Kyung Un Choi

Pusan National University, Tsau-liang-hai, Busan, South Korea

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Publications (50)72.74 Total impact

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    ABSTRACT: Pure squamous cell carcinoma (SCC) of the stomach is rare and resembles SCC arising elsewhere in the body. The pathogenesis of SCC remains unclear and controversial. At present, <100 cases of primary SCC of the stomach have been reported. The current study presents a case of SCC of the stomach in a 61-year-old male. Total gastrectomy was performed and a 7.0×6.7×4.5-cm tumor with a superiorly located ulcer was identified in the cardia. Upon histological examination, a moderately-differentiated SCC was observed. Tumor cells extended to the serosa, and the perigastric regional lymph node was also involved. No evidence of human papillomavirus (HPV) or Epstein-Barr virus (EBV) infection was identified using a DNA microarray and in situ hybridization, respectively. A post-operative computed tomography scan four months after the gastrectomy revealed tumor recurrence and dissemination of the tumor to the jejunum and pancreas. The patient succumbed to the disease six months later despite the administration of low-dose adjuvant 5-fluorouracil/cisplatin chemotherapy.
    Oncology letters 11/2014; 8(5):2122-2124. · 0.24 Impact Factor
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    ABSTRACT: Epithelial-mesenchymal transition (EMT) is associated with tumor hypoxia. EMT is regulated, in part, by the action of TWIST, which inhibits of E-cadherin expression and may interfere with the p53 tumor-suppressor pathway.
    The Korean Journal of Pathology 08/2014; 48(4):283-91. · 0.17 Impact Factor
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    ABSTRACT: Soft tissue sarcomas (STS) are rare. We evaluated the WT1 protein expression level in various types of STS and elucidated the value of WT1 as a prognostic factor and a possible therapeutic target.
    World Journal of Surgical Oncology 07/2014; 12(1):214. · 1.09 Impact Factor
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    ABSTRACT: The S100A4 protein, a member of the S100 family of calcium-binding proteins, has been considered as a candidate prognostic marker in patients with cancer. The present study was conducted to evaluate the prognostic value of S100A4 and to examine its correlation with the clinicopathological parameters and the overall survival and progression-free survival in patients with endometrial carcinoma (EC). To do this, we performed immunohistochemistry of formalin-fixed tissue sections obtained from 135 cases of EC. In addition, we quantified the level of S100A4 mRNA using the quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). The cytoplasmic expression of S100A4 protein was observed in 35 cases (25.9%). There was a significant association between the expression of S100A4 and clinicopathological parameters such as histologic grade, FIGO stage, lymph node metastasis and loss of progesterone receptor (PR). qRT-PCR demonstrated that the level of S100A4 mRNA was significantly higher in ECs as compared with normal endometrium. The cytoplasmic expression of S100A4 had a significant correlation with shorter overall survival and progression-free survival on the Kaplan-Meyer survival analysis. In multivariate analysis, there was a significant correlation between S100A4 expression and a poorer OS. In conclusion, our results indicate that S100A4 may be a biological marker indicating the recurrence and poor prognosis in patients with EC.
    Oncology Reports 04/2014; · 2.30 Impact Factor
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    ABSTRACT: Sparganosis is a parasitic infection caused by the plerocercoid tapeworm larva of the genus Spirometra. Although the destination of the larva is often a tissue or muscle in the chest, abdominal wall, extremities, eyes, brain, urinary tract, spinal canal, and scrotum, intramuscular sparganosis is uncommon and therefore is difficult to distinguish from a soft tissue tumor. We report a case of intramuscular sparganosis involving the gastrocnemius muscle in an elderly patient who was diagnosed using ultrasonography and MRI and treated by surgical excision. At approximately 1 cm near the schwannoma at the right distal sciatic nerve, several spargana worms were detected and removed.
    The Korean Journal of Parasitology 02/2014; 52(1):69-73. · 0.88 Impact Factor
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    ABSTRACT: Abstract Polycomb group (PcG) genes are evolutionary conserved regulators of gene expression that contribute to normal lymphocyte development, and are involved in malignant transformation of these cells. Recently, BMI1 and EZH2 have been shown to be involved in lymphomagenesis and oncogenesis. We tried to elucidate EZH2 as a prognostic factor for diffuse large B cell lymphoma (DLBCL). High-level expression of EZH2 (EZH≥70%) was associated with superior overall survival (OS) of 85.8%, which compares to those of low expression (EZH2<70%) with OS of 44.5% (p=0.005). Subgroup analysis showed that the ABC subtype with high EZH2 expression had the highest overall survival (p= 0.011). In the analysis of EZH2 expression within the low IPI score, high EZH2 expression had a significant statistical correlation with longer OS (p=0.034). With high IPI scores, high EZH2 expression tended to be associated with longer OS (p=0.130). Our results showed that EZH2 expression had a high prognostic relevance to survival outcomes. We demonstrated that DLBCL was associated with increased expression of the EZH2 PcG protein and Ki67. The distribution of EZH2 expression was wider than that of Ki67. In summary, increased EZH2 expression of tumor cells was associated with improvements in overall survival.
    Leukemia & lymphoma 12/2013; · 2.61 Impact Factor
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    ABSTRACT: Anticancer activity of silibinin, a flavonoid, has been demonstrated in various cancer cell types. However, the underlying mechanisms were not elucidated in human ovarian cancer cells. The present study was undertaken to examine the effect of silibinin in vitro and in vivo on tumor growth in human ovarian cancer cells. Silibinin decreased cell viability in a dose- and time-dependent manner. Silibinin caused an increase in reactive oxygen species (ROS) generation and the silibinin-induced cell death was prevented by the antioxidant N-acetylcysteine (NAC). Western blot analysis showed silibinin-induced down-regulation of extracellular signal-regulated kinase (ERK) and Akt. Transfection of constitutively active forms of MEK and Akt prevented the silibinin-induced cell death. Oral administration of silibinin in animals with subcutaneous A2780 cells reduced tumor volume. Subsequent tumor tissue analysis showed that silibinin treatment induced a decrease in Ki-67 positive cells, an increase in TUNEL-positive cells, activation of caspase-3, and inhibition of p-ERK and p-Akt. These results indicate that silibinin reduces tumor growth through inhibition of ERK and Akt in human ovarian cancer cells. These data suggest that silibinin may serve as a potential therapeutic agent for human ovarian cancers.
    Journal of Agricultural and Food Chemistry 04/2013; · 3.11 Impact Factor
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    ABSTRACT: Coronary artery embolism is an infrequent cause of acute myocardial infarction. In addition, native aortic valve thrombosis is a very rare condition. We report a case of native valve thrombosis causing acute ST-elevation myocardial infarction in healthy middle-aged man who has no established cardiovascular risk factor. We diagnosed native aortic valve thrombosis using various imaging techniques and confirmed our diagnosis histopathologically after surgical operation.
    Cardiovascular pathology: the official journal of the Society for Cardiovascular Pathology 01/2013; · 1.63 Impact Factor
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    ABSTRACT: Abstract Objective: To determine whether the levels of inflammatory mediators in gastric fluid (GF) of a premature newborn are associated with those in amniotic fluid (AF) of the newborn's mother. Patients: Twenty-three pairs of pregnant women and their premature newborns <35 weeks gestation, born by Cesarean sections. Methods: Amniotic fluids and newborn gastric fluids were obtained from women during Cesarean section procedure. The mother-premature newborn dyads were retrospectively assessed to analyze the clinical and laboratory data. Concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-α) and mannose-binding lectin (MBL) were compared between amniotic and newborn gastric fluids in each dyad. Results: Premature newborns and their mother with funisitis had significantly higher median AF IL-6 and TNF-α and GF IL-8 concentrations than those without funisitis (p = 0.022 for AF IL-6; p = 0.023 for AF TNF-α; p = 0.022 for GF IL-8). The concentrations of IL-6, IL-8, TNF-α and MBL in newborn GF were significantly correlated with those in AF in each dyad (p = 0.000, r = 0.872 for IL-6; p = 0.000, r = 0.851 for IL-8; p = 0.000, r = 0.768 for TNF-α; p = 0.000, r = 0.845 for MBL, respectively). Conclusion: The levels of inflammatory mediators in GF of a premature newborn immediately after birth are strongly associated with those in AF of the newborn's mother.
    The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 01/2013; · 1.36 Impact Factor
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    ABSTRACT: Myolipomas are very rare benign lipomatous soft tissue tumors which are usually located in retroperitoneum, abdominal and pelvic cavity, and the abdominal wall. They can be diagnosed histologically by the presence of irregularly admixed mature adipose tissue and smooth muscle fibers. The correct diagnosis of myolipoma is important, because it should be considered in the differential diagnosis of fat-containing lesions of the soft tissue and should follow a benign clinical course despite its frequently large size and deep location. We report here a case of myolipoma arising in the mesentery of the jejunum.
    Case reports in pathology. 01/2013; 2013:823823.
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    ABSTRACT: Tumor hypoxia is associated with malignant progression and treatment resistance. Hypoxia-related factors, such as carbonic anhydrase IX (CA IX), glucose transporter-1 (GLUT-1), and vascular endothelial growth factor (VEGF) permit tumor cell adaptation to hypoxia. We attempted to elucidate the correlation of these markers with variable clinicopathological factors and overall prognosis. Immunohistochemistry for CA IX, GLUT-1, and VEGF was performed on formalin-fixed, paraffin-embedded tissues from 125 cases of ovarian epithelial cancer (OEC). CA IX expression was significantly associated with an endometrioid and mucinous histology, nuclear grade, tumor necrosis, and mitosis. GLUT-1 expression was associated with tumor necrosis and mitosis. VEGF expression was correlated only with disease recurrence. Expression of each marker was not significant in terms of overall survival in OECs; however, there was a significant correlation between poor overall survival rate and high coexpression of these markers. The present study suggests that it is questionable whether CA IX, GLUT-1, or VEGF can be used alone as independent prognostic factors in OECs. Using at least two markers helps to predict patient outcomes in total OECs. Moreover, the inhibition of two target gene combinations might prove to be a novel anticancer therapy.
    The Korean Journal of Pathology 12/2012; 46(6):532-40. · 0.17 Impact Factor
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    ABSTRACT: Baker's cysts are one of the most common cystic lesions around the knee joint and mainly caused by fluid distension of the gastrocnemius-semimembranous bursa that is situated along the medial side of the popliteal fossa. Typically, a Baker's cyst extends along the intermuscular planes around the knee joint and may enlarge any direction. However, it is mostly located in the inferomedial or superficial layers of the knee joint and less commonly extends laterally or proximally. Expansion of the cyst tends to respect the intermuscular planes, and Baker's cysts along the intramuscular route have been rarely reported. Thus, we report a case of Baker's cyst with intramuscular extension into the vastus medialis muscle.
    Knee surgery & related research. 12/2012; 24(4):249-53.
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    ABSTRACT: Background and aimThe biologic behavior of gastrointestinal stromal tumors (GIST) is a topic of continuing controversy. The assessment of accurate mitotic figures is known to be one of the major indicators for patients with GIST. However, it is not always easy to search for mitotic figures (MFs) and count them accurately on hematoxylin and eosin stained (H&E) slides. Methods In this study, phopho-histone H3 (PHH3), which is a recently described specific mitosis marker, was immunohistochemically examined and compared to the mitotic count on H&E sections (H&E-MI) and Ki-67 expression (Ki-67 PI). A hundred cases of histologically confirmed GISTs were reviewed based on counting MF on H&E slides. PHH3 positive MFs (PHH3-MI) were counted in the same way, and the Ki-67 PI was calculated for each case. ResultsA strong correlation was found between PHH3-MI and H&E-MI. Recurrence-free survival was correlated with risk category by National Institutes of Health (NIH) consensus criteria (P = 0.017), mucosal invasion (P = 0.005), H&E-MI (P = 0.002), Ki-67 PI (P = 0.005), and PHH3-MI (P = 0.000). None of these factors was an independent prognostic factor. Conclusions Among GISTs, PHH3 staining was primarily found to support grading by facilitating mitotic counting, and it might have a prognostic value in GISTs.
    Basic and Applied Pathology 12/2012; 5(4).
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    ABSTRACT: BACKGROUND: Toll-like receptors (TLR) are a family of pattern recognition receptors that constitutes a major part of the innate immune system. The TLR4/(Myeloid differentiation factor 88 (MyD88) signaling pathway has been shown to have oncogenic effects. METHODS: To demonstrate the role of TLR4/MyD88 signaling in ovarian epithelial cancers (OECs), we examined the expression of TLR4, MyD88 and nuclear factor- kappaB (NF-kappaB) in OECs. The expression of TLR4, MyD88, and NF-kappaB was detected by immunohistochemistry, and the relationships between these and clinicopathologic features in 123 cases of OECs were also analyzed. RESULTS: The expression of TLR4, MyD88, and NF-kappaB in OECs was observed in 46.3% (57/123), 36.6% (45/123) and 65% (80/123) of OEC cases, respectively. The TLR4, MyD88, and NF-kappaB expressions were associated with the histologic type of OECs, particularly with the clear cell type of OEC. There was no significant correlation between TLR4 or NF-kappaB expression and histologic grade, tumor size, mitotic count, FIGO (International Federation of Gynecology and Obstetrics) stage, disease recurrence. However, there was a significant correlation between MyD88 expression and FIGO stage, disease recurrence as well as histologic type. In univariate analysis, the expression of TLR4 and MyD88, and the coexpression of TLR4/MyD88 and TLR4/MyD88/NF-kappaB had a significant impact on the survival of patients with OECs. Only MyD88 expression had an independent prognostic significance in multivariate analysis. CONCLUSIONS: Our findings suggest that the TLR4/MyD88 signaling pathway is associated with the survival of patients with OECs, and that MyD88 is an independent prognostic predictor in patients with OECs. The TLR4/MyD88 signaling pathway may be a mechanism responsible for poor prognosis in patients with clear cell type of OEC.
    World Journal of Surgical Oncology 09/2012; 10(1):193. · 1.09 Impact Factor
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    ABSTRACT: Whereas most carcinomas occur through a sequential step, atypical adenomatous hyperplasia and bronchioloalveolar carcinoma pathway is known for pulmonary adenocarcinoma. This type is known as terminal respiratory unit adenocarcinoma. Based on our observation of transitions from normal ciliated columnar cells to adenocarcinoma via dysplastic mucous columnar cells, we reviewed our archive of pulmonary adenocarcinoma. Terminal respiratory unit type adenocarcinoma was defined as adenocarcinoma with type II pneumocyte, Clara cell, or bronchiolar cell morphology according to previous reports. Among 157 cases, 121 cases have been identified as terminal respiratory unit type adenocarcinoma and 36 cases as non-terminal respiratory unit type adenocarcinoma. Among non-terminal respiratory unit type adenocarcinoma, 24 cases revealed mucous columnar cell changes that were continuous with bronchial ciliated columnar cells. The mucous columnar cells became dysplastic showing loss of cilia, disorientation, and enlarged nuclei. Adenocarcinoma arose from these dysplastic mucous columnar cells and, characteristically, this type of adenocarcinoma showed acute inflammation, and honeycombing changes in the background. TTF1 immunostaining was consistently negative. In a case study with 14 males and 10 females, including 12 smokers or ex-smokers, EGFR and KRAS mutations were detected in 3 and 6 patients, respectively. We think that this kind of adenocarcinoma arising through mucous columnar cell change belongs to non-terminal respiratory unit type adenocarcinoma, and mucous columnar cell change is a precursor lesion of pulmonary adenocarcinoma.
    Modern Pathology 05/2012; 25(9):1265-74. · 5.25 Impact Factor
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    ABSTRACT: Curcumin, a major active component of turmeric Curcuma longa, has been shown to have inhibitory effects on cancers. In vitro studies suggest that curcumin inhibits cancer cell growth by activating apoptosis, but the mechanism underlying the anticancer effects of curcumin is unclear. Recently, it has been suggested that autophagy may play an important role in cancer therapy. However, little data are available regarding the role of autophagy in oral cancers. In this study, we have shown that curcumin has anticancer activity against oral squamous cell carcinoma (OSCC). Induction of autophagy, marked by autophagic vacuoles formation, was detected by acridine orange staining and monodansylcadaverine (MDC) dye after exposure to curcumin. Conversion of LC3-I to LC3-II, a marker of active autophagosome formation, was also detectable by Western blot following curcumin treatment. We have also observed that curcumin induced reactive oxygen species (ROS) production and autophagic vacuoles formation by curcumin was almost completely blocked in the presence of N-acetylcystein (NAC), an antioxidant. Rescue experiments using an autophagy inhibitor suppressed curcumin-induced cell death in OSCC, confirming that autophagy acts as a pro-death signal. Furthermore, curcumin shows anticancer activity against OSCC via both autophagy and apoptosis. These findings suggest that curcumin may potentially contribute to oral cancer treatment and provide useful information for the development of a new therapeutic agent.
    Archives of oral biology 05/2012; 57(8):1018-25. · 1.65 Impact Factor
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    ABSTRACT: Ectomesenchymal chondromyxoid tumor (ECMT) is a rare tumor, exclusively arising in the anterior tongue. Thirty-eight cases have been reported in the English literature. It usually presents as a sessile protrusion and shows round to spindle cells embedded in myxoid to chondroid stroma. Tumor cells are almost always positive for polyclonal glial fibrillary acidic protein (GFAP). We report our experience in the recent treatment of a case of ECMT, the third case in 3 years. The mass in the anterior tongue revealed characteristic morphologic features of ECMT and the expression of polyclonal GFAP. Although ECMT should be differentiated from other mesenchymal tumors including myoepithelioma, its clinical, morphological, and immunohistochemical features enable its diagnosis, especially when pathologists are aware of it.
    Korean journal of pathology. 04/2012; 46(2):192-6.
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    ABSTRACT: Background and aim: With the increasing therapeutic use of endoscopic resection for intestinal early gastric cancer (EGC), it is very important to predict biological behaviors of intestinal type EGC prior to endoscopic resection. On this background, we tried to elucidate the presumptive clinicopathologic factors and biologic markers to predict submucosal invasion and lymph node metastasis based on mucin expression in EGCs. Methods: One hundred and thirty cases of intestinal EGCs were divided as EGCs with intestinal mucin phenotypes (EGC-IPs) and EGCs with gastric mucin phenotypes (EGC-GPs) based on mucin expression. The expressions of mucins (Muc2, Muc5Ac, Muc6, CD10), other protein markers (p53, CDX2, beta-catenin, E-cadherin, Smad4) by immunohistochemistry were studied. Results: EGC-IPs showed significantly increased p53 expression, CDX2 expression and beta-catenin delocalization than EGC-GPs. Using binary logistic regression analysis, expression of both gastric mucin and nuclear beta-catenin expression could be independent predictive factors of lymph node metastasis and submucosal invasion in intestinal EGCs. Lymphovascular emboli, and size of lesion could be clinicopathological independent predictive factors of lymph node metastasis and submucosal invasion in intestinal EGCs, respectively. Conclusions: Taken together, we suggest that beta-catenin expression based on mucin phenotype might be used to predict biologic behavior prior to endoscopic mucosal resection in intestinal EGC.
    Basic and Applied Pathology 09/2011; 4(3).
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    ABSTRACT: Despite wide acceptance of the chronic gastritis-intestinal metaplasia-dysplasia-carcinoma sequence, especially for intestinal-type gastric adenocarcinoma, the precise nature of the subtle precursor lesions of gastric cancer remains to be delineated. For example, pit dysplasia with surface foveolar maturation is not well defined, nor is its prevalence and biological characteristics well characterized. We have evaluated the surrounding gastric mucosa of 414 gastric cancers for the presence of gastric pit dysplasia. We investigated its relationship with various clinicopathological and immunophenotypic features of gastric adenocarcinoma, as well as the severity and extent of any surrounding gastritis and intestinal metaplasia. p53 expression and Ki-67 proliferation index were also evaluated. We have found that 21.0% (n=87) of gastric cancer cases showed pit dysplasia in adjacent gastric mucosa. Gastric cancers with pit dysplasia were significantly associated with older age, male sex, body/fundic location, and intestinal histologic type (P<0.05). Interestingly, gastric mucin-containing intestinal metaplasia (incomplete intestinal metaplasia) was highly associated with adenocarcinoma with pit dysplasia (P=0.000). In addition, MUC6 expression in gastric adenocarcinoma was associated with pit dysplasia (P=0.036). p53 overexpression and increased Ki-67 proliferation index were more evident in gastric pit dysplasia compared with adjacent gastric mucosa. We suggest that gastric pit dysplasia is an important candidate precursor of gastric adenocarcinoma and may represent another morphologic step in the pathogenesis of gastric adenocarcinoma, especially of intestinal type. More detailed prospective studies are needed to determine the precise significance of these findings.
    The American journal of surgical pathology 07/2011; 35(7):1021-9. · 4.06 Impact Factor
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    ABSTRACT: The diagnosis of clinically early-stage (T1) renal cell carcinoma (RCC) has increased. The present study evaluated the association of B7-H4 expression on the pathological outcome and recurrence of carcinoma in the T1 stage of RCC. Among patients who underwent partial or radical nephrectomy after diagnosis of T1 stage RCC during the period of January 2000 to March 2007, 102 pathologically confirmed cases of clear cell carcinoma were included in this study. The patients' medical records were reviewed retrospectively. For the immunohistochemical staining tests, the B7-H4 antibody (Abbiotec 1:500) was used, and clinicopathological characteristics were analyzed. The mean age of the patients (39 males: 38.2%, 63 females: 61.8%) was 53.0±12.0 years (range, 31-74 years), and the mean follow-up time was 33.4±21.0 months (range, 6-84 months). B7-H4 expression was positive in 18 cases and negative in 84 cases. Recurrence during the follow-up period occurred in 5 cases in the group with positive B7-H4 expression and in 7 cases in the group with negative B7-H4 expression, respectively (p=0.035). In the univariate analysis, a statistically significant relationship was observed only for the presence of B7-H4 expression (p=0.0019). In the multivariate analysis, other than the expression of B7-H4, cancer size and TNM stage had effects on the recurrence of cancer. For clear cell RCC, B7-H4 expression had a critical impact on the prognosis of the patients, particularly on the recurrence of the carcinoma in patients with clinical stage T1 RCC.
    Korean journal of urology 02/2011; 52(2):90-5.