• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2004년도 춘계학술대회
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• pp.71-71
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• 2004

• Radiation Oncology Journal
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• 제18권1호
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• pp.51-58
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• 2000

목적 : 방사선에 의해 유도되는 apoptosis에 내성을 가진 세포로 알려진 KS62 세포를 대상으로, PTK inhibitors인 herbimycin A와 genistein을 이용한 방사선에 의한 apoptosls의 내성 기전을 연구하고자 하였다. 대상 및 방법 : 6 MV 체외 X-선 방사선 치료기를 이용하여 200$\~$300 cGy/min의 선량률로 10 Gy의 X-선을 세포에 균일하게 조사하였다. Apoptosis의 관찰은 래arose gel electrophoresis를 이용하여 DNA frgmentation의 지표인 ladder를 관찰하였고, TUNEL 염색을 이용하여 정량 분석을 시행하였다. Western blot 방법으로 apoptosls 관련 유전 단백인 bel-2, bel-X$_L$ 및 bax들의 발현을 관찰하였다. 방사선 조사 및 약물 처치 후의 세포 주기 분석은 flow cytometry로 분석하였다. 결과 : Agarose gel electrophoresis 실험에서 방사선을 조사하지 않은 K562 세포와 방사선을 10 Gy 조사한 세포를 48시간에 걸쳐 12시간 간격으로 관찰하였을 때 DNA fragmentation를 관찰할 수 있었다. 이러한 현상은 genistein을 투여한 세포들에서도 동일한 현상을 관찰할 수 있었지만, 방사선 조사 후 herbimycin A를 투여한 세포들에서는 48 시간째 확연한 DNA fragmentation을 관찰할 수 있었다. 이를 TUNEL assay에서 정량적으로 확인하였다. 방사선만조사한 세포들과 방사선과 genistein 투여 후 48시간째 관찰한 세포들에서는 10$\%$, 미만의 apoptosis 양성 세포의 빈도를 관찰할 수 있었지만, 방사선 조사 후 herbimycin A를 투여한 세포들에서는 30$\~$35$\%$ 빈도로 apoptosis 양성 세포들이 관찰되었다. Western blot analysis에서 bcl-2의 경우 방사선을 조사하지 않았던 대조군에 비하여 전체적인 발현은 증가되었지만 방사선 및 약제간의 발현의 차이는 없었다. 그 외 bcl-X$_{L}$과 bax는 대조군에 비해 방사선 및 약제간의 발현의 차이를 관찰할 수 없었다. KS62 세포에 방사선을 10 Gy 조사하였을 때 나타나는 세포 주기의 변화는 시간이 경과함에 따라 전형적인 G2/M block의 소견을 보였다. 이러한 소견은 genistein을 투여했을 경우에는 특별한 변화를 보이지 않지만, herbimycin A를 투여했을 경우에는 12시간째부터 G2/M block이 소실되면서 세포가 세포 주기를 재 순환하는 양상을 보였고, 48시간째 관찰한 소견에서는 G2/M block이 거의 소실된 양상을 띠었다. 이러한 소견을 토대로 apoptosis 유도와의 상호 연관성을 유추할 수 있었다. 결론 : herbimycin A는 방사선에 의해 유도되는 apoptosis가 억제된 K562 세포에서 apoptosis를 유도할 수 있었다. 이러한 유도 기전에 apoptosis 관련 유전 단백들인 bcl-2, bcl-X$_{L}$ 및 bax와 관련된 영향은 관찰되지 않았다. 세포 주기의 분석에서 G2/M block의 해소와 apoptosis 유도와의 연관성을 유추할 때, 세포 주기 관련 인자들에 대한 연구가 방사선에 의한 apoptosis의 내성의 극복 및 방사선에 의한 세포의 감수성 조절 약제로서의 역할에 이바지할 것으로 생각한다.

• Biomolecules & Therapeutics
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• 제28권2호
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• pp.184-194
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• 2020

Histone deacetylase (HDAC) inhibitors represent a novel class of anticancer agents, which can be used to inhibit cell proliferation and induce apoptosis in several types of cancer cells. In this study, we investigated the anticancer activity of MHY4381, a newly synthesized HDAC inhibitor, against human prostate cancer cell lines and compared its efficacy with that of suberoylanilide hydroxamic acid (SAHA), a well-known HDAC inhibitor. We assessed cell viability, apoptosis, cell cycle regulation, and other biological effects in the prostate cancer cells. We also evaluated a possible mechanism of MHY4381 on the apoptotic cell death pathway. The IC₅₀ value of MHY4381 was lower in DU145 cells (IC₅₀=0.31 µM) than in LNCaP (IC₅₀=0.85 µM) and PC-3 cells (IC₅₀=5.23 µM). In addition, the IC₅₀ values of MHY4381 measured in this assay were significantly lower than those of SAHA against prostate cancer cell lines. MHY4381 increased the levels of acetylated histones H3 and H4 and reduced the expression of HDAC proteins in the prostate cancer cell lines. MHY4381 increased G2/M phase arrest in DU145 cells, and G1 arrest in LNCaP cells. It also activated reactive oxygen species (ROS) generation, which induced apoptosis in the DU145 and LNCaP cells by increasing the ratio of Bax/Bcl-2 and releasing cytochrome c into the cytoplasm. Our results indicated that MHY4381 preferentially results in antitumor effects in DU145 and LNCaP cells via mitochondria-mediated apoptosis and ROS-facilitated cell death pathway, and therefore can be used as a promising prostate cancer therapeutic.

• 생명과학회지
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• 제24권1호
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• pp.92-97
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• 2014

Cordycepin은 Cordyceps militaris에서 처음 유래된 nucleoside adenosine 유도체의 일종으로 면역증강 및 항암활성을 포함한 다양한 약리 기능이 있는 것으로 알려져 있다. 본 연구에서는 LNCap 인체 전립선 암세포 모델을 이용하여 cordycepin에 의한 항암활성 기전을 연구하였다. Cordycepin 처리에 따라 LNCap 세포는 처리 농도 의존적으로 증식이 억제되었으며, 이는 apoptosis 유발과 연관성이 있음을 poly ADP-ribose polymerase의 단편화 현상과 Annexin V 염색에 의한 정량적 분석으로 확인하였다. Cordycepin 처리에 따른 flow cytometric analysis 결과로서 cordycepin이 세포주기 G2/M기 정체 현상을 유발하였음을 알 수 있었으며, 이는 cyclin B1 및 cyclin A의 발현 감소와 연관성이 있었다. 또한 cordycepin이 처리된 LNCap 세포에서 cyclin-dependent kinase (CDK) inhibitor p21Waf1/Cip1의 발현이 증가되었지만, CDK2, CDC2 및 Cdc25C의 발현에는 큰 영향을 미치지 않았으며, cordycepin에 의하여 증가된 p21 단백질은 CDK2 및 CDC2와의 복합체를 형성하고 있었다. 본 연구의 결과는 LNCap 전립선 암세포에서 cordycepin에 의한 G2/M 및 apoptosis 유발은 p53 비존적인 CDK inhibitor p21의 발현 증가가 중요한 역할을 하고 있음을 보여주는 것이다.

• Biomolecules & Therapeutics
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• 제31권1호
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• pp.73-81
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• 2023

Sirtuins (SIRTs) belong to the nicotinamide adenine dinucleotide (NAD+)-dependent class III histone deacetylase family. They are key regulators of cellular and physiological processes, such as cell survival, senescence, differentiation, DNA damage and stress response, cellular metabolism, and aging. SIRTs also influence carcinogenesis, making them potential targets for anticancer therapeutic strategies. In this study, we investigated the anticancer properties and underlying molecular mechanisms of a novel SIRT1 inhibitor, MHY2251, in human colorectal cancer (CRC) cells. MHY2251 reduced the viability of various human CRC cell lines, especially those with wild-type TP53. MHY2251 inhibited SIRT1 activity and SIRT1/2 protein expression, while promoting p53 acetylation, which is a target of SIRT1 in HCT116 cells. MHY2251 treatment triggered apoptosis in HCT116 cells. It increased the percentage of late apoptotic cells and the sub-G1 fraction (as detected by flow cytometric analysis) and induced DNA fragmentation. In addition, MHY2251 upregulated the expression of FasL and Fas, altered the ratio of Bax/Bcl-2, downregulated the levels of pro-caspase-8, -9, and -3 proteins, and induced subsequent poly(ADP-ribose) polymerase cleavage. The induction of apoptosis by MHY2251 was related to the activation of the caspase cascade, which was significantly attenuated by pre-treatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, MHY2251 stimulated the phosphorylation of c-Jun N-terminal kinase (JNK), and MHY2251-triggered apoptosis was blocked by pre-treatment with SP600125, a JNK inhibitor. This finding indicated the specific involvement of JNK in MHY2251-induced apoptosis. MHY2251 shows considerable potential as a therapeutic agent for targeting human CRC via the inhibition of SIRT1 and activation of JNK/p53 pathway.

• Nutritional Sciences
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• 제8권1호
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• pp.16-22
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• 2005

The present study examined the effects of cyclooxygenase-2 (COX-2) inhibitor celecoxib or soy-isoflavones in the presence of estrogen on apoptosis related gene expression, COX-2 and mapkinase in 48-week old female rats. Expressions of bel-2 and bax proteins, which are known to be involved in the regulation of apoptosis, were investigated in mammary glands and heart tissues. The elevated expression of bel-2 expression was observed in mammary glands of celecoxib supplemented rats as well as soy-isoflavones. The mammary glands bel-2/bax ratio was found to be higher in celecoxib or soy-isoflavones supplemented rats. However, in heart tissues, expression of bel-2 and bax was in the order of control, celecoxib and soy-isoflavones. The up-regulation of COX-2 was observed in celecoxib or soy-isoflavones in mammary glands. 'The similar trend was not displayed with the mapkinase expression. In heart tissues, the down-regulation of COX-2 as well as mapkinase was observed in celecoxib or soy-isoflavones supplemented rats. Soy-isoflavones and celecoxib both had a similar regulatory pattern of bel-2, bax and COX-2 in mammary glands, and in heart tissues, only COX-2 exhibited a similar down-regulatory properly. These findings revealed that in estrogen sufficient state, celecoxib and soy-isoflavones might not exhibit proapoptotic potential or COX-2 inhibition in normal mammary glands.

• Parasites, Hosts and Diseases
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• 제48권4호
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• pp.285-290
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• 2010

Tyrosine kinases are one of the most important regulators for intracellular signal transduction related to inflammatory responses. However, there are no reports describing the effects of tyrosine kinases on neutrophil apoptosis induced by Entamoeba histolytica, In this study, isolated human neutrophils from peripheral blood were incubated with live trophozoites in the presence or absence of tyrosine kinase inhibitors. Entamoeba-induced receptor shedding of CD16 and PS externalization in neutrophils were inhibited by pre-incubation of neutrophils with the broad-spectrum tyrosine kinase inhibitor genistein or the Src family kinase inhibitor PP2. Entamoeba-induced ROS production was also inhibited by genistein or PP2, Moreover, genistein and PP2 blocked the phosphorylation of ERK and p38 MAPK in neutrophils induced by E. histolytica. These results suggest that Src tyrosine kinases may participate in the signaling event for ROS-dependent activation of MAPKs during neutrophil apoptosis induced by E. histolytica.

• International Journal of Oral Biology
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• 제40권2호
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• pp.85-91
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• 2015

Quercetin is a natural flavonoid phytochemical that is extracted from various plants. Having an advantages due to its varied biological properties, such as anti-inflammatory, anti-viral, anti-oxidant, and anti-cancer effects, quercetin is used to treat many diseases. Recently, it has been reported that autophagy inhibition may play a key role in anti-cancer therapy. Therefore, in this study, we investigated the molecular mechanisms and anti-cancer effects of quercetin in human osteosarcoma cells via autophagy inhibition. We ascertained that quercetin inhibited cell proliferation and induced cell death, these process is demonstrated that apoptosis via the mitochondrial pathway and the caspase cascade. Quercetin also induced autophagy which was inhibited by 3-MA, autophagy inhibitor and the blockade of autophagy promoted the quercetin-induced apoptosis, confirming that autophagy is a pro-survival process. Thus, these findings demonstrate that quercetin is an effective anti-cancer agent, and the combination of quercetin and an autophagy inhibitor should enhance the effect of anti-cancer therapy.

• Biomolecules & Therapeutics
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• 제31권4호
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• pp.425-433
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• 2023

During liver injury, hepatic stellate cells can differentiate into myofibroblast-like structures, which are more susceptible to proliferation, migration, and extracellular matrix generation, leading to liver fibrosis. Anaerobic glycolysis is associated with activated stellate cells and glyceraldehyde (GA) is an inhibitor of glucose metabolism. Therefore, this study aimed to investigate the anti-fibrotic effects of GA in human stellate LX-2 cells. In this study, we used cell viability, morphological analysis, fluorescence-activated cell sorting (FACS), western blotting, and qRT-PCR techniques to elucidate the molecular mechanism underlying the anti-fibrotic effects of GA in LX-2 cells. The results showed that GA significantly reduced cell density and inhibited cell proliferation and lactate levels in LX-2 cells but not in Hep-G2 cells. We found that GA prominently increased the activation of caspase-3/9 for apoptosis induction, and a pan-caspase inhibitor, Z-VAD-fmk, attenuated the cell death and apoptosis effects of GA, suggesting caspase-dependent cell death. Moreover, GA strongly elevated reactive oxygen species (ROS) production and notably increased the phosphorylation of ERK and JNK. Interestingly, it dramatically reduced α-SMA and collagen type I protein and mRNA expression levels in LX-2 cells. Thus, inhibition of ERK and JNK activation significantly rescued GA-induced cell growth suppression and apoptosis in LX-2 cells. Collectively, the current study provides important information demonstrating the anti-fibrotic effects of GA, a glycolytic metabolite, and demonstrates the therapeutic potency of metabolic factors in liver fibrosis.

• 생명과학회지
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• 제28권7호
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• pp.778-785
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• 2018

오토파지(Autophagy, 자가포식)는 복합적인 신호과정으로, 암세포의 증식 억제 및 항암제에 대한 내성 획득의 상반적인 조절에도 관여한다. 오토파지의 암 억제 효과는 아팝토시스(apoptosis)와 상호협력으로 오토파지성세포 사멸의 유도에 기인된다. 본 연구에서는 NSAID 계열의 다기능 약물인 celecoxib (CCB)이 아팝토시스 및 오토파지의 복합적인 유도로, 항암제 다제내성(multidrug resistant, MDR) 암세포의 Hsp90 molecular chaperone inhibitor인 17-allylamino-17-demethoxygeldanamycin (17-AAG)에 대한 감수성을 증가시키는 활성이 있음을 밝혔다. 17-AAG 처리에 의한 항암제 다제내성 암세포의 변이형p53 분해 및 caspase-3 활성은 CCB 처리로 촉진되었다. MCF7-MDR세포에서 Z-DEVD-FMK 처리에 의한 caspase-3-매개의 아팝토시스 경로 차단은 CCB 유도의 세포 사멸을 완전히 차단시키지 못함을 알 수 있었으며, 또한 17-AAG과 CCB 병합 처리에 의한 오토파지 활성화는 Z-DEVD-FMK에 의해 방해되지 않는 것을 알 수 있었다. 본 연구의 결과를 토대로, CCB의 오토파지 유도 활성은 항암제 다제내성 암의 Hsp90 inhibitor에 대한 감수성 증가를 위한 약물 개발에, CCB가 효과적인 병용 약물로서 제안 될 수 있다.