• Asian Pacific Journal of Cancer Prevention
• /
• 제15권9호
• /
• pp.3921-3925
• /
• 2014

RASSF1A has been reported to be a candidate tumor suppressor in esophageal squamous cell carcinoma (ESCC). However, the association between RASSF1A promoter methylation and ESCC remains unclear. Eligible studies were identified through searching PubMed, Medline, Web of Science, and the China National Knowledge Infrastucture database. Studies were pooled and odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated. Funnel plots were also performed to evaluate publication bias. Twelve studies involving 859 cases and 675 controls were included in this meta-analysis. A significant association was observed between RASSF1A methylation and ESCC overall (OR = 11.7, 95% CI: 6.59-20.9, z=8.36, P<0.00001). Subgroup analysis showed that the OR for heterogeneous tissues was 5.35 (95% CI = 2.95-9.71) while for autologous tissues it was 16.0 (8.31-30.96). For patient sample size, the OR for the <50 subgroup was 9.92 (95% CI = 2.88-34.2) and for the 50 case group was 13.1 (95% CI = 6.59-25.91). The OR for a relationship between RASSF1A methylation and TNM stages was 0.27 (95% CI=0.10-0.77), whereas there were no significant differences in RASSF1A methylation in relation to gender and differentiation among ESCC cases. This meta-analysis suggests a significant association between RASSF1A methylation and ESCC.

• BMB Reports
• /
• 제39권2호
• /
• pp.171-177
• /
• 2006

Nonsteroidal anti-inflammatory drugs such as indomethacin (IN) can exert anti-colorectal cancer (CRC) activity through cyclooxygenase independent mechanism, but the exactly biological mechanism is not completely known. Here we use proteomic tools to investigate the molecular mechanism of this action. First, nude mice bearing tumors derived from subcutaneous injection with human CRC cell line HCT116 were randomly allocated to groups treated with or without indomethacin. Later, tumor lumps were incised and then total proteins extracted. After separated with two-dimensional electrophoresis, thirty-one differently expressed spots were found between IN-treated and non-IN-treated groups, of which 25 spots decreased and 6 spots increased in abundance in IN-treated group. Through matrix-assisted laser desorption ionization time of flight mass spectrometry and then NCBInr and SWISS-PROT databases searching, 12 protein spots were finally identified including galectin-1, annexin A1, annexin IV, trancription factor BTF3A, calreticulin. Most of the identified proteins are correlated with tumor's biological prosperities of proliferation, invasion, apoptosis and immunity, or take part in cell's signal transduction. From above we thought that indomethacin can exert its effect on colorectal cancer through regulating several proteins' expression directly or indirectly. Further study of these proteins may be helpful in founding new targets of drugs for cancer chemotherapy.

• 생명과학회지
• /
• 제12권2호
• /
• pp.219-225
• /
• 2002

진핵세포의 염색체는 전사, 복제, 회복 등의 과정에서 관여하는 단백질의 기능으로 구조가 변하게 된다. 이때 관여하는 단백질은 DNA-단백질의 상호작용에 의해서 이루어지게 되는데, 이때 단백질의 일부분은 일정한 상동성이 존재하게 된다. 이러한 부분은 motif나 domain으로 구성되는데, 예를 들면, SAP domain등을 들 수 있다. S. pombe genomic DNA 데이터베이스를 검색하여 Arabidopsis PARP 과 KU70과 상동성을 보이는 새로운 유전자를 찾았다. 이를 SAPuvs (SAP UV Sensitive)라 명명하였으며, Ura4를 선별표지로 이용하여 S. pombe SAPuvs 유전자 결실세포를 구성하였다. SAPuvs 유전자 결실세포는 자외선 조사 실험에서 정상의 세포에 비해 현저하게 죽었다. 그러나, MMS 또는 MMS와 3AB의 처리 실험에서는 저항성을 보였다. 이러한 결과로 SAPuvs는 DNA 상해회복에서 염색사구조 형성에 연관되어 있음을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권6호
• /
• pp.1828-1847
• /
• 2014

Coordinated multi-point (CoMP) transmission has been regarded as a potential technology for LTE-Advanced. In frequency division duplexing systems, channel quantization is applied for reporting channel state information (CSI). Considering the dynamic number of cooperation base stations (BSs), asymmetry feature of CoMP channels and high searching complexity, simply increasing the size of the codebook used in traditional multiple antenna systems to quantize the global CSI of CoMP systems directly is infeasible. Per-cell codebook based channel quantization to quantize local CSI for each BS separately is an effective method. In this paper, the theoretical upper bounds of system throughput are derived for two codeword selection schemes, independent codeword selection (ICS) and joint codeword selection (JCS), respectively. The feedback overhead and selection complexity of these two schemes are analyzed. In the simulation, the system throughput of ICS and JCS is compared. Both analysis and simulation results show that JCS has a better tradeoff between system throughput and feedback overhead. The ICS has obvious advantage in complexity, but it needs additional phase information (PI) feedback for obtaining the approximate system throughput with JCS. Under the same number of feedback bits constraint, allocating the number of bits for channel direction information (CDI) and PI quantization can increase the system throughput, but ICS is still inferior to JCS. Based on theoretical analysis and simulation results, some recommendations are given with regard to the application of each scheme respectively.

• 한국구조물진단유지관리공학회 논문집
• /
• 제8권3호
• /
• pp.159-167
• /
• 2004

본 연구는 최적설계 프로그램에 의해 FSM 공법의 PSC 박스 거더교를 최소경비로 자동 설계하고 이를 다양한 교량 형식에 적용하여 적정 형고비 Span Length to Girder Depth와 교폭에 따른 적정 셀(cell )수를 검토하고 최적설계의 필요성을 알리는데 목적이 있다. 사용된 최적설계 프로그램은 축차 무제약 최소화 기법을 이용하였고, 설계과정에서 설계점들이 설계가능 영역밖에 있는것을 허용할 수 있도록 Kavlie가 제안한 확장 벌칙함수를 도입하였다. 또한 설계점들의 탐사 방법은 Powell's direct search method를 사용하며, 설계시간을 단축시키기 위해 설계점 변화에 따른 단면력 변화를 Gradient를 이용하여 근사화 시키는 방법을 사용하였다. 그리고 설계변수의 수렴성과 셀수 지간장 차선수별 최적비용의 상관관계를 도출하였다.

• 대한화장품학회지
• /
• 제28권1호
• /
• pp.135-149
• /
• 2002

To date, research on the regulation of melanogenesis has focused on factors which affect tyrosinase, the rate-limiting enzyme in the melanogenic pathway, by searching for chemicals which competitively inhibit tyrosinase function. Many types of tyrosinase inhibitors have been developed, but no satisfactory results have been made clinically until now, To find a new whitening agent, which effectively inhibits melanogenesis, we synthesized several compounds and selected compounds by cell-based assay system. Finally, 3, 4, 5-trimethoxy cinnamaie thymol ester(TCTE, Melasolv) was selected and the effects of TCTE on melanogenesis were investigated. Treatment of mouse-derived melanocyte melan-a cells with TCTE results in a marked down-regulation of tyrosinase activity. 80% decrease of tyrosinase activity occurs with 30uM TCTE treatment for 72 hours without affecting cell growth. The inhibition of tyrosinase activity is dose-dependent and melanin content was also decreased to 40%. From the in vitro tyrosinase assay using cell extract, TCTE does not act as a direct inhibitor of the enzyme. Treatment of melan-a cultures with TCTE blocks the increase in tyrosinase activity by either forskolin, 3-isobutyl-1-methtyl-xanthine. TCTE decreased the expression of tyrosinase, TRP-1 without effects on TRP-2 protein expression through the down regulation of tyrosinase and TRP-1 mRNA. From the results of cAMP immunoassays, intracellular levels of the cyclin nucleotide are unaffected in cells treated with TCTE. The inhibitory effects of melanin synthesis were also shown in reconstitute human epidermis model by topical application. These findings suggest that TCTE can be used for studying the regulation of melanogenesis and depigmenting agent.

• 대한한방부인과학회지
• /
• 제28권1호
• /
• pp.113-127
• /
• 2015

Objectives: This study was performed to analyze the trend of acne-related experimental studies in Korean medicine. Methods: We searched 17 articles related with experimental study of acne, published Korean medical journals from 2005 to 2014. We classified all articles according to the journal and checked on the kind of herbs. All articles were categorized into two types: cell experimental study and animal experimental study. Results: 1. Total 17 papers were searched; 7 articles (41.2%) were published in the Journal of Korean Medical Ophthalmology, Otolaryngology, Dermatology, 4 articles (23.5%) were published in the Journal of Korean Institute of Pharmacopuncture, 3 articles (17.6%) were published in Korean Journal of Oriental Physiology and Pathology, 2 articles (11.8%) were published in Korean Journal of Herbology, and 1 article (5.9%) was published in the Journal of Korean Medicine. 2. Total 17 kind of herbs were used in the studies; 10 articles (58.8%) used single herb, 7 articles (41.2%) used complex herbs. 3. Total 17 articles were categorized 2 types; 16 cell experimental studies (94.1%), 1 animal experimental study (5.9%). 4. Experimental researches were mainly investigated using Raw 264.7 cell line and P. acnes. The levels of NO, iNOS, $TNF-{\alpha}$, PGE, COX-2, $IL-1{\beta}$, IL-6, NF-kB were analyzed to confirm of herbs' antibacterial, anti-inflammatory, antioxidant activity. Conclusions: Searching for natural antibiotics, it is needed to do experimental studies continuously, and also needed to diversify the kind herbs and experimental bacteria.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2011년도 추계학술대회
• /
• pp.431-435
• /
• 2011

본 논문에서는 H.264/AVC CAVLC 부호기의 성능 향상을 위해 변환계수의 재정렬 과정이 필요 없는 탐색기법을 제안한다. 기존의 CAVLC 부호기는 변환계수의 재정렬 과정이 포함되어 변환계수를 저장해야 할 버퍼와 버퍼제어를 위한 추가적인 사이클이 필요하므로 하드웨어 면적이 증가하고 불필요한 사이클이 수행된다. 제안한 탐색기법은 CAVLC의 파라미터 중에 Level을 역방향 탐색기법으로 계산하고 그 외 파라미터들은 순방향 탐색기법으로 계산하여 변환계수의 재정렬 과정을 수행하지 않는다. 또한, 제안한 CAVLC 부호기에 조기 종료 모드를 적용하고 3단 파이프라인 구조를 사용하여 CAVLC의 수행 사이클 수를 감소시켰다. 제안한 CAVLC의 하드웨어 구조를 매그나칩 공정 $0.18{\mu}m$ 셀라이브러리로 합성한 결과, 최대동작 주파수는 125MHz이며 게이트 수는 15.6k이다. 제안한 CAVLC의 하드웨어 구조를 H.264/AVC 표준 참조 소프트웨어 JM13.2에서 추출한 데이터를 이용하여 테스트한 결과, $16{\times}16$ 매크로블록을 처리하는데 평균적으로 66.6사이클이 소요되어 기존의 CAVLC 부호기보다 성능이 13.8% 향상됨을 확인하였다.

• Parasites, Hosts and Diseases
• /
• 제58권3호
• /
• pp.237-247
• /
• 2020

Dendritic cell is one of the first innate immune cell to encounter T. gondii after the parasite crosses the host intestinal epithelium. T. gondii requires intact DC as a carrier to infiltrate into host central nervous system (CNS) without being detected or eliminated by host defense system. The mechanism by which T. gondii avoids innate immune defense of host cell, especially in the dendritic cell is unknown. Therefore, we examined the role of host PI3K/AKT signaling pathway activation by T. gondii in dendritic cell. T. gondii infection or T. gondii excretory/secretory antigen (TgESA) treatment to the murine dendritic cell line DC2.4 induced AKT phosphorylation, and treatment of PI3K inhibitors effectively suppressed the T. gondii proliferation but had no effect on infection rate or invasion rate. Furthermore, it is found that T. gondii or TgESA can reduce H₂O₂-induced intracellular reactive oxygen species (ROS) as well as host endogenous ROS via PI3K/AKT pathway activation. While searching for the main source of the ROS, we found that NADPH oxidase 4 (NOX4) expression was controlled by T. gondii infection or TgESA treatment, which is in correlation with previous observation of the ROS reduction by identical treatments. These findings suggest that the manipulation of the host PI3K/AKT signaling pathway and NOX4 expression is an essential mechanism for the down-regulation of ROS, and therefore, for the survival and the proliferation of T. gondii.

• KSBB Journal
• /
• 제24권3호
• /
• pp.312-320
• /
• 2009

치료용 단백질을 생산하는 생물의약품 산업이나 세포치료제 및 이식용 세포를 다루는 재생의학 분야 등의 세포기반 산업에서 안정적인 세포의 보존은 필수적인 요소이다. 본 연구에서는 인간 피부 섬 유아세포의 $4^{\circ}C$ 저온보존에서 우수한 성능을 나타내는 개선된 저온보존액을 개발하고, 저온에 의한 세포 손상을 보호함으로써 보다 안정적인 세포 저온보존 기술을 제공하고자 하였다. 세포의 저온보존에서 우수한 효능을 나타내는 핵심 성분을 탐색한 결과, yeast hydrolysate 등의 단백질 가수분해물을 첨가한 보존액에서 월등히 뛰어난 보존효과가 나타남을 확인하였다. 단백질 가수분해 물은 미생물, 식물, 동물유래 단백질 가수분해 물에서 모두 우수한 효과를 나타냈으며, 특히 단백질 가수분해물 성분 중 분자량 10kDa 이하의 펩타이드를 첨가한 저온보존에서 우수한 보존효과가 나타났다. 저온에 의한 세포손상에 대해 단백질 가수분해물은 세포내 ATP level의 감소를 막아주고 ROS 생성을 억제하는 것으로 나타났으며, 항산화제 및 삼투압 조절물질을 단백질 가수분해 물과 함께 첨가하였을 때 더욱 우수한 세포 보존효과를 보였다. 최종적으로 본 연구에서 개발한 KUL261 저은보존액 (DMEM/F12 1 : 1 medium, yeastolate 1%, $\alpha$-tocopherol $100{\mu}M$, dextran 2.5%)은 기존의 저온 보존액에 비해 세포 생존을 및 성장률에서 월등히 우수한 성능을 나타내었다. 결론적으로, 핵심 유효성분으로 단백질 가수분해물을 포함하는 개선된 저온보존액은 기존의 보존액보다 월등히 우수한 보존효과를 제공하며, 세포치료제 및 재생의학 분야의 발전과 글로벌 상업화에 기여할 수 있을 것이다.