• 대한두경부종양학회:학술대회논문집
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• 1995.11a
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• pp.201-202
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• 1995

• Microbiology and Biotechnology Letters
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• v.25 no.5
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• pp.483-489
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• 1997

Sulforhodamine B (SRB) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, RNA dot blot and Northern hybridization analysis were performed to screen microorganisms for the production of anticancer agent. Among microorganisms tested, strain YP-1 was selected for its cytotoxicity and ability to reduce the level of c-myc RNA. Strain YP-1 was identified as Streptomyces endus. The anticancer material produced by Streptomyces endus YP-1 was sequentially purified by solvent extraction, silica gel column chromatograpby, preparative TLC and preparative HPLC. The cancer material identified as azalomycin B by the instrumental analyses such as $^{1}$H-NMR, $^{13}$C-NMR, Mass, IR and UV absorption. It was colorless amorphous powder and its molecular weight was 1025.278. Azalomycin B, produced by Streptomyces endus YP-1, showed anticancer activity against several human cancer cell lines and reduction of c-Myc protein level in Colo320 DM cells which was determined by Western blot analysis.

• International Journal of Oral Biology
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• v.41 no.2
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• pp.69-74
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• 2016

Skin-derived precursors (SKPs) have potential to differentiate to various cell types including osteoblasts, adipocytes and neurons. SKPs are a candidate for cell-based therapy since they are easily accessible and have multipotency. Most mammalian cells are exposed to a low oxygen environment with 1 to 5% $O_2$ concentration in vivo, while 21% $O_2$ concentration is common in in vitro culture. The difference between in vitro and in vivo $O_2$ concentration may affect to the behavior of cultured cells. In this report, we investigated the effect of hypoxic condition on stemness and proliferation of SKPs. The results indicated that SKPs exposed to hypoxic condition for 5 days showed no change in proliferation. In terms of mRNA expression, hypoxia maintained expression of stemness markers; whereas, oncogenes, such as Klf4 and c-Myc, were downregulated, and the expression of Nestin, related to cancer migration, was also downregulated. Thus, SKPs cultured in hypoxia may reduce the risk of cancer in SKP cell-based therapy.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 1998.07a
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• pp.32-33
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• 1998

생물체에서 유전외적 변형의 하나인 DNA 메틸화는 cis-acting factor의 조성변화를 통하여 세포특이 유전자의 발현과 virus latency, genomic imprinting, mutagenesis등과 같은 생물학적 효과를 나타내는 것으로 알려져 있다.(reviewed by Olle Heby, 1995). 5-azaCR, 5-azaCdR 그리고 6-azaCR의 처리결과는 배아자체의 DNA 메틸화의 유지가 정상발생에 필수적임을 알 수 있으며, 메틸화에 의한 배아발생 조절기작이 존재함을 암시하고 있다. 이러한 과정에서 5-azaCR과 5-azaCdR은 서로다른 경로를 통하여 배아발생에 관여함을 보여주었다. 즉, 5-azaCdR은 주로 DNA에 incorporation되어 작용하는 것으로 여겨지며, 5-azaCR은 DNA 보다는 RNA에 incorporation되어 작용하는 것으로 나타났다. 그리고, 비록 소수의 유전자만이 조사되었지만, 5-azaCdR의 incorporation에 의한 cis-acting factor의 변화는 전사인자인 c-myc proto-oncogene과 fluid 수송에 관여하는 $Na^{+}$, $K^{+}$-ATPase 유전자의 전사를 억제하지 않았다. 반면, 5-azaCR의 RNA로의 incorporation은 전사인자인 c-myc proto-oncogene의 전사를 억제하였으며, 연이어 fluid 수송에 관련되어있는 $Na^{+}$, $K^{+}$-ATPase 유전자의 전사를 억제하였다. 이것은 아마도 RNA로 incorporation된 5-azaCR은 RNA의 post-transcriptional processing에 영향을 주어 trans-acting factor의 조성을 변화, 전사적 repression을 유발한 것으로 사료된다. 생쥐 착상전 초기배아에서 DNA 메틸화는 short-term하게는 cis-acting factor로써 전사적 수준에서 유전자발현 조절하며, 그리고 유전자발현을 통하여 long-term하게는 배아발생에 관여 할 것이라고 사료된다.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.1
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• pp.11-32
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• 2009

Objective : This study was designed to investigate anti-cancer and whitening activities (LC). So it was investigated the effects of LC on proliferation rates of melanoma genetic profile by LC. Methods : The genetic profile for the effect of LC on human derived melanoma cell, SK-MEL-2, was measured using microarray technique, and the functional analysis on these genes were conducted. Total 441 genes were up-regulated and 830 genes down-regulated in cells treated with LC. Genes induced or suppressed by LC were all mainly concerned with basic signalling pathways, which are involved in cell growth, differentiation and migration. Especially, many genes, which are related in apoptosis and cell cycle arrest were up-regulated by treatment with LC, and genes related in cell cycle were down-regulated. Result : The network of total protein interactions were identified by using cytoscape program, and some key molecules, such as BCL2L1, SIN3A, SMAD2 and c-myc that can be used for elucidation of therapeutical mechanism of medicine in the future. Conclusion : These results suggest possibility of LC as addition drug and whitening cosmetics. In addition, it was also suggested that related mechanisms are involved in BCL2L1, SIN3A, SMAD2 and c-myc related signalling pathways.

• The Korean Journal of Food & Health Convergence
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• v.5 no.2
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• pp.27-34
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• 2019

RNases plays a pivotal role in biological system and different RNases are known for their various functions like angiogenesis, immunological response, antiviral, antitumour activity and apoptosis. In which anti tumour activity of RNase is proved to improve genome stability in normal cells up to some extent. RNases like RNase L shows antiviral and antitumour activities against virus infected cells and cancer cells through 2'-5' oligo adenylate pathway and induces RNaseL dependent apoptosis where as RNase A modulates various proliferative pathways like MAP kinase, JNK, TGF-${\beta}$ and activates apoptosis in cancer cells and promotes immunological response through processing of Ags. IRE1 RNase acts as both tumour suppressor gene and oncogene in normal and cancer cells and involved in both antitumour and tumorigenic activities. RNase III upregulates miRNA in cancer cells there by acting via posttranscriptional level and proven to be effective against colorectal adeno carcinoma. In addition to this IRE1 RNase is a double edged sword through RIDD pathway in ER (18). To some of the cancers expressing c-myc IRE1 acts as tumour suppressor where as in cancers where myc is downregulated IRE1 acts as tumour provoking through RIDD pathway (18). Thus RNases play vital role in regulating the genome stability.

• BMB Reports
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• v.52 no.2
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• pp.151-156
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• 2019

RAD51 recombinase plays a critical role in homologous recombination and DNA damage repair. Here we showed that expression of RAD51 is frequently upregulated in lung cancer tumors compared with normal tissues and is associated with poor survival (hazard ratio (HR) = 2, P = 0.0009). Systematic investigation of lung cancer cell lines revealed higher expression of RAD51 in KRAS mutant (MT) cells compared to wildtype (WT) cells. We further showed that MT KRAS, but not WT KRAS, played a critical role in RAD51 overexpression via MYC. Moreover, our results revealed that KRAS MT cells are highly dependent on RAD51 for survival and depletion of RAD51 resulted in enhanced DNA double strand breaks, defective colony formation and cell death. Together, our results suggest that mutant KRAS promotes RAD51 expression to enhance DNA damage repair and lung cancer cell survival, suggesting that RAD51 may be an effective therapeutic target to overcome chemo/radioresistance in KRAS mutant cancers.

• Proceedings of the Korean Society of Toxicology Conference
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• 1998.10a
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• pp.36-36
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• 1998

Tumorigenicity of benzo(a)pyrene (BP) and benzo(a)pyrene diol epoxides ((+)BPDE-1, (-)BPDE-1) was investigated in transgenic TG-AC mice carrying v-Ha-ras oncogene fused to the promoter of the mouse embryonic a-like, z-globin gene. Animals were topically treated twice per week for 25weeks with BPDE (10$\mu$g/mouse) and BP (10, 20, 40$\mu$g/mouse). In addition, animals were treated with BPDE or BP (initiated) followed by TPA (2$\times$2.5$\mu$g/week, for 4 weeks) for promotion study. In the continuous treatment of BPDE or BP, animals treated with 40$\mu$g BP showed $100\%$ tumor response after 20 weeks, $40\%$ of mice for 20$\mu$g BP, and $20\%$ for (+)BPDE-1, but (-)BPDE-1 and 10$\mu$g BP did not show any tumor response. After 25 weeks, most tumors turned out to be carcinomas in animals treated with 40$\mu$g BP. In BPDE or BP/TPA Initiation-promotion study, papilloma response occurred earlier (6 weeks after TPA treatment) than in continuously treated animals with BPDE or BP. RT-PCR assay for transgene expression showed that BP or BPOE was not transgene dependent in its tumorigenicity, but TPA was. Several Cytokine genes(TGF-a, TNF-a) and c-myc gene expressions were monitored in skin tissues during BP carcinogenesis. In early stage of BP treatment, the gene expressions were elevated(c-myc,TGF-a) or unchanged(TNF-a) compared to control, but the levels were gradually decreased during both middle and late stages of cacinogenesis, Gene expression levels of skin papillomas in acetone initiated-TPA promoted animals were close to those of middle stage or between middle and late stages. i-NOS was also highly expressed in carcinoma and papilloma, These data suggest that transgene expressions of TG-AC mice were not dependent on BP carcinogenesis and that TG-AC mice were more sensitive to TPA regardless of types of initiators. In addition, genes(TGF-a, c-myc, TNF-a, i-NOS) were modulated in the skin during BP cacinogenesis or TPA promotion.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.11a
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• pp.27-30
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• 1994

잠재적으로 항감염 약제로 사용될 가능성이 있는 약제들의 초기 연구과정에서 주된 관심사는 이들이 미생물(세균, 바이러스, 기타 기생충)에 대한 작용들이 있는가 하는 점이다. 이러한 작용들이 실험적으로 충분히 연구가 된 후에야 실험동물에서 그 효과를 연구한다. 항 바이러스 제제의 경우에는 세포배양을 통한 연구가 그 약제의 독성과 효용성을 나타내는데 필수적인 것이 된다. 여러 종류의 동물을 이용한 생체실험에서 약제의 일반적인 흡수와 배설, 분포 등에 관한 정보와 약제 자체와 동물 내에서의 대사적 변화에 대한 정보가 제공된다. 여러 가지 미생물로 감염을 시킨 적합한 동물과 여러 가지 용량으로 치료하는 실험을 통하여 약제의 항 감염 능력이 알려지게 된다. 동물에서의 생체실험과 실험관내에서 실험을 하고 나서야 사람에서의 연구가 이루어지게 된다. 소위 전임상시험에서 대표적 병원성 미생물에 대한 생물학적효과, 약리학적 효과와 독성 그리고 동물실험모델에서의 가능한 효과가 결정된 후에 임상시험에 들어가기 마련이다. 항균제의 임상시험에는 각각의 감염질환에 대한 진단 및 치료기준을 반영하는 것이 기본이다. 새로운 항균제의 임상시험에서는 안전성과 효과가 반드시 밝혀져야 한다. 1상에서는 인체에서의 약리효과, 안전성이 주목적이며, 2상과 3상은 겹쳐지는 점도 있으나 하나 또는 그 이상의 적응증에 대한 항균제의 효과와 단기간의 부작용은 2상에서 관찰하여야하며, 다수의 환자에서 제안된 적응질환의 무작위임상시험과 다수에서의 안전성도 3상에서 관찰하여야 한다. 4상에서는 이상에서의 자료로 시판된 후에도 계속해서 감시하는 것으로 지속적으로 안전성을 관찰하는 것이다. 이러한 기본사항외에도 소아, 임산부, 고령자등에서의 임상시험도 넓은 의미에서 포함되어야 할 것이며 또한 질적인 면에서 조절하는 Quality Assurance도 중요하다.양상은 세 용량군 간 차이가 없었으나, 시험기에서 발열의 발현율이 낮았으며, 발열일 수와 항생제 사용일 수가 짧았다. 결론: 골수억제 조절 효과는 용량에 따른 혈액소견에 미치는 영향, 부작용, 감염의 빈도, 감염발생에 따른 항생제 사용기간 등을 고려하여 그 임상 유효성 평가시, 제 3상 시험에 사용할 권장량 (recommended dose) 은 250 ug/$m^2$/d $\times$ 10d 으로 관찰되었다.5주에 부검한 랫드의 간에서 c-myc 종양단백의 발현은 모든 처리군들이 대조군에 비하여 높게 발현되는. 것이 관찰되었으나 시험개시후 26주에 부검한 랫드의 간에서 c-myc 종양단백의 발현은 대조군에 비하여 차이가 거의 없었다. 따라서 랫드에서 화학적으로 유도한 간암발생 과정에서 NK 세포활성이 현저하게 억제되는 것으로 생각되며, c-myc 종양단백의 발현은 시험개시후 15주에 그 발현이 확실한 것으로 사료되어 진다.에 영향을 주는 성분이 있음을 제시하였다.1과 항우울약들의 항혈소판작용은 PKC-기질인 41-43 kD와 20 kD의 인산화를 억제함에 기인되는 것으로 사료된다.다. 것으로 사료된다.다.바와 같이 MCl에서 작은 Dv 값을 갖는데, 이것은 CdCl$_{4}$$^{2-}$ 착이온을 형성하거나 ZnCl$_{4}$$^{2-}$ , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 NH$_{4}$$^{+}$의 경우 Dv값이 제일 작았다. 바. 본 연구의 목적중의 하나인 인체유

• Nutrition Research and Practice
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• v.13 no.1
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• pp.58-63
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• 2019

BACKGROUND/OBJECTIVES: Telomeres are located at the chromosomal ends and progressively shortened during each cell cycle. Telomerase, which is regulated by hTERT and c-MYC, maintains telomeric DNA sequences. Especially, telomerase is active in cancer and stem cells to maintain telomere length for replicative immortality. Recently we reported that walnut phenolic extract (WPE) can reduce cell viability in a colon cancer stem cell (CSC) model. We, therefore, investigated the effect of WPE on telomere maintenance in the same model. MATERIALS AND METHODS: $CD133^+CD44^+$ cells from HCT116, a human colon cancer cell line, were sorted by Fluorescence-activated cell sorting (FACS) and treated with WPE at the concentrations of 0, 10, 20, and $40{\mu}g/mL$ for 6 days. Telomere lengths were assessed by quantitative real-time PCR (qRT-PCR) using telomere specific primers and DNA extracted from the cells, which was further adjusted with single-copy gene and reference DNA ($ddC_t$). Telomerase activity was also measured by qRT-PCR after incubating the PCR mixture with cell protein extracts, which was adjusted with reference DNA ($dC_t$). Transcriptions of hTERT and c-MYC were determined using conventional RT-PCR. RESULTS: Telomere length of WPE-treated cells was significantly decreased in a dose-dependent manner ($5.16{\pm}0.13$ at $0{\mu}g/mL$, $4.79{\pm}0.12$ at $10{\mu}g/mL$, $3.24{\pm}0.08$ at $20{\mu}g/mL$ and $3.99{\pm}0.09$ at $40{\mu}g/mL$; P = 0.0276). Telomerase activities concurrently decreased with telomere length ($1.47{\pm}0.04$, $1.09{\pm}0.01$, $0.76{\pm}0.08$, and $0.88{\pm}0.06$; P = 0.0067). There was a positive correlation between telomere length and telomerase activity (r = 0.9090; P < 0.0001). Transcriptions of both hTERT and c-MYC were also significantly decreased in the same manner. CONCLUSION: In the present cell culture model, WPE reduced telomere maintenance, which may provide a mechanistic link to the effect of walnuts on the viability of colon CSCs.