• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1617-1622
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• 2008

We report a new molecular detection process which measures the changes in the plasmon resonance peaks of periodic Au nanoparticle arrays fabricated using the electron beam lithography. As the Au nanoparticle arrays are modified by the chemical reaction in solutions having various concentrations of a target molecule, both the position and intensity of the plasmon peak change in proportion to the concentration of the target molecule. We expect that the process developed in this work can be employed for fine tuning of the plasmon peak wavelength and also for the optical detection of various kinds of molecules. Moreover, this method may improve the measurement accuracy compared with existing approaches that use only one change (peak wavelength or peak intensity) as a readout value for the molecular detection.

• Genomics & Informatics
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• v.12 no.3
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• pp.80-86
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• 2014

Foldback intercoil (FBI) DNA is formed by the folding back at one point of a non-helical parallel track of double-stranded DNA at as sharp as $180^{\circ}$ and the intertwining of two double helixes within each other's major groove to form an intercoil with a diameter of 2.2 nm. FBI DNA has been suggested to mediate intra-molecular homologous recombination of a deletion and inversion. Inter-molecular homologous recombination, known as site-specific insertion, on the other hand, is mediated by the direct perpendicular approach of the FBI DNA tip, as the attP site, onto the target DNA, as the attB site. Transposition of DNA transposons involves the pairing of terminal inverted repeats and 5-7-bp tandem target duplication. FBI DNA configuration effectively explains simple as well as replicative transposition, along with the involvement of an enhancer element. The majority of diverse retrotransposable elements that employ a target site duplication mechanism is also suggested to follow the FBI DNA-mediated perpendicular insertion of the paired intercoil ends by non-homologous end-joining, together with gap filling. A genome-wide perspective of transposable elements in light of FBI DNA is discussed.

• BMB Reports
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• v.33 no.5
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• pp.359-365
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• 2000

Ribozymes are catalytic RNAs that can cleave RNAs at specific sites, thus they have been employed to degrade a target mRNA in vivo. Development of allosterically controllable ribozymes is of great current interest, but it remained difficult to furnish such functions to ribozymes in cultured cells or in animals. Recently, we designed allosterically controllable ribozymes termed maxizymes, which have sensor arms that recognize target mRNA sequences and, in the presence of such target sequences only, they form a cavity that can capture catalytically indispensable $Mg^{2+}$ ions, cleaving the target. The maxizyme was applied to therapy for chronic myelogenous leukemia (CML). It cleaved specifically the chimeric BCR-ABL mRNA, which caused CML, without damaging the normal ABL or BCR mRNA in mammalian cells and also in mice, providing the first successful example for allosteric control of the activity of artificial ribozymes in vivo.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.79-82
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• 2019

⁶¹Cu is a promising PET radiometal having favorable nuclear decay characteristics with appropriate half-life of 3.3 h. Owing its promising capabilities in radiopharmaceutical chemistry and its chemical similarities with its isotopes ⁶⁴Cu and ⁶⁷Cu, in this work we have tried to optimize the production and separation conditions of ⁶¹Cu. ⁶¹Cu was produced via (p, x) reaction with natural nickel which was electroplated on the high purity silver coated copper backing target holder. The optimization of target electrodeposition, beam energy and current modulation, target dissolution and separation were optimized in this study. Preliminary studies show that ⁶¹Cu was successfully produced and separated which can be further extended for the production of ⁶⁴Cu and ⁶⁷Cu.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1408-1413
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• 2005

Elevated expression of carcinoembryonic antigen (CEA) has been implicated in various biological aspects of neoplasia such as tumor cell adhesion, metastasis, blocking of cellular immune mechanisms, and antiapoptosis function. Thus, the CEA could be an important target for anticancer therapy. In this study, we developed Tetrahymena group 1 intron-based trans-splicing ribozymes that can specifically target and replace CEA RNA. To this end, we first determined which regions of the CEA RNA were accessible to ribozymes by employing an RNA mapping strategy that was based on a trans-splicing ribozyme library. Next, we assessed the ribozyme activities by comparing the trans-splicing activities of several ribozymes that targeted different regions of the CEA RNA, and then the ribozyme that could target the most accessible site was observed to be the most active with high fidelity in vitro. Moreover, the specific trans-splicing ribozyme was found to react with and altered the target CEA transcripts in mammalian cells with high fidelity. These results suggest that the Tetrahymena ribozyme can be utilized to replace CEA RNAs in tumors with a new RNA-harboring anticancer activity, thereby hopefully reverting the malignant phenotype.

• Molecules and Cells
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• v.37 no.9
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• pp.691-698
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• 2014

SCYL1-BP1 is thought to function in the p53 pathway through Mdm2 and hPirh2, and mutations in SCYL1-BP1 are associated with premature aging syndromes such as Geroderma Osteodysplasticum; however, these mechanisms are unclear. Here, we report significant alterations in miRNA expression levels when SCYL1-BP1 expression was inhibited by RNA interference in HEK293T cells. We functionally characterized the effects of potential kernel miRNA-target genes by miRNA-target network and protein-protein interaction network analysis. Importantly, we showed the diminished SCYL1-BP1 dramatically reduced the expression levels of EEA1, BMPR2 and BRCA2 in HEK293T cells. Thus, we infer that SCYL1-BP1 plays a critical function in HEK293T cell development and directly regulates miRNA-target genes, including, but not limited to, EEA1, BMPR2, and BRCA2, suggesting a new strategy for investigating the molecular mechanism of SCYL1-BP1.

• BMB Reports
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• v.54 no.6
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• pp.305-310
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• 2021

Cereblon (CRBN) is a multi-functional protein that acts as a substrate receptor of the E3 ligase complex and a molecular chaperone. While CRBN is proposed to function in mitochondria, its specific roles are yet to be established. Here, we showed that knockdown of CRBN triggers oxidative stress and calcium overload in mitochondria, leading to disruption of mitochondrial membrane potential. Notably, long-term CRBN depletion using PROteolysis TArgeting Chimera (PROTAC) induced irreversible mitochondrial dysfunction, resulting in cell death. Our collective findings indicate that CRBN is required for mitochondrial homeostasis in cells.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1047-1051
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• 2008

Overexpression of HER2 in breast cancer cells is considered to induce the expression of acetyl-CoA carboxylase $\alpha$ (ACACA) and fatty acid synthase (FASN) through activation of mammalian target of rapamycin (mTOR) signaling pathway. Resveratrol, a red wine polyphenol, has been shown to induce apoptosis in several cancers by interfering in several signaling pathways. Present study elucidated the mechanism by which resveratrol downregulates ACACA and FASN in breast cancer cells. Resveratrol activated AMP-activated protein kinase (AMPK) and downregulated mTOR in BT-474 cells. These effects of resveratrol were mimicked by AICAR, an AMPK activator, and exogenously expressed constitutively active AMPK, while they were abolished by a dominant-negative mutant of AMPK. The downregulation of mTOR was not accompanied with changes in Akt, the upstream regulator of mTOR. These findings indicate that the downregulation of ACACA and FASN by resveratrol is mediated by the downregulation of mTOR signaling pathway via activation of AMPK.

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.171-174
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• 2004

Angiogenesis, the formation of new capillaries from existing vessels, increases oxygenation and nutrient supply to ischemic tissue and allows tumor growth and metastasis. As such, angiogenesis targeting provides a novel approach for cancer treatment with easier drug delivery and less drug resistance. Therapeutic anti-angiogenesis has shown impressive effects in animal tumor models and are now entering clinical trials. However, the successful clinical introduction of this new therapeutic approach requires diagnostic tools that can reliably measure angiogenesis in a noninvasive and repetitive manner. Molecular imaging is emerging as an exciting new discipline that deals with imaging of disease on a cellular or genetic level. Angiogenesis imaging is an important area for molecular imaging research, and the use of radiotracers offers a particularly promising technique for its development. While current perfusion and metabolism radiotracers can provide useful information related to tissue vascularity, recent endeavors are focused on the development of novel radioprobes that specifically and directly target angiogenic vessels. Presently available proges include RGD sequence containing peptides that target ${\alpha}_v\;{\beta}_3$ integrin, endothelial growth factors such as VEGF or FGF, metalloptoteinase inhibitors, and specific antiangiogenic drugs. It is now clear that nuclear medicine techniques have a remarkable potential for angiogenesis imaging, and efforts are currently continuing to develop new radioprobes with superior imaging properties. With future identification of novel targets, design of better probes, and improvements in instrumentation, radiotracer angiogenesis imaging promises to play an increasingly important role in the diagnostic evaluation and treatment of cancer and other angiogenesis related diseases.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1634-1639
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• 2006

Hepatitis C virus (HCV)-encoded nonstructural protein 5B (NS5B) possesses RNA-dependent RNA polymerase activity, which is considered essential for viral proliferation. Thus, HCV NS5B is a good therapeutic target protein for the development of anti-HCV agents. In this study, we isolated two different kinds of nuclease-resistant RNA aptamers with 2'-fluoro pyrimidines against the HCV NS5B from a combinatorial RNA library with 40 nucleotide random sequences, using SELEX technology. The isolated RNA aptamers were observed to specifically and avidly bind the HCV NS5B with an apparent $K_d$ of 5 nM and 18 nM, respectively, in contrast with the original RNA library that hardly bound the target protein. Moreover, these aptamers could partially inhibit RNA synthesis of the HCV subgenomic replicon when transfected into Huh-7 hepatoma cell lines. These results suggest that the RNA aptamers selected in vitro could be useful not only as therapeutic agents of HCV infection but also as a powerful tool for the study of the HCV RNA-dependent RNA polymerase mechanism.