Patient-Derived Xenograft Models of Epithelial Ovarian Cancer for Preclinical Studies

Heo, Eun Jin,Cho, Young Jae,Cho, William Chi,Hong, Ji Eun,Jeon, Hye-Kyung,Oh, Doo-Yi,Choi, Yoon-La,Song, Sang Yong,Choi, Jung-Joo,Bae, Duk-Soo,Lee, Yoo-Young,Choi, Chel Hun,Kim, Tae-Joong,Park, Woong- 대한암학회 2017 Cancer Research and Treatment Vol.49 No.4

<P><B>Purpose</B></P><P>Patient-derived tumor xenografts (PDXs) can provide more reliable information about tumor biology than cell line models. We developed PDXs for epithelial ovarian cancer (EOC) that have histopathologic and genetic similarities to the primary patient tissues and evaluated their potential for use as a platform for translational EOC research.</P><P><B>Materials and Methods</B></P><P>We successfully established PDXs by subrenal capsule implantation of primary EOC tissues into female BALB/C-nude mice. The rate of successful PDX engraftment was 48.8% (22/45 cases). Hematoxylin and eosin staining and short tandem repeat analysis showed histopathological and genetic similarity between the PDX and primary patient tissues.</P><P><B>Results</B></P><P>Patients whose tumors were successfully engrafted in mice had significantly inferior overall survival when compared with those whose tumors failed to engraft (p=0.040). In preclinical tests of this model, we found that paclitaxel-carboplatin combination chemotherapy significantly deceased tumor weight in PDXs compared with the control treatment (p=0.013). Moreover, erlotinib treatment significantly decreased tumor weight in epidermal growth factor receptor–overexpressing PDX with clear cell histology (p=0.023).</P><P><B>Conclusion</B></P><P>PDXs for EOC with histopathological and genetic stability can be efficiently developed by subrenal capsule implantation and have the potential to provide a promising platform for future translational research and precision medicine for EOC.</P>

Optimizing of a-IGZO TFT according to Pulse Duty ratio of Pulse-RF and Pulse-DC

Jaewoong Cho,Jaemin Kim,Eun-Chel Cho,Junsin Cho 한국진공학회 2021 한국진공학회 학술발표회초록집 Vol.2021 No.2

During the sputtering process, in the atmosphere of Ar: O2 – 19L 1, it was possible to confirm the change in the characteristics of the Bottom Gate TFT structure according to the plasma duty ratio change, and to find the optimal conditions in each condition of Pulsed-DC and Pulsed-RF. Afterwards, a-IGZO thin film according to each optimized condition was deposited to a thickness of 50 nm on a glass substrate to see the deposition characteristics of the thin film, and the stoichiometric investigation through XPS, surface roughness and optical bandgap through AFM were measured.

실리콘 태양전지의 금속전극 특성

조은철(Eun-Chel Cho),김동섭(Dong-Seop Kim),민요셉(Yo-Sep Min),조영현(Young-Hyun Cho),A.U.Ebong,이수홍(Soo-Hong Lee) 한국태양에너지학회 1997 한국태양에너지학회 논문집 Vol.17 No.1

개방전압과 단락전류와 같은 태양전지 출력변수들은 접합깊이, 도핑농도, 금속접합 및 태양전지 구조에 의한 변수들이다. 태양전지 설계의 중요한 요소로서 인이 도핑된 에미터와 금속사이의 금속접합은 일함수 차이가 작아 낮은 직렬저항을 가져야 한다. PESC 태양전지는 금속 접합장벽 전극으로 티타늄을 사용한다. 새로운 접합장벽 전극물질로 티타늄과 일함수가 비슷하지만 전기전도도가 우수한 크롬은 금속 접합장벽 전극으로 유망한 금속이다. 티타늄은 일함수 차가 작지만, 접합장벽으로 크롬은 태양전지 제조시 티타늄보다 우수한 전기적 특성들을 갖는다. 본 논문에서는 실리콘 태양전지의 접합장벽 금속전극의 특성을 비교 분석하였다. The solar cell electrical output parameters such as the open circuit voltage (Voc) and short circuit current density (J_sc) are intrinsic characteristics depending on junction depth, doping concentration, metal contacts barriers and cell structure. As a rule of thumb for solar cell design, the metal contact barriers for phosphorus doped emitter should have lower work function in order to provide lower series resistance. The fabrication of PESC (passivated emitter solar cell) structure usually involves the use of titanium as a metal contact barrier. Chromium, which work function is similar to titanium but conductance is higher than titanium is being investigated as the new metal contact barrier. Although titanium has lower work function difference than chromium, the electric performances of chromium as contact barrier are higher than titanium. This better performance is attributed to the lower resistivity from chromium. This paper, therefore, compares the attributes of metal barrier contacts using titanium and chromium.

전하선택형 태양전지의 연구개발 동향

조은철(Eun-Chel Cho),조영현(Young Hyun Cho),이준신(Junsin Yi) 한국태양광발전학회 2018 Current Photovoltaic Research Vol.6 No.2

The traditional silicon heterojunction solar cells consist of intrinsic amorphous silicon to prevent recombination of the silicon surface and doped amorphous silicon to transport the photo-generated electrons and holes to the electrode. Back contact solar cells with silicon heterojunction exhibit very high open-circuit voltages, but the complexity of the process due to form the emitter and base at the backside must be addressed. In order to solve this problem, the structure, manufacturing method, and new materials enabling the carrier selective contact (CSC) solar cell capable of achieving high efficiency without using a complicated structure have recently been actively developed. CSC solar cells minimize carrier recombination on metal contacts and effectively transfer charge. The CSC structure allows very low levels of recombination current (eg, Jo < 9fA/cm2), thereby achieves high open-circuit voltage and high efficiency. This paper summarizes the core technology of CSC solar cell, which has been spotlighted as the next generation technology, and is aiming to speed up the research and development in this field.

Analysis of Cell to Module Loss Factor for Shingled PV Module

Sanchari Chowdhury,Eun-Chel Cho,Younghyun Cho,Youngkuk Kim,Junsin Yi 한국신재생에너지학회 2020 신재생에너지 Vol.16 No.3

Shingled technology is the latest cell interconnection technology developed in the photovoltaic (PV) industry due to its reduced resistance loss, low-cost, and innovative electrically conductive adhesive (ECA). There are several advantages associated with shingled technology to develop cell to module (CTM) such as the module area enlargement, low processing temperature, and interconnection; these advantages further improves the energy yield capacity. This review paper provides valuable insight into CTM loss when cells are interconnected by shingled technology to form modules. The fill factor (FF) had improved, further reducing electrical power loss compared to the conventional module interconnection technology. The commercial PV module technology was mainly focused on different performance parameters; the module maximum power point (Pmpp), and module efficiency. The module was then subjected to anti-reflection (AR) coating and encapsulant material to absorb infrared (IR) and ultraviolet (UV) light, which can increase the overall efficiency of the shingled module by up to 24.4%. Module fabrication by shingled interconnection technology uses EGaIn paste; this enables further increases in output power under standard test conditions. Previous research has demonstrated that a total module output power of approximately 400 Wp may be achieved using shingled technology and CTM loss may be reduced to 0.03%, alongside the low cost of fabrication.

A Simple and Sensitive Liquid Chromatography Method for Analyzing 14 Sulfonamide Antibacterials in Milk

Min-A Kim,Eun Jeong Lee,Moon Ik Chang,Kyung A An,Hyun Suk Oh,Jee-Youn Shim,Hyo-Jung Lee,Sang-Chel Suh,Ryun Kyung Lee,Seong Min Park,Tae-Yong Cho 한국식품영양과학회 2011 한국식품영양과학회 학술대회발표집 Vol.2011 No.10

Effect on the reduction of the barrier height in rear-emitter silicon heterojunction solar cells using Ar plasma-treated ITO fi

Hyeongsik Park,Doyoung Kim,Eun-Chel Cho,Shahzada Qamar Hussain,Jeongeun Park,Donggun Lim,Sangho Kim,Subhajit Dutta,Mallem Kumar,Youngkuk Kim,Junsin Yi 한국물리학회 2020 Current Applied Physics Vol.20 No.1

In this study, we investigated the effect of plasma treatment on an indium tin oxide (ITO) film under an ambient Ar atmosphere. The sheet resistance of the plasma-treated ITO film at 250W (37.6 Ω/sq) was higher than that of the as-deposited ITO film (34 Ω/sq). Plasma treatment was found to decrease the ITO grain size to 21.81 nm, in comparison with the as-deposited ITO (25.49 nm), which resulted in a decrease in the Hall mobility. The work function of the Ar-plasma-treated ITO (WFITO=4.17 eV) was lower than that of the as-deposited ITO film (WFITO=5.13 eV). This lower work function was attributed to vacancies that formed in the indium and oxygen vacancies in the bonding structure. Rear-emitter silicon heterojunction (SHJ) solar cells fabricated using the plasma-treated ITO film exhibited an open circuit voltage (VOC) of 734 mV, compared to SHJ cells fabricated using the as-deposited ITO film, which showed a VOC of 704 mV. The increase in VOC could be explained by the decrease in the work function, which is related to the reduction in the barrier height between the ITO and a-Si:H (n) of the rear-emitter SHJ solar cells. Furthermore, the performance of the plasma-treated ITO film was verified, with the front surface field layers, using an AFORS-HET simulation. The current density (JSC) and VOC increased to 39.44 mA/cm2 and 736.8 mV, respectively, while maintaining a WFITO of 3.8 eV. Meanwhile, the efficiency was 22.9% at VOC=721.5 mV and JSC=38.55 mA/cm2 for WFITO=4.4 eV. However, an overall enhancement of 23.75% in the cell efficiency was achieved owing to the low work function value of the ITO film. Ar plasma treatment can be used in transparent conducting oxide applications to improve cell efficiency by controlling the barrier height.

Development of orthotopic patient-derived tumor xenograft models in endometrial cancer

( Hyun-jin Choi ),( Eun Jin Heo ),( Young Jae Cho ),( Ji Eun Hong ),( Hye-kyung Jeon ),( Doo-yi Oh ),( Yoon-la Choi ),( Sangyong Song ),( Jung-joo Choi ),( Yoo-young Lee ),( Chel Hun Choi ),( Tae-joon 대한산부인과학회 2016 대한산부인과학회 학술대회 Vol.102 No.-

목적: To evaluate orthotopic xenografting of endometrial cancer(EM Ca) in mice for development of novel translational research platform in endometrial cancer. 방법: Fresh surgical specimens were taken from patients with EM Ca after surgery at Department of Obstetrics and Gynecology, Samsung Medical Center, Seoul, Korea between December, 2011 to February, 2016. We successfully established PDXs by orthotopic and subrenal capsule implantation of patient’s EM Ca tissues into female BALB/C-nude mice. The subrenal capsule implatation method were that pieces of EM Ca specimens from patients were meticulosely grafted in the subrenal capsule. Mean while, estrogen preconditioning was done for orthotopic implatation by given a daily s.c injection of 0.1μg estradial for three days. After then, pieces of EM Ca specimens from patients were meticulosly grafted in the enlarged mice’s uterus. The H&E staining, short tandem repeat, array comparative genomic hybridization, human and mouse albumin test and cancer panel were conducted to verifythe histopathologic and genetic similarity between the PDXs and primary patient’s tissues. 결과: Orthotopic PDX engraftment rate were sucessful in 100% (3/3 cases). While, Successful rate of subrenal capsule implantation method was 55.6% (10/18 cases). In orthotopic PDXs, median duration of first generation of PDX develoment from implantation of patient’s tissues was 5.43month (range: 0.83-6.63 month). And, in subrenal capsule implantation PDXs, median duration of first generation was 5.05month (range : 4.17-9.33 month). Both methods were proved to preserve histopathologic and genetic silimarity between PDXs and the primary patient’s tissues. 결론: The PDXs for endometiral cancer with histopathologic and genetic stability can be efficiently developed by an orthotopic implantation method rather than a subrenal capsule implantation method. This method can a promising platform for conducting translational research and future precision medicine in endomerial cancer.

To Investigate the Optical Properties of Front Cover Sheet for Light Weight Module

Muhammad Aleem Zahid,Eun Chel Cho,Young Hyun Cho,Junsin Yi 한국신재생에너지학회 2020 한국신재생에너지학회 학술대회논문집 Vol.2020 No.8

HDAC1 Upregulation by NANOG Promotes Multidrug Resistance and a Stem-like Phenotype in Immune Edited Tumor Cells

Song, Kwon-Ho,Choi, Chel Hun,Lee, Hyo-Jung,Oh, Se Jin,Woo, Seon Rang,Hong, Soon-Oh,Noh, Kyung Hee,Cho, Hanbyoul,Chung, Eun Joo,Kim, Jae-Hoon,Chung, Joon-Yong,Hewitt, Stephen M.,Baek, Seungki,Lee, Kyun American Association for Cancer Research 2017 Cancer Research Vol.77 No.18

<P>These findings link a regulator of cancer stem-like cells to epigenetic silencing events that may improve immunotherapy outcomes.</P><P>Cancer immunoediting drives the adaptation of tumor cells to host immune surveillance. Immunoediting driven by antigen (Ag)-specific T cells enriches NANOG expression in tumor cells, resulting in a stem-like phenotype and immune resistance. Here, we identify HDAC1 as a key mediator of the NANOG-associated phenotype. NANOG upregulated HDAC1 through promoter occupancy, thereby decreasing histone H3 acetylation on K14 and K27. NANOG-dependent, HDAC1-driven epigenetic silencing of cell-cycle inhibitors CDKN2D and CDKN1B induced stem-like features. Silencing of TRIM17 and NOXA induced immune and drug resistance in tumor cells by increasing antiapoptotic MCL1. Importantly, HDAC inhibition synergized with Ag-specific adoptive T-cell therapy to control immune refractory cancers. Our results reveal that NANOG influences the epigenetic state of tumor cells via HDAC1, and they encourage a rational application of epigenetic modulators and immunotherapy in treatment of NANOG<SUP>+</SUP> refractory cancer types. <I>Cancer Res; 77(18); 5039–53. ©2017 AACR</I>.</P>