• Journal of Acupuncture Research
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• v.25 no.3
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• pp.53-69
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• 2008

목적 : 이 연구는 Vipera lebetina turanica의 사독약침액(蛇毒藥鍼液)(Snake venom toxin, SVT)이 인간 신경아세포종의 암세포주인 SK-N-SH 세포에서 암세포성장의 억제 및 그 기전에 대하여 살펴보고자 하였다. 방법 : SVT를 처리한 후 SK-N-SH의 성장억제를 관찰하기 위해 CCK-8 assay와 LDH assay를 시행하였고, apoptosis 평가에는 세포형태의 관찰과 DAPI, TUNEL, Annexin V-PI double staining assay 및 cell detachment assay를 시행하였다. 세포자멸사 관련 세포기전을 보기 위하여 세포주기, 세포내 칼슘량, 세포내 활성산소량 및 미토콘드리아의 세포막전위 변화를 측정하였고, DNA fragmentation assay를 시행하였으며, 세포자멸사 조절 단백인 Bax, Bcl-2, caspase-3, -9의 발현 변화 관찰에는 western blot analysis를 시행하였다. 결과 : SK-N-SH 세포에 SVT를 처리한 후, 신경아세포종 세포의 성장, Apoptosis의 유발 및 기전의 영향을 관찰하여 다음과 같은 결과를 얻었다. 1. SVT를 처리한 SK-N-SH 세포 관찰에서 세포독성은 농도의존적으로 증가하는 경향이 있는 반면 암세포성장의 유의한 억제는 $20{\mu}g/m{\ell}$ SVT에 의해서만 나타났다. 2. 세포자멸사 평가에서 SVT를 처리한 SK-N-SH 세포는 세포자멸사의 특징적 형태를 나타내었다. TUNEL assay에서는 세포자멸사 활성세포가 미약하게 나타난 반면 cell detachment assay와 Annexin V-PI double staining에서는 각각 세포박리와 세포자멸사 활성세포의 유의한 증가를 나타내었다. 3. 세포자멸사 관련 세포기전연구에서 SVT를 처리한 SK-N-SH 세포의 세포주기, 세포 내 칼슘양 및 DNA fragmentation에는 유의한 변화가 관찰되지 않은 반면 세포내 활성산소 양은 유의한 증가를 나타내었고, 그에 따른 미토콘드리아 세포막 전위의 유의한 변동이 관찰되었다. 4. SVT를 처리한 SK-N-SH는 세포자멸사 관련 단백 발현에서 Bax에 대해 유의한 증가를 나타내지 않았으나 caspase-3 및 caspase-9의 유의한 증가와 Bcl-2의 유의한 감소를 나타내었다. 결론 : 이상의 결과는 SVT가 세포 내 활성산소를 증가시킴으로써 미토콘드리아의 세포막전위에 변화를 일으켜 인간 신경아세포종 세포주인 SK-N-SH의 세포박리와 유관한 세포자멸사를 유발함으로써 증식억제 효과가 있음을 입증한 것이다.

• Journal of Acupuncture Research
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• v.25 no.2
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• pp.41-57
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• 2008

목적 : 이 연구는 Vipera lebetina turanica의 사독약침액(蛇毒藥鍼液)(Snake venom toxin, SVT)이 인간 신경아세포종의 암세포주인 SK-N-MC 세포에서 암세포성장의 억제 및 그 기전에 대하여 살펴보고자 하였다. 방법 : SVT를 처리한 후 SK-N-MC의 성장억제를 관찰하기 위해 CCK-8 assay와 LDH assay를 시행하였고, apoptosis 평가에는 세포형태의 관찰과 DAPI, TUNEL, Annexin V-PI double staining assay 및 cell detachment assay를 시행하였다. 세포자멸사 관련 세포기전을 보기 위하여 세포주기, 세포내 칼슘량, 세포내 활성산소량 및 미토콘드리아의 세포막전위 변화를 측정하였고, DNA fragmentation assay를 시행하였으며, 세포자멸사 조절 단백인 Bax, Bcl-2, caspase-3, -9의 발현 변화 관찰에는 western blot analysis를 시행하였다. 결과 : SK-N-MC 세포에 SVT를 처리한 후, 신경아세포종 세포의 성장, Apoptosis의 유발 및 기전에 영향을 관찰하여 다음과 같은 결과를 얻었다. 1. SVT를 처리한 SK-N-MC 세포 관찰에서 $20{\mu}g/m{\ell}$ SVT 처리가 암세포성장의 유의한 억제를 나타내었다. 세포독성 관찰에서 SVT처리는 처리하지 않은 것에 비하여 증가를 나타내었다. 2. 세포자멸사 평가에서 SVT를 처리한 SK-N-MC 세포는 세포자멸사의 특징적 형태를 나타내었다. TUNEL assay에서는 세포자멸사 활성세포가 미약하게 나타난 반면 cell detachment assay와 Annexin V-PI double staining에서는 각각 세포박리와 세포자멸사 활성세포의 유의한 증가를 나타내었다. 3. 세포자멸사 관련 세포기전연구에서 SVT를 처리한 SK-N-MC 세포의 세포주기, 세포내 칼슘량 및 DNA fragmentation에는 유의한 변화가 관찰되지 않은 반면 세포내 활성산소 양은 유의한 증가를 나타내었고, 그에 따른 미토콘드리아 세포막 전위의 유의한 변동이 관찰되었다. 4. SVT를 처리한 SK-N-MC는 세포자멸사 관련 단백 발현에서 caspase-9에 대해 유의한 증가를 나타내지 않았으나 Bax 및 caspase-3의 유의한 증가와 Bcl-2의 유의한 감소를 나타내었다. 결론 : 이상의 결과는 SVT가 세포내 활성산소를 증가시키므로 미토콘드리아의 세포막전위에 변화를 일으켜 인간 신경아세포종 세포주인 SK-N-MC의 세포박리와 유관한 세포자멸사를 유발하므로 증식억제 효과가 있음을 입증한 것이다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.5
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• pp.335-340
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• 2013

In this study, the plasma etching of the TaN thin film with $CH_4/BCl_3/Ar$ gas chemistries was investigated. The etch rate of the TaN thin film and the etch selectivity of TaN to $SiO_2$ was studied as a function of the process parameters, including the amount of $CH_4$. X-ray photoelectron spectroscopy (XPS) and Field-emission scanning electron microscopy (FE-SEM) was used to investigate the chemical states of the surface of the TaN thin film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.363-363
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• 2008

The development of dry etching process for sapphire wafer with plasma has been key issues for the opto-electric devices. The challenges are increasing control and obtaining low plasma induced-damage because an unwanted scattering of radiation is caused by the spatial disorder of pattern and variation of surface roughness. The plasma-induced damages during plasma etching process can be classified as impurity contamination of residual etch products or bonding disruption in lattice due to charged particle bombardment. Therefor, fine pattern technology with low damaged etching process and high etch rate are urgently needed. Until now, there are a lot of reports on the etching of sapphire wafer with using $Cl_2$/Ar, $BCl_3$/Ar, HBr/Ar and so on [1]. However, the etch behavior of sapphire wafer have investigated with variation of only one parameter while other parameters are fixed. In this study, we investigated the effect of pressure and other parameters on the etch rate and the selectivity. We selected $BCl_3$ as an etch ant because $BCl_3$ plasmas are widely used in etching process of oxide materials. In plasma, the $BCl_3$ molecule can be dissociated into B radical, $B^+$ ion, Cl radical and $Cl^+$ ion. However, the $BCl_3$ molecule can be dissociated into B radical or $B^+$ ion easier than Cl radical or $Cl^+$ ion. First, we evaluated the etch behaviors of sapphire wafer in $BCl_3$/additive gases (Ar, $N_2,Cl_2$) gases. The behavior of etch rate of sapphire substrate was monitored as a function of additive gas ratio to $BCl_3$ based plasma, total flow rate, r.f. power, d.c. bias under different pressures of 5 mTorr, 10 mTorr, 20 mTorr and 30 mTorr. The etch rates of sapphire wafer, $SiO_2$ and PR were measured with using alpha step surface profiler. In order to understand the changes of radicals, volume density of Cl, B radical and BCl molecule were investigated with optical emission spectroscopy (OES). The chemical states of $Al_2O_3$ thin films were studied with energy dispersive X-ray (EDX) and depth profile anlysis of auger electron spectroscopy (AES). The enhancement of sapphire substrate can be explained by the reactive ion etching mechanism with the competition of the formation of volatile $AlCl_3$, $Al_2Cl_6$ or $BOCl_3$ and the sputter effect by energetic ions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.477-477
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• 2008

For more than three decades, the gate dielectrics in CMOS devices are $SiO_2$ because of its blocking properties of current in insulated gate FET channels. As the dimensions of feature size have been scaled down (width and the thickness is reduced down to 50 urn and 2 urn or less), gate leakage current is increased and reliability of $SiO_2$ is reduced. Many metal oxides such as $TiO_2$, $Ta_2O_4$, $SrTiO_3$, $Al_2O_3$, $HfO_2$ and $ZrO_2$ have been challenged for memory devices. These materials posses relatively high dielectric constant, but $HfO_2$ and $Al_2O_3$ did not provide sufficient advantages over $SiO_2$ or $Si_3N_4$ because of reaction with Si substrate. Recently, $HfO_2$ have been attracted attention because Hf forms the most stable oxide with the highest heat of formation. In addition, Hf can reduce the native oxide layer by creating $HfO_2$. However, new gate oxide candidates must satisfy a standard CMOS process. In order to fabricate high density memories with small feature size, the plasma etch process should be developed by well understanding and optimizing plasma behaviors. Therefore, it is necessary that the etch behavior of $HfO_2$ and plasma parameters are systematically investigated as functions of process parameters including gas mixing ratio, rf power, pressure and temperature to determine the mechanism of plasma induced damage. However, there is few studies on the the etch mechanism and the surface reactions in $BCl_3$ based plasma to etch $HfO_2$ thin films. In this work, the samples of $HfO_2$ were prepared on Si wafer with using atomic layer deposition. In our previous work, the maximum etch rate of $BCl_3$/Ar were obtained 20% $BCl_3$/ 80% Ar. Over 20% $BCl_3$ addition, the etch rate of $HfO_2$ decreased. The etching rate of $HfO_2$ and selectivity of $HfO_2$ to Si were investigated with using in inductively coupled plasma etching system (ICP) and $BCl_3/Cl_2$/Ar plasma. The change of volume densities of radical and atoms were monitored with using optical emission spectroscopy analysis (OES). The variations of components of etched surfaces for $HfO_2$ was investigated with using x-ray photo electron spectroscopy (XPS). In order to investigate the accumulation of etch by products during etch process, the exposed surface of $HfO_2$ in $BCl_3/Cl_2$/Ar plasma was compared with surface of as-doped $HfO_2$ and all the surfaces of samples were examined with field emission scanning electron microscopy and atomic force microscope (AFM).

• Journal of Acupuncture Research
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• v.18 no.3
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• pp.134-142
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• 2001

목적 : 인진(茵蔯)이 SK-N-MC 신경아세포주에서 에탄올에 의해 유발된 아폽토시스에 대한 보호작용의 기전을 연구하였다. 방법 : SK-N-MC cell line에서의 세포 보호 기전을 알아보기 위하여 reverse transcription polymerase chain reaction (RT-PCR) 기법을 이용하여 bcl-2, bax 및 caspase-3의 변화를 관찰하였다. 결과 : RT-PCR을 이용하여 분석한 결과 SK-N-MC neuroblastoma에서 에탄올 처치는 bax, bcl-2 및 caspase-3 mRNA의 발현을 증가시켰다. 인진액의 전처치후 에탄올 처치한 신경 아세포에서는 에탄올에 의해서 증가된 bax와 caspase-3 mRNA 발현이 억제되었으나, bcl-2의 발현에는 유의한 증가를 나타내지 않았다. 결론 : 이상의 결과를 통하여 에탄올에 의해서 유발된 신경아세포의 아폽토시스에서 인진이 세포보호 효과가 있음이 확인되었고 그 기전은 bax와 caspase-3의 억제에 기인할 가능성을 시사한다고 할 수 있다.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.287-291
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• 2012

We investigated the etching characteristics of TaN thin films in an $O_2/BCl_3/Cl_2/Ar$ gas using a high density plasma (HDP) system. A maximum etch rate of the TaN thin films and the selectivity of TaN to $SiO_2$ were obtained as 172.7 nm/min and 6.27 in the $O_2/BCl_3/Cl_2/Ar$ (3:2:18:10 sccm) gas mixture, respectively. At the same time, the etch rate was measured as a function of the etching parameters, such as the RF power, DC-bias voltage, and process pressure. The chemical states on the surface of the etched TaN thin films were investigated using X-ray photoelectron spectroscopy. Auger electron spectroscopy was used for elemental analysis on the surface of the etched TaN thin films. These surface analyses confirm that the surface of the etched TaN thin film is formed with the nonvolatile by-product.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.74-74
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• 2009

Titanium nitride has been used as hardmask for semiconductor process, capacitor of MIM type and diffusion barrier of DRAM, due to it's low resistivity, thermodynamic stability and diffusion coefficient. Characteristics of the TiN film are high intensity and chemical stability. The TiN film also has compatibility with high-k material. This study is an experimental test for better condition of TiN film etching process. The etch rate of TiN film was investigated about etching in $BCl_3/Ar/O_2$ plasma using the inductively coupled plasma (ICP) etching system. The base condition were 4 sccm $BCl_3$ /16 sccm Ar mixed gas and 500 W the RF power, -50 V the DC bias voltage, 10 mTorr the chamber pressure and $40\;^{\circ}C$ the substrate temperature. We added $O_2$ gas to give affect etch rate because $O_2$ reacts with photoresist easily. We had changed $O_2$ gas flow rate from 2 sccm to 8 sccm, the RF power from 500 W to 800 W, the DC bias voltage from -50 V to -200 V, the chamber pressure from 5 mTorr to 20 mTorr and the substrate temperature from $20\;^{\circ}C$ to $80\;^{\circ}C$.

• The Journal of Korean Medicine
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• v.31 no.3
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• pp.55-65
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• 2010

Background: Nitric oxide (NO) is a reactive free radical gas and a messenger molecule. NO has many physiological functions, but excessive NO production induces neurotoxicity. Objective: The present study investigated whether the aqueous extract of Polygala tenuifolia Willdenow possesses a protective effect on NO-induced apoptosis in human neuroblastoma cell line SK-N-MC. Method: For this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and caspase-3 enzyme assay were performed. Result: Sodium nitroprusside (SNP) exposure significantly decreased the viability of cells. The cells treated with SNP exhibited several apoptotic features such as increasing of Bax expression, caspase-3 enzyme activity and inhibiting of Bcl-2 expression. On the other hand, the viability of cells pre-treated with the aqueous extract of Polygala tenuifolia Willdenow was increased dose-dependently. The cells pre-treated for 1 h with the aqueous extract of Polygala tenuifolia Willdenow followed by treatment with SNP showed a decreased occurrence of apoptotic features like decreasing Bax expressions, caspase-3 enzyme activity and increasing Bcl-2 expressions. The aqueous extract of Polygala tenuifolia Willdenow reduced apoptotic cell death in neuroblastoma cell line SK-N-MC through the inhibition of Bax-dependent caspase-3 activation and the increasing of Bcl-2 expression. Conclusion: Based on the present results, it is possible that Polygala tenuifolia Willdenow has therapeutic value for the treatment of a variety of NO-induced brain diseases.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.113-113
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• 2002

Phylogenetically conserved Bcl-2 family proteins play a pivotal role in the regulation of apoptosis from virus to human. Members of the Bcl-2 family consist of antiapoptotic proteins such as Bcl-2, Bcl-xL, and Bcl-w, and proapoptotic proteins such as BAD, Bax, BOD, and Bok. It has been proposed that anti- and proapoptotic Bcl-2 proteins regulate cell death by binding to each other and forming heterodimers. A delicate balance between anti- and proapoptotic Bcl-2 family members exists in each cell and the relative concentration of these two groups of proteins determines whether the cell survives or undergoes apoptosis. Mcl-1 (Myeloid cell :leukemia-1) is a member of the Bcl-2 family proteins and was originally cloned as a differentiation-induced early gene that was activated in the human myeloblastic leukemia cell line, ML-1 . Mcl-1 is expressed in a wide variety of tissues and cells including neoplastic ones. We recently identified a short splicing variant of Mcl-1 short (Mcl-IS) and designated the known Mcl-1 as Mcl-1 long (Mcl-lL). Mcl-lL protein exhibits antiapoptotic activity and possesses the BH (Bcl-2 homology) 1, BH2, BH3, and transmembrane (TM) domains found in related Bcl-2 proteins. In contrast, Mcl-1 S is a BH3 domain-only proapoptotic protein that heterodimerizes with Mcl-lL. Although both Mc1-lL and Mcl-lS proteins contain BH domains fecund in other Bcl-2 family proteins, they are distinguished by their unusually long N-terminal sequences containing PEST (proline, glutamic acid, serine, and threonine) motifs, four pairs of arginine residues, and alanine- and glycine-rich regions. In addition, the expression pattern of Mcl-1 protein is different from that of Bcl-2 suggesting a unique role (or Mcl-1 in apoptosis regulation. Tankyrasel (TRF1-interacting, ankyrin-related ADP-related polymerasel) was originally isolated based on its binding to TRF 1 (telomeric repeat binding factor-1) and contains the sterile alpha motif (SAM) module, 24 ankyrin (ANK) repeats, and the catalytic domain of poly(adenosine diphosphate-ribose) polymerase (PARP). Previous studies showed that tankyrasel promotes telomere elongation in human cells presumably by inhibiting TRFI though its poly(ADP-ribosyl)action by tankyrasel . In addition, tankyrasel poly(ADP-ribosyl)ates Insulin-responsive amino peptidase (IRAP), a resident protein of GLUT4 vesicles, and insulin stimulates the PARP activity of tankyrase1 through its phosphorylation by mitogen-activated protein kinase (MAPK). ADP-ribosylation is a posttranslational modification that usually results in a loss of protein activity presumably by enhancing protein turnover. However, little information is available regarding the physiological function(s) of tankyrase1 other than as a PARP enzyme. In the present study, we found tankyrasel as a specific-binding protein of Mcl-1 Overexpression of tankyrasel led to the inhibition of both the apoptotic activity of Mel-lS and the survival action of Mcl-lL in mammalian cells. Unlike other known tankyrasel-interacting proteins, tankyrasel did not poly(ADP-ribosyl)ate either of the Mcl-1 proteins despite its ability to decrease Mcl-1 proteins expression following coexpression. Therefore, this study provides a novel mechanism to regulate Mcl-1-modulated apoptosis in which tankyrasel downregulates the expression of Mcl-1 proteins without the involvement of its ADP-ribosylation activity.