• 한국환경성돌연변이발암원학회지
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• 제9권1호
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• pp.23-32
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• 1989

Chinese hamster ovary (CHO)-K1 cells echibited a differential sensitivity in the process of DNA repair synthesis induced by ethyl methanesulfonate (EMS) or bleomycin (BLM) in relation to cell cycle. Two assays were employed in this study: alkaline elution and unscheduled DNA synthesis. The post-treat-ment with aphidicolin (APC), an inhibitor of DNA polymerase alpha, inhibited DNA repair synthesis induced by EMS in G2 phase, while APC did not show any effect on BLM-induced DNA repair synthesis in all phases. On the other hands, the 2', 3'-dideoxythymidine (ddTTP), an inhibitor of DNA polymerase beta, inhibited DNA repair synthesis induced by EMS or BLM in both of G1 and G2 phases. These results suggested that the involvement of DNA polymerase alpha and beta in DNA repair was dependent on cell stage or used chemical agent.

• 한국식품과학회지
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• 제51권4호
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• pp.393-397
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• 2019

Persimmon leaf extract (PSE) 는 HepG2 인간 간암 세포에서 proteasome의 활성과 $NF-{\kappa}B$ 활성화를 억제하였고 cell cycle에서 G2/M기와 sub-G1기의 cell population을 유의하게 증가시켰다. 이러한 결과는 PSE의 식물생리활성물질을 proteasome 활성 억제제로 개발할 수 있는 가능성을 제시한다.

• Molecules and Cells
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• 제27권3호
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• pp.345-350
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• 2009

We previously reported that flavone induces embryonic lethality in Caenorhabditis elegans, which appeared to be the result of cell cycle arrest during early embryogenesis. To test this possibility, here we examined whether flavone inhibits the activity of a key cell cycle regulator, CDC-25.1 in C. elegans. A gain-of-function cdc-25.1 mutant, rr31, which exhibits extra cell divisions in intestinal cells, was used to test the inhibitory effects of flavone on CDC-25 activity. Flavone inhibited the extra cell divisions of intestinal cells in rr31, and modifications of flavone reduced the inhibitory effects. The inhibitory effects of flavone on CDC-25.1 were partly, if not completely, due to transcriptional repression.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.9-13
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• 2001

Genistein, a natural isoflavonoid phytoestrogen, is a strong inhibitor of protein tyrosine kinase and DNA topoisomerase II activities. Genistein has been shown to have anticancer proliferation, differentiation and chemopreventive effects. In the present study, we have addressed the mechanism of action by which genistein suppressed the proliferation of p53-null human prostate carcinoma cells.(omitted)

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.33-45
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• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bel-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MIT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG ($2{\mu}M$) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.

• 한국식품영양과학회지
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• 제31권2호
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• pp.329-332
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• 2002

본 연구는 사람의 간암세포인 HepG2 세포를 대상으로 강력한 암 예방 효과물질을 함유하고 있을 것으로 추측되는 향버섯 메탄올 추출물의 암세포 성장 저해 효과를 검토하고 또한 암세포 성장 억제 효과의 분자생물학적 기전을 파악하기 위하여 암세포주의 세포주기 조절인자들의 발현을 조사하였다. 향버섯 메탄을 추출물의 HePG2세포에 대한 성장 저해 효과를 MTT assay로 검토한 결과 높은 암세포 성장 저해 효과를 나타내었으며 사람의 정상 간세포인 Chang cell에서는 세포독성이 나타나지 않았다. 또한 향버섯 추출물의 작용으로 HepG2 세포에서 cyclin A와 Dl 단백질의 발현이 억제 되었으며 cyclin Bl 단백질의 발현은 증가하는 경향을 나타내었다. 그리고 암 억제 단백질인 p53의 발현은 전반적으로 증가되었으며, 이와 대조적으로 PCNA 단백질은 감소하는 경향을 나타내었고 세포분열 억제 단백질 p27의 발현은 증가 하는 경향을 나타내었다. 이러한 결과로 볼 때 향버섯 메탄올 추출물은 간암세포의 세포주기 중 Gl기 에서 S기로의 진행을 조절하는 인자인 cyclin A와 cyclin Dl 발현을 억제시키고 p53, p27 단백질을 활성화 시킴과 동시에 PCNA 작용을 억제 함으로써 세포주기 중 Gl/S기 차단을 유도하여 암세포 증식을 억제한 것으로 추정된다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권5호
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• pp.299-304
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• 2010

Losartan is a selective angiotensin II (Ang II) type 1 ($AT_1$) receptor antagonist which inhibits vascular smooth muscle cells (VSMCs) contraction and proliferation. We hypothesized that losartan may prevent cell proliferation by activating AMP-activated protein kinase (AMPK) in VSMCs. VSMCs were treated with various concentrations of losartan. AMPK activation was measured by Western blot analysis and cell proliferation was measured by MTT assay and flowcytometry. Losartan dose- and time-dependently increased the phosphorylation of AMPK and its downstream target, acetyl-CoA carboxylase (ACC) in VSMCs. Losartan also significantly decreased the Ang II- or 15% FBS-induced VSMC proliferation by inhibiting the expression of cell cycle associated proteins, such as p-Rb, cyclin D, and cyclin E. Compound C, a specific inhibitor of AMPK, or AMPK siRNA blocked the losartan-induced inhibition of cell proliferation and the $G_0/G_1$ cell cycle arrest. These data suggest that losartan-induced AMPK activation might attenuate Ang II-induced VSMC proliferation through the inhibition of cell cycle progression.

• Radiation Oncology Journal
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• 제28권3호
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• pp.147-154
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• 2010

목 적: 대장암 세포에서 epidermal growth factor receptor (EGFR) 저해제인 nimotuzumab에 의한 방사선 민감도 증진 효과를 살펴보고자 한다. 대상 및 방법: 총 4종류의 인간 유래 대장암 세포주인 HCT-8, LoVo, WiDr, HCT-116를 nimotuzumab과 방사선을 병합 처리한 후 세포증식, 생존율, 세포주기 진행에 미치는 영향을 MTT, clonogenic survival assay, flow cytometry와 western blot을 통해 분석하였다. 결 과: 대장암 세포주에서 nimotuzumab에 의해 EGFR 인산화가 억제됨을 확인하였고 이러한 조건에서 nimotuzumab이 HCT-116을 제외한 나머지 3종류의 대장암 세포주의 방사선 민감도를 증진시킴을 확인하였다. 반면에, nimotuzumab은 방사선 조사와 무관하게 대장암 세포의 증식이나 세포 주기에는 아무런 영향을 미치지 않았다. 결 론: Nimotuzumab은 EGFR에 의한 세포 생존 신호 전달을 억제함으로써 대장암 세포의 방사선에 대한 민감도를 증가시켰다. 본 연구는 대장암의 방사선 치료에 EGFR 특이적 저해제인 nimotuzumab의 임상 적용 근거를 제공하였다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.90-90
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• 2003

The acetylation of histone is one of the mechanisms involved in the regulation of gene expression and is tightly controlled by two core enzymes, histone acetyltransferase (HAT) and deacetylase (HDAC). There are several reports that imbalance of HAT and HDAC activity is associated with abnormal behavior of the cells in morphology, cell cycle, differentiation, and carcinogenesis. Recently, an increasing number of structurally diverse HDAC inhibitors have been identified that inhibit proliferation and induce differentiation and/or apoptosis of tumor cells in vivo and in vitro. In this study, we have investigated the effects of novel HDAC inhibitors, IN2001 on ER positive and ER negative human breast cancer cell lines. The growth inhibition, cell cycle arrest and apoptosis of cells by HDAC inhibitors were determined using SRB assay, DNA fragmentation, and flow cytometry. We found that IN 2001 as well as Trichostatin A inhibited cell growth dose-dependently in both ER positive and ER negative human breast cancer cell lines. The growth inhibition with HDAC inhibitors was associated with profound morphological change. The result of cell cycle analysis after 24 h exposure of IN2001 showed G2-M cell cycle arrest in MCF-7 cell and apoptosis in T47D and MDA-MB-231 cell. In summary, IN2001 has antiproliferative effect on human breast cancer cells regardless of the expression of estrogen receptor. These findings heights the possibility of developing HDAC inhibitors as potential anticancer therapeutic agents for the treatment of breast cancer.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.180-180
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• 2003

The acetylation of histone is one of the mechanisms involved in the regulation of gene expression and is tightly controlled by two core enzymes, histone acetyltransferase (HAT) and deacetylase (HDAC). There are several reports that imbalance of HAT and HDAC activity is associated with abnormal behavior of the cells in morphology, cell cycle, differentiation, and carcinogenesis. Recently, an increasing number of structurally diverse HDAC inhibitors have been identified that inhibit proliferation and induce differentiation and/or apoptosis of tumor cells in vivo and in vitro. In this study, we have investigated the effects of novel HDAC inhibitors, IN2001 on ER positive and ER negative human breast cancer cell lines. The growth inhibition, cell cycle arrest and apoptosis of cells by HDAC inhibitors were determined using SRB assay, DNA fragmentation, and flow cytometry. We found that IN 2001 as well as Trichostatin A inhibited cell growth dose-dependently in both ER Positive and ER negative human breast cancer cell lines. The growth inhibition with HDAC inhibitors was associated with profound morphological change. The result of cell cycle analysis after 24 h exposure of IN2001 showed G2-M cell cycle arrest in MCF-7 cell and apoptosis in T47B and MDA-MB-231 cell. In summary, IN2001 has antiproliferative effect on human breast cancer cells regardless of the expression of estrogen receptor. These findings heights the possibility of developing HDAC inhibitors as potential anticancer therapeutic agents for the treatment of breast cancer.