• KSBB Journal
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• v.15 no.5
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• pp.428-433
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• 2000

Cell cultures of Camptotheca acuminata, which is known to produce the anticancer indole alkaloid camptothecin and its dervatives, were made to enhance the productivity of camptothecin. In suspension cultures, the maximum cell growth rate in exponential growth phase was $0.269day^{-1}$ which was correlated to 2.58days of cell doubling time. The production of camptothecin was non-growth associated. The camptothecin production was the highest at 11th day form inoculation and then it decreased. Various elicitors were applied to enhance the production of camptothecin. Both of jasmonic acid and cellulase increased the production of camptothecin. The optimal dosing time of elicitor was the beginning of the cultures. The combination of two elicitors was more effective to produce camptothecin than single applications. $20.42{\times}10^{-3}mg/\ell$ of camptothecin was obtained with combined application of two elicitors in two days.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.581-590
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• 2016

Resistance to anoikis, a cell-detachment induced apoptosis, is one of the malignant phenotypes which support tumor metastasis. Molecular mechanisms underlying the establishment of this phenotype require further investigation. This study aimed at exploring protein expression profiles associated with anoikis resistance of a metastatic breast cancer cell. Cell survival of suspension cultures of non-metastatic MCF-7 and metastatic MDA-MB-231 cells were compared with their adherent cultures. Trypan blue exclusion assays demonstrated a significantly higher percentage of viable cells in MDA-MB-231 than MCF-7 cell cultures, consistent with analysis of annexin V-7-AAD stained cells indicating that MDA-MB-231 possess anti-apoptotic ability 1.7 fold higher than MCF-7 cells. GeLC-MS/MS analysis of protein lysates of MDA-MB-231 and MCF-7 cells grown under both culture conditions identified 925 proteins which are differentially expressed, 54 of which were expressed only in suspended and adherent MDA-MB-231 but not in MCF-7 cells. These proteins have been implicated in various cellular processes, including DNA replication and repair, transcription, translation, protein modification, cytoskeleton, transport and cell signaling. Analysis based on the STITCH database predicted the interaction of phospholipases, PLC and PLD, and 14-3-3 beta/alpha, YWHAB, with the intrinsic and extrinsic apoptotic signaling network, suggesting putative roles in controlling anti-anoikis ability. MDA-MB-231 cells grown in the presence of inhibitors of phospholipase C, U73122, and phospholipase D, FIPI, demonstrated reduced ability to survive in suspension culture, indicating functional roles of PLC and PLD in the process of anti-anoikis. Our study identified intracellular mediators potentially associated with establishment of anoikis resistance of metastatic cells. These proteins require further clarification as prognostic and therapeutic targets for advanced breast cancer.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.111-114
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• 1995

To produce ${\gamma}$-linolenic acid (GLA) by cell cultures of Lithospermum erythrorhizon, we optimized medium compositions including carbon sources, nitrogen sources and growth regulators. MS basal medium supplemented with 1.0 mg/L 2, 4-D was effective for callus induction from mesophyll tissue. Addition of sucrose at 88mM concentration induced active proliferation of suspension cells and increased GLA content. Increased supplement of potassium nitrate as nitrogen source resulted in proliferous cell growth and increased total fatty acid content Abscisic acid increased cell growth and fatty acid content in callus culture, whereas as it had an inhibitory effect in suspension cell culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.306-316
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• 1997

Embryogenic calli were induced from mature seed scutella of anther culture-derived rice variety Zhonghua 8. Cell suspension cultures were initiated from friable embryogenic calli and utilized as source material for protoplast isolation. Generally, the older and finer cell suspensions gave higher protoplast yields than younger suspension cultures. Protoplasts exhibited sustained cell division and formed microcalli when cultured in KPR medium supplemented with 0.5 mg $l^{-1}$ 2,4-D, 1.0 mg $l^{-1}$ NAA and 0.5 mg $l^{-1}$ zeatin using the agarose embedding procedure without feeder cells. Protoplast plating efficiencies ranged from 0.20 to 0.54％. Microcalli were transferred to MS medium supplemented with 2.0 mg $l^{-1}$ kinetin and 0.5mg $l^{-1}$ NAA for plant regeneration. The regeneration frequencies were 2 to 12％, depending on the cell suspension lines of Zhonghua 8. The plants were transferred to the glasshouse and were fertile.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.3
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• pp.138-149
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• 2002

Plant cell culture provides a viable alternative over whole plant cultivation for the production of secondary metabolites. In order to successfully cultivate the plant cells at large scale, several engineering parameters such as, cell aggregation, mixing, aeration, and shear sensitivity are taken into account for selection of a suitable bioreactor. The media ingredients, their concentrations and the environmental factors are optimized for maximal synthesis of a desired metabolite. Increased productivity in a bioreactor can be achieved by selection of a proper cultivation strategy (batch, fed-batch, two-stage etc.), feeding of metabolic precursors and extraction of intracellular metabolites. Proper understanding and rigorous analysis of these parameters would pave the way towards the successful commercialization of plant cell bioprocesses.

• Journal of Microbiology and Biotechnology
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• v.1 no.1
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• pp.79-83
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• 1991

The effects of phosphate concentration in the medium, feeding of biosynthetic precursor, and the addition of exogenous berberine on cell growth and berberine production were studied in cell suspension cultures of Thalictrum rugosum. The depletion of phosphate in the medium enhanced the specific productivity up to twofold with significant release of berberine into the medium. Extracellular berberine was 19% of the total in the culture without phosphate while it was 2-5% of total berberine in the culture with even low amounts of phosphate. Precursor feeding was not effective in enhancing alkaloid formation. Initial presence of exogenous berberine did not have much effect on cell growth and alkaloid production. It was found that the cells have the capacity to take up large quantities of berberine. When $500{\;}mg{\cdot}l^{-1}$ of berberine was added exogenously at the beginning, 81% of total berberine was found in the cells.

• KSBB Journal
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• v.13 no.6
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• pp.700-705
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• 1998

Studies were made to investigate effects of the scale-up of stirred tank bioreactors on cell growth and alkaloids production for suspension cultures of Eschscholtzia californica. In the 1.5 L STR, cell lysis was observed at 110 rpm or higher agitation speed. The agitation speed of 30 L STR was 43.7 rpm to maintain the same shear stress developed in 1.5 L STR of 100 rpm. As a result of scale-up from 1.5 L to 30 L STR, the specific growth rate was decreased from 0.12 to 0.07 day-1. The alkaloids productivity was also decreased from 0.24 to 0.14 mg/L-day. Changes of mixing performance and oxygen transfer were studied to explain the decrease of cell growth and alkaloids production. Decreased oxygen transfer rate coefficient(KLa) and increased mixing time by the scale-up was observed at various aeration rates.

• KSBB Journal
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• v.8 no.1
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• pp.55-61
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• 1993

Cell lines of Ginkgo biloba were derived from different plant parts and from ten varieties spanning various geographic locations. They had various properties of growth and product formation. More than three flavonol glycosides were present in low concentration in callus and suspension cultures. Cell growth and biosynthesis of flavonol glycosides were found to be affected by medium composition. Culture conditions which influenced cell growth and product formation were also examined. Light stimulated the flavonol glycosides biosynthesis and ten times higher flavonol glycosides content was obtained as compared with the result without light.

• KSBB Journal
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• v.30 no.2
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• pp.82-90
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• 2015

Plant cell immobilization can protect plant cells from shear forces and increase the stability of gene. An additional advantage of immobilization is the easiness for performing continuous culture with cell recycling. Therefore plant cell immobilization can overcome the limitations of plant cell applications. In addition, target protein should be selected from pharmaceutical proteins to get rid of low expression level problem. The enhanced production of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) was investigated in immobilized Nicotiana tabacum suspension cell cultures. When the cells were immobilized in polyurethane foam, specific production of hGM-CSF was higher than that in alginate bead immobilization. Optimum continuous culture condition was the addition of 60 g/L sucrose in growth media with exchanging media every 6 day. Under the same condition, specific hGM-CSF production was 7 times higher in a 500-mL spinner flask than that in 100-mL Erlenmeyer flasks. Therefore, development of an effective immobilization process would be possible when the advantage of easy cell recycling was used. Consequently, enhanced production of target proteins could be possible in immobilized continuous cultures when the advantages of immobilization were applied.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.255-260
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• 2006

Culture conditions for high frequency plant regeneration via somatic embryogenesis from embryogenic cell suspension cultures of Hovenia dulcis are described. Germinated somatic embryos were selected for induction of secondary embryogenesis. Friable embryogenic cells were induced directly from somatic embryos when transfer to 1/3 MS solid or liquid medium lacking plant growth regulators. The temperature strongly effected on induction of secondary embryognesis than other conditions in culture. All somatic embryos produced friable embryogenic cell clumps within 10 days when germinated somatic embryos cultured in 1/3 MS medium at $30^{\circ}C$ in suspension culture. No somatic embryos formed from embryogenic cell suspension cultures at $18^{\circ}C$. Numerous somatic embryos were induced and subsequently developed uniformly into germination stage from suspended cell clumps after 4 weeks of culture on $18^{\circ}C$. Plantlets conversion were observed on $18^{\circ}C$ when germinated somatic embryos were transferred to 1/3 MS solid medium without plant growth regulators or supplemented with 0.1-0.5 mg/l benzyladenine.