• The Korean Journal of Physiology and Pharmacology
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• 제13권4호
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• pp.309-313
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• 2009

Spontaneous hypertensive rats (SHR) are an established model of genetic hypertension. Vascular smooth muscle cells (VSMC) from SHR proliferate faster than those of control rats (Wistar-Kyoto rats; WKY). We tested the hypothesis that induction of heme oxygenase (HO)-1 induced by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats. Aprotinin treatment inhibited VSMC proliferation in SHR more than in normotensive rats. These inhibitory effects were associated with cell cycle arrest in the G1 phase. Tin protoporphyrin IX (SnPPIX) reversed the anti-proliferative effect of aprotinin in VSMC from SHR. The level of cyclin D was higher in VSMC of SHR than those of WKY. Aprotinin treatment downregulated the cell cycle regulator, cyclin D, but upregulated the cyclin-dependent kinase inhibitor, p21, in VSMC of SHR. Aprotinin induced HO-1 in VSMC of SHR, but not in those of control rats. Furthermore, aprotinin-induced HO-1 inhibited VSMC proliferation of SHR. Consistently, VSMC proliferation in SHR was significantly inhibited by transfection with the HO-1 gene. These results indicate that induction of HO-1 by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2006년도 춘계학술대회
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• pp.3-12
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• 2006

1 The present work was performed to investigate the effects of ginsenoside Rh2 on proliferation, cell cycle-regulation and differentiation of human leukemia HL-60 cells as well as the underlying mechanisms for these effects. 2 Ginsenoside Rh2 potently inhibited the proliferation of HL-60 cells in both a dose- and time-dependent manner with an $IC_{50}$, $20{\mu}M$. 3 DNA flow-cytometry indicated that ginsenoside Rh2 markedly induced a $G_1$ phase arrest of HL-60 cells. 4 Among the $G_1$ phase cell cycle-related proteins, the levels of cyclin-dependent kinase(CDK)4, 6 and cyclin D1, cyclin D2, cyclin D3 were reduced by ginsenoside Rh2, whereas the steadystate levels of CDK2 and cyclin E were unaffected. 5 The protein levels of a CDK inhibitor p16, $p21^{CIP1/WAF1}$ and $p27^{KIP1}$ were markedly increased by ginsenoside Rh2. 6 Ginsenoside Rh2 markedly enhanced the binding of $p21^{CIP1/WAF1}$ and $p27^{KIP1}$ with CDK2 and CDK6, resulting in the reduced activity of both kinases and the hypophosphorylation of Rb protein. 7 We furthermore suggest that ginsenoside Rh2 is a potent inducer of the differentiation of HL-60 cells, based on observations such as a reduction of the nitroblue tetrazolium level, an increase in the esterase activities and phagocytic activity, morphology changes, and the expression of CD11b, CD14, CD64 and CD66b surface antigens. 8 In conclusion, the onset of ginsenoside Rh2-induced the $G_0/G_1$ arrest of HL-60 cells prior to the differentiation is linked to a sharp up-regulation of the $p21^{CIP1/WAF1}$ level and a decrease in the CDK2, CDK4 and CDK6 activities. This is the first report demonstrating that ginsenoside Rh2 potently inhibits the proliferation of human promyelocytic HL-60 cells via the $G_1$ phase cell cycle arrest and differentiation induction.

• 한국가축번식학회지
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• 제20권2호
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• pp.143-153
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• 1996

To improve the efficiency of nuclear transplantation in the rabbit, this study were evaluated the influence of celly cycle of donor nuclei on the in vitro developmental potential in the nuclear transplant embryos. The embryos of 16-cell stage were collected from the mated does at 48h post-hCG injection and they were synchronized to G1 phase of 32-cell stage. Synchronization of the cell cylce of blastomeres were induced, first, using an microtubules polymerization inhibitor, 0.5$\mu\textrm{g}$/ml colcemid for 10h to arrest blastomeres in metaphase, and secondly, using a DNA synthesis inhibitor, 0.1$\mu\textrm{g}$/ml aphidicolin for 1.5 to 2h to cleave to 32-cell stage and arrest them in G1 phase. The separated G1 phase blastomeres of 32-cell stage were injectied into enucleated recipient cytoplasms by micromanipulation. After culture until 20h post-hCG injection, the nuclear transplant oocytes were electrofused and activated by electrical stimulation. The nuclear transplant embryos were co-cultured for 120h. In vitro cultured embryos were monitored every 24h to assess for development rate. After in vitro cultue for 120h, the nuclear transplant embryos developed to blastocyst stage were stained with Hoechst 33342 dye for counting the number of blastomeres under a fluorescence microscopy. The cleavage rate of blastomeres from 16-cell stage stage rabbit embryos treated with colcemid for 10h or aphidicolin for 6h following colcemid for 10h were not significantly different. The electrofusion rate was similar by high in S and G1 phase donor nuclei as 80.6 and 79.1%, respectively. However, the nuclear transplant embryos using G1 phase donor nuclei were developed to blastocyst at high rate(60.3%) than those using S phase donor nuclei(26.0%). Moreover, the mean blastocyst stage were increased significantly(P<0.05) with the G1 phase donor nuclei(176.6 cells and 1.50 cycles), as compared with the S phase donor nuclei(136.6 cells and 1.42 cycles). These results show that the blastomeres of G1 phase were more successful as donor nuclei in the nuclear transplant procedure, compared with S phase.

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.123-128
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• 2014

In this study, we have investigated the flow rate effects of Ag nanoparticle (NP) suspensions on the progress of the cell cycle by using a microfluidic image cytometry (${\mu}FIC$)-based approach. Compared with the conventional "static" exposure conditions, enhancements in G2 phase arrest were observed for the cells under continuously flowing "dynamic" exposure conditions. The "dynamic" exposure conditions, which mimic in vivo systems, induced an enhanced cytotoxicity by accelerating G2 phase arrest and subsequent apoptosis processes. Moreover, we have also shown that the increases in delivered NP dose due to the continuous supply of Ag NPs contributed dominantly to the enhanced cytotoxicity observed under the "dynamic" exposure conditions, while the shear stress caused by these slowly flowing fluids (i.e., flow rates of 6 and $30{\mu}L/h$) had only a minor influence on the observed enhancement in cytotoxicity.

• 방사선산업학회지
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• 제4권1호
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• pp.91-94
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• 2010

A number of epidemiological studies as well as biological experiments, showed that genistein, one of the isoflavone, prevents prostate cancer occurrence. In this study, we showed that genistein inhibited the cell proliferation of human promyeoltic leukemia HL-60 cells and induced G2/M phase arrest. In addition, combination of genistein treatment and ${\gamma}$-irradiation displayed synergistic effect in apoptotic cell death of HL-60 cells. This means that the repair of genistein-induced DNA damage was hindered by ${\gamma}$-radiation and thus cell death was increased. In conclusion, genistein is one of the important chemicals that sensitize radiation-induced cell death.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.86-86
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• 2003

In a continuous effort to develop novel anticancer agents we newly synthesized and evaluated the antitumor activity of nucleoside analogues. One analogue, 4 - ［2-Chlor-6- (3-iodo- benzy lamino) -purin -9-yl］- 2,3-dihydroxy-cyclopentanecarbo xylic acid methylamide (LJ-331), has been shown to exert a potent inhibition of human cancer cell growth in vitro including human lung (A549), stomach (SNU-638) and leukemia (HL-60) cancer cells. Following mechanism of action study revealed that LJ - 331induces cell cycle arrest at the G1 phase in HL-60 cells and evokes apoptotic phenomena such as an increase in DNA ladder intensity and chromatin condensation by a dose- and time-dependent manner. LJ-331 also activated the caspase-3 activity in HL-60. This result suggests that the growth inhibition of human cancer cells by LJ-331 might be related to the cell cycle arrest and induction of apoptosis.

• 미생물학회지
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• 제22권2호
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• pp.111-118
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• 1984

The changes of susceptibility of Bacillus subtilis SNU816 to bacteriophage SP816 were investigated. When B. sutilis SNU816 cells were infected by the phage during vegetative growth, rapid lysis was observed. But when they were infected after late logarismic phase, they were resistant to phage infection. Since asporogenic culture of this strain was invariably lysed regardless of time of infection, the arrest of phage multiplication seemed to be caused by sporulation. In reality, the arrest of phage multiplication occurred at early stage of sporulation. Electron microscopy revealed that the arrest of phage multiplication occurred just prior to or during septum formation (stage II sporulation).

• 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.

• Journal of Microbiology and Biotechnology
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• 제25권3호
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• pp.413-417
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• 2015

Recently, we isolated HY253, a novel decahydrofluorene analog with a molecular structure of 7,8a-divinyl-2,4a,4b,5,6,7,8,8a,9,9a-decahydro-1H-fluorene-2,4a,4b,9a-tetraol from the roots of Aralia continentalis, which is known as Dokwhal (獨活), a traditional medicinal herb. Moreover, we previously reported its cytotoxic activity on cancer cell proliferation in human lung cancer A549 and cervical cancer HeLa cells. The current study aimed to evaluate its detailed molecular mechanisms in cell cycle arrest and apoptotic induction in human hepatocellular carcinoma HepG2 cells. Flow cytometric analysis of HepG2 cells treated with $60{\mu}M$ HY253 revealed appreciable cell cycle arrest at the G1 phase via inhibition of Rb phosphorylation and down-regulation of cyclin D1. Furthermore, using western blots, we found that up-regulation of cyclin-dependent kinase inhibitors, such as p21^CIP1 and p27^KIP1, was associated with this G₁ phase arrest. Moreover, TUNEL assay and immunoblottings revealed apoptotic induction in HepG2 cells treated with $60{\mu}M$ HY253 for 24 h, which is associated with cytochrome c release from mitochondria, via down-regulation of anti-apoptotic Bcl-2 protein, which in turn resulted in activation of caspase-9 and -3, and proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). Accordingly, we suggest that HY253 may be a potent chemotherapeutic hit compound for treating human liver cancer cells via up-regulation and activation of the p53 gene.

• 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.