• Applied Biological Chemistry
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• 제33권4호
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• pp.343-348
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• 1990

CDDP를 처리한 pBR322 DNA로 형질변환된 대장균 LE392를 ampicillin이 포함된 한천평판배지위에 도말시켰다. Ampicillin을 함유하고 있는 평판배지위에 형성된 집락수는 13.3 ${\mu}M$의 CDDP를 처리한 뒤에는 검출되지 않을 정도로 감소하였다. CDDP를 처리한 pBR322 DNA는 외가닥 DNA에 특이성이 있는 S1 핵산분해호소에 의해 전달되었고 아가로즈 겔 전기영동상에서 이동 유형이 변했다. 이러한 결과에 의하면 CDDP가 pBR322 DNA에 반응하여 이증나선의 변성과 궁극적으로는 ampicillin 저항성 유전자를 불활성화시키는 구조변화를 일으키는 것 같다.

• 생명과학회지
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• 제16권7호
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• pp.1199-1206
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• 2006

Plasminogen kringle 5는 plasminogen kringles 1-4로 구성된 내생의 혈관 신생 억제제인 angiostatin과 같이 내피세포의 분열을 강력하게 억제한다고 알려져 있다. 본 연구에서는 plasminogen kringle 5의 재조합 단백질을 효모 발현 체계에서 생산하여 내피세포의 이동에 대한 저해 효과와 이에 대한 작용기전을 조사하였다 재조합 단백질 PK5는 plasminogen의 Thr456에서 Phe546까지 이르는 cDNA 부분을 ${\alpha}-factor$ prepro-peptide의 분비 신호 서열 뒤에 도입하여 Pichia pastoris GS115에서 발현시켰다. 메탄올 유도 후 얻은 배양액을 S-spin column을 이용하여 정제하였다. 정제된 단백질을 SDS-PACE하였을 때 약 10kDa의 단일 밴드를 나타냄을 확인할 수 있었다. 정제된 PK5는 bFGF나 VEGF에 의해 유도된 인간의 제대 유래 내피 세포의 이동을 약 500nM의 $IC_{50}$ 값으로 농도 의존적으로 감소시켰다. 내피 세포에 PK5 500M을 처리한 결과 bFGF에 의해 유도된 ERK1/2의 인산화를 감소시켰다 또한, PK5는 bFGF에 의해 유도된 내피세포의 골격 재형성을 강력하게 억제하는 것으로 관찰되었다. 따라서, 이러한 결과들은 효모 생산 PK5가 내피세포의 이동을 효과적으로 억제하며, 이는 ERK1/2의 활성과 세포골격의 재배열을 억제함으로써 나타나는 것으로 부분적으로 설명될 수 있다.

• 보존과학연구
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• 통권25호
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• pp.47-74
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• 2004

We investigated the nucleotide substitution and insertion polymorphism of the hypervariable region Ⅰ and Ⅱ in mt DNA by sequencing ancient DNA from 51 ancient bones and teeth excavated at Nuk-do and Yimdang-dong in Korea. It revealed 35 sequence types from the ancient Korean. Of these, different sequences were 34 sequences. There were 19 and 38 base substitutions in HVI and HVⅡ, respectively. Some substitutions were characteristic of East Asian populations as compared with data reported on Caucacianpopulations,16051, 16150, 16172, 16223 in region I and 73, 263 in region II were noted as polymorphic sites, respectively. These were distributed evenly along the control region, though the frequency of each site was variable. Nucleotide substitution rather than insertion and deletion was the prevalent pattern of variation. Insertion of cytosine between312 and 315 in region HVⅡ were detected up to 98% in 51 ancient bone samples. This sequence data represents a phylogenetic tree using NTI DNA Suite computer program. The phylogenetic tree showed that mt DNA sequences of Nuk-do bones were relative to west Siberian and Indonesian. The usefulness of mt DNA sequencing in ancient Korean population excavated atarchaeological sites is based on biological and historical evidence for origin and migration of ancient Korean.

• 대한의생명과학회지
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• 제17권1호
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• pp.69-77
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• 2011

In this study, we evaluated the protective effects of supercritical extracts and two step ethanol extracts after supercritical extraction from Schizandra chinensis on antioxidant activities and oxidative DNA and cell damages. Supercritical extracts removed DPPH (1,1-diphenyl-2-picryldrazyl) radical by 85.5% at 200 ${\mu}g$/ml, but showed low activities of scavenging and chelating the hydroxyl radical and ferrous iron. However, two step ethanol extracts showed low activities of scavenging the DPPH radical, but removed the hydroxyl radical by 86% at 200 ${\mu}g$/ml. In addition, we tested the activities of extracts for reducing hydroxyl radical-induced DNA and cell damage. Two step ethanol extracts showed protective effect against the oxidative DNA damage by reducing DNA segmentation, inhibiting DNA migration and decreasing the expression of phospho-H2AX. Also, two step ethanol extracts showed protective effect against the oxidative cell damage by inhibiting lipid peroxidation and increasing the expression of p21 protein. Taken together, we suggest that two step ethanol extracts from S. chinensis have a role as useful inhibitors against oxidative damages.

• 한국식품영양과학회지
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• 제29권6호
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• pp.1025-1029
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• 2000

방사선 조사된 쇠고기와 돼지고기의 방사선 조사 여부를 판별하는데 DNA comet assay의 활용 가능성을 검토하였다. 쇠고기와 돼지고기는 Co-60 동위 원소를 조사원으로 하여 0.1, 0.3, 0.5, 0.7, 1.0 kGy의 총흡수선량( $\pm$ 5.0%)이 되도록 조사하여, 냉동상태로 보관하였다. 시료로부터 분리 된 세포는 agarose gel과 혼합하여 슬라이드에 깔아주고, lysis 및 전기영동을 하였다. 방사선 조사된 시료의 경우 세포로부터 끌려나오는 DNA절편들은 양극을 방향으로 tail이 형성되었고, 비조사 시료의 경우 tail이 없거나, 일부에서만 작은 tail이 관찰되었다. 방사선 조사유무는 0.1 kGy부터 현미경상으로 검지가 가능하였고, 선량간 차이의 유의성 여부는 통계분석을 통하여 검지가 가능하여, 쇠고기와 돼지고기의 신속한 검지 방법으로 DNA comet assay를 활용할 수 있을 것이다.

• Biomolecules & Therapeutics
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• 제30권1호
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• pp.80-89
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• 2022

The targeting of DNA methylation in cancer using DNA hypomethylating drugs has been well known to sensitize cancer cells to chemotherapy and immunotherapy by affecting multiple pathways. Herein, we investigated the combinational effects of DNA hypomethylating drugs and ionizing radiation (IR) in human sarcoma cell lines both in vitro and in vivo. Clonogenic assays were performed to determine the radiosensitizing properties of two DNA hypomethylating drugs on sarcoma cell lines we tested in this study with multiple doses of IR. We analyzed the effects of 5-aza-dC or SGI-110, as DNA hypomethylating drugs, in combination with IR in vitro on the proliferation, apoptosis, caspase-3/7 activity, migration/invasion, and Western blotting using apoptosis- or autophagy-related factors. To confirm the combined effect of DNA hypomethylating drugs and IR in our in vitro experiment, we generated the sarcoma cells in nude mouse xenograft models. Here, we found that the combination of DNA hypomethylating drugs and IR improved anticancer effects by inhibiting cell proliferation and by promoting synergistic cell death that is associated with both apoptosis and autophagy in vitro and in vivo. Our data demonstrated that the combination effects of DNA hypomethylating drugs with radiation exhibited greater cellular effects than the use of a single agent treatment, thus suggesting that the combination of DNA hypomethylating drugs and radiation may become a new radiotherapy to improve therapeutic efficacy for cancer treatment.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3715-3721
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• 2013

In this study, the behavior of cells on the modified surface, and the correlation between the modified substrates and the response of cells is described. A close-packed layer of nano-sized silica beads was prepared on a coverslip, and the adhesion, proliferation, and migration of BALB/3T3 fibroblast cells on the silica layer was monitered. The 550 nm silica beads were synthesized by the hydrolysis and condensation reaction of tetraethylorthosilicate in basic solution. The amine groups were introduced onto the surfaces of silica particles by treatment with 3-aminopropyltrimethoxysilane. The close-packed layer of silica beads on the coverslip was obtained by the reaction of the amine-functionalized silica beads and the (3-triethoxysilyl)propylsuccinic anhydride treated coverslip. BALB/3T3 fibroblast cells were loaded on bare glass, APTMS coated glass, and silica bead coated glass with the same initial cell density, and the migration and proliferation of cells on the substrates was investigated. The cells were fixed and stained with antibodies in order to analyze the changes in the actin filaments and nuclei after culture on the different surfaces. The motility of cells on the silica bead coated glass was greater than that of the cells cultured on the control substrate. The growth rate of cells on the silica bead coated glass was slower than that of the control. Because the close-packed layer of silica beads gave an embossed surface, the adhesion of cells was very weak compared to the smooth surfaces. These results indicate that the adhesion of cells on the substrates is very important, and the actin filaments might play key roles in the migration and proliferation of cells. The nuclei of the cells were shrunk on the weakly adhered surfaces, and the S1 stage in which DNA is duplicated in the cell dividing processes might be retarded. As a result, the rate of proliferation of cells was decreased compared to the smooth surface of the control. In conclusion, the results described here are very important in the understanding of the interaction between implanted materials and biosystems.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4441-4446
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• 2013

Cholangiocarcinoma (CCA) is a tumor of biliary ducts, which has a high mortality rate and dismal prognosis. Constitutively activation of the transcription factor nuclear factor kappa-B (NF-${\kappa}B$) has been previously demonstrated in CCA. It is therefore a potential target for CCA treatment. Effects of diethyldithiocarbamate (DDTC) on NF-${\kappa}B$-dependent apoptosis induction in cancer have been reported; however, anti-metastasis has never been addressed. Therefore, here the focus was on DDTC effects on CCA migration and adhesiond. Anti-proliferation, anti-migration and anti-adhesion activities were determined in CCA cell lines, along with p65 protein levels and function. NF-${\kappa}B$ target gene expression was determined by quantitative RT-PCR. DDTC inhibited CCA cell proliferation. Suppression of migration and adhesion were observed prior to anti-CCA proliferation. These effects were related to decreased p65, reduction in NF-${\kappa}B$ DNA binding, and impaired activity. Moreover, suppression of ICAM-1 expression supported NF-${\kappa}B$-dependent anti-metastatic effects of DDTC. Taken together, DDTC suppression of CCA migration and adhesion through inhibition of NF-${\kappa}B$ signaling pathway is suggested from the current study. This might be a promising treatment choice against CCA metastasis.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4815-4822
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• 2012

Invasion and metastasis are the major causes of cancer-related death. Pharmacological or therapeutic interventions such as chemoprevention of the progression stages of neoplastic development could result in substantial reduction in the incidence of cancer mortality. (-)-Epigallocatechin-3-gallate (EGCG), a promising chemopreventive agent, has attracted extensive interest for cancer therapy utilizing its antioxidant, anti-proliferative and inhibitory effects on angiogenesis and tumor cell invasion. In this study, we assessed the influence of EGCG on the proliferative potential of HeLa cells by cell viability assay and authenticated the results by nuclear morphological examination, DNA laddering assay and cell cycle analysis. Further we analyzed the anti-invasive properties of EGCG by wound migration assay and gene expression of MMP-9 and TIMP-1 in HeLa cells. Our results indicated that EGCG induced growth inhibition of HeLa cells in a dose- and time-dependent manner. It was observed that cell death mediated by EGCG was through apoptosis. Interestingly, EGCG effectively inhibited invasion and migration of HeLa cells and modulated the expression of related genes (MMP-9 and TIMP-1). These results indicate that EGCG may effectively suppress promotion and progression stages of cervical cancer development.

• 헤리티지:역사와 과학
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• 제40권
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• pp.387-411
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• 2007

고대 DNA분석은 인류학, 고고학, 생물학자뿐만 아니라 대중의 관심사가 될 정도로 점차 중요성이 강조되고 있다. 고고학자와 생물학자는 인류의 기원과 집단의 이주, 민족의 형성 그리고 고대인의 질병과 매장문화를 규명하는데 있어 고대 DNA분석을 접목하고 있으며, 이미 멸종된 동물의 계통진화학적인 연구에도 이를 활용하고 있다. 고대 DNA분석의 새로운 전기가 마련된 계기는 고대 시료에서 추출되는 미량의 DNA 증폭을 가능하게 한 종합효소연쇄반응(Polymerase chain reaction, PGR)법이 개발되면서였다. 그러나 고대 DNA는 탈아미노화나 절편화 등의 분자 손상 정도가 심한데 이것은 PCR에서 중합효소의 정확한 DNA 증폭을 방해하는 요인으로 작용한다. 시토신이 탈아미노화되어 우라실을 형성하는 것은 DNA의 염기치환오류를 일으킬 수 있으며, 이런 현상은 증폭 과정에서 고유의 염기서열에 대한 고정치환($C{\rightarrow}T$, $G{\rightarrow}A$)을 유도하게 된다. 또한 대부분의 고대시료는 외부 오염물에 노출되어 있는데, 특히 외부 DNA의 오염은 고대 DNA의 염기서열을 결정함에 있어서 부정확한 결과를 도출시키는 심각한 문제를 초래하곤 한다. 이와 같이 고대 시료는 오랜 기간 동안 자연 분해과정과 다양한 오염물질에 노출되어 있어 그 훼손 정도가 심한 것이 일반적이다. 고대 DNA 연구에 있어서 많은 생화학적 손상과 외부 DNA의 오염을 극복하기 위해서는 보통의 분자생물학적인 방법과 기준보다 더욱더 엄격한 검증 절차에 의하여 연구가 진행되어야 하며, 연구 결과의 신뢰성을 확보하는 것이 무엇보다 중요하다. 따라서 본 글에서는 고대 DNA의 손상과 오염물질에 의한 부정확한 염기서열결정과 오류를 보정하고 예방할 수 있는 연구 기준과 실험적 절차를 설명하고자 한다.