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Featured researches published by Hyein Ahn.


Journal of Korean Medical Science | 2015

Increased Expression of Forkhead Box M1 Is Associated with Aggressive Phenotype and Poor Prognosis in Estrogen Receptor-Positive Breast Cancer

Hyein Ahn; Jongmin Sim; Rehman Abdul; Min Sung Chung; Seung Sam Paik; Young-Ha Oh; Chan Kum Park; Ki-Seok Jang

Fox transcription factors play a critical role in the regulation of a variety of biological processes. While FoxM1 behaves like the oncogenic transcription factor, FoxO3a is known as a tumor suppressor by inhibiting FoxM1. This study aimed to investigate the clinicopathological significance of FoxM1 and FoxO3a expression in breast cancer. Expression of FoxM1 and FoxO3a were analyzed by immunohistochemical staining on tissue microarray sections from 236 breast cancer patients, and correlated with various clinicopathological characteristics. Overexpression of FoxM1 correlated with adverse clinicopathological features, such as larger tumor size, lymph node metastasis, advanced tumor stage, and lymphovascular invasion. The Kaplan-Meier survival curves revealed no prognostic significance of FoxM1 expression. However, in subgroup analyses with patients of estrogen receptor (ER) positive breast cancers, FoxM1 overexpression associated with poor disease free and overall survival. No association was found between FoxO3a and FoxM1 expression. Regarding clinicopathological variables, the only association between histologic grade and FoxO3a was observed. In conclusion, FoxM1 overexpression was significantly associated with aggressive phenotypes and poor prognosis of ER-positive breast cancer. These findings suggest the possible role of FoxM1 as a prognostic biomarker and putative target of anti-cancer therapy. Graphical Abstract


Journal of Breast Cancer | 2015

Clinicopathological significance of dual-specificity protein phosphatase 4 expression in invasive ductal carcinoma of the breast.

Hyunsung Kim; Se Min Jang; Hyein Ahn; Jongmin Sim; Kijong Yi; Yumin Chung; Hulin Han; Abdul Rehman; Min Sung Chung; Ki-Seok Jang; Seung Sam Paik

Purpose Dual-specificity protein phosphatase 4 (DUSP4), also known as mitogen-activated protein kinase phosphatase (MKP) 2 is a member of the inducible nuclear MKP group. The role of DUSP4 in cancer development and progression appears to vary with the type of malignancy. The purpose of this study was to investigate DUSP4 expression in a case series of invasive ductal carcinoma of the breast. Methods We constructed tissue microarrays consisting of 16, 14, 47, and 266 cases of normal breast tissue, usual ductal hyperplasia, ductal carcinoma in situ, and invasive ductal carcinoma, respectively. DUSP4 expression was investigated by immunohistochemistry. Results Cytoplasmic DUSP4 expression was observed. DUSP4 was more frequently expressed in malignant than in benign cases (p=0.024). The mean DUSP4 expression score was significantly higher in malignant tumors than in benign lesions (p=0.019). DUSP4 expression was significantly correlated with a larger tumor size (>2 cm, p=0.015). There was no significant correlation between overall survival or disease-free survival and DUSP4 expression in all 266 patients. We evaluated the impact of DUSP4 expression on the survival of 120 patients with T1-stage tumors. Interestingly, Kaplan-Meier survival curves revealed that DUSP4 expression had a significant effect on both overall patient survival (p=0.034, log-rank test) and disease-free survival (p=0.045, log-rank test). In early T-stage breast cancer, DUSP4 expression was associated with a worse prognosis. Conclusion DUSP4 is frequently upregulated in breast malignancy, and may play an important role in cancer development and progression. In addition, it may be a marker of adverse prognosis, especially in patients with early T1-stage cancer.


Journal of Breast Cancer | 2015

High MicroRNA-370 Expression Correlates with Tumor Progression and Poor Prognosis in Breast Cancer

Jongmin Sim; Hyein Ahn; Rehman Abdul; Hyunsung Kim; Ki Jong Yi; Yu Min Chung; Min Sung Chung; Seung Sam Paik; Young Soo Song; Ki-Seok Jang

Purpose Deregulation of microRNA-370 (miR-370) has been reported in various cancers, in which it can act as either an oncogene or a tumor suppressor gene. However, the clinicopathologic significance of miR-370 expression in breast cancer has not been studied. Methods The expression of miR-370 was determined with quantitative real-time polymerase chain reaction in 60 formalin-fixed, paraffin-embedded primary breast cancer tissues. Additionally, the protein expression levels of previously known targets of miR-370, such as FOXM1, FOXO1, and FOXO3a, were detected using immunohistochemistry. Finally, we analyzed its correlation with target protein expression, clinicopathologic features, and clinical outcome. Results High levels of miR-370 expression correlated with lymph node metastasis (p=0.009), advanced stage (p=0.002), and frequent perineural invasion (p=0.042). Moreover, patients with high miR-370 expression had poor disease-free survival compared with the low-expression group. However, no correlation was observed between miR-370 and its target protein expression. Conclusion Our results indicate that upregulation of miR-370 in breast cancer is correlated with breast cancer progression and that it might be a potential biomarker for predicting clinical outcomes.


Journal of Clinical Pathology | 2018

FOXO3a expression is associated with lymph node metastasis and poor disease-free survival in triple-negative breast cancer

Abdul Rehman; Yeseul Kim; Hyunsung Kim; Jongmin Sim; Hyein Ahn; Min Sung Chung; Su-Jin Shin; Ki-Seok Jang

Aims Forkhead box O (FOXO) transcription factors, consisting of FOXO1, FOXO3a, FOXO4 and FOXO6, are involved in carcinogenesis and tumour progression. Recent studies have suggested that FOXOs act as tumour suppressors in a variety of human cancers. This study investigated the clinicopathological significance of FOXOs in triple-negative breast cancer (TNBC). Methods FOXO protein expressions were assessed by immunohistochemistry in 125 TNBC tissues. Correlations between FOXO protein expression and various clinicopathological parameters, including patients’ survival, were investigated. MDA-MB-468 cell line was used for in vitro cell proliferation and migration assay. Results FOXO1 protein expression was not observed in all 125 TNBC tissues. FOXO4 and FOXO6 protein expressions were detected in 11 (8.8%) and 14 (11.2%) TNBC tissues, respectively. Loss of FOXO4 expression was significantly associated with high histological grade (P=0.014, χ2 test), and TNBCs with positive FOXO6 expression correlated with high grade (P=0.020, χ2 test). FOXO3a expression was detected in 40 (32%) TNBC cases and correlated with adverse clinicopathological features, such as lymph node metastasis (P=0.021, χ2 test), perineural invasion (P=0.013, χ2 test) and higher Ki-67 proliferation index (P=0.048, t-test). Additionally, FOXO3a expression was significantly associated with poor disease-free survival (P=0.015, log-rank test). In the in vitro study, siRNA-mediated FOXO3a knockdown in the MDA-MB-468 cell line inhibited cell proliferation and migration. Conclusion Among FOXO members, FOXO3a may have a potential role in promoting tumour cell migration and proliferation and may serve as a prognostic biomarker and a potential therapeutic target for TNBC.


Gastroenterology Research and Practice | 2015

Immunohistochemical Expression of Dual-Specificity Protein Phosphatase 4 in Patients with Colorectal Adenocarcinoma

Jongmin Sim; Kijong Yi; Hyunsung Kim; Hyein Ahn; Yumin Chung; Abdul Rehman; Se Min Jang; Kang Hong Lee; Ki-Seok Jang; Seung Sam Paik

The role of dual-specificity protein phosphatase 4 (DUSP4) appears to vary with the type of malignant tumors and is still controversial. The purpose of our study was to clarify the exact role of DUSP4 expression in colorectal adenocarcinoma. We constructed tissue microarrays and investigated DUSP4 expression by immunohistochemistry. DUSP4 was more frequently expressed in adenocarcinomas and lymph node/distant metastases compared to that in normal colorectal tissues and tubular adenomas (P < 0.001). Mean DUSP4 expression score was significantly higher in malignant tumors than in benign lesions (P < 0.001). DUSP4 expression was significantly correlated with older age (P = 0.017), male gender (P = 0.036), larger tumor size (P = 0.014), nonmucinous tumor type (P = 0.023), and higher T stage (P = 0.040). Kaplan-Meier survival curves revealed a significant effect of DUSP4 expression on both overall survival and disease-free survival in AJCC stage I (P = 0.008 and P = 0.003, resp., log-rank test) and male gender (P = 0.017 and P = 0.049, resp., log-rank test). DUSP4 protein is frequently upregulated in colorectal adenocarcinoma and may play an important role in carcinogenesis and cancer progression and may be a marker of adverse prognosis.


American Journal of Clinical Pathology | 2018

Overexpression of Forkhead Box O3a and Its Association With Aggressive Phenotypes and Poor Prognosis in Human Hepatocellular Carcinoma

Hyein Ahn; Hyunsung Kim; Rehman Abdul; Yesul Kim; Jongmin Sim; Dongho Choi; Seung Sam Paik; Su-Jin Shin; Dong-Hoon Kim; Ki-Seok Jang

Objectives Recent research has demonstrated that forkhead box O3a (FoxO3a) may function as an oncogenic transcription factor. We sought to validate the clinicopathologic significance of FoxO3a expression in hepatocellular carcinoma (HCC). Methods Western blotting and immunohistochemistry were used to determine FoxO3a expression. In vitro cell proliferation and migration assays were performed in a HepG2 cell line. Results FoxO3a was overexpressed in 121 (64.71%) cases of HCC. FoxO3a overexpression was associated with aggressive phenotypes of HCC, such as histologic grade (P < .001), stage (P = .031), and small vessel invasion (P < .001). FoxO3a overexpression was also correlated with poor disease-free survival in both univariate and multivariate survival analyses (P = .001 and P = .018, respectively). Downregulation of FoxO3a in a HepG2 cell line inhibited cell proliferation and migration. Conclusions These results suggest a role for FoxO3a in HCC progression and support the potential use as a prognostic biomarker.


The Korean Journal of Gastroenterology | 2016

A Case of Myeloid Sarcoma of Intestine

Sung Won Lim; Hang Lak Lee; Kang Nyeong Lee; Dae Won Jun; In Young Kim; Eun Jin Kim; Hyein Ahn; Chan Kum Park

Myeloid sarcoma (MS) is an extramedullary involvement of immature myeloid proliferation. An isolated MS is defined as a myeloblastic tumor when it arises without any concomitant circulating disease. A diagnosis of MS is established using pathologic features including infiltration of myeloblasts and strong myeloperoxidase expression with negative cytokeratin immunohistochemical staining. We report a rare case of colonic MS without any peripheral blood abnormality. If the affected patient were left untreated, the MS could evolve into acute myeloid leukemia (AML) within one year. Several studies recommend the same regimens of chemotherapy as used for circulating AML to treat isolated MS. We focused on the diagnosis of MS in this study. The correct diagnosis of MS is important for adequate treatment. In conclusion, MS should be considered in the differential diagnosis of intestinal tumor.


Journal of pathology and translational medicine | 2016

Clinicopathologic Correlations of E-cadherin and Prrx-1 Expression Loss in Hepatocellular Carcinoma.

Kijong Yi; Hyunsung Kim; Yumin Chung; Hyein Ahn; Jongmin Sim; Young Chan Wi; Ju Yeon Pyo; Young-Soo Song; Seung Sam Paik; Young-Ha Oh

Background Developing predictive markers for hepatocellular carcinoma (HCC) is important, because many patients experience recurrence and metastasis. Epithelial to mesenchymal transition (EMT) is a developmental process that plays an important role during embryogenesis and also during cancer metastasis. Paired-related homeobox protein 1 (Prrx-1) is an EMT inducer that has recently been introduced, and its prognostic significance in HCC is largely unknown. Methods Tissue microarray was constructed using surgically resected primary HCCs from 244 cases. Immunohistochemical staining of E-cadherin and Prrx-1 was performed. The correlation between E-cadherin loss and Prrx-1 expression, as well as other clinicopathologic factors, was evaluated. Results E-cadherin expression was decreased in 96 cases (39.4%). Loss of E-cadherin correlated with a higher recurrence rate (p < .001) but was not correlated with patient’s survival. Thirty-two cases (13.3%) showed at least focal nuclear Prrx-1 immunoreactivity while all non-neoplastic livers (n = 22) were negative. Prrx-1 expression was not associated with E-cadherin loss, survival or recurrence rates, pathologic factors, or the Ki-67 labeling index. Twenty tumors that were positive for E-cadherin and Prrx-1 had significantly higher nuclear grades than the rest of the cohort (p = .037). In Cox proportional hazard models, E-cadherin loss and large vessel invasion were independent prognostic factors for shorter disease-free survival. Cirrhosis and high Ki-67 index (> 40%) were independent prognostic factors for shorter overall survival. Conclusions Prrx-1 was expressed in small portions of HCCs but not in normal livers. Additional studies with a large number of Prrx-1-positive cases are required to confirm the results of this study.


Korean Journal of Pathology | 2014

Lymphoepithelioma-like Carcinoma of the Renal Pelvis: A Case Report and Review of the Literature

Hyein Ahn; Jongmin Sim; Hyunsung Kim; Kijong Yi; Hulin Han; Yumin Chung; Abdul Rehman; Seung Sam Paik

Lymphoepithelioma is an undifferentiated epithelial tumor primarily described in the nasopharynx and characterized by syncytial nests of malignant epithelial cells with a prominent reactive lymphoid infiltrate [1]. A carcinoma that shows similar histological features but arises outside the nasopharynx is called lymphoepithelioma-like carcinoma (LELC). LELC has been described in a variety of organs including salivary glands, thymus, lungs, stomach, skin, uterine cervix, breast, prostate, and the urinary tract [2]. The renal pelvis is an extremely rare site for this tumor. To the best of our knowledge, only eight cases have been reported in the English literature and one case has been reported in the Korean literature [1-8]. We recently experienced a case of LELC arising in the right renal pelvis in a 65-year-old woman.


Oncotarget | 2017

Clinicopathologic implications of the miR-197/PD-L1 axis in oral squamous cell carcinoma

Hyein Ahn; Jeong Mi Yang; Hyojin Kim; Jin-Haeng Chung; Soon-Hyun Ahn; Woo-Jin Jeong; Jin Ho Paik

Immune escape of a tumor from tumor-infiltrating lymphocytes (TILs) is induced by PD-L1, which is suppressed by miR-197. We investigated the clinicopathologic implications of the miR-197/PD-L1 axis and its effects on TILs and the clinicopathologic features of oral squamous cell carcinoma (OSCC). We used RT-PCR and immunohistochemistry in 68 OSCC patients to analyze the correlations between tumoral expression of miR-197 and PD-L1 and the degree of tumoral invasion by TILs (CD3+, CD4+, CD8+, PD-1+, FoxP3+, and CD20+ lymphocytes). PD-L1 levels correlated inversely with miR-197 but correlated positively with TILs. The aggressive features of OSCC, including high stage, angiolymphatic invasion, perineural invasion, and death, were associated with TIL depletion. High T stage (T4) tumors also had low PD-L1 but had high miR-197 expression. In a univariate survival analysis of the full cohort, high miR-197 was associated with poor overall survival, whereas high PD-L1 expression (2+) associated with good overall survival. In a multivariate analysis stratified based on miR-197 (median), high PD-L1 expression (2+) was an independent favorable prognostic factor for overall survival (P = 0.040) in the miR-197high subgroup but not the miR-197low subgroup. These findings may have clinicopathologic implications for the miR-197/PD-L1 axis and TILs in OSCC.

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