• 동의생리병리학회지
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• 제18권4호
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• pp.1186-1191
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• 2004

The root of Saussurea lappa includes sesquiterpene lactones such as costunolide and dehydrocostus lactone, and has been shown to be anti-tumorigenic with being used in traditional medicinal therapy in the Eastern Asia. However, the molecular basis of the effects of Saussurea lappa on fate of gastric carcinoma, which incur very frequently in the area, has not been well identified. In this study, the cytostatic effects of Saussurea lappa were examined using gastric AGS cancer cells. Cell viability was dramatically reduced by Saussurea lappa, in a dose-dependent manner. As time passed after its treatment, apoptotic population was increased and clearly showed G2-arrest. Being consistent, its treatment resulted in maintaining of G1 and S-phase cyclins D1, E, and A even until a significant apoptotic population was observed, for example, at 24h after treatment. However, G2/M phase cyclin B1 was reduced even at 12 h after treatment. In addition, its treatment increased expression of p53, p21/sup Wafl / cyclin dependent kinase inhibitor (CKI), and Bax, resulted in cleavages of procaspase 3 and poly ADP-ribose polymerase(PARP), indicating that such G2 arrest- and apoptosis-related molecules are involved. Therefore, these suggest that extracts of Saussurea lappa root may be a safer and effective reagent to deal with gastric cancers either by traditional herbal therapy or combinational therapy with conventional chemotherapy.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.99-99
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• 2001

• Journal of Microbiology
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• 제34권1호
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• pp.30-36
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• 1996

We have exmained the re-establishment of HIMRE mediated silencing function on the transcriptional activity of yeast heast shock gene HSP82. To test whether the onset of SIR repression can occur in growing cells in the rpesence of a potent inhibitor of DNA replication, HMRa/HSP82 strains with SIR4- and SIR4S$^{+}$ genetic backgrounds were arrested in S phase by incubation of a culture in 200 mM hydroxyurea for 120 min. It was clear that following a 20 minute heat shock, silencing of the HMRa/HSP82 allele in cells pretreated with hydroxyurea does occur in a SIR4-dependen fashion, even though the kinetics of repression appears to be substantially delayed. We also have tested whether re- establishement of silencing at the HMR/hsp82 locus can occur in G1-arrested cells. Cell cycle arrest at G1 phase was achieved by treatment of early log a cell cultures with .alpha.-factor mating pheromone, which induces G1 arrest. The result suggests that passage through S phase (and therefore DNA replication) is nor required for re-establishing silencer-mediated repression at the HMNRa/HSP82 locus. Finally, to test whether de nono protein synthesis is required for re-establishment of silencer-mediated repression, cells were pretreated with cycloheximide (500 /.mu.g/ml) 120 min. It was apparent that inhibiting protein synthesis delays, but does not prevent, re-establishment of silencer-mediated repression. Altogether, these results indicate that re-establishment of silencer-mediated repression is not dependent on the DNA replication and has no requirement for protein synthesis.s.

• 한국미생물·생명공학회지
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• 제44권1호
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• pp.89-97
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• 2016

비만은 체내 지방이 과도하게 축적되어 일어나는 현상으로, 당뇨, 고혈압, 심혈관 질환 및 암과 같은 질병의 원인이 된다. 본 연구는 RLE에 의해 지방전구세포에서 지방세포로 분화 시, 세포 내 축적되는 Triglyceride 저해 및 발현되는 전사인자들의 발현양상에 미치는 영향에 대하여 조사하였다. 그 결과, RLE는 Oil Red O 염색에서 세포 내 triglyceride의 축적을 농도 의존적으로 억제하였다. 또한 CCAAT/enhancer binding protein(C/EBP) ${\alpha}$, ${\beta}$와 peroxisome proliferator activated receptor ${\gamma}$($PPAR{\gamma}$)과 같은 지방세포 분화 관련 전사인자들의 발현을 억제하였다. RLE는 clonal expansion 단계의 지방세포를 G1기에서 세포 주기를 정지시켜 세포의 증식을 억제하였으며, RLE 처리에 의해 p21의 증가, Cyclin E, Cdk2, Phospho-Rb의 발현 저해 등 G1 arrest 관련 단백질의 발현 변화가 유도되었다. 따라서, RLE는 분화 관련 전사인자들의 발현을 조절하고 지방세포 분화 초기에 G1기의 세포 주기 정지를 억제함으로써 지방전구세포에서 지방세포로의 분화를 억제한다고 사료된다.

• Biomolecules & Therapeutics
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• 제15권2호
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• pp.95-101
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• 2007

Resveratrol (3,5,4’-trihydroxy-trans-stilbene), a naturally occurring phytoallexin abundant in grapes and several plants, has been shown to be active in inhibiting proliferation and inducing apoptosis in several human cancer cell lines. On the line of the biological activity of resveratrol, a variety of resveratrol analogs were synthesized and evaluated for their growth inhibitory effects against several human cancer cell lines. In the present study, we found that one of the resveratrol analogs, 3,4,5-trimethoxy-4’-bromo-cis-stilbene, markedly suppressed human colon cancer cell proliferation (EC$_{50}$ = 0.01 ${\mu}$g/ml), and the inhibitory activity was superior to its corresponding trans-isomer (EC$_{50}$ = 1.6 ${\mu}$g/ml) and resveratrol (EC$_{50}$ = 18.7 ${\mu}$g/ml). Prompted by the strong growth inhibitory activity in cultured human colon cancer cells (Col2), we investigated its mechanism of action. 3,4,5-Trimethoxy-4’-bromo-cis-stilbene induced arrest of cell cycle progression at G2/M phase and increased at sub-G1 phase DNA contents of the cell cycle in a time- and dose-dependent manner. Colony formation was also inhibited in a dose-dependent manner, indicating the inhibitory activity of the compound on cell proliferation. Moreover, the morphological changes and condensation of the cellular DNA by the treatment of the compound were well correlated with the induction of apoptosis. These data suggest the potential of 3,4,5-trimethoxy-4’-bromo-cis-stilbene might serve as a cancer chemotherapeutic or chemopreventive agent by virtue of arresting the cell cycle and inducing apoptosis for the human colon cancer cells.

• 동의생리병리학회지
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• 제22권5호
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• pp.1250-1255
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• 2008

Onchungeum(OCE), a herbal formula, has been used for treatment of anemia, discharging blood and skin diseases. In the previous study, we investigated the anti-cancer effect of OCE by G1 arrest of the cell cycle in human hepatocarcinoma cells, Hep3B cells. In this study, it was examined that the difference of anti-proliferative mechanisms by change in the ratio of OCE composition (OCE I) in Hep3B cells. Treatment of OCE I exhibited a relatively strong anti-proliferative activity and caused various morphological changes such as membrane shrinkage and cell floating. In addition, OCE-I arrests the cell cycle at G1 phase, which was associated with the down-regulation of cyclin D1 and Cdk6 expressions. The G1 arrest was also associated with the induction of Cdk inhibitors p27 and p21. Moreover, both p21 and p27 were detected by immunoprecipitation with anti-Cdk4 and anti-Cdk2 antibodies in OCE I-treated cells but in case of OCE, p21 did not make any complexes with Cdk4 and Cdk2. These results suggest that the change in the ratio of OCE composition might induce different mechanisms in anti-cancer efficacy of OCE, which may confer characteristic principles in oriental medical formula.

• 약학회지
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• 제43권3호
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• pp.378-384
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• 1999

Retinoic acid (RA) and dibutyryl cyclic AMP (dbcAMP) induce the differentiation of the multipotent embryonic carcinoma cell line, F9 cells, into parietal endoderm like cell. The F9 cells are highly proliferative doubling approximately 12 hourse. S Phase is predominant, lasting 10 hours and G2/M phase occupies most of the remaining cycle (2 hours) and G1 phase is nearly non-existent. In this study, we showed the effect of RA and dbcAMPon the cell cycle associated molecules (especially around G1 phase) during F9 cell differentiation. Differentiation of F9 cells was induced by the combined addition of RA ($10^{-7}M$) and dbcAMP (0.5mM), and cells were harvested daily up to 4 days. Flow cytometric analysis showed the prolongation of G1 phase around 30 hours after induction. Western blot analysis revealed that the amount of cyclin D1 and cdk2 were increased at day 4. However, histone H1 kinase activity of cdk2 was decreased. These data strongly suggest that RA and dbcAMP induce the growth arrest of F9 cells at G1 phase by decreasing the activity of cdk2, although they have increased the protein contents of cyclin D1 and cdk2. The reason for the discrepancy between the H1 kinase activity and protein contents are not clear yet.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4357-4361
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• 2015

Thunbergia Laurifolia Linn. (TL) is one of the most familiar plants in Thai traditional medicine that is used to treat various conditions, including cancer. However, the antitumor activity of TL or its constituents has never been reported at the molecular level to support the folklore claim. The present study was designed to investigate the antitumor effect of an aqueous extract of TL in human breast cancer cells and the possible mechanism(s) of action. An aqueous crude extract was prepared from dried leaves of TL. Folin-Ciocalteu colorimetric assays were used to determine the total phenolic content. Antiproliferative and cell cycle effects were evaluated in human breast adenocarcinoma MCF-7 cells by MTT reduction assay, cell growth inhibition, clonogenic cell survival, and flow cytometric analysis. Free radical generation by the extracts was detected using electron paramagnetic resonance spectroscopy. The exposure of human breast adenocarcinoma MCF-7 cells to a TL aqueous extract resulted in decreases in cell growth, clonogenic cell survival, and cell viability in a concentration-dependent manner with an $IC_{50}$ value of $843{\mu}g/ml$. Treatments with extract for 24h at $250{\mu}g/ml$ or higher induced cell cycle arrest as indicated by a significant increase of cell population in the G1 phase and a significant decrease in the S phase of the cell cycle. The capability of the aqueous extract to generate radical intermediates was observed at both high pH and near-neutral pH conditions. The findings suggest the antitumor bioactivities of TL against selected breast cancer cells may be due to induction of a G1 cell cycle arrest. Cytotoxicity and cell cycle perturbation that are associated with a high concentration of the extract could be in part explained by the total phenolic contents in the extract and the capacity to generate radical intermediates to modulate cellular proliferative signals.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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• pp.1043-1048
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• 2012

The COPS3 gene has stimulating effect on cell proliferation and progression of osteosarcomas and related cells. However, the features of COPS3 and its potential application as a therapeutic target in other cancers has not yet been studied. In this study, therefore, the effect of COPS3 silencing via COPS3 siRNA on lung cancer cell proliferation was examined. Expression levels of COPS3 gene in COPS3 siRNA infected cells and control siRNA infected cells were compared with real time PCR and Western blot analysis. Cell proliferation levels were comprehensively analyzed by MTT, BrdU incorporationy, and colony formation assays. For mechanistic assessment the effects of COPS3 silencing on cell cycle and apoptosis were analyzed using flow cytometry. Results showed that successful silencing of the COPS3 gene at both translational and transcriptional levels significantly reduced the proliferation and colony formation by lung cancer cells (p<0.01). Flow cytometry showed cell cycle arrest in the G0/G1 phase after COPS3 silencing, and more importantly, apoptosis was induced as a result of COPS3 knockdown, which negatively affected cell survival. Therefore, these results provide another piece of important evidence that the COPS3 gene expressed in lung cancer cells may play a critical role in stimulating proliferation. Down-regulation of COPS3 could significantly inhibit lung cancer cell growth, which was most likely mediated via induction of cell cycle arrest in G0/G1 phase and apoptosis.

• 대한의생명과학회지
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• 제23권3호
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• pp.194-200
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• 2017

Bone-resorbing osteoclasts play a major role in maintaining bone homeostasis with bone-forming osteoblasts. Although it has been reported that A2B adenosine receptor (A2BAR) regulates osteoclast differentiation, its effects on apoptosis or proliferation of osteoclasts have been less-defined. Here, we demonstrate that A2BAR stimulation regulates macrophage-colony stimulating factor (M-CSF)-mediated osteoclast proliferation. Stimulation with a specific agonist of A2BAR, BAY 60-6583, significantly reduced M-CSF-mediated osteoclast proliferation in a time- and dose-dependent manner. In addition, A2BAR stimulation induced both apoptosis of the cells and cell arrest in the G1 phase with a decrease of cell number in the G2/M phase. Stimulation with BAY 60-6583 inhibited the activation of Akt by M-CSF, whereas M-CSF-induced ERK1/2 activation was not affected. These results suggest that the inhibition of M-CSF-mediated Akt activation by A2BAR stimulation increases apoptotic response of osteoclasts and induces cell cycle arrest in the G1 phase, thus contributing to the down-regulation of osteoclast proliferation.