AR-mTOR-SRF Axis Regulates HMMR Expression in Human Prostate Cancer Cells

( You Sun ),( Zewu Li ),( Kyung Song ) 한국응용약물학회 2021 Biomolecules & Therapeutics(구 응용약물학회지) Vol.29 No.6

The elevated expression of the hyaluronan-mediated motility receptor (HMMR) is known to be highly associated with tumor progression in prostate cancer, but the molecular mechanisms underlying the regulation of HMMR expression remain unclear. Here, we report that mammalian target of rapamycin (mTOR) is a key regulator of HMMR expression, for which its kinase activity is required. Pharmacological inhibitors of mTOR, such as rapamycin and Torin2, markedly suppressed the mRNA level as well as the protein level of HMMR in LNCaP and PC-3 cells. Our data demonstrate that such regulation occurs at the transcription level. HMMR promoter reporter assays revealed that the transcription factor SRF is responsible for the mTOR-mediated transcriptional regulation of HMMR gene. Consistently, the suppression of HMMR expression by Torin2 was noticeably reversed by the overexpression of SRF. Moreover, our findings suggest that the SRF binding sites responsible for the transcriptional regulation of HMMR through the mTOR-SRF axis are located in HMMR promoter sequences carrying the first intron, downstream of the translational start site. Furthermore, the upregulation of HMMR by DHT was abolished by stimulation with rapamycin, prior to DHT treatment, suggesting that mTOR activity is required for the induction of HMMR expression by androgen. Collectively, our study provides new mechanistic insights into the role of mTOR/SRF/AR signaling in HMMR regulation in prostate cancer cells.

Transcriptional suppression of androgen receptor by 18β-glycyrrhetinic acid in LNCaP human prostate cancer cells

You Sun,Mingyue Jiang,Pil‑Hoon Park,Kyung Song 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.4

Androgen receptor (AR) plays a pivotal role as atarget for amplification/mutation in pathogenesis and tumorprogression in prostate, and thus, controlling AR activityor expression might be a feasible therapeutic approach forthe treatment of prostate cancer. Here, we report the novelmechanisms by which 18β-glycyrrhetinic acid (GA) targetsAR to stimulate cell death in both hormone-responsive and-refractory prostate cancer cells. We found that miR-488, atumor suppressive microRNA, was markedly induced by GAtreatment, resulting in the down-regulation of AR expressionand inhibition of cellular responses mediated by androgens. Moreover, GA not only suppressed the expression of androgentarget genes (TMPRSS2, PSA, and NKX3.1), but alsoenhanced the suppressive effect of anti-androgens (bicalutamideand flutamide) on LNCaP cell growth. Our data furtherprovides evidence that down-regulation of AR expression byGA may occur through transcriptional suppression at AR promoter region between − 1014 and − 829. Ectopic expressionof SFR and E2F3α reversed the inhibitory effect of GAon AR promoter activity as well as protein expression, suggestingthat GA may target transcription factors SRF andE2F3α to regulate AR expression. Taken together, our studyprovides new insights on AR regulation and GA as a potentialtherapeutic candidate for human prostate cancer.

대학생의 그릿과 도움요청의 관계에서 성취목표의 매개효과

김유선 ( Kim¸ You-sun ),한천우 ( Han¸ Cheon-woo ) 한국아동교육학회 2021 아동교육 Vol.30 No.3

본 연구는 대학생을 대상으로 그릿과 성취목표, 도움요청행동 간의 구조적 관계를 살펴보고 성취 목표의 매개 효과에 대해 검증하고자 실시한 연구이다. 이를 위해 D광역시 소재 K대학 4년제 대학생 269명을 대상으로 설문 조사를 실시하였으며, 이 중 유효한 251명의 설문 자료를 최종분석에 사용하였다. 수집된 자료는 SPSS 25와 Mplus 8을 이용하여 구조방정식모형을 분석하였다. 본 연구의 주요 결과는 다음과 같다. 첫째, 그릿과 성취목표, 도움요청행동 간의 구조적 관계를 분석한 결과, 그릿은 도움회피만을 부적으로 예측하였다. 둘째, 성취목표 중 숙달목표는 대학생의 도움요청 행동에 직접적으로 유의미한 영향을 주었으며, 이 중 도구적 도움만을 긍정적으로 예측하였다. 셋째, 숙달목표만이 그릿과 도움요청행동 간의 관계에서 완전매개 또는 부분매개 역할을 하였다. 본 연구는 기존의 선행연구에서 다루지 않은 그릿과 도움요청행동 간의 관계를 살펴보고 대학생의 도움요청행동을 끌어낼 수 있는 변인으로 그릿의 역할과 숙달목표의 중요성을 시사해 주는 데에 의의를 가진다. This research was designed to investigate structural relationships among grit, achievement goals, help-seeking behaviors for university students. To do so, 269 university students in D city were participated for this study, but 19 of them were excluded for the final analyses. SPSS 25 and Mplus 8 were used to perform preliminary analyses and structural equation modeling. Major findings as follows. First of all, grit was positively associated with avoidant help-seeking behaviors. Second, direct effects of the mastery goals on college students’ help-seeking behaviors were significant. Specifically, the association with instrumental help-seeking was only positive. Third, mastery goals could partially or fully mediate between grit and help-seeking behaviors. This research has explored the relationships between grit and help-seeking behaviors which has not been directly tested, and theoretical and practical implication were suggested.

A Pilot Project for the Expansion of the External Quality Assessment Program in Transfusion Medicine: Anti-D Titer Test

Yousun Chung,Jin Seok Kim,육희정,Sang-Hyun Hwang,Heung-Bum Oh,Hyungsuk Kim,Dae-Hyun Ko 대한임상검사정도관리협회 2022 Journal of Laboratory Medicine And Quality Assuran Vol.44 No.2

Background: Many test items in transfusion medicine that are still not included in the Korean Association of External Quality Assessment Service. We performed a pilot project of anti-D titer test for the expansion of proficiency testing program in transfusion medicine. Methods: Proficiency testing materials with low (BBS2-21-01) and high (BBS2-21-02) anti-D titer were sent to 53 laboratories that agreed to participate in the pilot project for the 2nd Korean Association of External Quality Assessment Service on Transfusion Medicine in 2021. The results were entered on the website of the Korean Association of External Quality Assessment Service (http://eqas.keqas.org/). Results: A total of 47 laboratories submitted the results. For BBS2-21-01, the intended response of anti-D titer was 4–16 for tube technique with antihuman globulin (AHG) and 16–64 for column agglutination technique (CAT) with AHG. Meanwhile, for BBS2-21-02, the intended response was 8–32 for tube technique with AHG and 32–128 for CAT with AHG. The proportion of acceptable results was 90.9%–95.5% for tube technique with AHG and 95.8%–100.0% for CAT with AHG. Conclusions: The pilot project of anti-D titer test was successfully performed. This project will be expanded to a biannual proficiency testing program for anti-D antibody titer in the Korean Association of External Quality Assessment Service starting in 2022.

Investigating variability in rater groups on L2 writing in English

Yousun Shin 한국언어과학회 2011 한국언어과학회 학술대회 Vol.2011 No.08

The purpose of the study is to investigate how the judgment of raters is biased toward certain rating criteria or task types in assessing Korean university students’ L2 writing. In addition, the study aims to examine whether or not non-native rater group and native rater group share the same judgment of students’ written products. Six raters scored 258 compositions written by Korean university students on two topics. The written products were rated using an analytic scoring scale with content, organization, language in use, grammar, and mechanics. For the first part, the FACETS analysis revealed that all six raters showed self-consistent scoring patterns across the rating categories in the two tasks. However, each rater was biased towards certain type of tasks and rating categories. For the second part of the study, the results of ANOVA and MANOVA tests revealed that there were significant mean differences between the two groups across the rating categories in both tasks except content in Task 2. It is also shown that the non-native rater group is harsher in their rating than the native rater group regardless of the rating category.

Manifestation of Authoritarian Resilience?:

Yousun Chung 서울대학교 국제학연구소 2017 Journal of International and Area Studies Vol.24 No.1

This article discusses how middle-class homeowners in urban China have made advancement in collective interest representation and thus protection of private property rights in more systematic ways: not just by contending but by participating in public policy process. This is quite salient in their participation in relevant legislation, from the Property Law in 2007 to the Ordinance on Property Management in Beijing in 2010 and a new version of property management-related local legislation underway. Further investigation of this topic sheds lights on theoretical issues of in what ways and to what extents the state-society interaction in contemporary China is evolving.

Assessing the Relative Roles of Vocabulary and Syntactic Knowledge in Reading Comprehension

Yousun Shin,Yanghee Kim 한국응용언어학회 2012 응용 언어학 Vol.28 No.2

The purpose of the study was to explore the relative contribution of both vocabulary knowledge and grammatical knowledge as predictors of reading comprehension performance. To accomplish this, a total of 337 college students voluntarily participated in the study, all of whom were then taking an English reading course at two different universities. The measurement instruments used for the study were based on three sections: vocabulary, grammar, and reading comprehension. Each section consisted of two different tasks. For all the tasks except the recall task, the scoring procedure proved easy and expedient, with 1 point being assigned for correct items, and 0 point for incorrect ones. To obtain valid measures for the recall task, the learners were scored using Johnson’s (1970) unweighted pausal unit analysis. For the data analysis, structural equation modeling (SEM) was conducted to evaluate the role of syntactic knowledge and vocabulary knowledge where it predicts the L2 reading ability of the learners. The SEM analysis indicated that vocabulary knowledge and grammatical knowledge variables made contributions to the prediction of reading comprehension performance, with vocabulary knowledge outperforming grammar in its predictive power. Implications and limitations of the study are also discussed in this study.

Development of an Automated Image Analyzer for Microvessel Density Measurement in Bone Marrow Biopsies

Yousun Chung,Seungwon Shin,Hyoeun Shim,Ji Yeon Sohn,Dong-eun Lee,Lee Hyewon,Hyeon Seok Eom,Kwang Gi Kim,Sun-Young Kong 대한진단검사의학회 2020 Annals of Laboratory Medicine Vol.40 No.4

Angiogenesis is important for the proliferation and survival of multiple myeloma (MM) cells. Bone marrow (BM) microvessel density (MVD) is a useful marker of angiogenesis and an increase in MVD can be used as a marker of poor prognosis in MM patients. We developed an automated image analyzer to assess MVD from images of BM biopsies stained with anti-CD34 antibodies using two color models. MVD was calculated by merging images from the red and hue channels after eliminating non-microvessels. The analyzer results were compared with those obtained by two experienced hematopathologists in a blinded manner using the 84 BM samples of MM patients. Manual assessment of the MVD by two hematopathologists yielded mean±SD values of 19.4±11.8 and 20.0±11.8. The analyzer generated a mean±SD of 19.5±11.2. The intraclass correlation coefficient (ICC) and Bland-Altman plot of the MVD results demonstrated very good agreement between the automated image analyzer and both hematopathologists (ICC=0.893 [0.840–0.929] and ICC=0.906 [0.859–0.938]). This automated analyzer can provide time- and labor-saving benefits with more objective results in hematology laboratories.

Exploring Perspectives of Instructors and Learners on the Integration of AI-Based Tools in L2 Classrooms Focusing on Academic Integrity

Yousun Shin 한국언어과학회 2024 언어과학 Vol.31 No.1

The purpose of this study is to explore learners' and instructors' perceptions of AI-based technologies in higher education. 97 participants(learners: 61, L2 instructors: 36) participated in an online survey on academic integrity issues related to AI-based tools in educational settings. There were two research questions posed in the study. In the first question, five key factors were identified: attitudes toward AI-based tools, concerns about these tools, possible challenges, potential threats, and possible benefits. In relation to the second question, a one-way ANOVA revealed significant differences in perceptions concerning AI-based tools and potential threats, with learners and instructors showing distinct perspectives. Participants were keenly aware of the benefits and challenges of AI technologies, emphasizing the need for continuous training in their use. Consequently, in Korea, it calls for the development of flexible, culturally relevant guidelines that align with legal and regulatory standards, involving a range of stakeholders to ensure academic integrity. Research limitations and research directions were discussed further.

Fast distortion measurement method for MPEG point cloud compression

Yousun Park(박유선),Euee S. Jang(장의선) 대한전자공학회 2018 대한전자공학회 학술대회 Vol.2018 No.11

In this paper, we propose fast distortion quality measurement to improve efficient compression of massive point cloud data by introducing distortion search metric. In MPEG, point cloud compression standard is being actively standardized. As a new medium, point clouds pose new challenges in compression. One of them is to accurately assess the distortion of the encoded point clouds. If a point cloud is compressed lossy, there is no guarantee in mapping exact points between the original and encoded point clouds. For this reason, a tool called PC_ERROR [1] has been adopted for PCC. The PC_ERROR tool nicely solves the distortion measurement in an accurate manner; yet, it suffers from substantial computational complexity. To deal with this problem, we propose a fast distortion computing method to measure the Point Cloud Compression sequences. On top of PC_ERROR we designed new searching algorithm. Throughout the experimental results, we showed that the proposed method outperforms the PC_ERROR tool by 75 percent in execution time while preserving the accuracy in distortion measure.