• Biomedical Science Letters
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• v.29 no.4
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• pp.287-295
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• 2023

Amifostine was developed to protect cells, but it is known to induce cytotoxicity and apoptosis, and the exact mechanism is unknown. In this study, we investigated how the DNA mismatch repair (MMR) system interacts with p53 to prevent apoptosis, cell cycle arrest, and cytoprotective effects induced by amifostine. HCT116 colon cancer cells sublines HCT116/p53+,HCT116/p53+, HCT116/p53-, HCT116/E6 and HCT116+ch3/E6 cells were used for evaluation. Amifostine induced G1 arrest and increased toxicity two-fold in p53- cells regardless of MMR expression. Both G1 cell cycle arrest and induction of p53 protein peaked at 24 h after the start of amifostine exposure. Both G1 cell cycle arrest and induction of p53 protein peaked at 24 h after the start of amifostine exposure. Amifostine induced the expression of p21 protein in both p53+ and p53- cells. As for apoptosis, compared to p53- cells, p53+ cells showed 3.5~4.2 times resistance to amifostine-induced apoptosis. HCT116+E6 with both p53 and MMR loss showed maximum apoptosis at 48 h, and HCT116+ch3/E6HCT116+ch3/E6 with p53 loss showed maximum apoptosis at 24 h. As a result, it was confirmed through in vitro experiments that amifostine-induced G1 cell cycle arrest and apoptosis are mediated through a pathway dependent on MMR and p53 protein.

• Imaging Science in Dentistry
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• v.30 no.1
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• pp.71-79
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• 2000

Purpose : This study was aimed to evaluate the cell cycle arrest and apoptosis induction after irradiation and epidermal growth factor (EGF) treatment in three human epithelial tumor cell lines (A431, Siha, KB). Materials and Methods: Single irradiation of 2, 5 and 10 Gy was done on three cell lines with 5.38 Gy/min dose rate using Cs-137 irradiator at room temperature. Also, EGF of 10 ng/ml was added immediately after 10 Gy irradiation. Cell growth was evaluated by counting the living cell number using a hemocytometer at 1 day, 2 days, 3 days, 4 days and 5 days after irradiation. Cell cycle arrest and apoptosis induction were assayed with the flow cytometry at 8 hours, 12 hours, 1 day, 2 days, 3 days, 4 days and 5 days after irradiation. Results : Growth of irradiated three cell lines were inhibited in proportion to radiation dose. EGF treatment after irradiation showed various results according to cell lines. On all cell lines, G2 arrest was detected after 8 hours and maximized after 12 hours or 1 day. Amount of G2 arrest was positively dose dependent. However, EGF showed no significant change on G2 arrest. G2 arrest was recovered with time at 2 Gy and 5 Gy irradiation. However, at 10 Gy irradiation, G2 arrest was continued. Apoptosis was detected at 10 Gy irradiation. On EGF treated group after irradiation, A431 and Siha cell lines showed slightly increased apoptosis but there was no statistically significant difference. KB cell line showed no marked change of apoptosis induction. Conclusion : Irradiation effects on cell cycle arrest and apoptosis induction in three human epithelial tumor cell lines, however epidermal growth factor doesn't effect on.

• YAKHAK HOEJI
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• v.58 no.1
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• pp.33-39
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• 2014

The objective of this study is to evaluate the anticancer effects of the isoflavone extract from Chungkukjang in human breast cancer, MDA-MB-453 cells. For this study, MDA-MB-453 cells were treated with 12.5, 25, and $50{\mu}g$ isoflavone extract for 24, 48, and 72 hr. Cell proliferations were decreased in a time- and dose-dependent manner. Reduced cell proliferation was suspected by apoptosis or cell cycle arrest. Therefore, after treatment of $50{\mu}g$ isoflavone extract, apoptotic cells were investigated by annexin V staining. The results indicated that isoflavone extract increased the number of early apoptotic cells compared with control. Cleaved PARP was also increased. Next, we investigated the cell cycle and related proteins. The isoflavone extract leads to cell cycle arrest at the G2/M phase. Moreover isoflavone extract had influenced cell cycle relate proteins such as cyclin B1, cyclin A, and p21. These results suggest that isoflavone extract from Chungkukjang induce apoptosis and cell cycle arrest at G2/M phase via regulation of cell cycle-related proteins in MDA-MB-453 cells.

• Toxicological Research
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• v.21 no.1
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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.

• 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.

• Nutrition Research and Practice
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• v.2 no.4
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• pp.322-325
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• 2008

The aim of present study was to investigate the effects of kaempferol on cellular proliferation and cell cycle arrest and explore the mechanism for these effects in human breast carcinoma MDA-MB-453 cells. Cells were treated with kaempferol at various concentrations (ranging from 1 to $200\;{\mu}M$) for 24 and 48 hrs. Kaempferol significantly inhibited cancer cell growth in cells exposed to 50 and $10\;{\mu}M$ of kaempferol and incubated for 24 and 48 hrs, respectively. Exposure to kaempferol resulted in cell cycle arrest at the G2/M phase. Of the G2/M-phase related proteins, kaempferol down-regulated CDK1 and cyclin A and B in cells exposed to kaempferol. In addition, small DNA fragments at the sub-G0 phase were increased by up to 23.12 and 31.90% at 10 and $50\;{\mu}M$ incubated for 24 and 48 hrs, respectively. The kaempferol-induced apoptosis was associated with the up-regulation of p53. In addition, the phosphorylation of p53 at the Ser-15 residue was observed with kaempferol. Kaempferol inhibits cell proliferation by disrupting the cell cycle, which is strongly associated with the induction of arrest at G2/M phase and may induce apoptosis via p53 phosphorylation in human breast carcinoma MDA-MB-453 cells.

• Natural Product Sciences
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• v.19 no.2
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• pp.155-159
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• 2013

Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has exhibited a potential anti-proliferative activity in human cancer cells. However, the growth inhibitory activity against hepatocellular carcinoma cells and the underlying molecular mechanisms has been poorly determined. The present study was designed to examine the anti-proliferative effect of honokiol in SK-HEP-1 human hepatocellular cancer cells. Honokiol exerted anti-proliferative activity with cell-cycle arrest at the G0/G1 phase and sequential induction of apoptotic cell death. The cell-cycle arrest was well correlated with the down-regulation of checkpoint proteins including cyclin D1, cyclin A, cyclin E, CDK4, PCNA, retinoblastoma protein (Rb), and c-Myc. The increase of sub-G1 peak by the higher concentration of honokiol ($75{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by decreased expression of Bcl-2, Bid, and caspase-9. Hohokiol was also found to attenuate the activation of signaling proteins in the Akt/mTOR and ERK pathways. These findings suggest that the anti-proliferative effect of honokiol was associated in part with the induction of cell-cycle arrest, apoptosis, and dow-nregulation of Akt/mTOR signaling pathways in human hepatocellular cancer cells.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.1-9
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• 2021

Human prostate cancer is the second most frequently diagnosed cancer worldwide, and its incidence rate continues to increase. Advanced prostate cancer is more difficult to treat than early forms due to its chemotherapy resistance. There is need for more effective agents that can inhibit the progression of advanced prostate cancer. Demethoxyfumitremorgin C (DMFTC) was isolated from the fermentation extract of the marine fungus Aspergillus fumigatus. Antiproliferative activity of DMFTC against human prostate cancer PC3 cells was examined through cell cycle analysis by flow cytometry, the fluorescent nuclear imaging analysis with propidium iodide (PI), and proteins expression related to cell cycle arrest and apoptosis were investigated via Western blotting. DMFTC inhibited PC3 cells growth through G1 phase cell cycle arrest and apoptosis induction. It activated the tumor suppressor p53 and the Cdk inhibitor p21, which regulate the cell progression into the G1 phase. Additionally, PI-positive late apoptotic non-viable cells were increased and the expression levels of the G1-positive downstream regulators cyclin D, cyclin E, Cdk2, and Cdk4 were decreased by DMFTC treatment. These results suggest that DMFTC induces G1 arrest and apoptosis induction through regulation of p53/p21-dependent cyclin-Cdk complexes, and it may be a useful therapeutic agent for the treatment of human advanced prostate cancer.

• International Journal of Oral Biology
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• v.36 no.3
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• pp.129-134
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• 2011

Eugenol is an essential oil found in cloves and cinnamon that is used widely in perfumes. However, the significant anesthetic and sedative effects of this compound have led to its use also in dental procedures. Recently, it was reported that eugenol induces apoptosis in several cancer cell types but the mechanism underlying this effect has remained unknown. In our current study, we examined whether the cytotoxic effects of eugenol upon human melanoma G361 cells are associated with cell cycle arrest and apoptosis using a range of methods including an XTT assay, Hoechst staining, immunocyto-chemistry, western blotting and flow cytometry. Eugenol treatment was found to decrease the viability of the G361 cells in both a time- and dose-dependent manner. The induction of apoptosis in eugenol-treated G361 cells was confirmed by the appearance of nuclear condensation, the release of both cytochrome c and AIF into the cytosol, the cleavage of PARP and DFF45, and the downregulation of procaspase-3 and -9. With regard to cell cycle arrest, a time-dependent decrease in cyclin A, cyclin D3, cyclin E, cdk2, cdk4, and cdc2 expression was observed in the cells after eugenol treatment. Flow cytometry using a FACScan further demonstrated that eugenol induces a cell cycle arrest at S phase. Our results thus suggest that the inhibition of G361 cell proliferation by eugenol is the result of an apoptotic response and an S phase arrest that is linked to the decreased expression of key cell cycle-related molecules.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.204-208
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• 2007

Chaga mushroom extract is well known as immune modulator and anti-cancer agent. However, the molecular mechanism by which Chaga exerts cell cycle arrest and apoptosis of cancer cells is poorly understood. In this study, we demonstrated anti-proliferative effects of Chaga extract on murine melanoma B16 cells. Chaga extract dose-dependently inhibited cell growth along with the arrest of G0/G1 phase and the induction of apoptotic cell death. Treatment with Chaga extract resulted in a decrease of cyclin E, cyclin D1, cdk 2, cdk 4 expression levels. Furthermore, in vivo inoculation study of B16 melanoma cells into Balb/c mice Chaga extract markedly suppressed the metastatic growth of tumor cells (6 folds, p<0.05,). These results indicate that Chaga mushroom extract induces apoptosis of B16 melanoma cells through arrest of G0/G1 phase in cell cycle.