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Featured researches published by Rohyun Sung.


Diagnostic Pathology | 2013

Combined aberrant expression of E-cadherin and S100A4, but not β-catenin is associated with disease-free survival and overall survival in colorectal cancer patients

Sang-Jeon Lee; Song Yi Choi; Wun-Jae Kim; Meiying Ji; Taek-Gu Lee; Bo-Ra Son; Soon Man Yoon; Rohyun Sung; Eun Jeoung Lee; Sei Jin Youn; Seon Mee Park

Background/AimsEpithelial-to-mesenchymal transition (EMT) in cancers is related to metastasis, recurrence, and poor prognosis. We evaluated whether EMT-related proteins can act as prognostic biomarkers in colorectal cancer (CRC) patients.MethodsWe evaluated the expression of E-cadherin, β-catenin, and S100A4 by immunohistochemistry (IHC) in 333 CRC tissues from the tumor center and invasive margin. Tumor budding, cell grade, tumor stage, type of tumor growth, peritumoral lymphocyte infiltration (TLI), and perineural- or lymphovascular invasion were evaluated as pathological parameters. mRNA levels of E-cadherin, N-cadherin, β-catenin, and S100A4 from 68 specimens from the same set were analyzed by real time quantitative RT-PCR.ResultsLoss of E-cadherin, nuclear β-catenin, and gain of S100A4 were higher in the invasive margin than in the tumor center. Loss of E-cadherin was associated with cell grade, macroscopic type, perineural invasion, and tumor budding, β-catenin with microsatellite instability and tumor site, and S100A4 with growth type, macroscopic type, AJCC stage, lymphovascular invasion, and perineural invasion. The aberrant expression of E-cadherin and S100A4 not β-catenin in the invasive margin was a significant and independent risk factor for disease-free and overall-survival by multivariate analysis, along with AJCC stage and perineural invasion. mRNA levels of β-catenin and S100A4 were correlated with the IHC findings at the tumor invasive margin. E-cadherin and N-cadherin showed a weak inverse correlation.ConclusionsThe combination of loss of E-cadherin and gain of S100A4 in the tumor invasive margin can be used to stratify patients with the same AJCC stage into different survival groups.Virtual slidesThe virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9398289629244673


The Korean Journal of Physiology and Pharmacology | 2010

Regional Distribution of Interstitial Cells of Cajal (ICC) in Human Stomach.

Hyo-Yung Yun; Rohyun Sung; Young Chul Kim; Woong Choi; Hun Sik Kim; Heon Kim; Gwang Ju Lee; Ra Young You; Seon-Mee Park; Sei Jin Yun; Mi-Jung Kim; Won Seop Kim; Young-Jin Song; Wen-Xie Xu; Sang Jin Lee

We elucidated the distribution of interstitial cells of Cajal (ICC) in human stomach, using cryosection and c-Kit immunohistochemistry to identify c-Kit positive ICC. Before c-Kit staining, we routinely used hematoxylin and eosin (HE) staining to identify every structure of human stomach, from mucosa to longitudinal muscle. HE staining revealed that the fundus greater curvature (GC) had prominent oblique muscle layer, and c-Kit immunostaining c-Kit positive ICC cells were found to have typical morphology of dense fusiform cell body with multiple processes protruding from the central cell body. In particular, we could observe dense processes and ramifications of ICC in myenteric area and longitudinal muscle layer of corpus GC. Interestingly, c-Kit positive ICC-like cells which had morphology very similar to ICC were found in gastric mucosa. We could not find any significant difference in the distribution of ICC between fundus and corpus, except for submucosa where the density of ICC was much higher in gastric fundus than corpus. Furthermore, there was no significant difference in the density of ICC between each area of fundus and corpus, except for muscularis mucosa. Finally, we also found similar distribution of ICC in normal and cancerous tissue obtained from a patient who underwent pancreotomy and gastrectomy. In conclusion, ICC was found ubiquitously in human stomach and the density of ICC was significantly lower in the muscularis mucosa of both fundus/corpus and higher in the submucosa of gastric fundus than corpus.


Oncology Reports | 2015

HDAC inhibitors induce epithelial-mesenchymal transition in colon carcinoma cells

Meiying Ji; Eun Jeoung Lee; Ki Bae Kim; Yangmi Kim; Rohyun Sung; Sang-Jeon Lee; Don Soo Kim; Seon Mee Park

The effects of histone deacetylase (HDAC) inhibitors on epithelial-mesenchymal transition (EMT) differ in various types of cancers. We investigated the EMT phenotype in four colon cancer cell lines when challenged with HDAC inhibitors trichostatin A (TSA) and valproic acid (VPA) with or without transforming growth factor-β1 (TGF-β1) treatment. Four colon cancer cell lines with different phenotypes in regards to tumorigenicity, microsatellite stability and DNA mutation were used. EMT phenotypes were assessed by the expression of E-cadherin and vimentin using western blot analysis, immunofluorescence, quantitative real-time RT-PCR following treatment with TSA (100 or 200 nM) or VPA (0.5 mM) with or without TGF-β1 (5 ng/ml) for 24 h. Biological EMT phenotypes were also evaluated by cell morphology, migration and invasion assays. TSA or VPA induced mesenchymal features in the colon carcinoma cells by a decrease in E-cadherin and an increase in vimentin expression at the mRNA and protein levels. Confocal microscopy revealed membranous attenuation or nuclear translocation of E-cadherin and enhanced expression of vimentin. These responses occurred after 6 h and increased until 24 h. Colon cancer cells changed from a round or rectangular shape to a spindle shape with increased migration and invasion ability following TSA or VPA treatment. The susceptibility to EMT changes induced by TSA or VPA was comparable in microsatellite stable (SW480 and HT29) and microsatellite unstable cells (DLD1 and HCT116). TSA or VPA induced a mesenchymal phenotype in the colon carcinoma cells and these effects were augmented in the presence of TGF-β1. HDAC inhibitors require careful caution before their application as new anticancer drugs for colon cancers.


Journal of Korean Medical Science | 2010

Cholestatic Hepatitis and Thrombocytosis in a Secondary Syphilis Patient

Byeong Uk Kim; Ju Hee Lee; Yong Heok Choi; Hee Bok Chae; Seon Mee Park; Sei Jin Youn; Ji Yeoun Lee; Tae Young Yoon; Rohyun Sung

The incidence of acute hepatitis in syphilis patient is rare. First of all, our patient presented with hepatitis comorbid with thrombocytosis. To our knowledge, this is only the second report of syphilitic hepatitis with thrombocytosis. The 42-yr-old male complained of flulike symptoms and skin eruptions on his palms and soles. Laboratory findings suggested an acute hepatitis and thrombocytosis. Serologic test results were positive for VDRL. He recovered from his symptoms and elevated liver related enzymes with treatment. Because syphilitic hepatitis can present without any typical signs of accompanying syphilis, syphilis should be considered as a possible cause in acute hepatitis patients.


Journal of Gastroenterology and Hepatology | 2014

Epithelial-mesenchymal transition-related protein expression in biliary epithelial cells associated with hepatolithiasis

Rohyun Sung; Sang Hwa Lee; Meiying Ji; Joung-Ho Han; Min Ho Kang; Ji Hoon Kim; Jae-Woon Choi; Young Chul Kim; Seon Mee Park

Epithelial‐mesenchymal transition (EMT) of biliary epithelial cells (BECs) plays major roles in many cholangiopathies. This study evaluated whether EMT of BECs has a role in hepatolithiasis‐induced biliary fibrosis and types of BECs that are involved.


Journal of Korean Medical Science | 2013

Podoplanin, α-Smooth Muscle Actin or S100A4 Expressing Cancer-Associated Fibroblasts Are Associated with Different Prognosis in Colorectal Cancers

Song-Yi Choi; Rohyun Sung; Sang-Jeon Lee; Taek-Gu Lee; Nayoung Kim; Soon Man Yoon; Eun Jeoung Lee; Hee Bok Chae; Sei Jin Youn; Seon Mee Park

The interactions between the tumor microenvironment and tumor cells determine the behavior of the primary tumors. Whether cancer-associated fibroblasts (CAF) have a tumor progressive or a protective role likely depends on the type of tumor cells and the CAF subpopulation. In the present study, we analyzed the prognostic significance of CAF subpopulations in colorectal cancer (CRC). CAF phenotypes were analyzed in 302 CRC patients by using antibodies against podoplanin (PDPN), α-smooth muscle actin (α-SMA), and S100A4. The relationship between the CAF phenotypes and 11 clinicopathological parameters were evaluated and their prognostic significance was analyzed from the disease-free and overall survival times. We observed that at the tumor invasive front, PDPN CAFs were present in 40% of the cases, and S100A4 or α-SMA CAFs were detected in all the cases. PDPN/S100A4 and α-SMA/S100A4 dual-stained CAFs were observed in 10% and 40% of the cases, respectively. The PDPN+ CAFs were associated with 6 favorable clinicopathological parameters and prolonged disease-free survival time. The PDPN-/α-SMAhigh CAFs were associated with 6 aggressive clinicopathological parameters and tended to exhibit shorter disease-free survival time. On the other hand, the PDPN-/S100A4high CAFs were associated with 2 tumor progression parameters, but not with disease prognosis. The PDPN+ CAF phenotype is distinct from the α-SMA or S100A4 CAFs in that it is associated with less aggressive tumors and a favorable prognosis, whereas the PDPN-/α-SMAhigh or PDPN-/S100A4high CAFs are associated with tumor progression in CRC. These findings suggest that CAFs can be a useful prognostic biomarker or potential targets of anti-cancer therapy in CRC.


The Korean Journal of Internal Medicine | 2009

A Case of Idiopathic Adulthood Ductopenia

Byeong Chool Park; Seon Mee Park; Eun Young Choi; Hee Bok Chae; Se Jin Yoon; Rohyun Sung; Sung Koo Lee

Idiopathic adulthood ductopenia (IAD) is a chronic cholestatic liver disease of unknown etiology characterized by adult onset, an absence of autoantibodies, inflammatory bowel disease, and a loss of interlobular bile ducts. In the present report, a case fulfilling the IAD criteria is described. A 19-year-old man was admitted to the hospital for persistent elevation of transaminases and alkaline phosphatase without clinical symptoms. Viral hepatitis markers and autoantibodies were absent. The patient had a normal extrahepatic biliary tree and had no evidence of inflammatory bowel disease. A liver biopsy specimen showed absence of interlobular bile ducts from 58% of the portal tracts. He was diagnosed with IAD and was treated with ursodeoxycholic acid.


The Korean Journal of Physiology and Pharmacology | 2011

Nitric Oxide-mediated Relaxation by High K+ in Human Gastric Longitudinal Smooth Muscle

Young Chul Kim; Woong Choi; Hyo-Young Yun; Rohyun Sung; Ra Young Yoo; Seon-Mee Park; Sei Jin Yun; Mi-Jung Kim; Young-Jin Song; Wen-Xie Xu; Sang Jin Lee

This study was designed to elucidate high-K+induced response of circular and longitudinal smooth muscle from human gastric corpus using isometric contraction. Contraction from circular and longitudinal muscle stripes of gastric corpus greater curvature and lesser curvature were compared. Circular smooth muscle from corpus greater curvature showed high K+ (50 mM)-induced tonic contraction. On the contrary, however, longitudinal smooth muscle strips showed high K+ (50 mM)-induced sustained relaxation. To find out the reason for the discrepancy we tested several relaxation mechanisms. Protein kinase blockers like KT5720, PKA inhibitor, and KT5823, PKG inhibitor, did not affect high K+-induced relaxation. K+ channel blockers like tetraethylammonium (TEA), apamin (APA), glibenclamide (Glib) and barium (Ba2+) also had no effect. However, N(G)-nitro-L-arginine (L-NNA) and 1H-(1,2,4) oxadiazolo (4,3-A) quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC) and 4-AP (4-aminopyridine), voltage-dependent K+ channel (KV) blocker, inhibited high K+-induced relaxation, hence reversing to tonic contraction. High K+-induced relaxation was observed in gastric corpus of human stomach, but only in the longitudinal muscles from greater curvature not lesser curvature. L-NNA, ODQ and KV channel blocker sensitive high K+-induced relaxation in longitudinal muscle of higher portion of corpus was also observed. These results suggest that longitudinal smooth muscle from greater curvature of gastric corpus produced high K+-induced relaxation which was activated by NO/sGC pathway and by KV channel dependent mechanism.


Oncology Reports | 2011

Interstitial cells of Cajal (ICC)-like-c-Kit positive cells are involved in gastritis and carcinogenesis in human stomach

Rohyun Sung; Young Chul Kim; Hyo-Yung Yun; Woong Choi; Hun Sik Kim; Heon Kim; Kwang Ju Lee; Ra Young You; Seon Mee Park; Sei Jin Youn; Mi-Jung Kim; Won Seop Kim; Young-Jin Song; Seok-Yong Kim; Wen-Xie Xu; Sang Jin Lee

This study was executed to prove the existence of c-Kit-positive interstitial cells of Cajal (ICC)-like cells [c-Kit (+) ICC-like cells] and their possible role associated with gastric inflammation and/or carcinogenesis in human gastric mucosa. c-Kit (+) ICC-like cells were observed throughout all the layers of the gastric fundus along the greater curvature. Dense fusiform cell bodies with many processes were found in each layer. We also studied the c-Kit-positive immunoreactivity distribution pattern in the mucosa. c-Kit (+) cells were found mainly around the epithelial repair zone of the normal gastric fundus/corpus and of the fundus/corpus with non-metaplastic chronic gastritis. Notably, they were found attached to the epithelia of the repair zone in non-metaplastic chronic gastritis. In chronic gastritis with intestinal metaplasia, they were found scattered everywhere in the stroma of the gastric mucosa and did not attach to the metaplastic epithelium. We found c-Kit (+) ICC-like cells in human mucosa. They were present mainly in the stroma around the repair zone of the glands in chronic gastritis as well as in normal mucosa, whereas they seemed to redistribute over the whole mucosa in gastritis with intestinal metaplasia. These cells around the repair zone were found to be tightly attached to epithelial cells, but not to metaplastic epithelial cells. Thus, c-Kit (+) ICC-like cells appear to have a role in the epithelial recovery process and may be associated with carcinogenesis of human gastric mucosa.


Clinical Endoscopy | 2015

Diagnostic Accuracy of the Initial Endoscopy for Ampullary Tumors.

Hee Seung Lee; Jong Soon Jang; Seungho Lee; Myeong Ho Yeon; Ki Bae Kim; Jae Geun Park; Joo-Young Lee; Mi Jin Kim; Joung-Ho Han; Rohyun Sung; Seon Mee Park

Background/Aims Ampullary tumors come in a wide variety of malignant forms. We evaluated the diagnostic accuracy of endoscopy for ampullary tumors, and analyzed the causes of misdiagnosis. Methods We compared endoscopic imaging and biopsy results to final diagnoses. Types of endoscope, numbers of biopsy specimens taken, and final diagnoses were evaluated as possible factors influencing diagnostic accuracy. Results Final diagnoses were 19 adenocarcinomas, 18 normal or papillitis, 11 adenomas, two adenomyomas, one paraganglioma, and one neuroendocrine tumor. The diagnostic accuracy of endoscopic imaging or the initial biopsy was identical (67.3%). At least one test was concordant with the final diagnosis in all except two cases. Compared with the final diagnosis, endoscopic imaging tended to show more advanced tumors, whereas the initial biopsy revealed less advanced lesions. The diagnostic accuracy of the initial biopsy was influenced by the type of endoscope used and the final diagnosis, but not by the number of biopsies taken. Conclusions Endoscopy has limited accuracy in the diagnosis of ampullary tumors. However, most cases with concordant endoscopic imaging and biopsy results are identical to the final diagnosis. Therefore, in cases where both of these tests disagree, re-evaluation with a side-viewing endoscope after resolution of papillitis is required.

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Seon Mee Park

Chungbuk National University

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Hee Bok Chae

Chungbuk National University

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Sei Jin Youn

Chungbuk National University

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Joung-Ho Han

Chungbuk National University

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Young Chul Kim

Chungbuk National University

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Sang Jin Lee

Chungbuk National University

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Seon-Mee Park

Chungbuk National University

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Woong Choi

Chungbuk National University

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Heon Kim

Chungbuk National University

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Sei-Jin Youn

Chungbuk National University

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