• Molecules and Cells
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• 제28권5호
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• pp.489-494
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• 2009

We have previously shown that the down-regulation of protein kinase CKII activity is tightly associated with cellular senescence of human fibroblast IMR-90 cells. Here, we examined the roles of p53 and $p21^{Cip1/WAF1}$ in senescence development induced by CKII inhibition using wild-type, isogenic p53-/- and isogenic p21-/- HCT116 human colon cancer cell lines. A senescent marker appeared after staining for senescence-associated ${\beta}$-galactosidase activity in wild-type HCT116 cells treated with CKII inhibitor or $CKII{\alpha}$ siRNA, but this response was almost abolished in p53- or $p21^{Cip1/WAF1}$-null cells. Increased cellular levels of p53 and $p21^{Cip1/WAF1}$ protein occurred with the inhibition of CKII. CKII inhibition upregulated p53 and $p21^{Cip1/WAF1}$ expression at post-transcriptional level and transcription level, respectively. RB phosphorylation significantly decreased in cells treated with CKII inhibitor. Taken together, this study shows that the activation of the $p53-p21^{Cip1/WAF1}$ pathway acts as a major mediator of cellular senescence induced by CKII inhibition.

• Natural Product Sciences
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• 제23권4호
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• pp.227-234
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• 2017

Moringa oleifera Lam (M. oleifera, Moringaceae) is a tree of the Moringaceae family that can reach a height of between 5 and 10 m. The current paper presents cytotoxic effect of M. oleifera fruits and its flavonoids 1 and 2. The viability of HCT116 human colon cancer cells were 38.5% reduced by $150{\mu}g/mL$ of ethanolic extracts in a concentration-dependent manner; in addition, we observed the apoptotic features of cell shrinkage and decreased cell size. Bcl-2 family proteins were regulated as determined by Western blotting analysis, suggesting that M. oleifera fruits and their flavonoids 1 and 2 induced apoptosis through an intrinsic pathway. Based on our findings, 70% ethanolic extracts of M. oleifera fruits and flavonoids 1 and 2 might be useful as cytotoxic agents in colorectal cancer therapy.

• Asian Pacific Journal of Cancer Prevention
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• 제14권9호
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• pp.5031-5035
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• 2013

Zizyphus spina-christi (ZSC) fruit is a rich source of bioactive compounds but any medicinal properties in chemoprevention of colon cancer have hitherto not been studied. The aim of the present study was to examine in vivo protective effects of ZSC water extract on colon carcinogenesis in azoxymethane (AOM)-treated rats. Our results showed that ZSC significantly reduced AOM-induced colonic aberrant crypt foci development and AOM-induced oxidative stress as indicated by restoration of endogenous glutathione depletion and abrogating the impairment of total antioxidant capacity. Caspase-3 cleavage, which has been considered as an apoptotic index, was almost undetectable in AOM-treated rats and ZSC exhibited pro-apoptotic effects evidenced by increased levels of cleaved caspase-3. In the studied model, our findings provide the first in vivo evidence that ZSC extract could inhibit the early stage of colon carcinogenesis by preventing oxidative stress and inducing apoptosis.

• 생약학회지
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• 제38권2호통권149호
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• pp.117-122
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• 2007

The specific activation of the immune system to control cancer growth in vivo has been a long-standing goal in cancer immunology. Whole tumor Iysates have been used either alone or combined with adjuvants to induce specific immune response in vivo. Here, we examined whether freezing/thawing (F/T) colon26-M3.1 tumor cell admixed with EN-3, glycoprotein purified from Acanthopanx Senticosus, could stimulate in vivo immunity by using a murine experimental tumor metastasis model produced by colon26-M3.1 carcinoma cells. Vaccination of mice with F/T treated colon26-M3.1 carcinoma cells in combination with EN-3 as an adjuvant resulted in a significant inhibition in tumor metastasis of mice against live colon26-M3.1 carcinoma challenge. In addition, the splenocytes from vaccinated mice exhibited a higher proliferating activity and secreted interferon-${\gamma}$. These results suggest that EN-3 can be applied to immunoadjuvant to enhance the antitumor immunity in vivo.

• 한국식품영양학회지
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• 제15권1호
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• pp.23-28
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• 2002

감잎의 메탄을 추출물과 이를 극성이 다른 용매로 더욱 불리한 용매별 획분들의 돌연변이 유발 억제효과를 spore rec assay를 이용하여 검토하고 사람의 결장암 세포인 HT-29와 사람의 위암 세포인 AZ-521의 증식에 대한 저해효과를 실험하였다. 감잎의 메탄을 추출물은 spore rec assay에서 N-methyl- N'-nitro-N-nitrosoguanidine(MNNG) 의 돌연변이성을 61% 정도 억제하였으며, 감잎의 메탄을 추출물에서 효과가 있었던 활성물질을 정제하기 위하여 다시 극성이 다른 용매들로 각각 추출하여 얻은 획분 중에서는 헥산, 클로로포름 및 에틸아세테이트 획분이 강한 돌연변이 유발억제효과를 나타내었다. 그리고 감잎의 메탄을 추출물은 암세포의 증식을 억제시키는 항발암 효과가 관찰되었는데 사람의 결장암 세포인 UT-29와 사람의 위암 세포인 AZ-521에 감잎의 메탄을 추출물을 50$\mu\textrm{g}$/ml와 100$\mu\textrm{g}$/ml 첨가시 이들 암세포의 증식이 각각 90%와 99%가지 크게 억제되었다. 감잎의 메탄을 추출물을 다시 극성이 다른 용매들로 분리한 획분들 중에서는 사람의 결장암 세포인 HT-29와 사람의 위암세포인 AZ-521에 감잎의 클로로포름 획분을 각각 50$\mu\textrm{g}$/ml와 100$\mu\textrm{g}$/ml 첨가시 이들 암세포의 증식 억제율이 100%에 달하였고 감잎의 에틸아세테이트 획분도 사람의 결장암 세포(HT-29)와 사람의 위암세포(AZ-521)에 대해 클로로포름 획분 다음으로 강한 항발암 효과가 관찰되었으며, 헥산 획분도 이들 두 획분(클로로포름 및 에틸아세테이트)보다는 낮았으나 암세포 증식을 억제하는 효과가 관찰되어 항돌연변이 실험에서와 일치하는 결과를 얻었다.

• Journal of Microbiology and Biotechnology
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• 제26권8호
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• pp.1490-1503
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• 2016

Colorectal cancer (CRC) is the third most common cancer in the world. Although 5-fluorouracil (5-FU) is the representative chemotherapy drug for colorectal cancer, it has therapeutic limits due to its chemoresistant characteristics. Colorectal cancer cells can develop into cancer stem cells (CSCs) with self-renewal potential, thereby causing malignant tumors. The human gastrointestinal tract contains a complex gut microbiota that is essential for the host's homeostasis. Recently, many studies have reported correlations between gut flora and the onset, progression, and treatment of CRC. The present study confirms that the most representative symbiotic bacteria in humans, Lactobacillus plantarum (LP) supernatant (SN), selectively inhibit the characteristics of 5-FU-resistant colorectal cancer cells (HT-29 and HCT-116). LP SN inhibited the expression of the specific markers CD44, 133, 166, and ALDH1 of CSCs. The combination therapy of LP SN and 5-FU inhibited the survival of CRCs and led to cell death by inducing caspase-3 activity. The combination therapy of LP SN and 5-FU induced an anticancer mechanism by inactivating the Wnt/β-catenin signaling of chemoresistant CRC cells, and reducing the formation and size of colonospheres. In conclusion, our results show that LP SN can enhance the therapeutic effect of 5-FU for colon cancer, and reduce colorectal cancer stem-like cells by reversing the development of resistance to anticancer drugs. This implies that probiotic substances may be useful therapeutic alternatives as biotherapeutics for chemoresistant CRC.

• Biomolecules & Therapeutics
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• 제24권6호
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• pp.623-629
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• 2016

(1S,2S,3E,7E,11E)-3,7,11,15-cembratetraen-17,2-olide (LS-1), a marine cembrenolide diterpene, has anticancer activity against colon cancer cells such as HT-29, SNU-C5/5-FU (fluorouracil-resistant SNU-C5) and SNU-C5. However, the action mechanism of LS-1 on SNU-C5 human colon cancer cells has not been fully elucidated. In this study, we investigated whether the anticancer effect of LS-1could result from apoptosis via the modulation of $Wnt/{\beta}$-catenin and the TGF-${\beta}$ pathways. When treated with the LS-1, we could observe the apoptotic characteristics such as apoptotic bodies and the increase of sub-G1 hypodiploid cell population, increase of Bax level, decrease of Bcl-2 expression, cleavage of procaspase-3 and cleavage of poly (ADP-ribose) polymerase in SNU-C5 cells. Furthermore, the apoptosis induction of SNU-C5 cells upon LS-1 treatment was also accompanied by the down-regulation of $Wnt/{\beta}$-catenin signaling pathway via the decrease of GSK-$3{\beta}$ phosphorylation followed by the decrease of ${\beta}$-catenin level. In addition, the LS-1 induced the activation of TGF-${\beta}$ signaling pathway with the decrease of carcinoembryonic antigen which leads to decrease of c-Myc, an oncoprotein. These data suggest that the LS-1 could induce the apoptosis via the down-regulation of $Wnt/{\beta}$-catenin pathway and the activation of TGF-${\beta}$ pathway in SNU-C5 human colon cancer cells. The results support that the LS-1 might have potential for the treatment of human colon cancer.

• 대한핵의학회지
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• 제31권3호
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• pp.381-387
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• 1997

종양세포는 포도당섭취 및 포도당 대사가 정상세포에 비해 증가된 특징을 가진다. 포도당 유사체인 $^{18}F$ fluorodeoxyglucose(FDG)의 섭취를 이용한 PET 검사가 종양의 진단에 많이 쓰이고 있다. 이 연구에서는 유사한 성질을 가진 사람의 대장암 세포주간의 FDG 섭취량 및 섭취 속도의 차이점을 비교하고, 그 포도당 수송체의 발현의 관련성을 규명하고자 한다. 사람대장암 세포 SNU-C2A, SNU-C4, SNU-C5를 이용하여 FDG 섭취를 측정하였다. 또한 세포의 포도당 섭취에 중요 역할을 하는 포도당 수송체 1(GLUT1)의 발현을 Western blotting으로 비교하였다. $1{\times}10^6/ml$의 대장암 세포에 HEPES-buffered saline에 희석한 $1{\mu}Ci/ml$ FDG를 가하여 $37^{\circ}C$에서 1시간 배양하였을 때 SNU-C2A($16.8{\pm}1.36cpm/{\mu}g$ of protein), SNU-C4($12.3{\pm}5.55$), SNU-C5($61.7{\pm}2.17$) 섭취를 보였다. 시간당 FDG의 섭취는 SNU-C2A($0.29{\pm}0.03cpm/ min/{\mu}g$ of protein), SNU-C4($0.21{\pm}0.09$), SNU C5($1.07{\pm}0.07$)이었으며, 시간이 경과함에 따라 비례하여 증가하였다. Western blotting으로 측정한 GLUT1 은 SNU-C5의 경우 다량 발현되었으나 SNU-C2A와 SNU-C4는 소량 발현되었다. 따라서 SNU-C2A, SNU-C4, SNU-C5 세포는 이들 세포가 비록 유사한 특징을 가졌지만 FDG 섭취량과 섭취 속도 및 GLUT1의 발현이 다르고, 이들 세포의 배가시간(doubling time)은 FDG 섭취와 상관관계가 없었다. 이들 세포의 FDG 섭취와 GLUT1의 발현은 밀접한 상관관계가 있었다.

• 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.

• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.391-397
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• 2010

E2F transcription factors and their target genes have been known to play an important role in cell growth control. We found that curcumin, a polyphenolic phytochemical isolated from the plant Curcuma longa, markedly suppressed E2F4 expression in HCT116 colon cancer cells. Hydrogen peroxide was also found to decrease E2F4 protein level, indicating the involvement of reactive oxygen species (ROS) in curucmin-induced downregulation of E2F4 expression. Involvement of ROS in E2F4 downregulation in response to curcumin was confirmed by the result that pretreatment of cells with N-acetylcystein (NAC) before exposure of curcumin almost completely blocked the reduction of E2F4 expression at the protein as well as mRNA level. Anti-proliferative effect of curcumin was also suppressed by NAC which is consistent to previous reports showing curcumin-superoxide production and induction of poly (ADP-ribose) polymerase (PARP) cleavage as well as apoptosis. Expression of several genes, cyclin A, p21, and p27, which has been shown to be regulated in E2F4-dependent manner and involved in the cell cycle progression was also affected by curcumin. Moreover, decreased (cyclin A) and increased (p21 and p27) expression of these E2F4 downstream genes by curcumin was restored by pretreatment of cells with NAC and E2F4 overexpression which is induced by doxycycline. In addition, E2F4 overexpression was observed to partially ameliorate curcumin-induced growth inhibition by cell viability assay. Taken together, we found curcumin-induced ROS down-regulation of E2F4 expression and modulation of E2F4 target genes which finally lead to the apoptotic cell death in HCT116 colon cancer cells, suggesting that E2F4 appears to be a novel determinant of curcumin-induced cytotoxicity.