• Journal of Microbiology
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• 제37권2호
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• pp.90-96
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• 1999

The core protein of the hepatitis C virus (HCV) is a multifunctional protein. The HCV core protein was reported to regulate cellular gene expression and transform primary rat embryo fibroblast cells. However, the role of the core protein in the pathogenesis of HCV-associated liver diseases is not well understood. To investigate the functional role of the core protein in cytophathogenicity, we have constructed stable expression systems of full length or truncated HCV core protein lacking the C-terminal hyderophobic domains and established HepG2 cell clones constitutively expressing the core protein. The full length core protein was localized in the cytoplasm and the C-terminal truncated core protein was localized in the nucleus. HepG2 cells expressing nuclear, truncated core protein showed elevated cell death during cultivation compared to untransfected cells and full length core-expressing cells. In the treatment with bleomycin, both cell clones expressing full length or truncated core protein appeared to be more sensitive to blemoycin than the parental HepG2 cells. These results suggest that the core protein may play a role in HCV pathogenesis promoting apoptotic cell death of infected cells.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1310-1316
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• 2005

To evaluate the toxicological properties of human cytochrome P450 2E1 (CYP2E1) induced by ethanol and possible protective effects of various green tea catechins on alcohol-induced toxicity, transfected HepG2 cells that stably and constitutively express human CYP2E1 were established using the recombinant retroviral expression vector. Exposure of the CYP2E1-expressing HepG2 cells to high concentration of ethanol (200 mM) for 5 days resulted in a more than $50\%$ increase of cytotoxicity, assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction, lactate dehydrogenase (LDH) release, and reactive oxygen species (ROS) production, and loss of normal morphology, in comparison with HepG2 cells containing control vector. Treatment of the cells with various catechins increased cell viability by more than 2-fold. (-)-Epicatechin gallate and(-)-catechin gallate at the lowest concentration ($5\;{\mu}M$) attenuated cell death induced CYP2E1 by $60-65\%$. Therefore, the results showed that the catechins, including epimerized catechins, have strong protective effects against alcohol-induced CYP2E1 toxicity, and it is correlated with antioxidant effect.

• KSBB Journal
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• 제30권4호
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• pp.175-181
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• 2015

Cells proliferate via repeating process that growth and division. This process is G1, S, G2 and M four phases consists. Monitoring the progression of the cell cycle is a specific step that to be a continuous process is repeated to adjust the start of the next step. At this time, this process is called a Checkpoint. Currently, there are three known checkpoints that G1-S phase, G2-M phase, and the M phase. In this study, we confirmed that cell cycle arrest effects by ethanol extracts of Artemisia annua Linne (AAE) in Hep3B liver cancer cells. AAE was regulated proteins which involved in cell cycle such as pAkt, pMDM2, p53, p21, pCDK2 (T14/Y15). AAE induced cell cycle arrest in G1 checkpoint through phosphorylation of CDK2. Akt and p53 upstream is inhibited by AAE and p53 activated by non-activated pMDM2, p53 inhibitor. Thereby, activated p53 is transcript to p21 and activated p21 protein is combined with Cyclin E-pCDK2 complex. Therefore, we confirmed that AAE-induced cell cycle arrest was occurred by p21-Cyclin E-pCDK2 complex by inhibition of pAkt signal. Because of this cell cycle can't pass to S phase from G1 phase.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.43-53
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• 2019

The anticancer activity of guava (Psidium guajava L.) leaf extract (GLE) occurs via the induction of apoptosis in cancer cells. However, the mechanism behind GLE-induced apoptosis in the human hepatocellular carcinoma cell line HepG2 remains unclear. In the present study, we investigated the apoptotic effects and mechanism of action of GLE in cultured HepG2 cells. The results showed that GLE induced reactive oxygen species (ROS) synthesis and disrupted the mitochondrial membrane potential (${\Delta}{\Psi}m$). Moreover, GLE increased the expression of apoptotic pathway proteins, such as the cleaved forms of caspase-3, -8, and -9; the translocation of Bax and cytochrome c (cyt-c) from the mitochondria to the cytosol; and the downregulation of Bcl-2. In addition, p53 protein expression was increased upon GLE treatment. These observations indicate that the GLE-induced apoptosis in HepG2 cells is mediated by mitochondrial ROS generation, followed by caspase activation and cyt-c release, suggesting that GLE may be a promising candidate for the development of novel drugs for the treatment of liver cancers.

• 생명과학회지
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• 제20권6호
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• pp.877-884
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• 2010

본 연구에서는 군소내장을 각 용매별로 분획하여 암세포 성장 억제 효과와 quinone reductase (QR) 유도 활성증가 효과를 알아보았다. 간암 세포인 HepG2, 유방암 세포주인 MCF-7, 대장암 세포주인 HT-29 그리고 피부암 세포주인 B16-F10 를 이용하여 암세포 성장 억제 효과를 실험한 결과 모든 세포주에서 AKMM층에서 농도 의존적으로 가장 높은 암세포 성장 억제 효과를 나타내었다. 그리고 다음으로 AKMB층, AKMH층 및 AKMA층의 순이었다. 그리고 4종의 암세포주 중에서 B16-F10 세포주가 가장 높은 암세포 성장 억제 효과를 나타내어 특히 피부암에 대한 예방효과가 기대되어진다. 또한 암 예방 효과를 알아보기 위하여 4종의 암세포 중 유일하게 quinone reductase를 가지고 있는 인체 간암세포주인 HepG2를 이용하여 QR 유도 활성 증가 효과를 측정한 결과, 암세포 성장 억제 효과에 있어서 가장 높은 효과를 나타낸 AKMM층에서 가장 높은 QR 유도 활성 증가 효과를 나타내었다. 그러나 다른 분획층에서는 QR 유도 활성 증가 효과를 거의 볼 수 없었다. 이상으로 암세포 성장 억제 효과와 QR 유도 활성 효과에서 모두 methanol 분획층인 AKMM층에서 가장 높게 나타났으므로 이 분획층에 유효한 생리활성 물질이 함유되어 있을 가능성이 추정되어진다. 따라서 폐기되어지는 군소부산물인 내장을 이용한 암 예방 관련 기능성 식품의 개발 가능성이 기대되어지며, 이를 위한 AKMM분획층에 대한 더욱더 심도 높은 집중적인 연구가 요구되어진다.

• 한국식품과학회지
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• 제34권4호
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• pp.688-693
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• 2002

천연물을 이용하여 생리활성이 있는 성분을 추출 분리하여 그 유효 성분을 탐색함으로써 질병 예방 및 치료제로 이용하고자 하는 연구가 최근 활발히 진행되고 있다. 본 연구에서는 예부터 혈액 순환을 돕고, 지혈 작용에 효과가 있는 것으로 알려져 있는 식탁에 상용되는 야채인 부추를 이용하여 4종의 인체 암세포주인 HepG2, HeLa, MCF7 및 SK-N-MC를 이용하여 암세포 증식억제 및 암예방 QR 유도활성 효과를 측정하였다. MTT assay를 이용한 암세포 증식억제 실험 결과, 4종의 암세포주 모두 ethylether층인 ATMEE에서 아주 높은 농도 의존적이 암세포 증식억제 효과를 보였다. 즉 본 실험에 사용된 인체 암세포주 4종에서 시료의 농도가 $150\;{\mu}g/mL$일 때 각 세포주 모두 약 90% 이상의 높은 암세포 증식억제 효과가 나타났으며, 특히 신경아종세포주인 SK-N-MC 에서는 ethylether층의 시료 농도를 다른 층을 첨가시의 농도보다 적은 $100\;{\mu}g/mL$ 첨가에서도 이미 99.8%의 아주 높은 암세포 증식억제 효과를 나타내었다. 또 신경아종세포인 SK-N-MC에서는 ethylacetate층인 ATMEA의 경우에서도 최종 첨가 시료농도를 $200\;{\mu}g/mL$ 첨가했을 때 이미 91%의 높은 암세포 증식억제 효과가 나타났다. 암예방 quinone reductase(QR) 유도활성을 측정한 결과, 시료의 butanol 분획물 ATMB를 $50\;{\mu}g/mL$ 첨가했을 때 시료무처리구인 대조군을 1.0으로 한 경우 암예방 QR유도 효과가 아주 높은 3.92배의 활성이 나타났다. 본 연구 결과, 인체암세포 4종류에 대한 암세포 증식억제(cytotoxicity) 효과는 부추의 ethylether 분배층(ATMEE)에서 제일 뚜렷하였고, 암예방 QR 유도활성 효과는 butanol 분배층(ATMB)에서 가장 유도효과가 좋았다. 나아가 단계적인 생리활성 물질의 분리 동정이 계속 이루어져야 할 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제27권6호
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• pp.540-552
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• 2019

To determine the chemopreventive potential of alyssin and iberin, the in vitro anticancer activities and molecular targets of isothiocyanates (ITCs) were measured and compared to sulforaphane in hepatocellular carcinoma cell HepG2. The SR-FTIR spectra observed a similar pattern vis-a-vis the biomolecular alteration amongst the ITCs-treated cells suggesting a similar mode of action. All of the ITCs in this study cause cancer cell death through both apoptosis and necrosis in concentration dependent manner ($20-80{\mu}M$). We found no interactions of any of the ITCs studied with DNA. Notwithstanding, all of the ITCs studied increased intracellular reactive oxygen species (ROS) and suppressed tubulin polymerization, which led to cell-cycle arrest in the S and $G_2/M$ phase. Alyssin possessed the most potent anticancer ability; possibly due to its ability to increase intracellular ROS rather than tubulin depolymerization. Nevertheless, the structural influence of alkyl chain length on anticancer capabilities of ITCs remains inconclusive. The results of this study indicate an optional, potent ITC (viz., alyssin) because of its underlying mechanisms against hepatic cancer. As a consequence, further selection and development of effective chemotherapeutic ITCs is recommended.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.963-967
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• 2014

Previous studies have suggested anti-tumor effects of asiatic acid in some human cancer cell lines. This agent is reported to increase the levels of $p21^{WAF1/CIP1}$ in human breast cancer cell lines. However, the molecular mechanisms have not been established. Here we report that asiatic acid up-regulates $p21^{WAF1/CIP1}$ protein expression but not the level of $p21^{WAF1/CIP1}$ mRNA in HepG2 human hepatoma cells. Furthermore, we found that the asiatic acid induced increase of $p21^{WAF1/CIP1}$ protein was associated with decreased phosphorylation (ser-146) of $p21^{WAF1/CIP1}$. Knockdown of NDR1/2 kinase, which directly phosphorylates $p21^{WAF1/CIP1}$ protein at ser-146 and enhances its proteasomal degradation, increased the levels of $p21^{WAF1/CIP1}$ protein and eliminated the regulation of $p21^{WAF1/CIP1}$ stability by asiatic acid. At the same time, the expression of NDR1/2 kinase decreased during treatment with asiatic acid in HepG2 cells. Moreover, asiatic acid inhibited the proliferation of HepG2 cells, this being attenuated by knockdown of $p21^{WAF1/CIP1}$. In conclusion, we propose that asiatic acid inhibits the expression NDR1/2 kinase and promotes the stability of $p21^{WAF1/CIP1}$ protein through attenuating NDR1/2 dependent phosphorylation of $p21^{WAF1/CIP1}$ in HepG2 cells.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1332-1336
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• 2008

The water extract of Saururus chinensis was investigated for oxygen radical absorbance capacity (ORAC), reducing capacity, metal chelating activity, and intracellular antioxidant activity using HepG2 cell. When 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) was used for the generation of peroxyl radicals in vitro, S. chinensis extract (SC-E) showed the strong and concentration-dependent scavenging activity through donating protons which could be explained by its reducing property. When hydroxyl radicals were generated in vitro through the addition of $Cu^{2+}$ and $H_2O_2$, SC-E demonstrated the antioxidant activity depending on its concentration. In HepG2 cell model, most of intracellular oxidative stress generated by AAPH was efficiently removed by SC-E. However, when $Cu^{2+}$ without $H_2O_2$ was used as an oxidant in the intracellular assay, SC-E partially reduced the oxidative stress caused by $Cu^{2+}$ in cellular antioxidant activity assay system. These results indicate that SC-E could be utilized for the development of functional foods as antioxidant resource in the near future.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.1829-1832
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• 2013

In the present study, investigations were carried out to screen the anticancer activities of fenugreek seed oil against cancer cell lines (HEp-2, MCF-7, WISH cells), and a normal cell line (Vero cells). Cytotoxicity was assessed with MTT and NRU assays, and cellular morphological alterations were studied using phase contrast light microscopy. All cells were exposed toi 10-1000 ${\mu}g/ml$ of fenugreek seed oil for 24 h. The results show that fenugreek seed oil significantly reduced the cell viability, and altered the cellular morphology in a dose dependent manner. Among the cell lines, HEp-2 cells showed the highest decrease in cell viability, followed by MCF-7, WISH, and Vero cells by MTT and NRU assays. Cell viability at 1000 ${\mu}g/ml$ was recorded as 55% in HEp-2 cells, 67% in MCF-7 cells, 75% in WISH cells, and 86% in Vero cells. The present study provides preliminary screening data for fenugreek seed oil pointing to potent cytotoxicity against cancer cells.