• Animal cells and systems
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• v.9 no.4
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• pp.191-198
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• 2005

The effects of 6-aminonicotinamide (6-AN) on viability of IMR32 neuroblastoma cells in the presence of ATP or $NAD^+$ have been investigated. 6-AN caused marked reduction in cell viability and similar observations were also made with cells treated with 6-AN+ATP. However, cells treated with $6-AN+NAD^+$ showed cell viability similar to untreated cells. Morphologically, 6-AN and 6-AN+ATP treated cells showed loss of neurites, polyhedric shapes, shrinkage of cell bodies and formation of lysed cells, while $6-AN+NAD^+$ cells did not show any such changes. The flow cytometry analysis demonstrated that 6-AN increased cell population in $G_0/G_1$ phase and decreased cell population in Sand $G_2/M$ phase following a 72 h exposure. Western blot analysis showed that 6-AN stimulated a substantial increase in the level of the cdk inhibitor $p27^{kip1}$, but lowered the levels of cdk2, cyclin E and p-Rb. However, cdc25A and p53R2 were not significantly affected. Immunofluorscence staining of $p27^{kip1}$, cdk2, cyclin E and p-Rb revealed close correlation between the signal observed in the Western blot analysis. 6AN+ATP treated cells showed similar results obtained with 6-AN treated cells in expression of cdk2, cyclin E, p-Rb proteins and $p27^{kip1}$, $6-AN+NAD^+$ cells showed greater expression of cdk2, cyclin E and p-Rb than those in 6-AN and 6-AN+ATP treated cells. The results suggest that 6-AN induced the $G_0/G_1$ phase arrest in IMR32 neuroblastoma cell lines through the increase of $p27^{kip1}$ and the decrease of cdk2, cyclin E and p-Rb.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.5
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• pp.857-862
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• 2011

The purpose of this study is to investigate the anti-proliferative mechanism by Trichosanthes kirilowii (TCK) in MCF-7 human breast carcinoma cell. In this study, we used human breast cancer cell line, Michigan cancer foundation-7 cells (MCF-7 cells). They were co-incubated with 30~200 ${\mu}g$/ml TCK for 48 hours, and cell viability was measured by Water-soluble tetrazolium salt-1 (WST-1) assay. After MCF-7 cells were exposed to 60 ${\mu}g$/ml of TCK for 0, 3, 6, 12, 24, 48 hours, We performed flow analysis cytometry sorting(FACS) and western blot analysis. We investigated the effect of dose-dependent cell growth inhibition by TCK, which could be proved by WST-1 assay. Also, flow cytometry analysis showed that TCK increased percentage of subG1 phase and G2/M phase cell cycle. In addition, TCK induced apoptosis through the expression of caspase-9, -3 and poly(ADP-ribose) polymerase(PARP) activation. Moreover, we showed that ATM-dependent G2/M phase arrest by DNA damage and phosphorylation of chk2, cdc25C, cdc2(Tyr15). Taken together, these results suggest that by G2/M phase arrest through DNA damage and inducing of apoptosis through intrinsic pathway, TCK may have potential tumor suppressor in breast cancer.

• Journal of Life Science
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• v.29 no.6
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• pp.679-687
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• 2019

Litsea populifolia, a plant species of the Lauraceae family, is widely distributed in the tropical and subtropical areas of Asia. The phylogenetic relationships and botanical characteristics of L. populifolia have been reported; however, its anti-oxidative and anti-cancer activities remain unclear. In this study, we evaluated the anti-oxidative and anti-cancer effects of ethanol extracts of L. populifolia (EELP) together with the molecular mechanism of its anti-cancer activity in human lung adenocarcinoma A549 cells. EELP showed significant anti-oxidative effects with a 50% inhibitory concentration at $11.71{\mu}g/ml$, which was measured by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. EELP exhibited cytotoxic activity and induced cell cycle arrest at the G1 phase in A549 cells in a dose-dependent manner, whereas EELP did not have the cytotoxic effect on the normal human lung cell line IMR90. Treatment with EELP also resulted in a decreased expression of G1/S transition-related molecules-including cyclin-dependent kinase (CDK) 2, CDK6, cyclin D1, and cyclin E-both for the transcription and translation levels. EELP-induced G1 arrest was associated with the phosphorylation of checkpoint kinase 2 (CHK2), p53, cell division cycle 25 homolog A (CDC25A), and the reduction of CDC25A expression in A549 cells. Collectively, these results suggest that EELP may exert an anti-cancer effect by cell cycle arrest at the G1 phase through both p53-dependent and p53-independent (ATM/CHK2/CDC25A/CDK2) pathways in A549 cells.

• BMB Reports
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• v.39 no.6
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• pp.730-736
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• 2006

To evaluated the effect of recombinant adenovirus Ad-ODC-AdoMetDCas which can simultaneously express both antisense ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC) on cell cycle distribution in colorectal cancer cell and investigated underlying regulatory responses, human colorectal cancer cells HT-29 were cultured in RPMI 1640 medium and infected with Ad-ODC-AdoMetDCas. Cell cycle progression was detected by flow cytometry analysis. The expression levels of cell cycle regulated proteins were measured by Western blot analysis. The mRNA level of cyclin D1 was measured by RT-PCR. And a luciferase reporter plasmid of cyclin D1 promoter was constructed to observe the effect of Ad-ODC-AdoMetDCas on cyclin D1 promoter activity. The results showed that recombinant adenovirus Ad-ODC-AdoMetDCas significantly induced $G_1$ arrest, decreased levels of cyclin D1 protein and mRNA and suppressed the promoter activity. Ad-ODC-AdoMetDCas also inhibited nuclear translocation of $\beta$-catenin. In conclusion, downregulation of ODC and AdoMetDC mediated by Ad-ODC-AdoMetDCas transfection induces $G_1$ arrest in HT-29 cells and the arrest was associated with suppression of cyclin D1 expression and inhibition of $\beta$-catenin nuclear translocation. As a new anticancer reagent, the recombinant adenovirus Ad-ODC-AdoMetDCas holds promising hope for the therapy of colorectal cancers.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.607-612
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• 2003

To elucidate the action mechanism of MCS-C2, a novel analogue of toyocamycin and sangivamycin, its effect on the expression of cell cycle-related proteins in the human myelocytic leukemia cell line HL-60 was examined using Western blotting and a flow cytometric analysis. MCS-C2, a selective inhibitor of cyclin-dependent kinases, was found to inhibit cell growth in a time- and dose-dependent manner, and inhibits cell cycle progression by inducing the arrest at G1 and G2/M phases, in HL-60 cells. The flow cytometric analysis revealed an appreciable arrest of cells in the G2/M phase of the cell cycle after treatment with MCS-C2. The HL-60 cell population increased gradually from 13% at 0 h, to 28% at 12 h in the G2/M phase, after exposure to $2{\;}\mu\textrm{M}$ MCS-C2. Furthermore, Western blot analysis demonstrated that MCS-C2 induced the cell cycle arrest at G1 phase through the inhibition of pRb phosphorylation. Hypophosphorylated pRb accumulated after treatment with $5{\;}\mu\textrm{M}$ MCS-C2 for 12 h, whereas, the level of hyperphosphorylated pRb was reduced. Thus, treatment of the cell with MCS-C2 suppressed the hyperphosphorylated form of pRb with a commensurate increase in the hypophosphorylated form.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.1
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• pp.43-48
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• 2013

Cisplatin is a anti-neoplastic agent which is commonly used for the treatment of solid tumor. Cisplatin activates multiple signal transduction pathways involved in the stress-induced apoptosis in a variety of cell types. Previous study reported that cisplatin induces apoptosis through activation of ERK, p38 and JNK in rat mesangial cells, but apoptotic pathway remain known. The present study investigated the apoptotic pathway for cisplatin-indcued apoptosis in rat mesangial cells. cisplatin-induced apoptosis was associated with activation of caspase-3, caspase-8, caspase-9. Caspase-8 inhibition prevented the activation of both caspase-3 and caspase-9. In addition, cisplatin-induced apoptosis increased the expression of Bax, but not the level of Bcl-2. These change of Bax/bcl-2 ratio caused the release of cytochrome c from mitochondria into cytosol. In previous study, the ethanol extract of Bojungbangam-tang (EBJT) inhibited cisplatin-induced apoptosis in rat mesangial cells through inhibition of ERK and JNK activation. However, EBJT did not increase cell proliferation, because it did not prevent cisplatin-induced G2/M phase arrest. These effect of EBJT may be related to p38 activation. Cisplatin-induced G2/M phase arrest are inhibited by treatment with p38 inhibitor and EBJT in rat mesangial cells. Also, p38 inhibition and EBJT treatment on cisplatin-induced G2/M phase arrest are markedly increased the G0/G1 phase and reduced the sub-G1. In conclusion, anti-apoptotic effet of EBJT did not increases cell proliferation, because EBJT did not reduce p38 activation related to cisplatin-induced G2/M phase arrest.

• Herbal Formula Science
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• v.23 no.2
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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.

• The Korean Journal of Emergency Medical Services
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• v.19 no.3
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• pp.7-18
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• 2015

Purpose: The purpose of this study was to describe and compare the return of spontaneous circulation (ROSC) cases of out-of-hospital cardiac arrest on the basis of Heart Saver laureate. Methods: This study aimed to investigate the cardiopulmonary resuscitation (CPR) outcomes and the clinical characteristics of patients with out-of-hospital cardiac arrest by analyzing the data of two regions. The data were prehospital emergency reports of 473 patients who survived for > 72 hours after ROSC in two region from January 2012 to December 2013. Results: Among the ROSC patients, 86.8% (G), 77.9% (S) were men and 72.9% (G), 67.9% (S) were of age 41~70 years, 87.6% (G), 82.9% (S) had a witnessed cardiac arrest; and 66.7% (G), 70.6% (S) received cardiopulmonary resuscitation from bystander. Of those who performed the resuscitation, paramedics in 89.1% (G), 89.8% (S). Furthermore, 119 emergency medical technicians were involved in 69.0% of two-rescue teams in G and in 90.4% of three-rescue team in S. Conclusion: Most heart savers were qualified paramedics, and three-rescuer-teams resulted in better survival rate than two-rescuer-teams.