• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4891-4896
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• 2013

Objective: To separate/enrich tumor stem-like cells from the human esophageal carcinoma cell line OE-19 by using serum-free suspension culture and to identify their biological characteristics and radiation resistance. Methods: OE-19 cells were cultivated using adherent and suspension culture methods. The tumor stem-like phenotype of CD44 expression was detected using flow cytometry. We examined growth characteristics, cloning capacity in soft agar, and radiation resistance of 2 groups of cells. Results: Suspended cells in serum-free medium formed spheres that were enriched for CD44 expression. CD44 was expressed in 62.5% of suspended cells, but only in 11.7% of adherent cells. The suspended cells had greater capacity for proliferation and colony formation in soft agar than the adherent cells. When the suspended and adherent cells were irradiated at 5 Gy, 10 Gy, or 15 Gy, the proportion of CD44+ suspended cells strongly and weakly positive for CD44 was 77.8%, 66.5%, 57.5%; and 21.7%, 31.6%, 41.4%, respectively. In contrast, the proportion of CD44+ adherent cells strongly positive for CD44 was 18.9%, 14.%, and 9.95%, respectively. When the irradiation dose was increased to 30 Gy, the survival of the suspended and adherent cells was significantly reduced, and viable CD44+ cells were not detected. Conclusion: Suspended cell spheres generated from OE-19 esophageal carcinoma cells in serum-free stem medium are enriched in tumor stem-like cells. CD44 may be a marker for these cells.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.91-94
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• 2000

The suspension cells of Taxus cuspidata were transformed with Agrobacterium tumefaciens harboring binary vector pCAMBIE1302 encoding mgfp. Transient transfection efficiency was compared by using the fluoremetric measurement. The transient transfection efficiency was improved by transformation with DMSO and/or sonication treatment. Optimum conditions for DMSO and sonication treatment were 3% and 30sec, respectively. selection and maintenance of transformed cells were continued for 3 months. An insertion of the mgfp gene in transformed cells was detected by PCR and an expression of GFP confirmed by the western blot analysis.

• Journal of Plant Biology
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• 제37권3호
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• pp.263-269
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• 1994

Involvement of ethylene and Ca2+ on the induction of phenylalanine ammonia-lyase (PAL) was investigated in Daucus carota L. suspension culture system. Ethylene production started to increase about 3 h after glucan treatment. And the maximal induction of ethylene was preceded by PAL induction by 30 min. After the treatment of ethrel, PAL activity was increased. When cells were treated with glucan and Co2+, PAL activity was simultaneously reduced. Ethylene production was reduced dramatically in calcium-free medium, even though glucan was treated. PAL activity and ethylene producton was inhibited conspicuously when ethylene glycolbis($\beta$-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA) was treated with glucan. Verapamil and trifluoperazine also inhibited PAL activity. When cells were treated with calcium ionophore A23187, PAL activity was increased in nontreated medium. We report here PAl activity is increased in related to ethylene production and involvement of Ca2+ in glucan-treated carrot suspension cells.

• Journal of Plant Biotechnology
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• 제31권2호
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• pp.169-173
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• 2004

유소직 세포들은 aldose인 D-glucose ketose인 D-fructose에 대하여 다른 능동 수송계를 소유하고 있었다. D-glucose와 D-fructose 수송계의 $K_{m}$ 값은 각각 0.28 mM과 15.02mM이었다. D-mannose는 $K_{m}$ 값이 0.44 mM로 D-glucose와 유사하였지만, 그러나 D-glucose와는 다른 수송계를 소유하고 있었다. L-glucose도 고유한 수송계를 통하여 세포내로 수송되었으며, 그러나 그 기능을 전혀 알지 못하고 있다. 유조직 원형질체는 단당류 능동 수송계만을 소유하고, 이당류인 sucrose능동 수송계는 소유하지 않고 있었다. 발달 초기단계에 있는 사부 원형질체는 glucose와 sucrose 수송계를 동시에 소유하고 있었다. 완전히 발달된 사부세포에서는 이미 존재하였던 glucose 능동 수송계는 사라지고, 새로 유도된 sucrose 능동 수송계만 존재하는 것으로 측정되었다.

• 한국식품과학회지
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• 제36권1호
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• pp.58-63
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• 2004

수박과 참외의 황용도 증진을 위하여 조직을 개개의 세포로 분리할 수 있는 단세포화 기술을 적용하였다. 그 결과 이들을 시판 식물세포분리효소인 Macerozyme A와 Sumyzyme MC로 30분에서 120분간 반응시간별 단세포 함유 반응물의 특성을 조사하였다. 단세포화로 얻을 수 있는 수율, 반응률, 단세포 함유 반응물의 색도, 점도, 총당, 총펙틴, 총폴리페놀, 무기질, 유리 아미노산 함량을 조사하였으며 또한 분리된 단세포의 형태변화를 입도분포로 조사하였다. 전반적으로 효소반응시간이 경과 할수록 반응물의 성분 함량은 증가하였으나 세포벽에 의하여 내부 구성성분이 보호를 받아 안정하게 유지되는 것으로 나타났다. 수박과 참외의 무기질 함량은 주스보다는 단세포 함유 반응물에서 상대적으로 함량이 높게 나타났다. 참외의 경우 무기질인 K의 함량은 효소반응물과 주스에서 각각 240.8 mg%, 172.7 mg%였다. 본 연구 결과는 수박과 참외로부터 효소반응 물의을 이용하여 새로운 형태의 음료 개발을 위한 기초자료로 활용 가능할 것으로 판단되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.154-159
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• 2006

Interleukin-18 (IL-18), otherwise known as interferon-gamma-inducing factor (IGIF), is one of several well characterized and important cytokines that contribute to host defenses. The complementary DNA (cDNA) of mature human interleukin-18 gene (hIL-18) was fused with the signal peptide of the rice amylase 1A gene (Ramy1A) and introduced into the plant expression vector under the control of a duplicated CaMV 35S promoter. The recombinant plasmid was transformed into tobacco (Nicotiana tabacum L. cv Havana) using the Agrobacterium-mediated transformation method. The integration of the hlL-18 gene into the genome of transgenic tobacco plants was confirmed by polymerase chain reaction (PCR) amplification and its expression was observed in the suspension cells that were derived from the transgenic plant callus by using Northern blot analysis. The hlL-18 protein was detected in the extracts of the transgenic callus and in the medium of the transgenic tobacco suspension culture by using immunoblot analysis. Based upon enzyme-linked immunosorbant assay (ELISA) results, the expression level of the hlL-18 protein approximated $166{\mu}g/L$ in the suspension culture medium. Bioassay results from the induction of $interferon-{\gamma}$ from a KG-1 cell line indicated that the hlL-18 secreted into the suspension culture medium was bioactive.

• Journal of Microbiology and Biotechnology
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• 제6권3호
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• pp.209-212
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• 1996

A two-step cooling technique has been developed for cryopreservation of suspension cultured Scutellaria baicalensis cells. Efficient regrowth of cryopreserved cells was obtained in cryoprotected cells with a mixture of 1.5 M glycerol and 0.4 M sucrose in Schenk and Hildebrandt medium without pretreatment in high osmotic medium. Optimum freezing conditions were found to be a cooling rate of $0.5^{\circ}C$ min from $4^{\circ}C$ to $-40^{\circ}C$, and then retaining samples at $-40^{\circ}C$ for 30 min prior to plunging into liquid nitrogen. A regrowth rate of approximately 95$%$ was obtained after three month storage in liquid nitrogen. Callus cultures established from the cryopreserved cells were found to produce the same patterns of flavonoid accumulation and retain their baicalin producing activity.

• 식물조직배양학회지
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• 제27권3호
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• pp.233-238
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• 2000

야생 흰제비꽃의 엽병 유래 callus를 장기 계대배양하는 과정 중에 발생하는 순화된 friable callus와 분화능이 높은 compact callus를 비교 관찰한 바, friable callus는 연초록색으로 부서지기 쉬운 부드러운 callus이고, compact callus는 진녹색으로 단단한 callus였다. 동결처리 한 시료를 주사전자 현미경에서 동일하게 200배로 관찰하여 보면, friable callus 는 작은 세포집단으로 이루어진 세포군의 주변부에 고도로 액포화된 세포가 광범위하게 분포되어 있는 반면, compact callus는 거의 균일한 세포들로 구성되어 세포구성이 치밀한 것으로 관찰되었다. 또한 friable callus와 compact callus로 부터의 체세포배형성은 배양세포에서 배가 발생하여 배양기간이 지남에 따라 식물체로 분화하였다. 이와 같은 과정은 배양세포의 세포질이 보다 충만한 부위에서 배유사체 (embryo like body)의 발생이 이루어지는 것으로 관찰되었다.

• Natural Product Sciences
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• 제3권1호
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• pp.71-74
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• 1997

Cell suspension cultures of Solanum mammosum transformed inoculated salicyl alcohol into salicin $(salicyl\;alcohol\;2-0-{\beta}-D-glucopyranoside)$. The highest level of salicin (59.3 mg/flask) in the cells was formed within 3 days after inoculating with salicyl alcohol (50 mg /flask containing 50 ml medium). The glucosylation capability of salicyl alcohol by cell suspension cultures of S. mammosum was relatively higher than that reported previously.

• 식물조직배양학회지
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• 제25권1호
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• pp.7-11
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• 1998

Streptanthus 조직 배양 세포를 사용하여 사부를 순수분리 시키고, 분리된 사부에서 사부 하적에 대한 기작을 규명하기 위해 다음 연구를 하였다. 유조직 세포는 0.2% macerase 와 0.03% cellulase의 가수분해 효소로 처리하여 원형질체를 얻었고, 분화된 세포에서는 0.03% cellulase + 0.02% pectinase + 0.2% macerase + 0.025% rohamet PC로 가수분해시켜서 순수한 사부 세포와 사부 원형질체와 반세포의 원형질체를 분리하였다. 분리된 유조직 세포와 반세포의 원형질체에서는 단당류인 포도당을 수송시키나, 설탕은 수송시키지 못했다. 반면 분리된 사부 세포는 설탕을 능동수송 시키나 포도당은 수송시키지 못했다. 이는 설탕의 사부 하적은 반세포 없이도 가능하며, 반세포는 설탕 운반체가 없어서 설탕을 직접 수송할 수 있는 능력이 없다는 것을 보여주는 것이다. 그리고 사부 세포에서 설탕의 수송은 에너지대사에 의존하는 능동수송으로 나타났다.