Genetic Polymorphisms and Cancer Susceptibility of Breast Cancer in Korean Women

Kang, Daehee 한국생화학분자생물학회 2003 BMB Reports Vol.36 No.1

Breast cancer is the most prevalent cancer among women in Western countries, and its prevalence is increasing in Asia. The major risk factor for breast cancer can be traced to reproductive events that influence the lifetime levels of hormones. However, a large percentage of breast cancer cases cannot, be explained by these risk factors. The identification of susceptibility factors that predispose individuals to breast cancer (for instant, if they are exposed to particular environmental agents) could possibly give further insight into the etiology of this malignancy and provide targets for the future development of therapeutics. The most interesting candidate genes include those that mediate a range of functions. These include carcinogen metabolism, DNA repair, steroid hormone metabolism, signal transduction, and cell cycle control. We conducted a hospital-based case-control study in South korea to evaluated the potential modifying role of the genetic polymorphisms of selected low penetrance genes that are involved in carcinogen metabolisms (i.e., CYPIAI, CYP2EI, GSTM1/T1/P1, NAT1/2, etc.), estrogen synthesis and metabolism (i.e., XRCC1/3, ERCC2/4, ATM, AGT, etc.), and signal transduction as well as others (i.e., TGF-β, IGF-1, TNF-β, IL-1B, IL-1RN, etc.). We also took into account the potential interaction between these and the known risk factors of breast cancer. The results of selected genes will be presented in this mini-review.

Design issues in cross-sectional biomarkers studies: Urinary biomarkers of PAH exposure and oxidative stress

Kang, Daehee,Lee, Kyoung-Ho,Lee, Kyoung-Mu,Kwon, Ho-Jang,Hong, Yun-Chul,Cho, Soo-Hun,Strickland, Paul T. Elsevier 2005 Mutation research Vol.592 No.1-2

<P><B>Abstract</B></P><P>Cross-sectional biomarker studies can provide a snapshot of the frequency and characteristics of exposure/disease in a population at a particular point in time and, as a result, valuable insights for delineating the multi-step association between exposure and disease occurrence. Three major issues should be considered when designing biomarker studies: selection of appropriate biomarkers, the assay (laboratory validity), and the population validity of the selected biomarkers. Factors related to biomarker selection include biological relevance, specificity, sensitivity, biological half-life, stability, and so on. The assay attributes include limit of detection, reproducibility/reliability, inter-laboratory variation, specificity, time, and cost. Factors related to the population validity include the frequency or prevalence of markers, greater inter-individual variation than intra-individual variation, intra-class correlation coefficients (ICC), association with potential confounders, invasiveness of specimen collection, and subject selection.</P><P>Three studies are selected to demonstrate different features of cross-sectional biomarker studies: (1) characterizing the determinants of the biomarkers (study I: urinary PAH metabolites and environmental particulate exposure), (2) relationship of multiple biomarkers of exposure and effect (study II: relationship between urinary PAH metabolites and oxidative stress), and (3) evaluating gene–environmental interaction (study III: effect of genetic polymorphisms of <I>GSTM1</I> on the association of green tea consumption and urinary 1-OHPG levels in shipbuilding workers).</P>

DNA Methylation Regulates the Differential Expression of CX3CR1 on Human IL-7Rα^low and IL-7Rα^high Effector Memory CD8⁺ T Cells with Distinct Migratory Capacities to the Fractalkine

Shin, Min Sun,You, Sungyong,Kang, Youna,Lee, Naeun,Yoo, Seung-Ah,Park, Kieyoung,Kang, Ki Soo,Kim, Sang Hyun,Mohanty, Subhasis,Shaw, Albert C.,Montgomery, Ruth R.,Hwang, Daehee,Kang, Insoo American Association of Immunologists 2015 Journal of Immunology Vol. No.

<P>DNA methylation is an epigenetic mechanism that modulates gene expression in mammalian cells including T cells. Memory T cells are heterogeneous populations. Human effector memory (EM) CD8<SUP>+</SUP> T cells in peripheral blood contain two cell subsets with distinct traits that express low and high levels of the IL-7Rα. However, epigenetic mechanisms involved in defining such cellular traits are largely unknown. In this study, we use genome-wide DNA methylation and individual gene expression to show the possible role of DNA methylation in conferring distinct traits of chemotaxis and inflammatory responses in human IL-7Rα<SUP>low</SUP> and IL-7Rα<SUP>high</SUP> EM CD8<SUP>+</SUP> T cells. In particular, IL-7Rα<SUP>low</SUP> EM CD8<SUP>+</SUP> T cells had increased expression of CX3CR1 along with decreased DNA methylation in the <I>CX3CR1</I> gene promoter compared with IL-7Rα<SUP>high</SUP> EM CD8<SUP>+</SUP> T cells. Altering the DNA methylation status of the <I>CX3CR1</I> gene promoter changed its activity and gene expression. IL-7Rα<SUP>low</SUP> EM CD8<SUP>+</SUP> T cells had an increased migratory capacity to the CX3CR1 ligand fractalkine compared with IL-7Rα<SUP>high</SUP> EM CD8<SUP>+</SUP> T cells, suggesting an important biological outcome of the differential expression of CX3CR1. Moreover, IL-7Rα<SUP>low</SUP> EM CD8<SUP>+</SUP> T cells induced fractalkine expression on endothelial cells by producing IFN-γ and TNF-α, forming an autocrine amplification loop. Overall, our study shows the role of DNA methylation in generating unique cellular traits in human IL-7Rα<SUP>low</SUP> and IL-7Rα<SUP>high</SUP> EM CD8<SUP>+</SUP> T cells, including differential expression of CX3CR1, as well as potential biological implications of this differential expression.</P>

Nitrated Proteome in Human Embryonic Stem Cells

Kang, Jeong Won,Hwang, Daehee,Kim, Kwang Pyo Korean Society for Mass Spectrometry 2016 Mass spectrometry letters Vol.7 No.4

Post-translational modifications (PTMs) of proteins regulate self-renewal and differentiation in embryonic stem cells (ESCs). Nitration of tyrosine residues of proteins in ESCs modulates their downstream pathways, which can affect self-renewal and differentiation. However, protein tyrosine nitration (PTN) in ESCs has been rarely studied. We reviewed 23 nitrated sites in stem cell proteins. Functional enrichment analysis showed that these nitrated proteins are involved in signal transduction, cell adhesion and migration, and cell proliferation in ESCs. Comparison between the nitrated and known phosphorylated sites revealed that 7 nitrated sites had overlapping phosphorylated sites, indicating functional links of PTNs to their associated signaling pathways in ESCs. Therefore, nitrated proteome provides a basis for understanding potential roles of PTN in self-renewal and differentiation of ESCs.

Atomic-scale symmetry breaking for out-of-plane piezoelectricity in two-dimensional transition metal dichalcogenides

Kang, Seunghun,Kim, Sera,Jeon, Sera,Jang, Woo-Sung,Seol, Daehee,Kim, Young-Min,Lee, Jaekwang,Yang, Heejun,Kim, Yunseok Elsevier 2019 Nano energy Vol.58 No.-

<P><B>Abstract</B></P> <P>It is known that only in-plane piezoelectricity exists in pristine two dimensional (2D) transition metal dichalcogenides (TMDs). In this study, we demonstrate the creation of strong out-of-plane piezoelectricity in semiconducting 2H-MoTe<SUB>2</SUB> flakes by an artificial atomic-scale symmetry breaking. The atomic-scale symmetry breaking associated with flexoelectricity was realized through Te vacancy formation by a simple thermal annealing of the 2D TMDs. The strong out-of-plane piezoelectricity was experimentally measured and confirmed by theoretical calculations. This strategy of atomic-scale symmetry modulation for out-of-plane piezoelectricity can be easily applied to a broader class of 2D TMD materials that have not been used for applications with out-of-plane piezoelectricity. Accordingly, it can stimulate the expansion of practical energy device applications with 2D TMD materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Achievement of strong out-of-plane piezoelectricity. </LI> <LI> Atomic-scale symmetry breaking via Te vacancy formation. </LI> <LI> Simple strategy for inducing out-of-plane piezoelectricity by thermal annealing. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

사무실 근로자들에서의 sick building syndrome

강대희 大韓産業醫學會 1996 대한직업환경의학회지 Vol.8 No.3

A cross-sectional study was conducted to evaluate the relationship between sick building syndrome (SBS) and the factors affecting SBS among 90 office workers. The study consisted of 1) a review of previous environmental investigations, 2) measurement of CO₂, temperature, and relative humidity (RH), 3) a questionnaire survey of symptom prevalence and perception of environmental conditions using the National Institute for Occupational Safety and Health Indoor Air Quality (NIOSH IAQ) questionnaire, and 4) confidential interview and a review of medical records of employees having respiratory symptoms. CO₂, temperature, and RH measured on the day of questionnaire survey were within the recommended range by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). Sixty-six percent of respondents were women and 60% considered their job description either "managerial(28%)" or "professional(32%)". Respondents had worked in the building for an average of 5.8 years. Forty-four percent reported having SBS defined as "having one or more symptoms that had occurred at work one or more days a week and tended to get better when away from work". Sex(p=0.001), duration of computer use(p=0.02), use of laser printer(p=0.02), use of cleanser or other office chemicals(p=0.004), feeling too little air movement(0.001), feeling air too dry(p=0.001), and unsatisfied with the current job(p=0.02) were related to an increased prevalence of SBS. Use of cleanser or other office chemicals(p=0.01), feeling too little air movement(p=0.01), and feeling air too dry(p=0.02) remained significant predictors of SBS when adjusting other variables by logistic regression analysis. The results of medical record review revealed a discrepancy in the number of diagnosed asthma cases by personal physician an dan independent physician. Although this study contains several limitations (e.g. cross-sectional study, small numbers of study subjects, etc.), these results indicated that SBS is related to personal, environmental, and psychosocial factors and the precision of diagnosis is critical when evaluating environment-relatedness during disease cluster investigation.

Tunable Out-of-Plane Piezoelectricity in Thin-Layered MoTe₂ by Surface Corrugation-Mediated Flexoelectricity

Kang, Seunghun,Jeon, Sera,Kim, Sera,Seol, Daehee,Yang, Heejun,Lee, Jaekwang,Kim, Yunseok American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.32

<P>Piezoelectricity crystallographically exists only in the in-plane direction in two-dimensional transition metal dichalcogenides. Here, we demonstrated flexoelectricity-tunable out-of-plane piezoelectricity in semiconducting 2H-MoTe<SUB>2</SUB> flakes by creating surface corrugation. In particular, the strong out-of-plane piezoelectricity and its spatial variation depending on local flexoelectricity was observed even though crystallographically there exists only in-plane piezoelectricity. Surface corrugation-mediated flexoelectricity tuning can be applied to other two-dimensional or thin-layered materials and, furthermore, the results could provide useful information on the interweaving nature between mechanical stimulus and electric dipole in low-dimensional materials.</P> [FIG OMISSION]</BR>

Urinary Proteome Profile Predictive of Disease Activity in Rheumatoid Arthritis

Kang, Min Jueng,Park, Yune-Jung,You, Sungyong,Yoo, Seung-Ah,Choi, Susanna,Kim, Dong-Ho,Cho, Chul-Soo,Yi, Eugene C.,Hwang, Daehee,Kim, Wan-Uk American Chemical Society 2014 JOURNAL OF PROTEOME RESEARCH Vol.13 No.11

<P>Current serum biomarkers for rheumatoid arthritis (RA) are not highly sensitive or specific to changes of disease activities. Thus, other complementary biomarkers have been needed to improve assessment of RA activities. In many diseases, urine has been studied as a window to provide complementary information to serum measures. Here, we conducted quantitative urinary proteome profiling using liquid chromatography–tandem mass spectrometry (LC–MS/MS) and identified 134 differentially expressed proteins (DEPs) between RA and osteoarthritis (OA) urine samples. By integrating the DEPs with gene expression profiles in joints and mononuclear cells, we initially selected 12 biomarker candidates related to joint pathology and then tested their altered expression in independent RA and OA samples using enzyme-linked immunosorbent assay. Of the initial candidates, we selected four DEPs as final candidates that were abundant in RA patients and consistent with those observed in LC–MS/MS analysis. Among them, we further focused on urinary soluble CD14 (sCD14) and examined its diagnostic value and association with disease activity. Urinary sCD14 had a diagnostic value comparable to conventional serum measures and an even higher predictive power for disease activity when combined with serum C-reactive protein. Thus, our urinary proteome provides a diagnostic window complementary to current serum parameters for the disease activity of RA.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jprobs/2014/jprobs.2014.13.issue-11/pr500467d/production/images/medium/pr-2014-00467d_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/pr500467d'>ACS Electronic Supporting Info</A></P>

순천시 기후학교 환경교육에 대한 초등학생들의 인식 및 교육효과

김대희(Daehee Kim),안삼영(Samyoung Ahn),강아름(A-reum Kang),유보람(Boram Yoo),이복남(Boknam Lee) 한국환경교육학회 2009 環境 敎育 Vol.22 No.4

While global warming and climate change have been issues with global implications for ecology and nature as well as for the economy, politics and social sector, Korean's climate change awareness has been reported to be low. This phenomenon can be attributed to the fact that there is neither a systematic and continuous educational program for climate change nor a system to implement and support it. Although environmental education traditionally has not been a center of focus in most schools, the move towards green growth in national policies are slowly influencing school education as well. Throughout the year 2009, Green Suncheon 21 has offered a program called 'Suncheon Climate School' designed for elementary schools and regional centers for underprivileged children. Program instructors were sent to schools and centers that requested such climate change education. The aim of this study is to evaluate the success of the program and to provide feedback on its impacts. According to the study, students' interests in climate change have increased after the climate change education, and students found the lectures to be informative and interesting. Students said that they became more aware of the serious consequences of global warming and climate change and found that such education is beneficial and should be available to a wider population. This study suggests that first, school teachers should be aware of climate change and support such educational programs to be a part of the regular curriculum. Second, the content and the level of the program should be designed in consideration of the corresponding school curriculum to make the subject relevant and accessible to students.

Secure and Efficient Time Synchronization for Border Surveillance Wireless Sensor Networks

KIM, Daehee,KANG, Sangwook,AN, Sunshin 'Institute of Electronics, Information and Communi 2016 IEICE transactions on fundamentals of electronics, Vol.ea99 No.1

<P>Time synchronization is of paramount importance in wireless sensor networks (WSNs) due to the inherent distributed characteristics of WSNs. Border surveillance WSNs, especially, require a highly secure and accurate time synchronization scheme to detect and track intruders. In this paper, we propose a Secure and Efficient Time synchronization scheme for Border surveillance WSNs (SETB) which meets the requirements of border surveillance WSNs while minimizing the resource usage. To accomplish this goal, we first define the performance and security requirements for time synchronization in border surveillance WSNs in detail. Then, we build our time synchronization scheme optimized for these requirements. By utilizing both heterogeneous WSNs and one-way key chains, SETB satisfies the requirements with much less overhead than existing schemes. Additionally, we introduce on-demand time synchronization, which implies that time synchronization is conducted only when an intruder enters the WSN, in order to reduce energy consumption. Finally, we propose a method of deploying time-source nodes to keep the synchronization error within the requirement. Our analysis shows that SETB not only satisfies the performance and security requirements, but also is highly efficient in terms of communication and computation overhead, thus minimizing energy consumption.</P>