• 대한생식의학회:학술대회논문집
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• 대한불임학회 2001년도 제41차 추계학술대회
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• pp.100-100
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• 2001

• KSBB Journal
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• 제30권4호
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• pp.175-181
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• 2015

Cells proliferate via repeating process that growth and division. This process is G1, S, G2 and M four phases consists. Monitoring the progression of the cell cycle is a specific step that to be a continuous process is repeated to adjust the start of the next step. At this time, this process is called a Checkpoint. Currently, there are three known checkpoints that G1-S phase, G2-M phase, and the M phase. In this study, we confirmed that cell cycle arrest effects by ethanol extracts of Artemisia annua Linne (AAE) in Hep3B liver cancer cells. AAE was regulated proteins which involved in cell cycle such as pAkt, pMDM2, p53, p21, pCDK2 (T14/Y15). AAE induced cell cycle arrest in G1 checkpoint through phosphorylation of CDK2. Akt and p53 upstream is inhibited by AAE and p53 activated by non-activated pMDM2, p53 inhibitor. Thereby, activated p53 is transcript to p21 and activated p21 protein is combined with Cyclin E-pCDK2 complex. Therefore, we confirmed that AAE-induced cell cycle arrest was occurred by p21-Cyclin E-pCDK2 complex by inhibition of pAkt signal. Because of this cell cycle can't pass to S phase from G1 phase.

• 대한한방내과학회지
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• 제28권4호
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• pp.694-708
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• 2007

Objectives : Jageum-Jung is used as an anti-cancer agent in oriental medicine, but the mechanism by which it induces cell death in cancer cells is still unclear. The purpose of this study was to investigate the effects of Jageum-Jung on apoptosis and cell cycle arrest in HepG2 hepatoma cells. Methods : Various cancer cell lines including HepG2, C6 glioma, SH-SY5Y, PANC-1, and MCF-7 cells, were used. Apoptosis was determined by DAPI nuclei staining and flow cytometry in HepG2 cells treated with various concentrations (from 25 to 200 ${\mu}g/ml$) of $H_2O$ extract of Jageum-Jung (JGJ) for 48 hrs. Expression of cell cycle arrest mediators including Rb, p53, p21, cyclin B1, cdk4, and cyclin E proteins were measured by Western blot analysis. To estimate intracellular hydrogen peroxide levels and intracellular nitric oxide levels, HepG2 cells were stained with DCFH-DA dye and DAF dye, subjected on flow cytometric analysis. Results : 1. Jageum-Jung decreased the viability of HepG2 cells in a dose-dependent manner. 2. Jageum-Jung induced the catalytic activation of caspase-3 in HepG2 cells. 3. Jageum-Jung increased the intracellular hydrogen peroxide and NO in HepG2 cells. 4. Jageum-Jung increased the expression of Rb, p53 and p21 in HepG2 cells. 5. Jageum-Jung induced the expression of cyclin B1, cdk4, and cyclin E in HepG2 cells. Conclusions : Taken together, we suggest that Jageum-Jung exhibits cytotoxic effects on HepG2 cells, causing apoptosis and cell cycle arrest. The results showed that Jageum-Jung may do so by regulating the expression of specific target molecules that promote efficient apoptotic cell death following $G_2$/M phase arrest in a dose-dependent manner.

• Radiation Oncology Journal
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• 제19권2호
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• pp.146-152
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• 2001

목적 : 마우스 대뇌조직에 방사선이 조사되었을 경우 아포토시스와 세포주기의 조절작용에 어떤 영향을 미치는 지를 연구하고자 하였다. 대상 및 방법 : 8주간 성숙된 C57B1/6J 마우스의 전뇌에 코발트 방사선조사기로 25 Gy의 방사선을 단일 조사하였다. 방사선조사후 1, 2, 4, 8, 24시간 간격으로 마우스를 경추 탈구사시킨 후 뇌조직을 채취하였다. 채취한 뇌조직을 TUNEL 분석법에 의하며 아포토시스 유도 수준을 평가하였으며 Western blotting법을 이용하여 유전자 산물인 p53, Bcl-2, Bax 그리고 세포주기 조절인자인 cyclin Bl, Dl, E, cdk2, cdk4, $p34^{cdc2}$를 분석하였다. 세포주기의 변화는 유세포분석법에 의하여 분석되었다. 결과 : 아포토시스는 방사선조사후 8시간에서 최고치를 보였고 아포토시스 지수는 $24.0{\pm}0.25$ (p<0.05)였다. 세포주기에서 조절인자의 변화는 cyclin D1를 제외하고는 특이하지 않았다. 결론 : 마우스의 전뇌에 방사선을 조사한 결과 아포토시스는 대뇌의 상의하(subependyma)에서 주로 일어났으며 세포주기의 조절인자에는 영향을 미치지 않는 것으로 판명되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제16권5호
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• pp.321-326
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• 2012

Resveratrol, a natural compound, has been shown to possess anti-cancer, anti-aging, anti-inflammatory, anti-microbial, and neuroprotective activities. In this study, we examined the antiproliferative and cytotoxicity properties of resveratrol in Rat B103 neuroblastoma cells; although it's molecular mechanisms for the biological effects are not fully defined. Here, we examined the cellular cytotoxicity of resveratrol by cell viability assay, antiproliferation by BrdU assay, DNA fragmentation by DNA ladder assay, activation of caspases and Bcl-2 family proteins were detected by western blot analyses. The results of our investigation suggest that resveratrol increased cellular cytotoxicity of Rat B103 neuroblastoma cells in a dose-and time-dependent manner with $IC_{50}$ of 17.86 ${\mu}M$ at 48 h. On the other hand, incubation of neuroblastoma cells with resveratrol resulted in S-phase cell cycle arrests which dose-dependently and significantly reduced BrdU positive cells through the downregulation of cyclin D1 protein. In addition, resveratrol dose-dependently and significantly downregulated the expression of anti-apoptotic protein includes Bcl-2, Bcl-xL and Mcl-1 and also activates cleavage caspase-9 and-3 via the downregulation of procaspase-9 and -3 in a dose-dependent manner which indicates that involvement of intrinsic mitochondria-mediated apoptotic pathway. In conclusion, resveratrol increases cellular cytotoxicity and inhibits the proliferation of B103 neuroblastoma cells by inducing mitochondria-mediated intrinsic caspase dependent pathway which suggests this natural compound could be used as therapeutic purposes for neuroblastoma malignancies.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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• pp.83-83
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• 2002

To assess the role of 8-oxoguanine glycosylase (OGG1) in the cell defense against radiation injury, the radiation-induced cytotoxicities were compared between the mutant type KG-1 featuring a loss of OGG1 activity due to a homozygous mutation of Arg 229 G1n, and the wild type U937.(omitted)

• The Korean Journal of Physiology and Pharmacology
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• 제16권3호
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• pp.153-158
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• 2012

Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.

• Toxicological Research
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• 제21권1호
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• pp.77-85
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• 2005

Cadmium is an environmental pollutant exposed from contaminated foods or cigarette smoking and known to cause oxidative damage in organs. We investigated the cadmium-induced apoptosis and cell arrest in human breast cancer cells, MCF-7 cells and MDA-MB-231 cells. Obvious apoptotic cell death was shown in CdCl₂ 100 μM treatment for 12 hr, which were determined by DAPI staining and flow cytometric analysis. In cell cycle analysis, MCF-7 cells and MDA-MB-231 cells were arrested in S phase and G2/M phase respectively. These could be explained by the induction of cell cycle inhibitory protein, p21/sup Waf1/Cip1/ and p27/sup Kip1/, expression and reduction of cyclin/Cdk complexes in both cell lines. The decreased expression of cyclin A and Cdk2 in MCF-7 cells and cyclin B1 and Cdc2 in MDA-MB-231 cells were consistent with the flow cytometric observation. p-ERK expression was increased dose-dependent manner in both cell lines. It suggests that ERK MAPK pathway are involved in cadmium-induced cell cycle arrest and apoptosis. Moreover, cotreatment of zinc (100 μM, 12 hr) recovered the cadmium-induced cell arrest in both cells, which shows cadmium-induced oxidative stress mediates apoptosis and cell cycle arrest in human breast cancer cells.

• Biomolecules & Therapeutics
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• 제17권3호
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• pp.282-287
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• 2009

Ochnaflavone is a natural biflavonoid and mainly found in the caulis of Lonicera japonica (Caprifoliaceae). Biological activities such as anti-inflammatory and anti-atherogenic effects have been previously reported. The anticancer activity of ochnaflavone, however, has been poorly elucidated yet. In the present study, we investigated the effect of ochnaflavone on the growth inhibitory activity in cultured human colon cancer cell line HCT-15. Ochnaflavone inhibited the proliferation of the cancer cells with an $IC_{50}$ value of $4.1{\mu}M$. Flow cytometric analysis showed that ochnaflavone arrested cell cycle progression in the G2/M phase, and induced the increase of sub-G1 peak in a concentration-dependent manner. Induction of cell cycle arrest was correlated with the modulation of the expression of cell cycle regulating proteins including cdc2 (Tyr15), cyclin A, cyclin B1 and cyclin E. The increase of sub-G1 peak by the higher concentrations of ochnaflavone (over $20{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, activation of caspase-3, -8 and -9, and cleavage of poly-(ADP-ribose) polymerase. These findings suggest that the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of ochnaflavone in human colon cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• 제15권15호
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• pp.6247-6251
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• 2014

Background: The aim of the present study was to investigate the involvement of emodin on the growth of human breast cancer MCF-7 and MDA-MB-231 cells and the estrogen (E2) signal pathway in vitro. Materials and Methods: MTT assays were used to detect the effects of emodin on E2 induced proliferation of MCF-7 and MDA-MB-231 cells. Flow cytometry (FCM) was applied to determine the effect of emodin on E2-induced apoptosis of MCF-7 cells. Western blotting allowed detection of the effects of emodin on the expression of estrogen receptor ${\alpha}$, cyclin D1 and B-cell lymphoma-2 (Bcl-2), mitogen-activated protein kinases (MAPK) and phosphatidylinostiol 3-kinases (PI3K). Luciferase assays were emplyed to assess transcriptional activity of $ER{\alpha}$. Results: Emodin could inhibit E2-induced MCF-7 cell proliferation and anti-apoptosis effects, and arrest the cell cycle in G0/G1 phase, further blocking the effect of E2 on expression and transcriptional activity of $ER{\alpha}$. Moreover, Emodin influenced the ER ${\alpha}$ genomic pathway via downregulation of cyclin D1 and Bcl-2 protein expression, and influenced the non-genomic pathway via decreased PI3K/Akt protein expression. Conclusions: These findings indicate that emodin exerts inhibitory effects on MCF-7 cell proliferation via inhibiting both non-genomic and genomic pathways.