Sun-Hee Leem

Prof. Sun-Hee Leem

Department of Cardiology, Dong-A University Hospital, Busan 49201, Korea

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

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

Representative Publications

View All Publications
30 November 2015 in Clinical Cancer Research
Verified
Journal Article
Closed access
PDF file
SLSe-Ra Lee
Se-Ra Lee
YRYun-Gil Roh
Yun-Gil Roh
SKSeon-Kyu Kim
Seon-Kyu Kim
JLJu-Seog Lee
Ju-Seog Lee
SSSo-Young Seol
So-Young Seol
Sun-Hee LeemSun-Hee Leem
Sun-Hee Leem
Purpose: Previous study identified E2F1 as a key mediator of non–muscle-invasive bladder cancer (NMIBC) progression. The aim of this study was to identify the E2F1-related genes associated with poor prognosis and aggressive characteristics of bladder cancer. Experimental Design: Microarray analysis was performed to find E2F1-related genes associated with tumor progression and aggressiveness in the gene expression data from 165 primary patients with bladder cancer. The biologic activity of E2F1-related genes in tumor progression and aggressiveness was confirmed with experimental assays using bladder cancer cells and tumor xenograft assay. Results: The expression of E2F1 was significantly associated with EZH2 and SUZ12. The overexpression of E2F1, EZH2, and SUZ12 enhanced cancer progression including cell colony formation, migration, and invasiveness. Knockdown of these genes reduced motility, blocked invasion, and decreased tumor size in vivo. E2F1 bound the proximal EZH2 and SUZ12 promoter to activate transcription, suggesting that E2F1 and its downstream effectors, EZH2 and SUZ12, could be important mediators for the cancer progression. In addition, we confirmed an association between these genes and aggressive characteristics. Interestingly, the treatment of anticancer drugs to the cells overexpressing E2F1, EZH2, and SUZ12 induced the expression of CD44, KLF4, OCT4, and ABCG2 known as cancer stem cell (CSC)–related genes. Conclusions: The link between E2F1, EZH2, and/or SUZ12 revealed that E2f1 directly regulates transcription of the EZH2 and SUZ12 genes. The signature of E2F1–EZH2–SUZ12 shows a predictive value for prognosis in bladder tumors and the E2F1–EZH2–SUZ12–driven transcriptional events may regulate the cancer aggressiveness and chemo-resistance, which may provide opportunity for development of new treatment modalities. Clin Cancer Res; 21(23); 5391–403. ©2015 AACR.

12 June 2014 in Clinical Cancer Research
Verified
Journal Article
Open access
PDF file
SKSeon-Kyu Kim
Seon-Kyu Kim
YRYun-Gil Roh
Yun-Gil Roh
KPKiejung Park
Kiejung Park
Tae-Hong KangTae-Hong Kang
Tae-Hong Kang
WKWun-Jae Kim
Wun-Jae Kim
ICIn-sun Chu
In-sun Chu
Purpose: Although standard treatment with transurethral resection and intravesical therapy (IVT) is known to be effective to address the clinical behavior of non–muscle-invasive bladder cancer (NMIBC), many patients fail to respond to the treatment and frequently experience disease recurrence. Here, we aim to identify a prognostic molecular signature that predicts the NMIBC heterogeneity and response to IVT. Experimental Design: We analyzed the genomic profiles of 102 patients with NMIBC to identify a signature associated with disease recurrence. The validity of the signature was verified in three independent patient cohorts (n = 658). Various statistical methods, including a leave-one-out cross-validation and multivariate Cox regression analyses, were applied to identify a signature. We confirmed an association between the signature and tumor aggressiveness with experimental assays using bladder cancer cell lines. Results: Gene expression profiling in 102 patients with NMIBC identified a CCNB1 signature associated with disease recurrence, which was validated in another three independent cohorts of 658 patients. The CCNB1 signature was shown to be an independent risk factor by a multivariate analysis and subset stratification according to stage and grade [HR, 2.93; 95% confidence intervals (CI), 1.302–6.594; P = 0.009]. The subset analysis also revealed that the signature could identify patients who would benefit from IVT. Finally, gene network analyses and experimental assays indicated that NMIBC recurrence could be mediated by FOXM1–CCNB1–Fanconi anemia pathways. Conclusions: The CCNB1 signature represents a promising diagnostic tool to identify patients with NMIBC who have a high risk of recurrence and to predict response to IVT. Clin Cancer Res; 20(12); 3233–43. ©2014 AACR.

1 December 2019 in EBioMedicine
Verified
Journal Article
Open access
BSBic-Na Song
Bic-Na Song
SKSeon-Kyu Kim
Seon-Kyu Kim
JMJeong-Yeon Mun
Jeong-Yeon Mun
YCYoung Deuk Choi
Young Deuk Choi
Sun-Hee LeemSun-Hee Leem
Sun-Hee Leem
ICIn-sun Chu
In-sun Chu
Although various molecular subtypes of bladder cancer (BC) have been investigated, most of these studies have focused on muscle-invasive BC (MIBC). A few studies have investigated non-muscle-invasive BC (NMIBC) or NMIBC and MIBC together, but none has classified progressive NMIBC or immune checkpoint inhibitor (ICI)-based therapeutic responses in early-stage BC patients. A total of 1,934 samples from seven patient cohorts were used. We performed unsupervised hierarchical clustering to stratify patients into distinct subgroups and constructed a classifier by applying SAM/PAM algorithms. We then investigated the association between molecular subtypes and immunotherapy responsiveness using various statistical methods. We explored large-scale genomic datasets encompassing NMIBC and MIBC, redefining four distinct molecular subtypes, including a subgroup containing progressive NMIBC and MIBC with poor prognosis that would benefit from ICI treatment. This subgroup showed poor progression-free survival with the distinct features of high mutation load, activated cell cycle, and inhibited TGFβ signalling. Importantly, we verified that BC patients with this subtype were significantly responsive to an anti-PD-L1 agent in the IMvigor210 cohort. Our results reveal an immunotherapeutic option for ICI treatment of highly progressive NMIBC and MIBC with poor prognosis. This research was supported by the National Research Foundation of Korea grant funded by the Korean government, a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute, funded by the Ministry of Health and Welfare, Republic of Korea, and a grant from the KRIBB Research Initiative Program.

Verified
Journal Article
Open access
PDF file
DRDong-Won Rhyu
Dong-Won Rhyu
YKYun-Jeong Kang
Yun-Jeong Kang
MOMee-Sun Ock
Mee-Sun Ock
JEJung-Woo Eo
Jung-Woo Eo
Yung Hyun ChoiYung Hyun Choi
Yung Hyun Choi
Hee-Jae ChaHee-Jae Cha
Hee-Jae Cha
Human endogenous retroviruses (HERV) env proteins have been recently reported to be significantly up-regulated in certain cancers. Specifically, mRNA and protein levels of HERV-K (HML-2) are up-regulated in the blood plasma or serum of breast cancer patients. Here, we collected blood samples of 49 breast cancer patients and analyzed mRNA expressions of various HERVs env genes including HERV-R, HERV-H, HERV-K, and HERV-P by real-time PCR. The expression of env genes were significantly increased in the blood of primary breast cancer patients but were decreased in patients undergoing chemotherapy to a similar level with benign patients. When we compared the group currently undergoing chemotherapy and those patients undergoing chemotherapy simultaneously with radiotherapy, HERVs env genes were reduced more in the chemotherapy only group, suggesting that chemotherapy is more effective in reducing HERV env gene expression than is radiotherapy. Among chemotherapy groups, HERV env gene expression was the lowest in the taxotere- or taxol-treated group, suggesting that taxotere and taxol can reduce HERVs env expression. These data suggest the potential to use HERVs env genes as a diagnosis marker for primary breast cancer, and further studies are needed to identify the mechanism and physiological significance of the reduction of HERV env gene expression during chemotherapy.

19 February 2011 in BMC Cancer
Verified
Journal Article
Open access
MSMin-A Seol
Min-A Seol
ICIn-sun Chu
In-sun Chu
MLMi-Jin Lee
Mi-Jin Lee
GYGoung-Ran Yu
Goung-Ran Yu
XCXiang-Dan Cui
Xiang-Dan Cui
DKDae-Ghon Kim
Dae-Ghon Kim
Background: The molecular mechanisms of CC (cholangiocarcinoma) oncogenesis and progression are poorly understood. This study aimed to determine the genome-wide expression of genes related to CC oncogenesis and sarcomatous transdifferentiation. Methods: Genes that were differentially expressed between CC cell lines or tissues and cultured normal biliary epithelial (NBE) cells were identified using DNA microarray technology. Expressions were validated in human CC tissues and cells. Results: Using unsupervised hierarchical clustering analysis of the cell line and tissue samples, we identified a set of 342 commonly regulated (>2-fold change) genes. Of these, 53, including tumor-related genes, were upregulated, and 289, including tumor suppressor genes, were downregulated (4-fold change), and 267 differentially downregulated genes (<0.25 fold change). The expression of 12 proteins was validated in the CC cell lines by immunoblot analysis and immunohistochemical staining. Of the proteins analyzed, we found upregulation of the expression of the epithelial-mesenchymal transition (EMT)-related proteins VIM and TWIST1, and restoration of the methylation-silenced proteins LDHB, BNIP3, UCHL1, and NPTX2 during sarcomatoid transdifferentiation of CC. Conclusion: The deregulation of oncogenes, tumor suppressor genes, and methylation-related genes may be useful in identifying molecular targets for CC diagnosis and prognosis.

28 February 2018 in BMB Reports
Verified
Journal Article
Open access
PDF file
YRYun-Gil Roh
Yun-Gil Roh
MMMi-Hye Mun
Mi-Hye Mun
MJMi-So Jeong
Mi-So Jeong
WKWon-Tae Kim
Won-Tae Kim
SLSe-Ra Lee
Se-Ra Lee
Sun-Hee LeemSun-Hee Leem
Sun-Hee Leem
Yun-Gil Roh, Mi-Hye Mun, Mi-So Jeong, Won-Tae Kim, Se-Ra Lee, Jin-Woong Chung, Seung Il Kim, Tae Nam Kim, Jong Kil Nam, and Sun-Hee Leem. BMB Reports 2018;51:98-103. https://doi.org/10.5483/BMBRep.2018.51.2.222