• Food Science and Biotechnology
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• 제15권5호
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• pp.799-804
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• 2006

Ingestion of green tea has been shown to decrease prostaglandin $E_2$ levels in human colorectum, suggesting that tea constituents modulate arachidonic acid metabolism. In the present study, we investigated the effects of four purified green tea catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG), and (-)-epicatechin-3-gallate (ECG), on the catalytic activity of cytosolic phospholipase $A_2$ ($cPLA_2$) and release of arachidonic acid and its metabolites from intact cells. At $50\;{\mu}M$, EGCG and ECG inhibited $cPLA_2$ activity by 19 and 37%, respectively, whereas EC and EGC were less effective. The inhibitory effects of these catechins on arachidonic acid metabolism in intact cells were much more pronounced. At $10\;{\mu}M$, EGCG and ECG inhibited the release of arachidonic acid and its metabolites by 50-70% in human colon adenocarcinoma cells (HT-29) and human esophageal squamous carcinoma cells (KYSE-190 and 450). EGCG and ECG also inhibited arachidonic acid release induced by A23187, a calcium ionophore, in both HT-29 and KYSE-450 cell lines by 30-50%. The inhibitory effects of green tea catechins on $cPLA_2$ and arachidonic acid release may provide a possible mechanism for the prevention of human gastrointestinal inflammation and cancers.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3009-3016
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• 2011

To investigate the possible isosteric replacement of imidazolidinone moiety in 4-phenyl-N-arylsulfonylimidazolidinone for broad and potent anticancer agents, a series of 4-phenyl-l(N)-arylsulfonylimidazolidinones 6a-k, imidazolidinethione analogs 7a-i, and imidazolidine oxime analogs 8a-c were prepared and evaluated for their in vitro anticancer activity against four human cancer cell lines (human lung A549, human colon COLO205, human leukemia K562, human ovary SK-OV-3). Among all the derivatives of N-arylsulfonylimidazolidinone 6a-k, compounds 6f and 6g showed the best inhibition comparable to doxorubicin against all cancer cell lines. Increasing the carbon chain on alkyl moieties of carbamates as shown in 6c-g did not alter the activity. The imidazolidinethione analogs 7a-i and imidazolidin-2-one oxime derivatives 8a-c did not possess any good activity. Therefore, imidazolidinone moiety is the best pharmacophore among the 4-phenyl-Narylsulfonylimidazolidinone derivatives.

• 한국지역사회생활과학회지
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• 제16권2호
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• pp.3-9
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• 2005

The study was carried out to evaluate the antimutagenic and anticancer effects of small water dropwort. The methanol extracts from small water dropwort significantly reduced the mutagenicity induced by aflatoxin $B_1\;(AFB_1)$ and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) in Salmonella typhimutium TA 100. Also, the methanol extracts inhibited the growth of AZ-521 human gastric cancer cells and HT-29 colon cancer cells. The chloroform fraction from methanol extracts of small water dropwort inhibited $40\;to\;80\%$ of the mutagenicity by $AFB_1$ in Sal. typhimurium TA 100 by the addition of 2.5 to $10\%$. To separate active compounds, the chloroform fraction was subjected to column chromatography on a silica gel and separated into five fractions. Among the five fractions, fraction 4 showed the highest antimutagenic effect against $AFB_1$ and an anticancer effect in the HT-29 colon cancer cell. As the result of the analysis in GC-MS, 1-napthalene carbonitrile, 5,6,7,8-tetrahydrol and benzene, 1,1'-(1,4-pentadiene-1,5-diyl) bis-,(E,E) were identified potentially from fraction 4.

• 생약학회지
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• 제25권2호
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• pp.171-177
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• 1994

Antineoplastic activity against human gastric and colon carcinoma cell lines was measured in 100 extracts from 90 plants using MTT (3-[4,5-dimethyl thiazo-2-yl]-2, 5-diphenyl tetrazolium bromide) method. Four extracts from four plants have been reported to have antineoplastic effect. Extracts from remaining 86 plants failed to show significant cytotoxic effect at the concentration of less than $230\;{\mu}/ml$.

• 한국축산식품학회지
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• 제22권4호
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• pp.348-351
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• 2002

유황오리 추출물의 각종 암세포에 대한 생육억제효과를 MTT assay를 이용하여 검토한 결과 10 mg/$m\ell$의 농도에서 KB(구강상피암) 89.5$\pm$0.7%, SNU-1(위암) 69.8$\pm$1.7%, K-562(백혈병) 79.8$\pm$2.8%, Farrow(흑색종) 82.7$\pm$2.6%, WiDr 결장암) 76.3$\pm$2.5%, SK-MES-1(폐암) 59.2 $\pm$4.4%, HL6O(백혈병) 60.5 +3.5%, Calu-3(폐암) 53.2$\pm$1.6%, HEP-2(후두암) 80.7$\pm$0.5%, P388(마우스 백혈병) 79.9$\pm$3.7%, 3LL(마우스 폐암) 87.2$\pm$3.3%의 효과가 있다는 사실이 판명되었다. 그리고 유황오리 추출물의 HP-20 column chromatography에서는 100% methyl alcohol 용출물이 HEP-2에 대한 생육억제효과가 있었으며, 10 mg/$m\ell$에서 99.1$\pm$0.4%의 생육억제효과가 나타났다. 또한 일반오리 추출물과 유황오리 추출물의 각종 암세포에 대한 생육억제효과를 비교하였을 때 거의 모든 암세포에서 유황오리 추출물의 효과가 더 높았다.

• International Journal of Oncology
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• 제54권6호
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• pp.2117-2126
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• 2019

Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine that functions as a growth suppressor in normal epithelial cells and early stage tumors, but acts as a tumor promoter during malignant progression. However, the molecular basis underlying the conversion of TGF-β1 function remains largely undefined. X-linked inhibitor of apoptosis-associated factor 1 (XAF1) is a pro-apoptotic tumor suppressor that frequently displays epigenetic inactivation in various types of human malignancies, including colorectal cancer. The present study explored whether the anti-apoptotic effect of TGF-β1 is linked to its regulatory effect on XAF1 induction in human colon cancer cells under stressful conditions. The results revealed that TGF-β1 treatment protected tumor cells from various apoptotic stresses, including 5-fluorouracil, etoposide and γ-irradiation. XAF1 expression was activated at the transcriptional level by these apoptotic stresses and TGF-β1 blocked the stress-mediated activation of the XAF1 promoter. The study also demonstrated that mitogen-activated protein kinase kinase inhibition or extracellular signal-activated kinase (Erk)1/2 depletion induced XAF1 induction, while the activation of K-Ras (G12C) led to its reduction. In addition, TGF-β1 blocked the stress-mediated XAF1 promoter activation and induction of apoptosis. This effect was abrogated if Erk1/2 was depleted, indicating that TGF-β1 represses XAF1 transcription through Erk activation, thereby protecting tumor cells from apoptotic stresses. These findings point to a novel molecular mechanism underlying the tumor-promoting function of TGF-β1, which may be utilized in the development of a novel therapeutic strategy for the treatment of colorectal cancer.

• Food Science and Biotechnology
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• 제16권2호
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• pp.260-264
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• 2007

Gleditsiae Semen (GS) has been used in both Korea and China as herbal medicine for the treatment of cephalalgia, catharsis, and other diseases. However, the apoptosis of GS against human cancer cells has not previously been investigated. The primary objective of this study was to determine the mechanisms inherent in GS-induced cytotoxicity and apoptosis, using methanolic extract of GS (GSE) in HT-29 human colon carcinoma cells. We found that GSE induced cytotoxicity in HT-29 cells in a dose-dependent manner, and this effect was verified via a lactate dehydrogenase release assay and a colony formation assay. In particular, HT-29 cells showed extensive cell death when treated with $50\;{\mu}g/mL$ of GSE; the calculated $IC_{50}$ value was $20\;{\mu}g/mL$. It induced characteristic apoptotic signs in HT-29 cells, including chromatin condensation and DNA fragmentation, occurring within 6-24 hr when the cells were treated at a concentration of $50\;{\mu}g/mL$. Interestingly, we detected the activation of caspase-3 and -9, but not caspase-8, and apoptotic bodies in GSE-treated HT-29 cells. Collectively, our results indicate that GSE induces apoptosis via a mitochondria-mediated apoptotic pathway, and these findings may be significant with regard to the development of a new drug for the treatment of human colon carcinoma cells.

• The Korean Journal of Physiology and Pharmacology
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• 제3권1호
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• pp.75-82
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• 1999

It has been reported that activation of sphingomyelin pathway and nonsteroidal anti-inflammatory drugs (NSAIDS) inhibit the promotion of colon carcinoma. Ceramide, a metabolite of sphingomyelin, and indomethacin were shown to induce apoptosis in colon carcinoma cells. However, the mechanisms of ceramide- and indomethacin-induced apoptosis in the colon carcinoma cells are not clearly elucidated. Recent studys showed that indomethacin-induced apoptosis in colon cancer cells through the cyclooxygenase-independent pathways, and that may be mediated by generation of ceramide. In this study, we compared effects of ceramide and indomethacin on important modulators of apoptotic processes in HT29 cells, a human colon cancer cell line. Ceramide and indomethacin induced apoptosis dose- and time- dependently. Ceramide and indomethacin increased stress-activated protein kinase (SAPK) activity, and decreased mitogen-activated protein kinase (MAPK) activity. The expression of Bak was increased by the treatment of ceramide and indomethacin. The expression of other Bcl-2 related proteins (Mcl-1, $Bcl-X_L,$ Bax) which were known to be expressed in colon epithelial cells was not changed during the ceramide- and indomethacin-induced apoptosis. Our results suggest that ceramide and indomethacin share common mechanisms for induction of apoptosis in HT29 cells.

• 생명과학회지
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• 제27권10호
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• pp.1215-1224
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• 2017

현재까지 다양한 암의 발병 원인이 밝혀졌는데, 그 중 하나로써 DNA에 돌연변이가 축적되어 유전체가 불안정 해짐에 따라 암이 발생될 수 있는 기작들이 주목받고 있다. 생물정보학과 유전체학의 발달에 따라 질병 연구에 있어서 보다 더 정확하고 신뢰성 있는 바이오마커를 찾는 것이 가능해졌다. 따라서, 생물정보학과 유전체학의 연구 기반을 바탕으로 한 암의 바이오마커는 암의 조기진단뿐만 아니라, 더 나아가 암 발생 예측과 암환자의 예후 진단에 적용될 수 있다. 최근 들어 인간 유전체에서 약 45%를 차지하는 이동성 유전인자(transposable elements, TEs)가 유전자의 발현 조절과 DNA의 돌연변이를 유도함으로써 다양한 질병에 영향을 미친다는 사실이 밝혀짐에 따라, 이러한 이동성 유전인자들이 암의 발생과 어떤 연관이 있는지에 대한 연구 또한 활발히 진행되고 있다. 따라서 우리는 이동성 유전인자가 대장암과 어떤 연관성이 있는지에 대해 조사를 하였으며, 이를 어떻게 바이오마커로 활용할 수 있는지 알아보았다. 우선, 이동성 유전인자 중 인간 유전체에 많이 존재하면서 유전체에 많은 영향을 미치는 LINE-1 (long interspersed nuclear element-1, L1)과 Alu, LTR (long terminal repeat) 위주로 확인하였다. 흥미롭게도, 대장암 세포에서 LINE-1의 저메틸화, APC 유전자 내에 LINE-1 삽입, Alu의 저메틸화와 과메틸화, LTR 삽입에 따른 isoform 발생 등이 특징적으로 나타나는 것을 알 수 있었다. 또한 원발암유전자에서의 L1 저메틸화가 대장암 전이의 바이오마커로 쓰일 수 있다는 것과 Alu에 의한 MLH1 돌연변이가 가족성 및 유전성 대장암에서 흔히 발견된다는 것을 알 수 있었다. 이 때 이동성 유전인자에 의하여 영향 받는 유전자들의 발현을 in silico 발현 분석을 통하여 분석하였으며, 조직별, 성별 특이적 발현 양상을 제시하였다. 이들을 토대로 대장암 바이오마커를 개발하여 유전성 대장암의 예측 및 대장암 진단 또는 대장암 예후 예측을 통한 개인 맞춤형 치료에 활용할 수 있을 것으로 예상된다.

• 한국식품과학회지
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• 제40권2호
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• pp.207-214
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• 2008

목향(Saussurea lappa)은 항암효과를 비롯하여 다양한 생리활성을 나타내는 것으로 알려지고 있으나 목향이 대장암에 미치는 영향에 대해 자세히 연구된 바가 없다. 본 연구에는 목향 헥산추출물이 인간의 대장에서 유래한 암세포인 HT-29 세포의 증식에 미치는 영향과 그 작용 기전에 대해 연구하였다. 헥산으로 목향을 추출하여 얻은 목향 헥산추출물을 HT-29 세포의 세포 배양액에 0, 1, 3, 5 ${\mu}g/mL$로 첨가하여 세포를 배양하였다. HT-29 세포의 증식은 목향 헥산추출물 처리 농도가 증가할수록 현저히 감소하였다. 인간의 대장에서 유래한 정상 상피세포인 FHC 세포의 증식은 목향 헥산추출물에 의해 변화하지 않았고, 인간의 피부에서 유래한 정상 섬유아세포인 CCD 1108Sk 세포 증식은 목향을 5${\mu}g/mL$ 농도로 72 시간 배양한 경우에만 감소하였다. 목향 헥산 추출물 처리에 의해 HT-29 세포의 세포주기 진행 중 sub G1기에 머무른 세포수가 증가하였고, 세포사멸 세포수가 현저히 증가하였다. 세포사멸의 주요한 조절인자인 Bcl-2 family 단백질 중 Bcl-2은 목향 헥산추출물에 의해 변화하지 않았으나 Bax는 유의적으로 증가하였다. Bcl-2 family 단백질과 더불어 세포사멸 조절에 중요한 역할을 하는 caspases의 활성형인 cleaved caspase-8, -9, -7, -3가 목향 헥산추출물에 의해 증가하였다. 또한 목향 헥산추출물 처리 농도가 증가할수록 cleaved PARP 단백질 수준도 현저히 증가하였다. 이 결과는 목향 헥산추출물이 세포사멸을 유도하여 대장암세포인 HT-29 세포의 증식을 억제함을 나타내며, 목향 헥산추출물에 의해 HT-29 세포의 세포사멸은 Bax 증가와caspases의 활성 증가에 의한 것임을 나타낸다. 본 연구는 목향을 독성과 부작용이 적은 암예방제나 항암제로 개발할 수 있는 가능성을 제시한다. 그러나 목향을 이용하여 제품 개발을 위해서는 유효 성분 동정 및 동물시험 등의 연구 수행이 필요할 것으로 사료된다.