Publications by authors named "Kyu-Woong Hahn"

The effectiveness of chemotherapy and radiotherapy to treat lung cancer is limited because of highly metastatic nature. Novel strategies and drugs to attenuate metastatic activity are urgently required. In this study, red fluorescence proteins (RFP)-labeled A549 human lung cancer cells were orthotopically implantation, where they developed primary tumors.

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Neutrophil activity, including trapping of damage-associated molecular patterns by neutrophil extracellular traps (NETs), is an important response to microbial infection. Most activated neutrophils commit to apoptosis and are removed by activated macrophages in the process of efferocytosis. Improper clearance of apoptotic neutrophils often causes an unnecessary and exaggerated immune response and subsequent chronic inflammation.

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Mealybugs are under a strict regulation at foreign trades of agricultural products because they are one of the most economically damaging groups of insects on food crops and ornamental plants. However, the absence of morphological characteristics enabling the discrimination of early life stages often cause a significant delay or rejection of a shipment when infested fruit is discovered, causing significant economic loss. A polymerase chain reaction-based method for species identification was developed for six mealybug species known to infest Korean pears including two regulated insects, Planococcus kraunhiae (Kuwana) and Crisicoccus matsumotoi (Siraiwa).

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Article Synopsis
  • Patatins, major glycoproteins in potato tubers, were targeted for elimination using RNA interference (RNAi) to create more efficient systems for producing therapeutic proteins in potatoes.
  • A specific 635-nucleotide sequence of the patatin gene was used to develop a hairpin RNAi vector, successfully transforming the Desiree potato cultivar and producing ten transgenic lines with a 99% reduction in patatin levels.
  • The resulting potato tubers maintained similar growth characteristics to wild-type plants and allowed for easier glycoprotein purification with reduced contamination from patatins, demonstrating the potential for improved protein expression systems in plant biotechnology.
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Transgenic potato plants (SS2 and SS4) that overexpressed a chloroplastic copper/zinc superoxide dismutase lily gene were utilized as an H(2)O(2)-inducible system in order to study the role of H(2)O(2) as a signaling molecule in the biosynthesis of ethylene. SS2 and SS4 plants grown in vitro under sealed microenvironment (SME) conditions displayed anomalous phenotypes including reduction of stem elongation, radial stem growth, and promotion of root hair formation in the generated root, which were similar to ethylene-induced responses. In addition, SS4 plants showed severe vitrification in developing leaves and elevated ethylene production under SME conditions.

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Article Synopsis
  • Higher levels of hydrogen peroxide (H2O2) were found in sense transgenic potato plants (SS4) with a specific gene sequence, while antisense plants (SA1) had higher superoxide (O2(-)) levels compared to wild-type (WT) plants.
  • The growth of SA1 was inhibited by a chemical blocking O2(-) but promoted in SS4 by a herbicide that generates O2(-).
  • The observed effects on elongation and tuber development in the transgenic plants were primarily linked to varying levels of gibberellins (GAs), suggesting superoxide functions as a signaling molecule in plant growth regulation.
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The esterase-encoding gene, estA, was cloned from Acinetobacter lwoffii I6C-1 genomic DNA into Escherichia coli BL21(DE3) with plasmid vector pET-22b (pEM1). pEM1 has a 4.4-kb EcoRI insert that contained the complete estA gene.

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