• 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.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.282-287
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• 2009

Ochnaflavone is a natural biflavonoid and mainly found in the caulis of Lonicera japonica (Caprifoliaceae). Biological activities such as anti-inflammatory and anti-atherogenic effects have been previously reported. The anticancer activity of ochnaflavone, however, has been poorly elucidated yet. In the present study, we investigated the effect of ochnaflavone on the growth inhibitory activity in cultured human colon cancer cell line HCT-15. Ochnaflavone inhibited the proliferation of the cancer cells with an $IC_{50}$ value of $4.1{\mu}M$. Flow cytometric analysis showed that ochnaflavone arrested cell cycle progression in the G2/M phase, and induced the increase of sub-G1 peak in a concentration-dependent manner. Induction of cell cycle arrest was correlated with the modulation of the expression of cell cycle regulating proteins including cdc2 (Tyr15), cyclin A, cyclin B1 and cyclin E. The increase of sub-G1 peak by the higher concentrations of ochnaflavone (over $20{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, activation of caspase-3, -8 and -9, and cleavage of poly-(ADP-ribose) polymerase. These findings suggest that the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of ochnaflavone in human colon cancer cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1309-1314
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• 2003

We examined the effects of Oak Smoke Flavoring (OSF, Holyessing) on the cell proliferation of DU145 and PC3 human prostate carcinoma cell line. OSF treatment resulted in a concentration-dependent inhibition of the cell viability in both DU145 and PC3 cell lines. The anti-proliferative effects by OSF treatment in DU145 and PC3 cells were associated with morphological changes such as membrane shrinking and cell rounding up. DNA flow cytometric histograms showed that population of S phase of the cell cycle was increased by OSF treatment in a dose-dependent manner. Western blot analysis revealed that cyclin B1 and cdc2 proteins were reduced by OSF treatment in DU145 cells, whereas cyclin A was markedly inhibited in PC3 cells. Furthermore, we observed an increase of Cdk inhibitor p16 and p27 protein, and an inhibition of phosphorylation of pRB by OSF treatment in a dose-dependent manner. The present results indicated that OSF-induced inhibition of human prostate carcinoma cell proliferation is associated with the blockage of S phase progression.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6247-6251
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• 2014

Background: The aim of the present study was to investigate the involvement of emodin on the growth of human breast cancer MCF-7 and MDA-MB-231 cells and the estrogen (E2) signal pathway in vitro. Materials and Methods: MTT assays were used to detect the effects of emodin on E2 induced proliferation of MCF-7 and MDA-MB-231 cells. Flow cytometry (FCM) was applied to determine the effect of emodin on E2-induced apoptosis of MCF-7 cells. Western blotting allowed detection of the effects of emodin on the expression of estrogen receptor ${\alpha}$, cyclin D1 and B-cell lymphoma-2 (Bcl-2), mitogen-activated protein kinases (MAPK) and phosphatidylinostiol 3-kinases (PI3K). Luciferase assays were emplyed to assess transcriptional activity of $ER{\alpha}$. Results: Emodin could inhibit E2-induced MCF-7 cell proliferation and anti-apoptosis effects, and arrest the cell cycle in G0/G1 phase, further blocking the effect of E2 on expression and transcriptional activity of $ER{\alpha}$. Moreover, Emodin influenced the ER ${\alpha}$ genomic pathway via downregulation of cyclin D1 and Bcl-2 protein expression, and influenced the non-genomic pathway via decreased PI3K/Akt protein expression. Conclusions: These findings indicate that emodin exerts inhibitory effects on MCF-7 cell proliferation via inhibiting both non-genomic and genomic pathways.

• Journal of Acupuncture Research
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• v.20 no.3
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• pp.45-62
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• 2003

Objective : To examine the effects of Beevenom on the cell proliferation of human breast carcinoma cell line MCF-7, we performed various experiments such as does-dependent effect of Beevenom on cell proliferation and viability, morphological changes, and alterations of apoptosis/cell cycle-regulatory gene products. Methods : Beevenom induced cell viability and proliferation of MCF-7 cells in a concentration-dependent manner. The anti-proliferative effect by Beevenom treatment in MCF-7 cells was associated with morphological changes such as membrance shrinking and cell rounding up. Results : Beevenom induced apoptotic cell death in a concentration-dependent manager, which was associated with degradation of ${\beta}$-catenin, an apoptotic target protein. Beevenom induced the Bax expressions, a pro-apoptotic gene, both in protein and mRNA levels, however, the levels of Bcl-$X_{S/L}$ expression, an anti-apoptotic gene, were down-regulated in Beevenom-treated cells. Western blot analysis and RT-PCT data revealed that the levels of cyclin of B1 protein and cyclin E mRNA were reduced by Beevenom treatment in MCF-7 cells, respectively, where as the expression of tumor suppressor p53 and cyclin dependent kinase inhibitor p21 mRNA were markedly increased in a concentration-dependent fashion. Conclusions : Taken together, these findings suggest that Beevenom induced inhibition of human breast cancer cell proliferation is associated with the induction of apoptotic cell death and Beevenom may have therapeutic potential in human breast cancer.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.3
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• pp.153-158
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• 2012

Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.146-152
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• 2001

Purpose : To investigate the regulation of apoptosis and cell cycle in mouse brain irradiation. Materials and Methods : 8-week old male mice, C57B1/6J were given whole body $\gamma-radiation$ with a single dose of 25 Gy using Cobalt 60 irradiator. At different times 1, 2, 4, 8 and 24hr after irradiation, mice were killed and brain tissues were collected. Apoptotic cells were scored by TUNEL assay. Expression of p53, Bcl-2, and Bax and cell cycle regulating molecules; cyclins Bl, Dl, E and cdk2, cdk4, $p34^{cdc2}$ were analysed by Western blotting. Cell cycle was analysed by Flow cytometry. Results : The peak of radiation induced apoptosis is shown at 8 hour after radiation. With a single 25 Gy irradiation, the peak of apoptotic index in C57B1/6J is $24.0{\pm}0.25$ (p<0.05) at 8 hour after radiation. Radiation upregulated the expression of p53/tubulin, Bax/tubulin, and Bcl-2/tubulin with 1.3, 1.1 and 1.45 fold increase, respectively were shown at the peak level at 8 hour after radiation. The levels of cell cycle regulating molecules after radiation are not changed significantly except cyclin D1 with 1.3 fold increase. Fractions of Go-Gl, G2-M and S phase in the cell cycle does not specific changes by time. Conclusion : In mouse brain tissue, radiation induced apoptosis is particularly shown in a specific area, subependyma. These results and lack of radiation induced changes in cell cycle ofter better understanding of radiation response of noraml brain tissue.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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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.

• 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.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.32 no.4
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• pp.1-12
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• 2019

Objectives : The purpose of this study was to identify the anticancer effect of biological substances of ethylacetate(EtOAc) fraction from Orostachys japonicus(OJEF), their effect on human melanoma A375 cells and the related molecular mechanisms. Methods : The MTS assay was used to confirm the inhibition of cancer cell proliferation in A375 cells. And the $MUSE^{TM}$ analyzer was used to determine the ability of OJEF to induce cell cycle arrest. Western blotting was used to determine the changes in protein expression in A375 cells after treatment with OJEF. Results : OJEF showed cytotoxicity to A375 cells. And cell cycle arrest occurred in G1 phase and G2/M phase owing to inhibition of CDK1, cyclin B1, CDK4, and cyclin D, which are related to cell cycle regulation and cell division control. Conclusion : OJEF is effective in regulating cell cycle of human melanoma cells and thus can be a good theraputic agent to treat patients with melanoma.