• Journal of Oral Medicine and Pain
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• 제30권2호
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• pp.231-238
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• 2005

항암제의 연구는 화학물질에 민감한 암세포를 죽음에 이르게 하는 세포자멸사와 같은 다양한 세포기능에 초점을 맞추어 왔다. 그러나 약물이 유도한 세포의 죽음에 있어서 핵심적인 분자적 기작은 아직 잘 이해되지 않고 있다. Etoposide는 폐암과 고환암에 사용되는 항암제로서, 본 연구는 etoposide가 사람구강편평상피암종세포(OSC9)에도 세포독성효과와 세포자멸사를 일으키는지를 알아보기 위해 실행하였다. 이 실험에서 etoposide는 농도와 시간 의존적으로 OSC9 세포의 생존율를 현저하게 저해시켰다. TUNEL 염색과 Hoechst 염색을 이용한 핵의 형태학적 관찰에서는 etoposide에 의해 핵이 응축되고 분절되었다. p53의 발현은 48 시간에 증가했으며, etoposide 처리로 인해 caspase-3의 활성을 관찰할 수 있었으며, 그 기질에 해당되는 PARP 단백질은 116-kDa과 89-kDa으로 분절되었다. 위의 결과들은 OSC9 세포에서 etoposide가 유도한 세포자멸사는 caspase-3의 활성과 관련됨을 설명하고 있다.

• 생명과학회지
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• 제17권6호통권86호
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• pp.748-755
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• 2007

본 연구에서는 전이성 암세포와 항암제 다제내성 세포에 있어서 항암제 내성에 영향을 미치는 것으로 알려진 DNA-dependent protein kinase (DNA-PK) 가 Abl protein-tyrosine kinases저해제인 STl571 내성에도 연관되어 있는지에 대하여 조사하였다. 또한 STl571 과 topoisomerase I 저해제인 camptothecin (CPT) 의 단독 및 병용처리에 의한 항암 활성을 전이성 암세포와 항암제 다제내성 세포를 대상으로 조사하였다. 세포의 전이도와 내성정도에 따라 STl571 의 감수성이 다르게 나타났다. 이와 함께 ST1571의 처리후 농도에 따라 전이도가 낮은 KMl2, PC3 세포와 항암제 감수성인 CEM, MCF-7 세포에서는 DNA-PK 의 발현이 감소하는 반면, 전이도가 높은 KML4a, PC-MM2 세포와 다제내성 CEM/MDR 및 MCR/MDR 세포에서는 그 발현이 증가되어 있음을 알 수 있었다. 이는 DNA-PK 의 발현이 STl571 의 내성에 관여한다는 것을 시사한다. 이와 같은 결과에 근거하여 DNA-PK 의 발현을 감소시키는 CPT를 STl571 내성을 나타내는 암세포에 대하여 STl571 과 병용처리 하였다. 그 결과 DNA-PK의 발현이 감소되고 세포증식이 억제됨으로써 ST1571 의 감수성이 CPT에 의해 증가하는 것을 알 수 있었다. 따라서 본 연구에서는 DNA-PK가 STl571 의 내성을 극복하는데 있어서 새로운 표적이 될 수 있으며, STl571 의 치료내성 극복에 CPT 와의 병용처리가 유효함을 알 수 있었다.

• 생명과학회지
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• 제28권7호
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• pp.765-771
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• 2018

$PPAR{\gamma}$는 지방세포의 분화를 조절하는 핵심적인 전사 인자로서 이를 조절하는 후성유전학적 조절 기전이 비만억제 연구에서 중요하게 주목 받고 있다. 선행연구에서 CACUL1이 $PPAR{\gamma}$의 전사 활성 및 지방세포의 분화를 억제하는 corepressor로서 작용함을 밝힌 바 있으며 본 연구에서는 CACUL1의 새로운 결합 단백질로 발굴된 protein arginine methyltransferase 5 (PRMT5)의 $PPAR{\gamma}$ 조절 기능을 분석하였다. PRMT5가 CACUL1과 결합함을 immunoprecipitation assay in vivo와 GST-pull down assay in vitro를 통하여 확인하였다. Luciferase reporter assay 결과로 두 단백질이 상호 협력하여 $PPAR{\gamma}$의 전사 활성을 억제함을 확인하였다. PRMT5가 안정적으로 과발현 또는 knockdown되는 3T3-L1 세포주를 제작하여 지방세포 분화에 미치는 영향을 분석한 결과, PRMT5가 3T3-L1세포의 지방세포 분화를 억제함을 증명하였다. 같은 맥락으로 PRMT5는 $PPAR{\gamma}$의 타겟 유전자인 Lpl과 aP2의 발현을 억제하는 것을 RT-qPCR로 확인하였다. 이상의 연구 결과로 PRMT5이 CACUL1과 결합하여 $PPAR{\gamma}$의 전사 활성을 방해, 나아가 지방세포의 분화를 억제하는 기존에 알려지지 않은 분자적 기전을 처음으로 밝혔다. 따라서, PRMT5 효소 활성의 조절은 비만 억제를 위한 약물 개발에 단서를 제공할 것이다.

• BMB Reports
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• 제48권11호
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• pp.618-623
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• 2015

FK506 binding protein 12 (FK506BP) is a small peptide with a single FK506BP domain that is involved in suppression of immune response and reactive oxygen species. FK506BP has emerged as a potential drug target for several inflammatory diseases. Here, we examined the protective effects of directly applied cell permeable FK506BP (PEP-1-FK506BP) on corneal alkali burn injury (CAI). In the cornea, there was a significant decrease in the number of cells expressing pro-inflammation, apoptotic, and angiogenic factors such as TNF-α, COX-2, and VEGF. Both corneal opacity and corneal neovascularization (CNV) were significantly decreased in the PEP-1-FK506BP treated group. Our results showed that PEP-1-FK506BP can significantly inhibit alkali burn-induced corneal inflammation in rats, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors and inflammatory cytokines. These results suggest that PEP-1-FK506BP may be a potential therapeutic agent for CAI.

• Biomolecules & Therapeutics
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• 제28권5호
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• pp.443-455
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• 2020

The thioredoxin (Trx) system plays critical roles in regulating intracellular redox levels and defending organisms against oxidative stress. Recent studies indicated that Trx reductase (TrxR) was overexpressed in various types of human cancer cells indicating that the Trx-TrxR system may be a potential target for anti-cancer drug development. This study investigated the synergistic effect of auranofin, a TrxR-specific inhibitor, on sulforaphane-mediated apoptotic cell death using Hep3B cells. The results showed that sulforaphane significantly enhanced auranofin-induced apoptosis by inhibiting TrxR activity and cell proliferation compared to either single treatment. The synergistic effect of sulforaphane and auranofin on apoptosis was evidenced by an increased annexin-V-positive cells and Sub-G1 cells. The induction of apoptosis by the combined treatment caused the loss of mitochondrial membrane potential (ΔΨm) and upregulation of Bax. In addition, the proteolytic activities of caspases (-3, -8, and -9) and the degradation of poly (ADP-ribose) polymerase, a substrate protein of activated caspase-3, were also higher in the combined treatment. Moreover, combined treatment induced excessive generation of reactive oxygen species (ROS). However, treatment with N-acetyl-L-cysteine, a ROS scavenger, reduced combined treatment-induced ROS production and apoptosis. Thereby, these results deduce that ROS played a pivotal role in apoptosis induced by auranofin and sulforaphane. Furthermore, apoptosis induced by auranofin and sulforaphane was significantly increased through inhibition of the phosphoinositide 3-kinase (PI3K)/Akt pathway. Taken together, the present study demonstrated that down-regulation of TrxR activity contributed to the synergistic effect of auranofin and sulforaphane on apoptosis through ROS production and inhibition of PI3K/Akt signaling pathway.

• 생명과학회지
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• 제33권11호
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• pp.876-886
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• 2023

두경부암(HNC)의 경우, 외과적 개입은 환자의 삶의 질에 심각한 영향을 미칠 수 있으며, 화학요법을 병행하게 된다. 그러나 화학요법에는 현저한 부작용이 있으므로 환자의 고통을 최소화하기 위한 보조 방법의 개발이 필요하다. 천궁(Ligusticum chuanxiong)은 동양 의학에서 뇌혈관 장애 및 두통에 사용되는 천연 허브이다. 본 연구에서는 네트워크 기반 약리학 및 분자 도킹 분석을 통해 천궁의 근본적인 항암기전을 예측하였다. 본 연구에서 HNC와 관련된 천궁의 공통 유전자를 밝혀내어 신경 활성 리간드의 대사 및 신경 전달 물질 경로와의 연관성을 확인했다. 본 연구는 천궁의 성분 중 하나인 (Z)-ligustilide 가 암세포 활성화에 관련된 heat shock protein 90의 ATP 결합 부위를 공유함을 입증했다. 이 결과는 천궁이 보조 항암제 개발을 위한 유망한 후보임을 시사하며, 향 후 더욱 새롭고 안전한 항암제의 연구개발에 과학적 근거를 제시하는 새로운 발견이다.

• Molecules and Cells
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• 제20권1호
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• pp.1-16
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• 2005

The peptidyl transferase center (PTC) is located in a protein free environment, thus confirming that the ribosome is a ribozyme. This arched void has dimensions suitable for accommodating the 3'ends of the A-and the P-site tRNAs, and is situated within a universal sizable symmetry-related region that connects all ribosomal functional centers involved in amino-acid polymerization. The linkage between the elaborate PTC architecture and the A-site tRNA position revealed that the A-to P-site passage of the tRNA 3'end is performed by a rotatory motion, which leads to stereochemistry suitable for peptide bond formation and for substrate mediated catalysis, thus suggesting that the PTC evolved by genefusion. Adjacent to the PTC is the entrance of the protein exit tunnel, shown to play active roles in sequence-specific gating of nascent chains and in responding to cellular signals. This tunnel also provides a site that may be exploited for local co-translational folding and seems to assist in nascent chain trafficking into the hydrophobic space formed by the first bacterial chaperone, the trigger factor. Many antibiotics target ribosomes. Although the ribosome is highly conserved, subtle sequence and/or conformational variations enable drug selectivity, thus facilitating clinical usage. Comparisons of high-resolution structures of complexes of antibiotics bound to ribosomes from eubacteria resembling pathogens, to an archaeon that shares properties with eukaryotes and to its mutant that allows antibiotics binding, demonstrated the unambiguous difference between mere binding and therapeutical effectiveness. The observed variability in antibiotics inhibitory modes, accompanied by the elucidation of the structural basis to antibiotics mechanism justifies expectations for structural based improved properties of existing compounds as well as for the development of novel drugs.

• Journal of Acupuncture Research
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• 제20권5호
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• pp.93-106
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• 2003

Objective : To investigate the possible molecular mechanism(s) of melittin as a candidate of anti-cancer drug, we examined the effects of the compound on the growth of human lung carcinoma cell line A549. Methods: MTT, morphological changes, DAPI staining, Western blot, RT-PCR and in vitro prostaglandin E2 (PGE2) accumulation assays were performed. Results: The anti-proliferative effect by melittin treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. Melittin induced apoptotic cell death in a concentration-dependent manner, which was associated with inhibition or degradation of apoptotic target proteins such as ${\beta}$-catenin, poly(ADP-ribose) polymerase(PARP) and phospholipase $C-{\gamma}1(PLC-{\gamma}1)$. Melittin treatment inhibited the expression of cyclooxygenase-2(COX-2) and accumulation of PGE2 in aconcentration-dependent fashion. In addition, Melittin treatment induced the down-regulation of telomerase reverse transcriptase(hTERT) and proto-oncogene c-myc expression of A549 cells. Conclusions: Taken together, these findings suggest that melittin-induced inhibition of human lung cancer cell proliferation is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products, and melittin may have therapeutic potential in human lung cancer.

• BMB Reports
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• 제34권2호
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• pp.176-181
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• 2001

Using a retrovirus, foreign genes can be introduced into mammalian cells. The purpose of this study is to produce a retrovirus that can make the infected cells express two genes; the human multidrug resistance gene (MDR1) and the HLA-B7 gene, which is one of the major human histocompatibility complex (MHC) class I genes. For the expression of these genes, the internal ribosome entry site (IRES) was used, which was derived from the encephalomyocarditis (EMC) virus. In order to produce retroviruses, a retroviral vector was transfected into a packaging cell line and the transfected cells were treated with vincristine, which is an anti-cancer drug and a substrate for the MDRI gene product. This study revealed that two genes were incorporated into chromosomes of selected cells and expressed in the same cells. The production of the retrovirus was confirmed by the reverse transcription (RT)-PCR of the viral RNA. The retrovirus that was produced infected mouse fibroblast cells as well as the human U937. This study showed that packaging cells produced the retroviruses, which can infect the target cells. Once the conditions for the high infectivity of retrovirus into human cells are optimized, thus virus will be used to infect hematopoietic stem cells to co-express MDRl and HLA-B7 genes, and develop the lymphocytes that can be used for the immnogene therapy.

• BMB Reports
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• 제34권1호
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• pp.80-84
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• 2001

The human papillomavirus E7 protein can form a specific complex with a retinoblastoma tumor suppressor gene product (p105-Rb) that results in the release of the E2F transcription factor, which is critical for the growth-deregulation and transforming properties of the viral E7 oncoprotein. In an attempt to apply interaction between the E7 oncoprotein and a target cellular protein Rb for an in vitro screening system for drugs against human papillomavirus infection, we primarily investigated the E7Rb binding through a pull down assay and enzyme-linked immunosorbent assay. The pull down assay showed that both glutathione S-transferase-tagged E7 and His-tagged E7 immobilized on resins specifically produced complexes with bacterially expressed Rb in a dose-dependent manner, as determined by immunoblot analyses. This result coincided with that of an enzyme-linked immunosorbent assay, which is a useful system for the mass screening of potential drugs. Taken together, this screening system (based on the interaction between E7 and Rb) can be a promising system in the development of drugs against cervical cancers caused by human papillomavirus infection.