• 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.

• 대한한의학방제학회지
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• 제23권2호
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• pp.199-208
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• 2015

Objectives : In the present study, we investigated the effects of ethanol extract of Scutellaria baicalensis (EESB) on the progression of cell cycle in human renal cell carcinoma Caki-1 cells. Methods : The effects of EESB on cell growth and apoptosis induction were evaluated by trypan blue dye exclusion assay and flow cytometry, respectively. The mRNA and protein levels were determined by Western blot analysis and reverse transcription-polymerase chain reaction, respectively. Results : It was found that EESB treatment on Caki-1 cells resulted in a dose-dependent inhibition of cell growth and induced apoptotic cell death as detected by Annexin V-FITC staining. The flow cytometric analysis indicated that EESB resulted in G2/M arrest in cell cycle progression which was associated with the down-regulation of cyclin A expression. Our results also revealed that treatment with EESB increased the mRNA and proteins expression of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1), without any noticeable changes in cyclin B1, Cdk2 and Cdc2. In addition, the incubation of cells with EESB resulted in a significant increase in the binding of p21 and Cdk2 and Cdc2. These findings suggest that EESB-induced G2/M arrest and apoptosis in Caki-1 cells is mediated through the p53-mediated upregulation of Cdk inhibitor p21. Conclusions : Taken together, these findings suggest that EESB may be a potential chemotherapeutic agent and further studies will be needed to identify the biological active compounds that confer the anti-cancer activity of S. baicalensis.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.71.1-71.1
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• 2003

We show that Cdc6, an essential initiation factor for DNA replication, undergoes caspase-3-mediated cleavage in the early stages of apoptosis in HeLa cells and SK-HEP-1 cells induced by etoposide, paclitaxel, ginsenoside Rh2, or TRAIL. The cleavage occurs at the SEVD$\^$442//G motif and generates an N-terminal truncated Cdc6 fragment (p49-tCdc6) that lacks the carboxy-terminal nuclear export sequence (NES). Cdc6 is known to be phosphorylated by cyclin A-Cyclin A-dependent kinase 2 (Cdk2), an event that promotes its exit from the nucleus and probably blocks it from initiating inappropriate DNA replication. (omitted)

• 한국환경성돌연변이발암원학회지
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• 제21권2호
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• pp.82-88
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• 2001

Recently, there has been significant progress in understanding the control process of the cell division cycle. To investigate the influence of toxic substances on the cell cycle, the effect of benzo(a)pyrene (BAP) and mitomycine C (MMC) on synchronized HeLa cells was analyzed during the cell cycle. To synchronize the HeLa cells, 10$^{6}$ cells were grown for 1 day and then treated with 1 mM hydroxyurea for 14 h. The arrested cells were then allowed to proceed through their cell cycle by removing the hydroxyurea and resupplying a fresh medium. The arrested cells in the G1/S transition then proceeded to the S phase after 4 h, the G2/M phase after 8h, and the G1 phase after 12 h, subsequent to the resupply of a fresh medium. In the untreated HeLa cells, the p34$^{cdc2}$ kinase activity, measured using a p34$^{cdc2}$ specific peptide, peaked after 8h (G2/M) and then declined after 12 h (G1). However, treatment with 30 $\mu$M BAP delayed the peak of the p34$^{cdc2}$ kinase activity. The amount of p34$^{cdc2}$ remained unchanged in the untreated, BAP-, and MMC-treated cells throughout the cell cycle. The cyclin B level peaked after 8 h in the untreated cells, yet peaked after 10-12 h in the BAP-treated cells. There was no significant change in the cyclin B level in the MMC-treated cells.

• Mycobiology
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• 제48권3호
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• pp.219-227
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• 2020

Androgen-independent prostate cancer accounts for mortality in the world. In this study, various extracts of a medical fungus dubbed Ganoderma formosanum were screened for inhibition of DU145 cells, an androgen-independent prostate cancer cell line. Results demonstrated that both hexane (GF-EH) and butanol (GF-EB) fraction of G. formosanum ethanol extract inhibited DU145 cell viability in a dose-dependent manner. GF-EH induced cell-cycle arrest in G1 phase of DU145 cells via downregulation of cyclin E2 protein expression. In addition, GF-EB triggered extrinsic apoptosis of DU145 cells by activating caspase 3 gene expression resulting in programed cell death. Above all, both GF-EH and GF-EB show lower toxicity to normal human fibroblast cell line compared to DU145 cell, implying that they possess specific drug action on cancer cells. This study provides a molecular basis of G. formosanum extract as a potential ingredient for treatment of androgen-independent prostate cancer.

• The Korean Journal of Physiology and Pharmacology
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• 제22권2호
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• pp.193-201
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• 2018

Connective tissue growth factor (CTGF) is a novel fibrotic mediator, which is considered to mediate fibrosis through extracellular matrix (ECM) synthesis in diabetic cardiovascular complications. Statins have significant immunomodulatory effects and reduce vascular injury. We therefore examined whether fluvastatin has anti-fibrotic effects in vascular smooth muscle cells (VSMCs) and elucidated its putative transduction signals. We show that advanced glycation end products (AGEs) stimulated CTGF mRNA and protein expression in a time-dependent manner. AGE-induced CTGF expression was mediated via ERK1/2, JNK, and Egr-1 pathways, but not p38; consequently, cell proliferation and migration and ECM accumulation were regulated by CTGF signaling pathway. AGE-stimulated VSMC proliferation, migration, and ECM accumulation were blocked by fluvastatin. However, the inhibitory effect of fluvastatin was restored by administration of CTGF recombinant protein. AGE-induced VSMC proliferation was dependent on cell cycle arrest, thereby increasing G1/G0 phase. Fluvastatin repressed cell cycle regulatory genes cyclin D1 and Cdk4 and augmented cyclin-dependent kinase inhibitors p27 and p21 in AGE-induced VSMCs. Taken together, fluvastatin suppressed AGE-induced VSMC proliferation, migration, and ECM accumulation by targeting CTGF signaling mechanism. These findings might be evidence for CTGF as a potential therapeutic target in diabetic vasculature complication.

• 대한한방내과학회지
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• 제36권1호
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• pp.13-21
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• 2015

Objectives : In Korea, Rhus verniciflua Stokes (RVS) has been used in traditional medicine for various diseases such as back pain, syndromes of the blood system in women, gastrointestinal disease, and cancer. However, the molecular mechanisms of its anti-cancer activity have not been clearly elucidated yet. Methods : This study investigated the possible mechanisms by which RVS extract (RVE) exerts its anti-proliferative action in cultured human breast carcinoma MCF-7 cells. Results : Treatment with RVE in MCF-7 cells resulted in inhibition of cell viability through G1 arrest of the cell cycle and induction of apoptosis in a time- and concentration-dependent manner, as determined by MTT assay and flow cytometry analysis. The induction of G1 arrest by RVE treatment was associated with the inhibition of cyclin D1, cyclin-dependent kinase (Cdk) 2, retinoblastoma protein (pRB), and mouse double minute 2 (MDM2) expression. Moreover, RVE treatment concentration dependently increased the levels of tumor suppressor p53, which was associated with the marked induction of Cdk inhibitors such as p21 (Waf1/Cip1) and p27 (Kip1). However, the inhibition of p53 function by the wild-type p53-specific inhibitor, pifithrin-α, abolished the above-mentioned effects of RVE, showing that p53 was responsible for the cytotoxicity of RVE Conclusions : These data indicate that a molecular pathway involving p53-dependent G1 cell cycle arrest plays a pivotal role in the cellular response to RVE, and demonstrate the potential applications of RVE as an anti-cancer drug for breast cancer treatment.

• 대한임상검사과학회지
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• 제56권1호
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• pp.73-84
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• 2024

펄스 전자기장(pulsed electromagnetic field, PEMF)은 여러 항암제의 항암 효과를 향상시키는 것으로 알려져 있고 독소루비신(doxorubicin, DOX)은 유방암을 포함한 다양한 종류의 악성 종양을 치료하는 데 사용되는 항암제이다. 본 연구는 PEMF가 MCF-7 유방암 세포에 대한 DOX의 항암 효과 증진 여부를 조사하고 관련기전을 규명하기 위해 진행되었다. 본 연구팀은 DOX와 PEMF를 동시에 처리하면 DOX 단독 처리에 비해 MCF-7 유방암 세포의 생존율 감소가 더 커지는 것을 확인하였다. PEMF는 cyclin-dependent kinase 2의 인산화와 p53, p21, 사이클린 E2 및 polo like kinase 1의 단백질 발현에 영향을 주어 DOX 처리에 의한 G1 세포주기 정지를 더욱 증가시켰다. 또한, PEMF는 DOX 처리에 의한 Fas와 Bcl-2-associated X의 증가, myeloid leukemia 1과 survivin의 감소, 카스파제(caspase)-8/9/7의 활성 및 poly (adenosine diphosphate-ribose) polymerase 절단을 더욱 증가시켰다. 이러한 연구결과를 바탕으로, 본 연구팀은 PEMF는 DOX 처리에 의한 G1 세포주기 정지와 카스파제 의존적 세포자멸사를 더욱 증가시켜 DOX 처리에 의한 MCF-7 세포의 생존율 감소를 더욱 증진시킴을 확인할 수 있었다.

• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.185-189
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• 2019

To identify the component(s) involved in cell cycle control in the protozoan Giardia lamblia, cells arrested at the G1/S- or G2-phase by treatment with nocodazole and aphidicolin were prepared from the synchronized cell cultures. RNA-sequencing analysis of the 2 stages of Giardia cell cycle identified several cell cycle genes that were up-regulated at the G2-phase. Transcriptome analysis of cells in 2 distinct cell cycle stages of G. lamblia confirmed previously reported components of cell cycle (PcnA, cyclin B, and CDK) and identified additional cell cycle components (NEKs, Mad2, spindle pole protein, and CDC14A). This result indicates that the cell cycle machinery operates in this protozoan, one of the earliest diverging eukaryotic lineages.

• BMB Reports
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• 제43권4호
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• pp.273-278
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• 2010

The cell cycle is regulated by cyclin-dependent kinase (CDK)-cyclin complexes as well as other regulators. We isolated Kip-related protein 4 (KRP4) cDNA that encodes 289 amino acids including six conserved domains. To investigate the expression pattern of KRP4 as well as of other cell cycle-related genes associated with plant hormones, Arabidopsis seedlings were cultured on MS medium containing auxin or cytokinin. All seedlings treated with phytohormones displayed an increased proportion of cells in S phase. A higher proportion of cells in G2 phase was observed in seedlings treated with NAA. RT-PCR confirmed that the expression of KRP4 was decreased after treatment with phytohormones, and that CDKA and D-type cyclin transcription was increased. Additionally, mitotic cyclins were up-regulated by NAA treatment. These results suggest that KRP4 as well as other cell cycle-related genes might contribute to the control of plant growth in response to exogenous hormones.