• Journal of Yeungnam Medical Science
• /
• 제6권2호
• /
• pp.195-205
• /
• 1989

암의 화학요법에 있어서 내성생성으로 인한 치료의 장애가 암 치료 실패의 중요 원인이 되며, 분 연구는 암세포의 항암제에 대한 내성 생성에 대한 특성을 연구 보고하였다. 사람의 위암 세포주 SNU-1에 대한 내성 유발을 위하여 세포배양액에 adriamycin(ADR) 농도를 $10^{-8}M$에서 $10^{-7}M$에 까지 적용시켜 내성세포주를 얻어 SUN-1/ADR로 나타내었으며 세포 성장은 SUN-1에서는 2일부터 6일까지 서서히 상승하였고 SNU-1/ADR은 $5{\times}10^3$celles/ml 농도 이상에서 상승을 보였다. 각 세포의 doubling 시간과 doubling 수를 비교하였으며 SNU-1은 doubling 시간이 평균 27.2 시간 doubling 수가 3.56번 이었으며, SNU-1/ADR은 52.2 시간 1.85번으로 내성세포가 더욱 성장이 왕성한 것을 관찰할 수 있다. MTT assay를 위하여 4일간의 성장으로 세포의 적절한 생존도를 관찰하였다. SNU-1과 내성세포주 SNU-1/ADR을 각각 항암제에 대한 약제 감수성 검사를 실시하였으며 약제농도 50%에서 생존도($IC_{50}$)를 비교하여 상관내성도(relative resistance : RR)을 측정 하였으며 vinblastine이 31.62이상으로 가장 높고, vincristine이 29.5, dactinomycin 21.37, epirubicin 17.78, daunorubicin 14.12였고, adriamycin 7.76이었으며 etoposide 4.46 이었다. 그 외의 약제 5-fluorouracil, cisplatin, cyclophosphamide, methotrexate, aclarubicin은 감수성이 낮았다. 위의 결과로 RR가 높은 약제들에 대해서는 multidrug resistance(복합내성)의 존재를 의미한다고 할 수 있으며 내성생성 SNU-1/ADR 세포주의 염색체의 검사에서 double minute chromosome(DMs)을 확인함으로서 내성 생성 세포를 확인 하였다.

• 천문학회지
• /
• 제54권3호
• /
• pp.89-102
• /
• 2021

Even in an era where 8-meter class telescopes are common, small telescopes are considered very valuable research facilities since they are available for rapid follow-up or long term monitoring observations. To maximize the usefulness of small telescopes in Korea, we established the SomangNet, a network of 0.4-1.0 m class optical telescopes operated by Korean institutions, in 2020. Here, we give an overview of the project, describing the current participating telescopes, its scientific scope and operation mode, and the prospects for future activities. SomangNet currently includes 10 telescopes that are located in Australia, USA, and Chile as well as in Korea. The operation of many of these telescopes currently relies on operators, and we plan to upgrade them for remote or robotic operation. The latest SomangNet science projects include monitoring and follow-up observational studies of galaxies, supernovae, active galactic nuclei, symbiotic stars, solar system objects, neutrino/gravitational-wave sources, and exoplanets.

• BMB Reports
• /
• 제41권11호
• /
• pp.803-807
• /
• 2008

We investigated the expression of muscarinic acetylcholine receptors (mAChRs) and their possible involvement in the regulation of cell proliferation in four colon cancer cell lines (SNU-61, SNU-81, SNU-407, and SNU-1033) derived from Korean colon carcinoma patients. A ligand binding assay showed that all four cell lines expressed mAChRs. Treatment of the four cell lines with the cholinergic agonist carbachol led to the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). In SNU-407 cells, carbachol significantly stimulated cell proliferation, which could be abolished by the muscarinic antagonist atropine and the ERK1/2 kinase inhibitor PD98059. These results indicate that mAChRs specifically mediate the proliferation of SNU-407 colon cancer cells via the ERK1/2 pathway.

• 천문학회보
• /
• 제32권1호
• /
• pp.71.2-71.2
• /
• 2007

• 대한예방의학회:학술대회논문집
• /
• 대한예방의학회 1996년도 제48차 추계 학술대회 연제집
• /
• pp.353-354
• /
• 1996

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 1996년도 추계 학술대회지
• /
• pp.52-53
• /
• 1996

• 천문학회보
• /
• 제31권1호
• /
• pp.31-31
• /
• 2006

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 1996년도 춘계 학술대회지
• /
• pp.14-15
• /
• 1996

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 C
• /
• pp.1991-1993
• /
• 1996

This paper describes a standardized micromachinung project (SMP) performed at Seoul National University (SNU). The SNU SMP uses a 3-mask, 2-polysilicon surface micromaching process. The entire process is performed at SNU Inter-University Semiconductor Research Institute(ISRC). In this first SNU SMP attemp, 16 $1cm^2$ cells containing different designs were fabricated.

• IMMUNE NETWORK
• /
• 제1권2호
• /
• pp.151-161
• /
• 2001

Background: Inactivation in p53 tumor suppressor gene through a point mutation and deletion is one of the most frequent genetic changes found in human cancer, with 50% of an incidence. This high rate of mutation mostly suggests that the gene plays a central role in the development of cancer and the mutations detected so far were found in exons 5 to 8. Mutation of p53 locus produced accumulation of abnormal p53 protein, and negative regulation of cell proliferation and transcriptional activation as a suppressor of transformation were lost. In addition, inhibition of its normal cellular function of wild-type by mutant is an important step in tumorigenesis. Method: 4 colon cancer cell lines (SNU C1, C2A, C4, C5) were examined for mutation in exons 5 to 8 of the p53 tumor suppressor gene by PCR-SSCP analysis and expression pattern by western blotting and immunoprecipitation. p53-mediated transactivation ability were examined by CAT assay and base substitution of p53 in SNU C2A cell were detected by DNA sequencing. Results: 1) SNU C2A cell and SNU C5 cell were detected mobility shifts each in exon 5 and exon 7 of p53 gene by the PCR-SSCP method, implicating being of p53 mutation. 2) 3 colon cancer cell lines (SNU C1, SNU C2A, SNU C5) expressed wild type and mutant type p53 protein. 3) In northern blot experiment, SNU C2A and SNU C5 cell expressed high level of p53 mRNA. 4) Results of p53-mediated transactivation in colon cancer cell lines by CAT assay represented only SNU C2A cell has transcriptional activity. 5) DNA sequencing in SNU C2A cell showed missense mutation in codon 179 of one allele, histidine to arginine and wild type p53 in the other allele. Conclusion: Colon cancer cell lines showed correlation with mutation in p53 gene and accumulation of abnormal p53 protein. Colon cancer cell SNU C2A retained p53-mediated transactivation as heterozygous p53 with one mutant allele in 179 codon and the other wild-type allele.