• 한국미생물·생명공학회지
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• 제29권3호
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• pp.181-185
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• 2001

유방암 세포주에서는 우수한 항암활성을 가진 것으로 알려진 indole-3-carbinol을 HepG2세포주에 시간과 농도별로 처리한 결과 cell growth inhibition을 확인하였으며, $IC_{50}$ 값은 48시간배양에서 $446\mu$M 72시간 배양에서 444$\mu$M로 나타났다. $400\mu$M의 I3C을 투여하고, 24, 48, 72시간에 HePG2 세포주의 cell cycle pattern을 분석한 결과, G1 phase에서 P21의증가와 함께 Cdk 6와 cyclin D의 확연한 감소와 Pb protein의 hypo-phosphorylation을 확인하였다. 반면 G2 phase에서는 I3C의 직접적인 억제로 인해 24시간 후부터 Cdc2와 cyclin B1가 급격히 감소하는것을 확인하였다. Flow cytomery 분석결과 I3C 처리 24시간 뒤 G2 arrest (25%)가 발생하였으며, 72시간이 지난후 G1 arrest (53%)가 발생하였다. 이러한 I3C의 간암세포주인 HePG2 cell의 cell cycle arrest가 apoptosis를 유발하는지를 알고자 caspase 3 Bcl2 Bax protein의 발현양상을 확인한 결과 아무런 변화가 보이지 않았다. 즉 I3C은 간암세포주인 HepG2 cell에서 apoptosis를 유도하지 못한다는것을 확인하였따. 결론적으로 I3C은 HepG2 세포주에서 G1와 G2 phase에서 cell cycle arrest는 발생시키나, 특이적으로 apoptosis 와는 연관되지 않는다는 사실을 확인하였다.

• KSBB Journal
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• 제30권5호
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• pp.223-229
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• 2015

In this study, extract from Artemisia annua in L. (AAE) is known as a medicinal herb that is effective against cancer. The cell cycle is regulated by the activation of cyclin-dependent kinase (CDK)/cyclin complex. We will focus on regulation of CDK2 by cyclin E. cyclin E is associated with CDK2 to regulate progression from G1 into S phase. Akt is known to play an important role in cell proliferation and cell survival. Activation of Akt increases mTOR activity that promotes cell proliferation and cancer growth. In this study, we investigated that AAE-induced cell cycle arrest at G1/S phase in HCT116 colon cancer. Treatment of AAE shows that reduced activation of Akt decreases mTOR/Mdm2 activity and then leads to increase the activation of p53. The active p53 promotes activation of p21. p21 induces inactivation of CDK2/cyclin E complex and occurs cell cycle arrest at G1/S phase. We treated LY294002 (Akt inhibitor) and Rapamycin (mTOR inhibitor) to know the relationship between the signal transduction of proteins associated with cell cycle arrest. These results suggest that AAE induces cell cycle arrest at G1/S phase by Akt/mTOR pathway in HCT116 colon cancer cell.

• 동의생리병리학회지
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• 제25권5호
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제15권9호
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• pp.4101-4107
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• 2014

Protein phosphatase 1 (PP1) is a major serine/threonine phosphatase that controls gene expression and cell cycle progression. The active mutant IPP5 ($8-60hIPP5^m$), the latest member of the inhibitory molecules for PP1, has been shown to inhibit the growth of human cervix carcinoma cells (HeLa). In order to elucidate the underlying mechanisms, the present study assessed overexpression of $8-60hIPP5^m$ in HeLa cells. Flow cytometric and biochemical analyses showed that overexpression of $8-60hIPP5^m$ induced G2/M-phase arrest, which was accompanied by the upregulation of cyclin B1 and phosphorylation of G2/M-phase proteins ATM, p53, $p21^{cip1/waf1}$ and Cdc2, suggesting that $8-60hIPP5^m$ induces G2/M arrest through activation of the ATM/p53/$p21^{cip1/waf1}$/Cdc2/cyclin B1 pathways. We further showed that overexpression of $8-60hIPP5^m$ led to delayed nuclear translocation of cyclin B1. $8-60hIPP5^m$ also could translocate to the nucleus in G2/M phase and interact with $pp1{\alpha}$ and Cdc2 as demonstrated by co-precipitation assay. Taken together, our data demonstrate a novel role for $8-60hIPP5^m$ in regulation of cell cycle in HeLa cells, possibly contributing to the development of new therapeutic strategies for cervix carcinoma.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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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.

• 동의생리병리학회지
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• 제25권2호
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• pp.189-194
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• 2011

Nardostachys chinensis (N. Chinensis) belonging to the family Valerianaceae have been used in traditional medicine to elicit stomachic and sedative effects. The present study investigated the effects of water extract of N. Chinensis in human lymphoma U937 cells. The proliferation of U937 cells was decreased by N. Chinensis. Anti-proliferative effect of N. Chinensis on U937 cells was associated with G0/G1 phase arrest, which was mediated by regulating the expression of p21 and p27 protein. In addition, the levels of CDK2, CDK4, CDK6, Cyclin D3, and Cyclin A were decreased, but Cyclin D1, Cyclin D2 and Cyclin E were essentially undetectable. N. Chinensis induced the differentiation of U937 as shown by increased expression of differentiation surface antigen CD11b, but not CD14. Taken together, these results demonstrated that N. Chinensis potently inhibits the proliferation of U937 cells via the G0/G1 phase cell cycle arrest in association with p21 and p27, and induces granulocytic differentiation.

• Archives of Pharmacal Research
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• 제28권6호
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• pp.685-690
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• 2005

We recently reported that the ginseng saponin metabolite, compound K (20-O-$\beta$-D-glucopyra-nosyl-20(S)-protopanaxadiol, IH901), inhibits the growth of U937 cells through caspase-dependent apoptosis pathway. In this study, we further characterized the effects of compound K on U937 cells and found that, in addition to apoptosis, compound K induced the arrest of the G1 phase. The compound K treated U937 cells showed increased p21 expression; an inhibitory protein of cyclincdk complex. The up-regulation of p21 was followed by the inactivation of cyclin D and the cdk4 protein, which act at the early $G_1$ phase, and cyclin E, which acts at the late $G_1$ phase. Furthermore, compound K induced the activation of JNK and the transcription factor AP-1, which is a downstream target of JNK. These findings suggest that the up-regulation of p21 and activation of JNK in the compound K treated cells contribute to the arrest of the $G_1$ phase.

• Radiation Oncology Journal
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• 제16권2호
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• pp.91-98
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• 1998

목적 : SCK 선암 세포주에서 방사선 조사에 의해 일어나는 apoptosis와 세포 주기와의 연관성을 규명하고자하였다. 대상 및 방법 : SCK 선암 세포주를 apoptosis의 통상적인 정성 분석 방법인 agarose gel electrophoresis 방법을 이용하여 방사선 조사량과 배지 pH 환경과의 연구에서 2-l2Gy의 방사선 조사량과 pH 7.5 및 5.6의 배양 배자 조건하에서 다양한 배양 시간의 경과에 따른 DNA fragmentation의 지표인 laddering을 관찰하였다. 실험 조작으로 apoptosis가 유발된 세포군을 정량적으로 분석하고 세포 주기 분석을 위해 FACScan을 이용하였다. 결과 : apoptosis가 왕성히 발현되었던 pH 7.5 배지에서 배양하였던 세포에서는 방사선 조사직후부터 $G_2M$ phase의 세포들의 분획이 증가하기 시작하여 12시간째 약 $70\%$까지의 최고치를 보인 후 36시간째에 방사선을 조사하지 않았던 상태의 분획으로 정상화되었다. 하지만 pH 6.6 배지에서 배양하였던 세포에서의 $G_2/M$ phase의 세포들의 분획의 증가는 pH 7.5 배지에서 배양하였던 세포들에 비해 비교적 천천히 일어나고 그 최고치도 24시간째에 약 $45\%$로 관찰되었다. 특이한 것은 $G_2/M$ phase의 세포들의 분획이 그 이후 감소되는 정도가 pH 7.5 배지에서 배양하였던 세포들에 비해 미약하여 48시간 배양 이후에도 약 $30-35\%$의 세포는 $G_2/M$ Phase의 세포들의 분획으로 관찰되었다. 결론 : 연구자들은 이러한 현상이 세포들이 GJM phase에서 많은 양의 세포들이 집적되어 세포주기를 순환하지 못하는 $G_2M$ arrest 현상으로 이해하였다. 세포 내외의 산성환경 상태에서 방사선을 조사 받은 SCK 종양세포는 $G_2/M$ arrest 상태가 지속되며 이는 post-mitotic apoptosis를 억제한다고 추론하였다.

• 생명과학회지
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• 제23권6호
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• pp.832-837
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• 2013

본 연구에서는 생체 내 구성요소 및 에너지원으로서 중요한 역할을 하는 글루타민 결핍에 의한 인체 전립선 PC3 암세포의 증식에 관한 기전 연구를 실시하였다. 글루타민 결핍에 의한 PC3 세포의 증식억제는 세포주기 G2/M arrest와 연관성이 있었으나, apoptosis 유발 현상은 관찰되지 않았다. 글루타민 결핍에 의한 G2/M arrest는 전사 및 번역 수준에서 Cdc2, cyclin A 및 cyclin B1의 발현 억제 및 p53 비의존적인 p21(WAF1/CIP1)의 발현 증가와 연관성이 있었다. 아울러 글루타민 결핍은 Chk1 및 Chk2의 인산화를 증가시켰으나, Cdc25C의 인산화는 감소시켰다. 본 연구의 결과는 글루타민 결핍에 의한 PC3 세포의 증식억제가 apoptosis 유발과는 상관없이 G2/M arrest를 유발시킨다는 첫 번째 증거이다.

• Natural Product Sciences
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• 제19권2호
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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.