• Molecules and Cells
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• 제43권7호
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• pp.662-670
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• 2020

We have investigated the involvement of the pre-mRNA processing factor 4B (PRP4) kinase domain in mediating drug resistance. HCT116 cells were treated with curcumin, and apoptosis was assessed based on flow cytometry and the generation of reactive oxygen species (ROS). Cells were then transfected with PRP4 or pre-mRNA-processing-splicing factor 8 (PRP8), and drug resistance was analyzed both in vitro and in vivo. Furthermore, we deleted the kinase domain in PRP4 using Gateway™ technology. Curcumin induced cell death through the production of ROS and decreased the activation of survival signals, but PRP4 overexpression reversed the curcumin-induced oxidative stress and apoptosis. PRP8 failed to reverse the curcumin-induced apoptosis in the HCT116 colon cancer cell line. In xenograft mouse model experiments, curcumin effectively reduced tumour size whereas PRP4 conferred resistance to curcumin, which was evident from increasing tumour size, while PRP8 failed to regulate the curcumin action. PRP4 overexpression altered the morphology, rearranged the actin cytoskeleton, triggered epithelial-mesenchymal transition (EMT), and decreased the invasiveness of HCT116 cells. The loss of E-cadherin, a hallmark of EMT, was observed in HCT116 cells overexpressing PRP4. Moreover, we observed that the EMT-inducing potential of PRP4 was aborted after the deletion of its kinase domain. Collectively, our investigations suggest that the PRP4 kinase domain is responsible for promoting drug resistance to curcumin by inducing EMT. Further evaluation of PRP4-induced inhibition of cell death and PRP4 kinase domain interactions with various other proteins might lead to the development of novel approaches for overcoming drug resistance in patients with colon cancer.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.84.2-84.2
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• 2007

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• Molecules and Cells
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• 제24권1호
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• pp.95-104
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• 2007

The mechanism of acacetin-induced apoptosis of human breast cancer MCF-7 cells was investigated. Acacetin caused 50% growth inhibition ($IC_{50}$) of MCF-7 cells at $26.4{\pm}0.7{\mu}M$ over 24 h in the MTT assay. Apoptosis was characterized by DNA fragmentation and an increase of sub-G1 cells and involved activation of caspase-7 and PARP (poly-ADP-ribose polymerase). Maximum caspase 7 activity was observed with $100{\mu}M$ acacetin for 24 h. Caspase 8 and 9 activation cascades mediated the activation of caspase 7. Acacetin caused a reduction of Bcl-2 expression leading to an increase of the Bax:Bcl-2 ratio. It also caused a loss of mitochondrial membrane potential that induced release of cytochrome c and apoptosis inducing factor (AIF) into the cytoplasm, enhancing ROS generation and subsequently resulting in apoptosis. Pretreatment of cells with N-acetylcysteine (NAC) reduced ROS generation and cell growth inhibition, and pretreatment with NAC or a caspase 8 inhibitor (Z-IETD-FMK) inhibited the acacetin-induced loss of mitochondrial membrane potential and release of cytochrome c and AIF. Stress-activated protein kinase/c-Jun $NH_4$-terminal kinase 1/2 (SAPK/JNK1/2) and c-Jun were activated by acacetin but extracellular-regulated kinase 1/2 (Erk1/2) nor p38 mitogen-activated protein kinase (MAPK) were not. Our results show that acacetin-induced apoptosis of MCF-7 cells is mediated by caspase activation cascades, ROS generation, mitochondria-mediated cell death signaling and the SAPK/JNK1/2-c-Jun signaling pathway, activated by acacetin-induced ROS generation.

• 한국식품영양과학회지
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• 제40권9호
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• pp.1201-1207
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• 2011

TRAIL은 최근 암세포의 apoptosis 유도를 위한 효율적인 도구로 제시되었으나 많은 암세포들이 TRAIL 저항성을 획득한 것으로 알려져 TRAIL 저항성 극복을 위한 새로운 방법론의 제시가 요구되어지고 있다. Genistein은 대두의 대표적인 생리활성 물질인 isoflavonoid의 일종으로 많은 암세포에서 G2/M arrest를 유발하면서 apoptosis를 유도하는 것으로 알려져 있다. 본 연구에서는 U937 인체백혈병세포를 대상으로 genistein에 의한 TRAIL 유도 apoptosis의 감수성 증대 여부를 조사하였다. 본 연구의 결과에 의하면 U937 세포에서 세포독성이 없는 범위의 genistein 처리는 TRAIL에 의한 apoptosis 유도를 매우 증진시켰으며, 이는 tBid의 발현 증가와 cFLIPL의 발현 감소와 연계된 caspase의 활성 증가와 연관성이 있었다. 또한 caspase의 활성 저해제는 genistein과 TRAIL의 복합처리에 의한 apoptosis를 유의적으로 감소시켜 복합 처리에 의한 apoptosis의 유도에 caspase의 활성 증대가 필수적임을 알 수 있었다. 따라서 genistein은 TRAIL 저항성을 획득한 암세포의 효율적인 combined therapy approach를 위해 유용하게 사용될 수 있음을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.6991-6996
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• 2015

In the past decade, the incidence and mortality rates of cholangiocarcinoma (CCA) have been increasing worldwide. The relatively low responsiveness of CCA to conventional chemotherapy leads to poor overall survival. Recently, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL or Apo2L) has emerged as the most promising anti-cancer therapeutic agent since it is able to selectively induce apoptosis of tumor cells but not normal cells. In this study, we aimed to investigate the therapeutic effect of TRAIL in CCA cell lines (M213, M214 and KKU100) compared with the immortal biliary cell line, MMNK1, either alone or in combination with a subtoxic dose of 5-fluorouracil (5-FU). We found that recombinant human TRAIL (rhTRAIL) was a potential agent which significantly inhibited cell proliferation and mediated caspase activities (caspases 8, 9 and 3/7) and apoptosis of CCA cells. The combined treatment of rhTRAIL and 5-FU effectively enhanced inhibition of CCA cell growth with a smaller effect on MMNK1. Our finding suggests TRAIL to be a novel anti-cancer therapeutic agent and advantage of its combination with a conventional chemotherapeutic drug for effective treatment of CCA.

• The Korean Journal of Physiology and Pharmacology
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• 제21권4호
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• pp.397-405
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• 2017

MDL-12330A is a widely used adenylyl cyclase (AC) inhibitor that blocks AC/cAMP signaling. In this study, we demonstrated a novel antitumor activity of this drug in gastric carcinoma (GC) cell lines. In these GC cells, MDL-12330A reduced cell viability and induced cell death in a concentration-dependent manner. At a moderate concentration (${\sim}20{\mu}M$), MDL-12330A mainly induced apoptotic death whereas at concentrations greater than $20{\mu}M$, it increased non-apoptotic cell death. The induction of apoptosis was at least partially regulated by CHOP-mediated DR5 upregulation, as detected by immunoblotting and gene interference assays. More importantly, low concentrations of MDL-12330A effectively enhanced recombinant human tumor necrosis factor (TNF)-related apoptosis-inducing ligand (rhTRAIL)-induced apoptosis and clonogenicity in these gastric cancer cells. This study demonstrates a possible role of MDL-12330A as a potential sensitizer to TRAIL, and suggests a novel therapeutic strategy targeting gastric cancer cells.

• 통합자연과학논문집
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• 제6권3호
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• pp.125-137
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• 2013

Promising evidence suggests that amyloid beta peptide ($A{\beta}$), a key mediator in age-dependent neuronal and cerebrovascular degeneration, activates death signalling processes leading to neuronal as well as non-neuronal cell death in the central nervous system. A major cellular event in $A{\beta}$-induced apoptosis of non-neuronal cells, including cerebral endothelial cells, astrocytes and oligodendrocytes, is mitochondrial dysfunction. The apoptosis signalling cascade upstream of mitochondria entails $A{\beta}$ activation of neutral sphingomyelinase, resulting in the release of ceramide from membrane sphingomyelin. Ceramide then activates protein phosphatase 2A (PP2A), a member in the ceramide-activated protein phosphatase (CAPP) family. PP2A dephosphorylation of Akt and FKHRL1 plays a pivotal role in $A{\beta}$-induced Bad translocation to mitochondria and transactivation of Bim. Bad and Bim are pro-apoptotic proteins that cause mitochondrial dysfunction characterized by excessive ROS formation, mitochondrial DNA (mtDNA) damage, and release of mitochondrial apoptotic proteins including cytochrome c, apoptosis inducing factor (AIF), endonuclease G and Smac. The cellular events activated by $A{\beta}$ to induce death of non-neuronal cells are complex. Understanding these apoptosis signalling processes will aid in the development of more effective strategies to slow down age-dependent cerebrovascular degeneration caused by progressive cerebrovascular $A{\beta}$ deposition.

• BMB Reports
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• 제35권1호
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• pp.127-133
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• 2002

Nitrosative stress can prevent or induce apoptosis. It occurs via S-nitrosylation by the interaction of nitric oxide (NO) with the biological thiols of proteins. Cellular redox potential and non-heme iron content determine S-nitrosylation. Apoptotic cell death is inhibited by S-nitrosylation of the redox-sensitive thiol in the catalytic site of caspase family proteases, which play an essential role in the apoptotic signal cascade. Nitrosative stress can also promote apoptosis by the activation of mitochondrial apoptotic pathways, such as the release of cytochrome c, an apoptosis-inducing factor, and endonuclease G from mitochondria, as well as the suppression of NF-${\kappa}B$ activity. In this article we reviewed the mechanisms whereby S-nitrosylation and nitrosative stress regulate the apoptotic signal cascade.

• Journal of Acupuncture Research
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• 제31권2호
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• pp.87-98
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• 2014

Objectives : We investigated whether snake venom toxin(SVT) from Vipera lebetina turanica sensitizes HT29 human epithelial colorectal cancer cells to tumor necrosis factor(TNF)-related apoptosis-inducing ligand(TRAIL) induced apoptosis in cancer cells. Methods : Cell viability assay was used to assess the inhibitory effect of TRAIL on cell growth of HT29 human colorectal cancer cells. And 6-diamidino-2-phenylindole(DAPI), terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay(TUNEL) staining assay were used to evaluate cell-apoptosis. Western blot analysis were conducted to observe apoptosis related proteins and death receptor. To assess whether the synergized inhibitory effect of SVT and TRAIL on reactive oxygen species(ROS) generation was reversed by strong anti-oxidative agent. Results : SVT with TRAIL inhibited HT29 cell growth different from TRAIL alone. Consistent with cell growth inhibition, the expression of TRAIL receptors; Expression of death receptor(DR)4 and DR5 was significantly increased and intrinsic pro-apoptotic cleaved caspase-3, -9 was subsequently increased together with increase of Bax/Bcl-2 ratio and extrinsic pro-apototic caspase-8 was also activated. In addition, the expression of anti-apoptotic survival proteins, a marker of TRAIL resistance(eg, cFLIP, survivin, X-linked inhibitor of apoptosis protein(XIAP) and Bcl-2) was suppressed by the combination treatment of SVT and TRAIL. Pretreatment with the ROS scavenger N-acetylcysteine abolished the SVT and TRAIL-induced upregulation of DR4 and DR5 expression and expression of the intrinsic pro-apoptotic caspase-3 and-9. Conclusion : The collective results suggest that SVT facilitates TRAIL-induced apoptosis in $HT_{29}$ human epithelial colorectal cancer cells through up-regulation of the TRAIL receptors; DR4 and DR5 and consecutive induction of bilateral apoptosis via regulating apoptosis related proteins.

• 대한수의학회지
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• 제44권2호
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• pp.195-200
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• 2004

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family and potent inducer of apoptosis. TRAIL has been shown to effectively limit tumor growth in vivo without detectable cytotoxic side effects. Interferon (IFN)-${\gamma}$ often modulates the anti-cancer activities of TNF family members including TRAIL. We previously reported that IFN-${\gamma}$ enhanced TRAIL-induced Apoptosis in HeLa cells without the unknown mechanism. In this study, we investigated whether IRF-1 involves in IFN-${\gamma}$-enhanced TRAIL-induced apoptosis. We exposed HeLa cells to IFN-${\gamma}$ for 12 hours and then treated with recombinant TRAIL protein. No apoptosis was induced in cells pretreated with IFN-${\gamma}$, and TRAIL only induced 30% apoptosis after 3 hours treatment. In HeLa cells pretreated with IFN-${\gamma}$, TRAIL induced cell death to more than 75% at 3 hours, showed that IFN-${\gamma}$-pretreatment enhanced HeLa cell death to TRAIL-induced apoptosis. To investigate the functional role of IRF-1 in IFN-${\gamma}$-enhanced TRAIL-induced apoptosis, IRF-1 was overexpressed by using an adenoviral vector AdIRF-1. IRF-1 overexpression increased apoptotic cell death and significantly enhanced apoptotic cell death induced by TRAIL when infected cells were treated with TRAIL. Our findings show that IFN-${\gamma}$ enhances TRAIL-induced apoptosis by IRF-1 in HeLa cells.