간암조직에서 DNA methyltransferase의 발현

이귀연,박혜정,심용희 建國大學校基礎科學硏究所 2002 理學論集 Vol.27 No.-

암억제유전자의 과메틸화는 유전자의 발현을 억제하는 작용으로 암발생 기전에 중요한 요인으로 알려져 왔다. DNA 과메틸화는 DNA methyltransferase (Dnmt)에 의해서 생성되는데 현재까지 그 기능이 알려진 것으로 Dnmt1, Dnmt3a, Dnmt3b가 있다. 본 논문에서는 한국인의 간암조직 27개과 각 예에 상응되는 정상조직 27 개에서 위의 세 효소의 발현정도를 역전사효소-중합연쇄반응으로 조사하였다. Dnmt1는 정상조직에서 40.7% (11/27), 간암조직에서 33.3% (9/27); Dnmt3a는 정상조직에서 22.2% (6/27), 간암조직에서 63% (17/27); Dnmt3b는 정상조직에서는 전혀 발현 되지 않았으며 간암조직에서 51.9% (14/27)가 발현되었다. Dnmt1은 유전자의 메틸화정도를 유지시키는 기능을 하는 반면에 Dnmt3a와 Dnmt3b는 de novo 메틸화를 담당한다. Dnmt3a와 Dnmt3b의 발현이 Dnmt1보다 1.6-1.9 배 간암조직에서 높았으며 정상조직에서는 Dnmt1 (40.7%)의 발현이 22.2%인 Dnmt3a와 전혀 발현을 보이지 않은 Dnmt3b보다 훨씬 높았다. 위의 실험결과는 정상조직에서는 유전자의 메틸화를 유지하기 위하여 DNA 메틸화가 되는 반면에 종양조직에서는 새로운 유전자의 메틸화가 유발됨을 시사한다. 이는 새로운 유전자의 과메틸화의 증가가 암 발생기전의 요인이 될 가능성을 제시하는 결과이다. Hypermethylation on CpG islands of a tumor suppressor gene has been frequently detected in a variety of cancer cells and known to repress the level of transcription. To identify the molecular mechanism for hypermethylation of tumor suppressor genes in hepatocellular carcinomas (HCC), we examined DNA methyltransferase (Dnmt) expression level in HCC. Three Dnmts, Dnmt1, Dnmt3a and Dnmt3b that have been identified as being enzymatically active were examined by RT-PCR. Expression of Dnmts was detected in both non-neoplastic control liver and in HCC. Eleven out of 27 (40.7%) controls and 9 out of 27 (33.3%) HCC; 6 out of 27 (22.2%) controls and 17 out of 27 (63%) HCC; none of 27 controls and 14 out of 27 (51.9%) HCC revealed expression of Dnmt1, Dnmt3a, and Dnmt3b, respectively. The relatively high frequency of Dnmt1 expression in non-neoplastic control suggests that expression of Dnmt1 is required for maintenance of methylation profile in non-neoplastic cells. In addition, higher frequencies of Dnmt3a and Dnmt3b expression in HCC suggest that de novo DNA methylation in tumor cells may be the major process for gene inactivation during hepatocarcinogenesis.

New Heteroleptic Tris-Cyclometalated Iridium(III) Complexes Containing Difluorophenylpyridine and Phenylpyridine

Gui Youn Park,Yunkyoung Ha,Ji-Hyeon Seo,Young Kwan Kim,Young Sik Kim 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.6

The synthesis and the photophysical properties of iridium (III) complexes having two different (C$\hat{~}$N) ligands, F$_2$-ppy and ppy, were studied, and their photonic properties were investigated to study the effect of the phenylpyridine (ppy) / difluorophenylpyridine (F$_2$-ppy) ratio in the complex on the emission properties. Ir(ppy)$_3$ is known to have a high phosphorescence efficiency in EL emissions owing to its strong metal-to-ligand charge transfer (MLCT) excited state. However, the emissive quantum efficiency of Ir(F$_2$-ppy)$_3$ was found to be low due to weak MLCT. Thus, for tuning of blue phosphors, heteroleptic tris-cyclometalated iridium complexes, Ir(ppy)$_2$(F$_2$-ppy) and Ir(ppy)(F$_2$-ppy)$_2$, were prepared with systematic changes in their ligand systems and were investigated. Replacement of ppy by F$_2$-ppy in the iridium complex system stepwise leads to an increase in the HOMO-LUMO gap, resulting in a hypsochromic shift in emission wavelength. The emission wavelengths of Ir(ppy)$_3$, Ir(ppy)$_2$(F$_2$-(ppy)), Ir(ppy)(F$_2$-ppy)$_2$, and Ir(F$_2$-ppy)$_3$ were thus, observed at 514, 502, 495, and 474 nm, respectively. To investigate the suggested luminescent mechanism, we calculated these complexes theoretically by using a computational method.

Phosphorescent iridium(III) complexes with hetero (C^N) ligands

Gui Youn Park,Young Sik Kim,Yunkyoung Ha 한국물리학회 2007 Current Applied Physics Vol.7 No.4

In order to improve luminescence eciency, it is necessary to design a phosphorescent material which is capable of transferring theexcited energy without triplettriplet (TT) annihilation. For this purpose, new types of metal complexes were designed with dierentspecies of (CN) ligands. Herein, Ir(ppy)2(piq), Ir(ppy)2(piq-F) and Ir(ppy)2(piq-CF3) were designed and prepared, where ppy, piq,piq-F and piq-CF3 represent 2-phenylpyridine, 1-(phenyl)isoquinoline, 1-(40-uorophenyl)isoquinoline and 1-(40-triuoromethylphe-nyl)isoquinoline, respectively. These Ir(III) complexes having two dierent ligands (hetero-Ir complexes) are expected to have a highluminescence eciency by intramolecular energy transfer from the energy absorbing ligand to the luminescent ligand leading to adecrease in quenching or energy deactivation. To compare luminescent characteristics of these hetero-Ir complexes, homo-Ir complexesIr(ppy)3, Ir(piq)3, Ir(piq-F)3 and Ir(piq-CF3)3 were prepared and investigated photophysically

제주지역 폐열배출실태 및 이용가능성 연구

박윤철(Youn Cheol Park),김귀식(Gui-Shik Kim),박준택(Jun-Taek Park) 대한설비공학회 2003 대한설비공학회 학술발표대회논문집 Vol.2003 No.-

Aggressive angiomyxoma of the vulva: a case report(초)

정윤지 ( Youn Jee Chung ),( Sung Jong Lee ),( Min Jung Seo ),( Dong Choon Park ),( Gui Sera Lee ),( Dong Jin Kwon ),( Young Oak Lew ),( Joo Hee Yoon ) 대한산부인과학회 2009 대한산부인과학회 학술대회 Vol.95 No.-

White Light Emission Using Heteroleptic Tris-Cyclometalated Iridium (III) Complexes

YoungHee Lee,Gui Youn Park,Young Sik Kim 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.6

The synthesis and photophysical study of efficient phosphorescent heteroleptic tris-cyclometalated iridium (III) complexes for white organic light-emitting devices (WOLEDs) are reported. In order to obtain a large broad band, we designed and prepared Ir(dfppy)$_2$(pq) and Ir(pq)$_2$(dfppy), where dfppy and pq are 2-(2,4-difluorophenyl) pyridine and 2-phenylquinoline, respectively. The emission wavelengths and the lifetimes of Ir(dfppy)$_2$acac and Ir(pq)$_2$acac (acac = acetyl acetonate) were reported as 469 nm and 596 nm, and 1.6 $\mu$s and 2.0 $\mu$s, respectively. A reasonably similar phosphorescent lifetime is crucial for white light emission materials. The luminescence mechanism is determined by using the decay times of two different cyclometalated (C$\hat{~}$N) ligands. As similar phosphorescent lifetimes are possible for luminescence in two ligands at the same time, the emission wavelengths of Ir complexes have large broad peaks, leading a white color. Our experimental results provide evidence that the absorption of Ir complexes occurs at each ligand upon excitation. Thus, the excitation energy causes blue and orange colors to be emitted in each ligand of the complex. To realize this idea, we synthesized an iridium complex having two different ligand structures and theoretically calculated the complex by using a computational method.\\

다운증후군과 동반된 부갑상선 기능저하증 1예

김필호,박연호,남궁준,문귀애,김상현,엄태찬,김성준,고경수,이병두,박미정 인제대학교 1998 仁濟醫學 Vol.19 No.2

다운증후군은 특이한 외모, 지능 발달 저하 등의 임상상으로 나타나는 가장 흔한 상염색체 수 이상 증후군이다. 저자들은 전신 경련을 주소로 내원한 환자에서 염색체 검사를 실시하여 Robertsonian translocation에 의한 부분 삼체성의 다운증후군 및 특발성 부갑상선 기능저하증이 동반된 증례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다. Down syndrome is perhaps the oldest condition associated with mental retardation and the most common genetic cause of developmental disability. It is presumed that the additional gene products of the triplicated chromosome 21 cause alterations in the normal processes regulating embryogenesis. Ninety-five percent of cases are caused by trisomy 21, whereas the remainder are translocations. Mainly, the chromosomal translocation is made of Robertsonian translocation. Clinically it consists of cranio-facial abnormality, such as microcephaly, with flattening both of the occiput and face, an upward slant to the eyes with epicanthal folds, and the ears are small. Congenital heart disease, musculoskeletal abnormalities, gastrointestinal disorders, hematologic abnormalities and associated developmental disabilities. And thyroid dysfunction and infertility are the most significant endocrinologic disorders in individuals with Down syndrome. But we could not find any reported case of hypoparathyroidism associated with Down syndrome in worldwide search of literatures. Even though some cases of hereditary hypoparathyroidism, which is not associated with Down syndrome were reported. We experienced a rare case of 15-year-old male diagnosed as hypoparathyroidism associated with Down syndrome, which is diagnosed by cytogenetic chromosomal study and by radioimmunoassay for PTH wish symptoms of seizure disorder due to hypocalcemid and typical cranio-facial abnormalities.

조기분만과 TNF-α 및 IL-1β 유전자의 다형성과의 연관성

박철훈 ( Cheol Hoon Park ),박인양 ( In Yang Park ),고현선 ( Hyun Sun Ko ),안현영 ( Hyun Young Ahn ),김수평 ( Soo Pyung Kim ),신종철 ( Jong Chul Shin ),김연희 ( Youn Hee Kim ),이귀세라 ( Gui Se Ra Lee ),이희중 ( Hee Joong Lee ) 대한산부인과학회 2004 Obstetrics & Gynecology Science Vol.47 No.12

목적 : 조기분만은 신생아 사망 및 이환의 가장 중요한 원인이지만 아직 원인이나 병태생리가 잘 밝혀져 있지 않다. 조기분만의 위험인자로서 자궁내 감염이 주로 거론되고 있으며, tumor necrotic factor-α(TNF-α)와 interleukin-1β(IL-1β)가 염증의 진행과정에 중요한 역할을 하는 것으로 알려졌다. 연구 방법 : 조기 진통에 의한 조산모 66명과 조기 파수에 의한 조산모 27명을 연구대상으로 하였으며 만삭에 분만한 288명을 Objective : To elucidate whether polymorphisms of tumor necrotic factor-α (TNF-α) and interleukin-1β (IL-1β) are associated with preterm delivery caused by preterm labor and preterm premature rupture of membrane (PPROM) in korean pregnant women. Methods :

실험 ; 조기진통으로 조산한 산모의 융모 영양막에서 Tissue-transglutaminase-2와 Cyclo-oxygenase의 발현 양상에 대한 연구

박인양 ( In Yang Park ),양동은 ( Dong Eun Yang ),김연희 ( Youn Hee Kim ),권지영 ( Ji Young Kwon ),안현영 ( Hyun Young Ahn ),이영 ( Young Lee ),이귀세라 ( Gui Se Ra Lee ),김사진 ( Sa Jin Kim ),신종철 ( Jong Chul Shin ) 대한주산의학회 2007 大韓周産醫學會雜誌 Vol.18 No.2

Whole genome analysis for liver metastasis gene signatures in colorectal cancer

Ki, Dong Hyuk,Jeung, Hei-Cheul,Park, Chan Hee,Kang, Seung Hee,Lee, Gui Youn,Lee, Won Suk,Kim, Nam Kyu,Chung, Hyun Chul,Rha, Sun Young Alan R. Liss, Inc 2007 International journal of cancer Vol.121 No.9

<P>Liver metastasis is one of the major causes of death in colorectal cancer (CRC) patients. To understand this process, we investigated whether the gene expression profiling of matched colorectal carcinomas and liver metastases could reveal key molecular events involved in tumor progression and metastasis. We performed experiments using a cDNA microarray containing 17,104 genes with the following tissue samples: paired tissues of 25 normal colorectal mucosa, 27 primary colorectal tumors, 13 normal liver and 27 liver metastasis, and 20 primary colorectal tumors without liver metastasis. To remove the effect of normal cell contamination, we selected 4,583 organ-specific genes with a false discovery rate (FDR) of 0.0067% by comparing normal colon and liver tissues using significant analysis of microarray, and these genes were excluded from further analysis. We then identified and validated 46 liver metastasis-specific genes with an accuracy of 83.3% by comparing the expression of paired primary colorectal tumors and liver metastases using prediction analysis of microarray. The 46 selected genes contained several known oncogenes and 2 ESTs. To confirm that the results correlated with the microarray expression patterns, we performed RT-PCR with WNT5A and carbonic anhydrase II. Additionally, we observed that 21 of the 46 genes were differentially expressed (FDR = 2.27%) in primary tumors with synchronous liver metastasis compared with primary tumors without liver metastasis. We scanned the human genome using a cDNA microarray and identified 46 genes that may play an important role in the progression of liver metastasis in CRC. © 2007 Wiley-Liss, Inc.</P>