• Radiation Oncology Journal
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• 제21권4호
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• pp.306-314
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• 2003

목적: K562 세포의 방사선에 의한 세포 사망은 mitotic catastrophe 현상이 위주로 나타나지만 herbimycin A (HMA)에 의하여 apoptosis 반응이 촉진되는 반면 genisteln에 의하여 두 가지 형태의 세포사망이 모두 억제된다. 본 연구에서는 HMA와 genistein에 의한 K562세포의 방사선 유도 세포주기 조절 변화와 세포 사망 양상의 연관성을 조사하였다. 대상 및 방법: 지수증식기의 KS62 세포에 6 MV 선형가속기(Clinac 1,m C, Varian)를 이용하여 200~300 cGy/min의 선량률로 10 Gy를 균일하게 조사하였다. HMA와 genistein은 각각 250 nM와 25$\mu$M농도로 방사선 조사 후 즉시 투여하였다. 실험에서는 세포주기, 오절인자의 발현 및 활성, 노화 및 분화정도 등에 있어서의 시간에 따른 변화를 조사하였다. 결과: 방사선 단독조사에서 KS62세포는 G2기의 정체를 보였으나 정상적인 053을 가지는 세포와는 달리 지속적인 세포주기의 정체를 보이지 않았다. G2정체가 유지되는 동안 cyclin Bl의 점진적인 증가를 관찰할 수 있었으며, 이는 염색체의 복제가 완료되지 않은 상태에서 M기로 진행하여 미성숙한 염색체 응축과 mitotic catastrophe 현상이 나타나는 것과 일치한다. 방사선 조사와 함께 HMA를 투여한 경우에는 G2정체가 빠르게 해소되었으며 동시에 Gl기에서 세포가 정체되는 양상을 보였다. 세포주기 조절인자 cdc2 kinase 활성 증가와 cyclln I와 A 발현 및 CDK2 활성의 감소 등의 현상으로 설명되며, 이는 apoptosis의 증가와 연관성을 갖는다. 반면 genistein의 경우에는 cyclin Bl과 떨cfsc 발현 및 cdc2활성이 모두 감소하는 등 G2정체를 계속 유지하였다. 이와 함께 방사선에 의한 노화와 megakaryocyte로의 분화도 지속되는 것을 관찰할 수 있었다. 결론: HMA와 genistein에 의한 KS62세포의 방사선 유도 세포사망의 변화는 세포주기 조절과 밀접하게 연관되어 있음을 확인하였다. 이는 다양한 방사선 유도 세포사망의 기전을 이해하는 데 독창적인 모델을 제공하며, 방사선을 이용한 암 치료법의 개발에 새로운 표적을 제공할 수 있을 것이다.

• 한국식품영양과학회지
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• 제41권7호
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• pp.907-913
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• 2012

포도, 대황, 사탕수수 등을 포함한 다양한 식물에서 발견되는 hydroxystilbene의 일종인 piceatannol은 암세포의 증식을 억제하고 apoptosis를 유발하는 것으로 알려져 있다. 본 연구에서는 AGS 인체위암세포를 대상으로 piceatannol에 의한 암세포 증식억제 과정에서 나타나는 또 다른 현상들을 조사하기 위하여 실시되었다. Piceatannol이 처리된 AGS 위암세포는 piceatannol의 처리 농도의 증가에 따라 생존율이 감소되었으며, 이는 세포주기 G1 arrest 유발과 연관이 있음을 MTT assay와 flow cytometry 분석을 통하여 확인하였다. Piceatannol에 의한 AGS 세포의 G1 arrest는 Cdks 및 cyclins의 발현 변화 및 Cdk 저해제인 p21의 발현을 전사 및 번역 수준에서 증가시켰으며, pRB 단백질의 인산화 감소 및 E2F1의 발현 억제와 연관성이 있었다. 아울러 piceatannol은 COX-2의 mRNA 및 단백질의 발현을 억제하였으나 COX-1의 발현에는 영향을 미치지 않았으며, piceatannol에 의한 COX-2의 발현억제는 PGE2의 생성 저하와 관련이 있었다. 본 연구의 결과는 piceatannol에 의한 세포주기 G1 arrest 유발이 COX-2의 선택적 발현 차단과 연관이 있음을 보여 주는 것이다.

• Experimental and Molecular Medicine
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• 제51권2호
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• pp.9.1-9.10
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• 2019

Mesangial cell proliferation has been identified as a major factor contributing to glomerulosclerosis, which is a typical symptom of diabetic nephropathy (DN). Lysophosphatidic acid (LPA) levels are increased in the glomerulus of the kidney in diabetic mice. LPA is a critical regulator that induces mesangial cell proliferation; however, its effect and molecular mechanisms remain unknown. The proportion of ${\alpha}-SMA^+/PCNA^+$ cells was increased in the kidney cortex of db/db mice compared with control mice. Treatment with LPA concomitantly increased the proliferation of mouse mesangial cells (SV40 MES13) and the expression of cyclin D1 and CDK4. On the other hand, the expression of $p27^{Kip1}$ was decreased. The expression of $Kr{\ddot{u}}ppel$-like factor 5 (KLF5) was upregulated in the kidney cortex of db/db mice and LPA-treated SV40 MES13 cells. RNAi-mediated silencing of KLF5 reversed these effects and inhibited the proliferation of LPA-treated cells. Mitogen-activated protein kinases (MAPKs) were activated, and the expression of early growth response 1 (Egr1) was subsequently increased in LPA-treated SV40 MES13 cells and the kidney cortex of db/db mice. Moreover, LPA significantly increased the activity of the Ras-related C3 botulinum toxin substrate (Rac1) GTPase in SV40 MES13 cells, and the dominant-negative form of Rac1 partially inhibited the phosphorylation of p38 and upregulation of Egr1 and KLF5 induced by LPA. LPA-induced hyperproliferation was attenuated by the inhibition of Rac1 activity. Based on these results, the Rac1/MAPK/KLF5 signaling pathway was one of the mechanisms by which LPA induced mesangial cell proliferation in DN models.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.34-42
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• 2019

Apigenin, a common natural product that is found in many plants and vegetables, has been reported to have many biological activities, including antioxidative, anti-inflammatory, and anticancer effects. The triple-negative breast carcinoma cell line MDA-MB-231 is known to be highly invasive and resistant to chemotherapy. In this study, we investigated the anticancer effect of apigenin on human MDA-MB-231 cells. First, the cytotoxicity of apigenin toward MDA-MB-231 cells was analyzed by MTT assay. Then, the cell cycle and apoptotic effects of apigenin were examined, and the molecular mechanism underlying its anticancer activity was explored. Apigenin inhibited the growth of the cells in a dose-dependent manner, correlating with the cell cycle arrest at the G2-M phase as well as an increase of early apoptosis. The cell-cycle inhibitory effect was highly associated with the increased expression of p21 and decreased expression of CDK6, cyclin D1, and cyclin B1. The induction of apoptosis by apigenin was associated with the upregulated expression of cleaved PARP and cleaved caspase-3, -7, and -9.

• Biomolecules & Therapeutics
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• 제19권2호
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• pp.187-194
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• 2011

Atherosclerosis and post-angiography restenosis are associated with intimal thickening and concomitant vascular smooth muscle cell (VSMC) proliferation. Obovatol, a major biphenolic component isolated from the Magnolia obovata leaf, is known to have anti-inflammatory and anti-tumor activities. The goal of the present study was to enhance the inhibitory effects of obovatol to improve its potential as a preventive or therapeutic agent in atherosclerosis and restenosis. Platelet-derived growth factor (PDGF)-BB-induced proliferation of rat aortic smooth muscle cells (RASMCs) was examined in the presence or absence of a newly synthesized obovatol derivative, OD78. The observed anti-proliferative effect of OD78 was further investigated by cell counting and [$^3H$]-thymidine incorporation assays. Treatment with 1-4 ${\mu}M$ OD78 dose-dependently inhibited the proliferation and DNA synthesis of 25 ng/ml PDGF-BB-stimulated RASMCs. Accordingly, OD78 blocked PDGF-BB-induced progression from the $G_0/G_1$ to S phase of the cell cycle in synchronized cells. OD78 decreased the expression levels of CDK4, cyclin E, and cyclin D1 proteins, as well as the phosphorylation of retinoblastoma protein and proliferating cell nuclear antigen; however, it did not change the CDK2 expression level. In addition, OD78 inhibited downregulation of the cyclin-dependent kinase inhibitor (CKI) $p27^{kip1}$. However, OD78 did not affect the CKI $p21^{cip1}$ or phosphorylation of early PDGF signaling pathway. These results suggest that OD78 may inhibit PDGF-BB-induced RASMC proliferation by perturbing cell cycle progression, potentially through $p27^{kip1}$ pathway activation. Consequently, OD78 may be developed as a potential anti-proliferative agent for the treatment of atherosclerosis and angioplasty restenosis.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1294-1298
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• 2014

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer representing 85% of lung cancer patients. Despite several EGFR-targeted drugs have been developed in the treatment of NSCLC, the clinical efficacy of these EGFR-targeted therapies is being challenged by the occurrence of drug resistance. In this regard, Hsp90 represents great promise as a therapeutic target of cancerous diseases due to its role in modulating and stabilizing numerous oncogenic proteins. Accordingly, inhibition of single Hsp90 protein simultaneously disables multiple signaling networks so as to overcome drug resistance in cancer. In this study, we synthesized a series of 11 butein analogues and evaluated their biological activities against gefitinibresistant NSCLC cells (H1975). Our study indicated that analogue 1h inhibited the proliferation of H1975 cells, down-regulated the expression of Hsp90 client proteins, including EGFR, Met, Her2, Akt and Cdk4, and upregulated the expression of Hsp70. The result suggested that compound 1h disrupted Hsp90 chaperoning function and could serve a potential lead compound to overcome the drug resistance in cancer chemotherapy.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1482-1489
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• 2009

In this study, we investigated the anti-proliferative effect of polysaccharides from Salicornia herbacea on HT-29 human colon cancer cells. Crude polysaccharides from S. herbacea (CS) were prepared by extraction with hot steam water, and fine polysaccharides from S. herbacea (PS) were obtained through further size exclusion chromatography. The anti-proliferative effect of CS and PS were measured using the MTS assay, apoptosis analysis, cell cycle analysis, and RT-PCR. HT-29 cells were treated with CS or PS at different dosages (0.5, 1, 2, 4 mg $ml^{-1}$) for 24 or 48 h. CS and PS inhibited proliferation and stimulated apoptosis of cells in a dose-dependent manner. Flow cytometric analysis after Annexin V-FITC and PI staining revealed that treatment with CS or PS increased total apoptotic death of cells to 24.99% or 91.59%, respectively, in comparison with the control (13.51 %). PS increased early apoptotic death substantially - up to 12 times more than the control. Treatment with CS or PS resulted in a concentration-dependent increase of the G2/M cell population of the cell cycle as determined by flow cytometry. G2/M arrest was induced significantly with the highest concentration (4 mg $ml^{-1}$) of PS. RT-PCR was performed to study the correlation between G2/M arrest and transcription of cell cycle control genes. The anti-proliferative activity of CS and PS was accompanied by inhibition of cyclin B1, and Cdc 2 mRNA. Moreover, both CS and PS induced expression of the p53 tumor suppressor gene and the Cdk inhibitor p21. These results suggest that polysaccharides from S. herbacea have anti-cancer activity in human colon cancer cells.

• Animal cells and systems
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• 제4권3호
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• pp.279-285
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• 2000

Vitamin E-succinate (VES) treatment of U937 human monoblasts induced cells to undergo apoptosis. After 96 h of VES treatment at 10 $\mu$/ml, more than 80% of cells appeared apoptotic. Evidence for apoptosis by VES was based on propidium iodide staining for detection of chromatin condensational fragmentation and electrophoretic DNA ladder formation. Western blot analyses showed a transient increase in Fas and p21 protein levels up to 48 h alter the VES treatment. Protein expression and activity of CDK1 and lamin B degradation were remarkably induced by VES, following the cleavage of caspase-3 after 48 h. The VES-induced apoptosis was found to involve activation of PKC as shown by increases in membrane translocation of PKC$\beat$II and PKC activity. Pretreatment of GF109203X (PKC inhibitor) prior to VES treatment almost completely inhibited the induction of apoptosis as assessed by blockage of VES-induced caspase-3 activity and DNA fragmentation. However, GF109203X h8d no effect on the VES-induced nitric oxide synthesis, which was required for monocvtic differentiation in our previous report (J Cell Sci 111, 435, 1998). Taken together, our data suggest that induction of apoptosis by VES in U937 cells occurs through activation of PKC-$\beat$II resulting in the activation of caspase-3 cascade and is independent of nitric oxide.

• 생명과학회지
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• 제15권5호
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• pp.726-733
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• 2005

Histone deacetylase (HDAC) 억제제가 새로운 항암치료제 후보물질로서 유용성이 높은 것으로 평가되지만, 아직까지 인체폐암세포에 관한 연구는 상대적으로 미미한 실정이다. 따라서 본 연구에서는 폐암세포에 미치는 HDAC 억제제의 항암작용 기전을 조사하기 위하여 A549 인체폐암세포주를 대상으로 암세포의 증식에 미치는 대표적인 HDAC 억제제인 tichostatin A (TSA)에 의한 영향을 세포주기 조절관련인자 중심으로 조사하였다. TSA의 처리에 의하여 A549 폐암세포의 증식은 처리 농도 의존적으로 억제되었으며, 심한 형태적 변형을 동반하였다. 저농도 처리군에서는 TSA 농도가 증가할수록 세포주기 G1기의 빈도가 증가하였으나, 고농도 처리군에서는 G2/M기에 속하는 세포의 빈도가 증가되었다. 또한 apoptosis 유발의 간접적인 지표가 되는 sub-G1기에 속하는 세포의 빈도 역시 TSA 처리 농도 의존적으로 매우 증가되었다. 이러한 TSA의 A549 폐암세포 증식억제 효과는 cyclins 및 CdkS의 발현 억제, 종양억제유전자인 p53 및 Cdks 억제제인 p21과 p27의 발현 증가와도 연관성이 있었다. TSA의 항암 기전을 규명하기 위해서는 더 많은 연구가 부가적으로 필요하겠지만, 본 연구의 결과들에 의하면 TSA는 강력한 인체폐암세포의 증식 억제 및 항암작용이 있음을 시사하여 준다고 할 수 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9915-9919
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• 2014

Lamellarin D (LamD) is a marine alkaloid with a pronounced cytotoxicity against a large panel of cancer cells, affecting cell growth and inducing apoptosis. However, the molecular mechanisms of action of this compound are poorly understood. In this study, the anticancer efficacy of LamD was investigated in human leukemia K562 cells. The results showed suppressed cell proliferation and induction of G0/G1-phase arrest,while expression of CDK1, and activity of smad3 and smad5 were reduced, but that of p27, p53 and STGC3 was increased. LamD induced cell apoptosis through activation of caspases-8/-3, inhibition of survivin and Bcl-2, suggesting that this compound may also act through a caspase-independent pathway. Moreover, LamD inhibited the secretion of TGF-${\beta}$, IL-$1{\beta}$, IL-6, IL-8 and other inflammatory cytokines and the transcriptional activity of transcription factor NF-${\kappa}B$ in human leukemia K562 cells.Taken together, our results suggest that LamD-mediated inhibition of leukemia cell proliferation may be related to the induction of apoptosis and the regulation of cell cycle, tumor-related gene expression and cytokine expression, which may provide a new way of thinking for the treatment leukemia.