• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.174-185
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• 2010

Full-length cDNAs are essential for the correct annotation of genomic sequences and for the functional analysis of genes and their products. To elucidate the functions of a large population of Chinese cabbage (Brassica rapa) genes and to search efficiently for agriculturally useful genes, we have been taking advantage of the full-length cDNA Over-eXpresser (FOX) gene hunting system. With oligo dT column it purify the each mRNA from the flower organs, leaf and stem tissue. And about 120,000 cDNAs from the library were transformed into $\lambda$-pFLCIII-F vector. Of which 115,000 cDNAs from the library were transformed into T-DNA binary vector, pBigs for transformation study. We used normalized full-length cDNA and introduced each cDNA into Arabidopsis by in planta transformation. Full-length Chinese cabbage cDNAs were expressed independently under the CaMV 35S promoter in Arabidopsis. Selfed seeds were harvested from transgenic Arabidopsis. We had selected 2,500 transgenic plants by hygromycin antibiotic tolerant test, and obtained a number of transgenic mutants. Each transgenic Arabidopsis was investigated in morphological changes, fertility and leaf colour. As a result, 285 possible morphological mutants were identified. Introduced cDNA was isolated by PCR amplification of the genomic DNA from the transgenic mutants. Sequencing result and BLAST analysis showed that most of the introduced cDNA were complete cDNAs and functional genes. Also, we examined the effect of Bromelain on enhancing resistance to soft rot in transgenic Chinese cabbage 'Osome'. The bromelain gene identified from FOX hunting system was transformed into Chinese cabbage using Agrobacterium methods. Transformants were screened by PCR, then RT-PCR and real time PCR were performed to analyze gene expression of cysteine protease in the T1 and T2 generations. The anti-bacterial activity of bromelain was tested in Chinese cabbages infected with soft rot bacteria. The results showed that the over-expressed bromelain gene from pineapple conferred enhanced resistance to soft rot in Chinese cabbage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.299-306
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• 2009

Oxidative stress is the main limiting factor in crop productivity. To solve global environmental problems using the plant biotechnology, we have developed on the oxidative stress-tolerant transgenic tall fescue plants via Agrobacterium-mediated genetic transformation method. In order to develop transgenic tall fescue (Festuca arundinacea Schreb.) plants with enhanced tolerance to multiple environmental stresses, nucleotide diphosphate kinase gene under the control of CaMV35S promoter were introduced into genome of tall fescue plants. Proteomic analysis revealed that transgenic tall fescue not only accumulated NDP kinase 2 protein in their cells, but also induced several other antioxindative enzyme-related proteins. When leaf discs of transgenic plants were subjected to cold stress, they showed approximately 30% less damage than wild-type plants. In addition, transgenic tall fescue plants showed normal growth when transgenic plants were subjected to $4^{\circ}C$ for 3 days treatments. These results suggest that transgene is important in ROS scavenging by induction of antioxidative proteins, and could improve abiotic stress tolerance in transgenic tall fescue plants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.2
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• pp.109-116
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• 2007

Environmental stress is the major limiting factor in plant productivity. As an effort to solve the global food and environmental problems using the plant biotechnology, we have developed transgenic tall fescue (Festuca arundinacea Schreb.) plants via Agrobacterium-mediated gene transfer method. To develop transgenic tall fescue plants with enhanced tolerance to the environmental stresses, both CuZn superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) genes were incorporated in a pIG121 binary vector and the both of the genes were controlled separately by an oxidative stress-inducible sweet potato peroxidase 2 (SWPA2) premoter expressed in chloroplasts. Leaf discs of transgenic plants showed 10-30% less damage compared to the wild-type when they exposed to a wide range of environmental stresses including methyl viologen (MV), $H_2O_2$ and heavy metals. In addition, when $200{\mu}M$ MV was sprayed onto the whole plants, transgenic plants showed a significant reduction of visible damage compared to wild-type plants that were almost damaged. These results suggest that over expression of CuZnSOD and APX genes in transgenic plants might be a useful strategy to protect the crops against a wide range of environmental stresses.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.2
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• pp.118-122
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• 2015

Suicidal gene therapy is based on the transduction of tumor cells with "suicide" genes encoding for prodrug-activating enzymes that render target cells susceptible to prodrug treatment. Suicidal gene therapy results in the death of tumor with the expression of gene encoding enzyme that converts non-toxic prodrug into cytotoxic product. Cytochrome P450 4B1 (CYP4B1) activates 4-ipomeanol (4-IPO) or 2-aminoanthracene (2-AA) to cytotoxic furane epoxide and unsaturated dialdehyde intermediate.In this study, therapeutic effects of suicidal gene therapy with rabbit CYP4B1/2-AA or 4-IPO system were evaluated in HT-29 (human colon cancer cell). pcDNA-CYP4B1 vector was transfected into HT-29 by lipofection and stable transfectant was selected by treatment of hygromycin ($500{\mu}g/mL$) for 3 weeks. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed for confirmation of CYP4B1 expression in CYP4B1 gene transduced cell. The cytotoxic effects of CYP4B1 transduced cell were determined using dye-exclusion assay after treatment of 2-AA or 4-IPO for 96 hrs. Dye-exclusion assay showed that $IC_{50}$ of HT-29 and CYP4B1 transduced HT-29 was 0.01 mM and 0.003 mM after 4-IPO or 2-AA treatment at 96 hrs exposure, respectively. In conclusion, CYP4B1 based prodrug gene therapy probably have the potential for treatment of colorectal adenocarcinoma.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.99-108
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• 2004

Purpose: The ability to noninvasively track the migration of neural progenitor cells would have significant clinical and research implications. We generated stably transfected F3 human neural progenitor cells with human sodium/iodide symporter (hNIS) for noninvasively tracking F3. In this study, the expression patterns of hNIS gene in F3-NIS were examined according to the cultured time and the epigenetic modulation. Materials and Methods: F3 human neural stem cells had been obtained from Dr. Seung U. Kim (Ajou University, Suwon, Korea). hNIS and hygromycin resistance gene were linked with IRES (Internal Ribosome Entry Site) under control of CMV promoter. This construct was transfected to F3 with Liposome. To investigate the restoration of hNIS gene expression in F3-NIS, cells were treated with demethylating agent (5-Azacytidine) and Histone deacetylase inhibitor (Trichostatin A: TSA). The expression of hNIS was measured by I-125 uptake assay and RT-PCR analysis. Results: The iodide uptake of the F3-NIS was higher 12.86 times than F3 cell line. According to the cell passage number, hNIS expression in F3-NIS gradually diminished. After treatment of 5-Azacytidine and TSA with serial doses (up to $20{\mu}M$, up to 62.5nM, respectively) for 24 hours, I-125 uptake and mRNA of hNIS in F3-NIS were increased. Conclusion: These results suggest that hNIS transfected F3 might undergo a change in its biological characters by cell passage. Therefore, the gene ex[ressopm of exogenous gene transferred human stem cell might be affected to the epigenetic modulation such as promoter methylation and Histone deacetylation and to the cell culture conditions.

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.123-130
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• 2014

A simultaneous determination was developed for 9 aminoglycoside antibiotics (amikacin, apramycin, dihydrostreptomycin, gentamicin, hygromycin B, kanamycin, neomycin, spectinomycin, and streptomycin) in meat by liquid chromatography tandem mass spectrometry (LC-MS/MS). Each parameter was established by multiple reaction monitoring in positive ion mode. The developed method was validated for specificity, linearity, accuracy, and precision based on CODEX validation guideline. Linearity was over 0.98 with calibration curves of the mixed standards. Recovery of 9 aminoglycosides ranged on 60.5~114% for beef, 60.1~112% for pork and 63.8~131% for chicken. The limit of detection (LOD) and limit of quantification (LOQ) were 0.001~0.009 mg/kg and 0.006~0.03 mg/kg, respectively in livestock products including beef, pork and chicken. This study also performed survey of residual aminoglycoside antibiotics for 193 samples of beef, pork and chicken collected from 9 cities in Korea. Aminoglycosides were not found in any of the samples.