• 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.

• 생명과학회지
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• 제23권9호
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• pp.1109-1117
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• 2013

본 연구에서는 인체 폐암 세포인 A549를 사용하여 택란 메탄올 추출물의 항암활성과 그 분자적 기전에 관하여 연구하였다. 먼저 택란 추출물이 A549의 세포증식에 미치는 영향을 알아본 결과 처리 농도 및 시간 의존적으로 A549의 성장이 저해되었으며, 세포 주기 변화를 분석한 결과 강력한 G1 arrest가 유도되는 것을 확인하였다. 이러한 택란 추출물에 의한 G1 arrest는 세포주기 조절 단백질인 Cyclin D1, Cyclin E 및 Cyclin-dependent kinase인 CDK2, CDK4, CDK6의 발현 감소와 연관되어 있었다. 또한 택란 추출물에 의한 CDK/Cyclin complex의 발현 저해는 DNA 손상에 의해 활성화되는 CHK2의 활성화 형태인 p-CHK2의 발현 증가에 따른 CDK 활성화 효소인 Cdc25A phosphatase의 발현 억제에 의해 나타나는 결과로 사료된다. 반면 종양억제유전자인 p53 및 CDK 억제제인 p21과 p27의 발현량은 증가되지 않았다. 이러한 결과들로부터 택란 추출물은 DNA damage에 의한 ATM/CHK2/Cdc25A/CDK2 pathway를 통해 A549의 G1 arrest를 유도하여 세포의 증식을 억제할 것으로 판단되며, 이때 택란 추출물에 의해 유도되는 G1 arrest는 p53 비의존적인 경로일 것으로 사료된다. 본 연구결과는 택란이 Cdc25A를 target으로 하는 새로운 항암활성 소재로서 사용될 수 있는 가능성을 시사한다. 또한 본 연구결과는 택란 추출물의 세포주기 조절에 의한 항암기전을 이해하고 향후 지속적 연구를 하는 데 있어서 귀중한 기초자료로 사용될 수 있을 것이다.

• Journal of Ginseng Research
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• 제39권2호
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• pp.125-134
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• 2015

Background: Black ginseng (Ginseng Radix nigra, BG) refers to the ginseng steamed for nine times and fine roots (hairy roots) of that is called fine black ginseng (FBG). It is known that the content of saponin of FBG is higher than that of BG. Therefore, in this study, we examined antitumor effects against MCF-7 breast cancer cells to target the FBG extract and its main component, ginsenoside Rg5 (Rg5). Methods: Action mechanism was determined by MTT assay, cell cycle assay and western blot analysis. Results: The results from MTT assay showed that MCF-7 cell proliferation was inhibited by Rg5 treatment for 24, 48 and 72 h in a dose-dependent manner. Rg5 at different concentrations (0, 25, 50 and $100{\mu}M$), induced cell cycle arrest in G0/G1 phase through regulation of cell cycle-related proteins in MCF-7 cells. As shown in the results from western blot analysis, Rg5 increased expression of p53, $p21^{WAF1/CIP1}$ and $p15^{INK4B}$ and decreased expression of Cyclin D1, Cyclin E2 and CDK4. Expression of apoptosiserelated proteins including Bax, PARP and Cytochrome c was also regulated by Rg5. These results indicate that Rg5 stimulated cell apoptosis and cell cycle arrest at G0/G1 phase via regulation of cell cycle-associated proteins in MCF-7 cells. Conclusion: Rg5 promotes breast cancer cell apoptosis in a multi-path manner with higher potency compared to 20(S)-ginsenoside Rg3 (Rg3) in MCF-7 (HER2/ER+) and MDA-MB-453 (HER2+/ER) human breast cancer cell lines, and this suggests that Rg5 might be an effective natural new material in improving breast cancer.

• Toxicological Research
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• 제21권1호
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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.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.978-984
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• 2004

In the course of screening for a novel inhibitor of CDC2, HY558-1 was isolated from a culture broth of Penicillium minioluteum F558. Moreover, it was found that HY558-1 had an effect on both the cell cycle regulation and apoptosis of human cervical adenocarcinoma HeLa cells. A flow cytometric analysis of HeLa cells revealed appreciable cell cycle arrest at the G1 and G2/M phases following treatment with HY558-1. Furthermore, DNA fragmentation due to apoptosis was observed in HeLa cells treated with HY558-1. To obtain further information on the cell cycle arrest and apoptotic induction induced by HY558-1, the expression of certain cell cycle and apoptosis-associated proteins was examined using a Western blot analysis. The results revealed that HY558-1 inhibited the phosphorylation of pRb and decreased the expression levels of CDK2, CDC2, and cyclin A in the cell cycle progression. It was also shown that the level of $p21^{WAF1/CIP1}$ was increased in HeLa cells treated with 0.52 mM of HY558-1. Accordingly, HY558-1 was found to inhibit the proliferation of HeLa cells through the induction of G1 phase arrest by inhibiting pRb phosphorylation via an upregulation of $p21^{WAF1/CIP1}$, and G2/M phase arrest by directly inhibiting CDC2 and cyclin A. Moreover, HeLa cells treated with 0.52 mM of HY558-1 exhibited apoptotic induction associated with the cleavage of Bid and release of cytochrome c from mitochondria into the cytosol. Subsequent investigation of the activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP) suggested that the mitochondrial pathway was primarily involved in the HY558-1-induced apoptosis in HeLa cells.

• Natural Product Sciences
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• 제18권1호
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• pp.16-21
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• 2012

Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has been shown to have the anti-angiogenic, anti-invasive and cancer chemopreventive activities, but the molecular mechanism of actions has not been fully elucidated yet. In the present study, we investigated the effect of honokiol on the growth inhibitory activity in cultured SNU-638 human gastric cancer cells. We found that honokiol exerted potent antiproliferative activity against SNU-638 cells. Honokiol also arrested the cell cycle progression at the G0/G1 phase and induced the apoptotic cell death in a concentration-dependent manner. The cell cycle arrest was well correlated with the downregulation of Rb, cyclin D1, cyclin A, cyclin E, and CDK4 expression, and the induction of cyclin-dependent kinase inhibitor p27. The increase of sub-G1 peak by honokiol was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, the cleavage of poly(ADPribose) polymerase, and the sequential activation of caspase cascade. These findings suggest the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of honokiol in human gastric cancer cell.

• Preventive Nutrition and Food Science
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• 제21권1호
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• pp.31-37
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• 2016

Opuntia humifusa (OHF) has been used as a nutraceutical source for the prevention of chronic diseases. In the present study, the inhibitory effects of ethyl acetate extracts of OHF on the proliferation of AGS human gastric cancer cells and the mode of action were investigated. To elucidate the antiproliferative mechanisms of OHF in cancer cells, the expression of genes related to apoptosis and cell cycle arrest were determined with real-time PCR and western blot. The cytotoxic effect of OHF on AGS cells was observed in a dose-dependent manner. Exposure to OHF ($100{\mu}g/mL$) significantly induced (P<0.05) the G1 phase cell cycle arrest. Additionally, the apoptotic cell population was greater (P<0.05) in OHF ($200{\mu}g/mL$) treated AGS cells when compared to the control. The expression of genes associated with cell cycle progression (Cdk4, Cdk2, and cyclin E) was significantly downregulated (P<0.05) by the OHF treatment. Moreover, the expression of Bax and caspase-3 in OHF treated cells was higher (P<0.05) than in the control. These findings suggest that OHF induces the G1 phase cell cycle arrest and activation of mitochondria-mediated apoptosis pathway in AGS human gastric cancer cells.

• 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.

• 한국식품영양과학회지
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• 제46권4호
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• pp.417-425
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• 2017

벌사상자는 여성의 생식기 질환이나 화농성 피부염에 주로 사용되어온 한약재로, 최근 들어 암과 관련된 연구가 많이 이루어짐에 따라 벌사상자의 항암 효과에 대한 관심이 높아지고 있다. 벌사상자의 대표적인 성분인 osthole, xanthotoxol 등은 벤젠고리 화합물로 에탄올과 같은 유기용매에 잘 용해된다. 이에 따라 본 연구에서는 AGS 위암세포에서 벌사상자 에탄올 추출물(CME)에 대한 세포주기 정지 유도 효과를 확인하고자 하였다. CME 처리에 의한 AGS 위암세포의 증식 억제 유도 효과 및 세포독성 효과를 확인하기 위하여 MTT assay와 LDH release assay를 실시한 결과, 농도 및 시간 의존적으로 세포생존율이 감소하였으며, 농도 의존적인 세포독성 효과를 확인하였다. 또한, CME의 농도가 증가할수록 AGS 위암세포의 형태학적 변화가 관찰되었다. 이러한 세포증식 억제 유도 효과가 세포주기 정지에 의한 것인지 확인하기 위하여 CME를 농도별로 24시간 동안 처리한 후 세포주기를 측정하였다. 그 결과 G1기의 세포가 농도 의존적으로 증가함을 확인하였다. 그리고 CME의 처리가 세포주기와 관련된 단백질에 미치는 영향을 알아보기 위하여 western blot analysis를 실시하여 G1기 세포주기 정지와 관련된 신호 단백질들의 발현 변화를 확인하였다. 그 결과 CME의 처리가 세포 증식과 분열에 중요한 역할을 하는 p-Akt와 p-GSK-$3{\beta}$의 발현을 저해하는 것을 확인하였고, 이에 따라 p53의 발현과 활성이 증가하여 p21의 발현이 증가함을 확인하였다. 또한, p21의 증가에 따른 cyclin E의 발현 감소와 CDK2의 비활성화 상태인 p-CDK(T14), p-CDK(Y15)의 발현 증가를 확인하였다. 이와 같은 CME의 세포주기 억제 유도 효과가 일어나는 신호경로를 확인하기 위하여 LY294002(PI3K/Akt 저해제), BIO(GSK-$3{\beta}$ 저해제), Pifithrin-${\alpha}$(p53 저해제)를 CME와 각각 또는 병행 처리한 후 MTT assay, 세포주기 측정, western blot analysis를 진행하였다. 그 결과 LY294002의 처리는 CME 처리군과 유사하게 세포생존율을 저해시키고 G1기 정지를 유도했으며, 세포주기 단백질을 조절하였다. 또한, GSK-$3{\beta}$와 p53 저해제를 처리하였을 때 CME를 병행 처리했음에도 불구하고 세포증식 억제나 G1기 정지와 같은 항암 효과가 나타나지 않았으며, 관련 신호경로 단백질의 변화도 관찰되지 않았다. 이러한 결과는 CME의 처리가 Akt/GSK-$3{\beta}$/p53 신호경로를 조절하여 cyclin E의 발현을 감소시키고 CDK2의 활성을 억제함으로써 G1기 세포주기 정지를 유도함을 확인하였다.

• 생명과학회지
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• 제19권1호
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• pp.1-8
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• 2009

본 연구에서는 monofunctional alkylating agent인 N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) 에 의한 인체 백혈병 U937 세포의 증식억제에 관한 기전 확인하였다. MNNG에 의한 U937 세포의 증식억제는 세포주기 G2/M arrest 및 apoptosis 유방과 연관이 있었으며, MNNG 는 G2/M기 조절에 관여하는 주요 cyclin 및 Cdk들의 발현 수준에는 큰 영향이 없었으나 cyclin B1 및 Cdk2-associated kinase의 활성을 매우 저하시켰다. MNNG 처리로 Cdk inhibit p2l(WAF1/CIP1)이 전사 및 번역 수준에서 발연이 증가되었으며, p21 promoter 의 활성도 증가되었다. p21 promoter deletion constructs을 이용한 연구에서 MNNG의 responsive element 부위는 전사 개시 부위 113-61 부근임을 확인하였다. 이 결과들은 MNNG에 의한 cyclin/Cdk 복합체의 kinase 활성 저하가 p53 비의존적인 p21의 활성 증가에 기인한 것임을 보여주는 것이며, 이는 MNNG의 암세포에서의 항암기전을 이해하는 귀중한 자료로서 제공될 것으로 기대된다.