appropriate animal models to develop or validate preclinical immunotherapeutic trials is now an important aspect of many cancer research programs. Here we discuss the advantages and limitations of using genetically engineered immunodeficient mouse models, patient-derived xenografts (PDXs), and humanized mouse models for developing and testing immunotherapeutic strategies.

25 April 2012 in Bioinformatics
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JKJi-Hong Kim
Ji-Hong Kim
HHHae-Jin Hu
Hae-Jin Hu
SYSeon-Hee Yim
Seon-Hee Yim
JBJoon Seol Bae
Joon Seol Bae
SKSeon-Young Kim
Seon-Young Kim
Yeun-Jun ChungYeun-Jun Chung
Yeun-Jun Chung
Summary: The method for genome-wide association study (GWAS) based on copy number variation (CNV) is not as well established as that for single nucleotide polymorphism (SNP)–GWAS. Although there are several tools for CNV association studies, most of them do not provide appropriate definitions of CNV regions (CNVRs), which are essential for CNV-association studies. Here we present a user-friendly program called CNVRuler for CNV-association studies. Outputs from the 10 most common CNV defining algorithms can be directly used as input files for determining the three different definitions of CNVRs. Once CNVRs are defined, CNVRuler supports four kinds of statistical association tests and options for population stratification. CNVRuler is based on the open-source programs R and Java from Sun Microsystems. Availability: CNVRuler software is available with an online manual at the website, www.ircgp.com/CNVRuler/index.html Contact:yejun@catholic.ac.kr. Supplementary information: Supplementary data are available at Bioinformatics online.

15 October 2008 in International Journal of Cancer
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TKTae‐Min Kim
Tae‐Min Kim
SYSeon‐Hee Yim
Seon‐Hee Yim
SSSeung‐Hun Shin
Seung‐Hun Shin
HXHai‐Dong Xu
Hai‐Dong Xu
YJYu‐Chae Jung
Yu‐Chae Jung
Yeun-Jun ChungYeun-Jun Chung
Yeun-Jun Chung
To elucidate the pathogenesis of hepatocellular carcinoma (HCC) and develop useful prognosis predictors, it is necessary to identify biologically relevant genomic alterations in HCC. In our study, we defined recurrently altered regions (RARs) common to many cases of HCCs, which may contain tumor‐related genes, using whole‐genome array‐CGH and explored their associations with the clinicopathologic features. Gene set enrichment analysis was performed to investigate functional implication of RARs. On an average, 23.1% of the total probes were altered per case. Mean numbers of altered probes are significantly higher in high‐grade, bigger and microvascular invasion (MVI) positive tumors. In total, 32 RARs (14 gains and 18 losses) were defined and 4 most frequent RARs are gains in 1q21.1‐q32.1 (64.5%), 1q32.1‐q44 (59.2%), 8q11.21‐q24.3 (48.7%) and a loss in 17p13.3‐p12 (51.3%). Through focusing on RARs, we identified genes and functional pathways likely to be involved in hepatocarcinogenesis. Among genes in the recurrently gained regions on 1q, expression of KIF14 and TPM3 was significantly increased, suggesting their oncogenic potential in HCC. Some RARs showed the significant associations with the clinical features. Especially, the recurrent loss in 9p24.2‐p21.1 and gain in 8q11.21‐q24.3 are associated with the high tumor grade and MVI, respectively. Functional analysis showed that cytokine receptor binding and defense response to virus pathways are significantly enriched in high grade‐related RARs. Taken together, our results and the strategy of analysis will help to elucidate pathogenesis of HCC and to develop biomarkers for predicting behaviors of HCC.