Comparison between screen-detected and symptomatic breast cancers according to molecular subtypes.

Kim, Jiyoung,Lee, SeKyung,Bae, Sooyoun,Choi, Min-Young,Lee, Jeonghui,Jung, Seung Pil,Kim, Sangmin,Choe, Jun-Ho,Kim, Jung-Han,Kim, Jee Soo,Lee, Jeong Eon,Nam, Seok Jin,Yang, Jung-Hyun M. Nijhoff ; Kluwer Academic Publishers 2012 Breast cancer research and treatment Vol.131 No.2

<P>Breast cancer screening programs make it possible to detect early cancer, thus reducing breast cancer mortality. We studied the clinicopathologic characteristics and prognosis of screen-detected invasive breast cancer compared with symptomatic breast cancer. And we compared the result according to molecular subtypes (luminal A, luminal B, Her2, and triple negative), with the goal of identifying the role of screening in each subtypes. From January 2002 to June 2008, 3,141 patients who underwent surgery for the treatment of invasive ductal carcinoma at Samsung Medical Center were included. Among them, 1,025 patients were screen-detected, and 2,116 patients who were screened over 2 years or never were symptomatic. We retrospectively reviewed the clinical and pathologic data. Screen-detected breast cancer was associated with older age, smaller tumor size, more hormone-receptor positive, less lymph node involvement, earlier stage, and reduced mortality compared with symptomatic breast cancer (P < 0.001). According to the molecular subtype, luminal A was most common (63.6%) and showed the most obvious survival benefit in screen-detected tumors in comparison with symptomatic tumors (5-year OS: 99.7 vs. 96.5%, 5-year DFS: 96.4 vs. 90.7%). Screen detection was independently associated with improved overall and disease-free survival outcomes after adjustment for covariates (HR 0.32, P = 0.035; HR 0.58, P = 0.020, respectively) only in the luminal A subtype. Differences in pathological features such as tumor size, nodal status, grade, and age at diagnosis with different molecular subtype distributions may explain the survival advantage of patients with screen-detected breast cancer. Screening programs seem to have a different efficacy depending on the molecular subtype of the breast cancer, especially in the luminal A subtype, for which screen detection acts as an independent prognostic factor itself.</P>

Regulation of anoikis resistance by NADPH oxidase 4 and epidermal growth factor receptor

Kim, Hyeryeong,Sung, Jee Young,Park, Eun-Kyung,Kho, Seongho,Koo, Kyung Hee,Park, Seog-Yun,Goh, Sung-Ho,Jeon, Yoon Kyung,Oh, Sekyung,Park, Byung-Kiu,Jung, Yong-Keun,Kim, Yong-Nyun Nature Publishing Group 2017 The British journal of cancer Vol.116 No.3

<P><B>Background:</B></P><P>Normal cells are sensitive to anoikis, which is a cell detachment-induced apoptosis. However, cancer cells acquire anoikis resistance that is essential for successful metastasis. This study aimed to demonstrate the function and potential mechanism of NADPH oxidase 4 (<I>NOX4</I>) and EGFR activation in regulating anoikis resistance in lung cancer.</P><P><B>Methods:</B></P><P>Cells were cultured either in the attached or suspended condition. Cell viability was measured by cell counting and live and dead cell staining. Expression levels of NOX4 and EGFR were measured by PCR and immunoblotting. Reactive oxygen species (ROS) levels were measured by flow cytometry. Effects of NOX4 overexpression or <I>NOX4</I> knockdown by si-NOX4 on anoikis sensitivity were explored. Levels of NOX4 and EGFR in lung cancer tissues were evaluated by IHC staining.</P><P><B>Results:</B></P><P>NOX4 was upregulated but EGFR decreased in suspended cells compared with attached cells. Accordingly, ROS levels were increased in suspended cells, resulting in the activation of Src and EGFR. <I>NOX4</I> knockdown decreased activation of Src and EGFR, and thus sensitised cells to anoikis. NOX4 overexpression increased EGFR levels and attenuated anoikis. NOX4 expression is upregulated and is positively correlated with EGFR levels in the lung cancer patient tissues.</P><P><B>Conclusions:</B></P><P>NOX4 upregulation confers anoikis resistance by ROS-mediated activation of EGFR and Src, and by maintaining EGFR levels, which is critical for cell survival.</P>

Alternative new mesenchymal stem cell source exerts tumor tropism through ALCAM and N-cadherin via regulation of microRNA-192 and -218

Kim, Ran,Park, Sang In,Lee, Chang Youn,Lee, Jihyun,Kim, Pilseog,Oh, Sekyung,Lee, Hojin,Lee, Min Young,Kim, Jongmin,Chung, Yong-An,Hwang, Ki-Chul,Maeng, Lee-So,Chang, Woochul Springer US 2017 MOLECULAR AND CELLULAR BIOCHEMISTRY - Vol.427 No.1

<P>Gliomas are the most common type of malignant primary brain tumors. Some treatments of gliomas exist, but they are rarely curative. Mesenchymal stem cells (MSCs) are emerging as potential modes of targeted cancer therapy owing to their capacity for homing toward tumor sites. It has been proposed that MSCs derived from various sources, such as bone marrow, adipose tissue and umbilical cord blood, can be used as cell-based therapy for brain tumors. Here, MSCs obtained from the synovial fluid of osteoarthritis or rheumatoid arthritis patients were investigated as therapeutic candidates. Specifically, we compared migratory and adhesive abilities, as well as expression levels of related genes and microRNA in bone marrow derived-MSCs (BMMSCs), adipose derived-MSCs (ADMSCs), and synovial fluid derived-MSCs (SFMSCs) after treatment with conditioned medium from gliomas. Migration and adhesion of SFMSCs increased through upregulation of the activated lymphocyte cell adhesion molecule (ALCAM) and N-cadherin by microRNA-192 and -218 downregulation, similar to BMMSCs and ADMSCs. Migratory capacities of all types of MSCs were evaluated in vivo, and SFMSCs migrated intensively toward gliomas. These results suggest that SFMSCs have potential for use in cell-based antitumor therapies.</P>

텍스트마이닝을 활용한 장애인 돌봄 연구의 동향

김정석 ( Kim Cheong-seok ),곽정란 ( Kwak Jeongran ),김미선 ( Kim Miseon ),박세경 ( Park Sekyung ) 대구대학교 한국특수교육문제연구소 2022 특수교육저널 : 이론과 실천 Vol.23 No.2

[Purpose] The purpose of this study was to empirically analyze how changes in social and policy perceptions and approaches to caring for the disabled are reflected in academic discourse using text mining techniques. [Methods] The analysis targeted the 170 papers in the Korean Citation Index, registered between January 2005 and March 2022, that included the term care for the disabled. After examining the distribution of articles by period of publication and academic discipline, keyword frequency analysis, semantic network analysis, and topic modeling were conducted using the Korean-languages titles and abstracts. To examine periodic trends, publication dates were divided into four periods, namely the late 2000s, early 2010s, late 2010s, and early 2020s. [Results] First, papers about caring for disabled people have increased significantly in recent years and have been produced across various academic fields. Second, the keyword frequency and semantic network analyses show that terms relating to family care, such as 'children', 'mother', 'parent', and 'family', have high frequency and high centrality throughout the publication period. On the other hand, keywords relating to social care, such as ‘self-reliance’, ‘de-facility’, and ‘community integrated care’, occupy more peripheral positions. In the analysis by period, the frequency of family-based keywords was maintained while their centrality decreased somewhat, and both the frequency and centrality of 'community' gradually increased. Third, topic modeling for this research on caring for the disabled extracted four groups: Topic 1 is support for community-care services for those with developmental disabilities; Topic 2 is personal assistant services and care labor; Topic 3 is the burden on parents and families of caring for children with disabilities and social support for them; and Topic 4 is the care experience and stress of mothers caring for children with developmental disabilities. The number of articles in the social care Topics 1 and 2 increased significantly over time, and family-based articles in Topics 3 and 4 accounted for a large proportion of research throughout. [Conclusion] In the context of caring for the disabled, the research paradigm that the family is the main agent of care while society plays a partial role has persisted. This suggests a necessity for academic discourse that promotes the socialization of care.

경기도 낙엽송 임분의 지위지수 함수식 추정

김형호 ( Hyungho Kim ),정주상 ( Joosang Chung ),정세경 ( Sekyung Chong ),손영모 ( Yeongmo Son ),김의경 ( Euigyeong Kim ) 산림경영정보학회 2009 산림경영정보 Vol.12 No.0

Enhanced Healing of Rat Calvarial Bone Defects with Hypoxic Conditioned Medium from Mesenchymal Stem Cells through Increased Endogenous Stem Cell Migration via Regulation of ICAM-1 Targeted-microRNA-221

Chang, Woochul,Kim, Ran,Park, Sang In,Jung, Yu Jin,Ham, Onju,Lee, Jihyun,Kim, Ji Hyeong,Oh, Sekyung,Lee, Min Young,Kim, Jongmin,Park, Moon-Seo,Chung, Yong-An,Hwang, Ki-Chul,Maeng, Lee-So Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.7

The use of conditioned medium from mesenchymal stem cells may be a feasible approach for regeneration of bone defects through secretion of various components of mesenchymal stem cells such as cytokines, chemokines, and growth factors. Mesenchymal stem cells secrete and accumulate multiple factors in conditioned medium under specific physiological conditions. In this study, we investigated whether the conditioned medium collected under hypoxic condition could effectively influence bone regeneration through enhanced migration and adhesion of endogenous mesenchymal stem cells. Cell migration and adhesion abilities were increased through overexpression of intercellular adhesion molecule-1 in hypoxic conditioned medium treated group. Intercellular adhesion molecule-1 was upregulated by microRNA-221 in mesenchymal stem cells because microRNAs are key regulators of various biological functions via gene expression. To investigate the effects in vivo, evaluation of bone regeneration by computed tomography and histological assays revealed that osteogenesis was enhanced in the hypoxic conditioned medium group relative to the other groups. These results suggest that behavioral changes of endogenous mesenchymal stem cells through microRNA-221 targeted-intercellular adhesion molecule-1 expression under hypoxic conditions may be a potential treatment for patients with bone defects.

하이브리드 지게차 엔진-발전기의 제어 개념 및 연비 추정의 신뢰성 평가

김성철(Seongcheol Kim),최세경(Sekyung Choi),정명길(Myungkil Jung),김준혁(Junhyuk Kim) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5

This paper presents control concepts of engine-generator and reliability evaluation of fuel efficiency estimation through engine dynamometer test. In terms of speed or torque control concepts, the control methods of engine-generator are tested about four cases, and the response characteristics were analyzed. This test was carried out assuming engine-generator system similar to engine dynamometer. The control concept of engine-generator is needed to develop a higher level control algorithm of the hybrid forklifts such as HCU (Hybrid Control Unit). When HCU algorithm is developed, the engine static fuel efficiency map is mostly used to evaluate fuel efficiency of HCU algorithm even if simulation profiles are under dynamic situation. To verify reliability of estimated fuel efficiency based on the engine static fuel efficiency map, the estimated fuel consumption was compared to measured fuel consumption in the dynamic operation situation of an engine. This test result showed usability of a fuel consumption estimation using engine static fuel efficiency map.

Therapeutic Potential of Stem Cells Strategy for Cardiovascular Diseases

Lee, Chang Youn,Kim, Ran,Ham, Onju,Lee, Jihyun,Kim, Pilseog,Lee, Seokyeon,Oh, Sekyung,Lee, Hojin,Lee, Minyoung,Kim, Jongmin,Chang, Woochul Hindawi Publishing Corporation 2016 Stem cells international Vol.2016 No.-

<P>Despite development of medicine, cardiovascular diseases (CVDs) are still the leading cause of mortality and morbidity worldwide. Over the past 10 years, various stem cells have been utilized in therapeutic strategies for the treatment of CVDs. CVDs are characterized by a broad range of pathological reactions including inflammation, necrosis, hyperplasia, and hypertrophy. However, the causes of CVDs are still unclear. While there is a limit to the currently available target-dependent treatments, the therapeutic potential of stem cells is very attractive for the treatment of CVDs because of their paracrine effects, anti-inflammatory activity, and immunomodulatory capacity. Various studies have recently reported increased therapeutic potential of transplantation of microRNA- (miRNA-) overexpressing stem cells or small-molecule-treated cells. In addition to treatment with drugs or overexpressed miRNA in stem cells, stem cell-derived extracellular vesicles also have therapeutic potential because they can deliver the stem cell-specific RNA and protein into the host cell, thereby improving cell viability. Here, we reported the state of stem cell-based therapy for the treatment of CVDs and the potential for cell-free based therapy.</P>

Exogenous miRNA-146a Enhances the Therapeutic Efficacy of Human Mesenchymal Stem Cells by Increasing Vascular Endothelial Growth Factor Secretion in the Ischemia/Reperfusion-Injured Heart

Seo, Hyang-Hee,Lee, Se-Yeon,Lee, Chang Youn,Kim, Ran,Kim, Pilseog,Oh, Sekyung,Lee, Hojin,Lee, Min Young,Kim, Jongmin,Kim, Lark Kyun,Hwang, Ki-Chul,Chang, Woochul S. Karger 2017 Journal of vascular research Vol.54 No.2

<P>Adult stem cells have been studied as a promising therapeutic modality for the functional restoration of the damaged heart. In the present study, a strategy for enhancing the angiogenic efficacy of human mesenchymal stem cells (hMSCs) using micro-RNA was examined. We investigated whether micro-RNA-146a (miR-146a) influences the secretion of vascular endothelial growth factor (VEGF) and angiogenesis of MSCs. Our data indicated that miR-146a-transfected hMSCs (hMSC<SUP>miR-146a</SUP>) decreased the expression of neurofibromin 2, an inhibitor of p21-activated kinase-1 (PAK1). miR-146a also increased the expression of Ras-related C3 botulinum toxin substrate 1 and PAK1, which are known to induce VEGF expression, and the formation of vascular branches was increased in hMSC<SUP>miR-146a</SUP> compared to hMSCs treated with VEGF. VEGF and p-Akt were increased in hMSC<SUP>miR-146a</SUP>. Furthermore, injection of hMSC<SUP>miR-146a</SUP> after ischemia/reperfusion (I/R) injury led to a reduction of fibrosis area and increased VEGF expression, confirming the regenerative capacity such as reparative angiogenesis in the infarcted area. Cardiac functions in I/R injury were improved following injection of hMSC<SUP>miR-146a</SUP> compared to the I/R group. Taken together, these data suggest that miR-146 is a novel microRNA that regulates VEGF expression, and its use may be an effective strategy for enhancing the therapeutic efficacy of hMSC transplantation into the I/R-injured heart.</P>

Different Motives and Different Market Reactions to Convertible Bonds and Bonds with Warrants Issuance in Korea

Sekyung Oh,Woo Sung Kim 한국재무학회 2012 한국재무학회 학술대회 Vol.2012 No.05

We examine why firms issue hybrid securities including CBs and BWs, what are the determinants of choice of issuers between CBs and BWs and why market reactions to CBs and BWs issues are different in Korea. Our study is based on the sample of CBs and BWs that were issued in Korea between 2000 and 2010. Our empirical results are as follows. First, we find that the characteristics of hybrid security issuers are quite different from those of non-hybrid security issuers. Second, we find that difference in motives of issuing firms between CBs and BWs largely exist, even though these securities have very similar characteristics. Specifically, CBs are more likely issued by firms with more future growth opportunity whereas BWs are more likely issued by firms with higher short term growth rate. Third, we also find that the announcement effects of CBs are negative and statistically insignificant whereas the announcement effects of BWs are statistically significant and positive.