• Journal of the Korean Vacuum Society
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• v.11 no.2
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• pp.113-118
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• 2002

We developed engineering methods to control gas flow in a plasma reactor in order to achieve good etch depth uniformity for large area GaAs etching. Finite difference numerical method was found quite useful for simulation of gas flow distribution in the reactor for dry etching of GaAs. The experimental results in $BCl_3/N_2/SF_6/He$ ICP plasmas confirmed that the simulated data fitted very well with real data. It is noticed that a focus ring could help improve both gas flow and etch uniformity for 150 mm diameter GaAs plasma etch processing. The simulation results showed that optimization of clamp configuration could decrease gas flow uniformity as low as $\pm$ 1.5% on an 100 mm(4 inch) GaAs wafer and $\pm$ 3% for a 150 m(6 inch) wafer with the fixed reactor and electrode, respectively. Comparison between simulated gas flow uniformity and real etch depth distribution data concluded that control of gas flow distribution in the chamber would be significantly important in order or achieve excellent dry etch uniformity of large area GaAs wafers.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.62-68
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• 2020

Cisplatin (CDDP) is a chemotherapy agent used for patients with ovarian cancers. CDDP activates multiple signaling pathways, which causes various cellular reactions according to the type of cancer cells. Therefore, it is difficult to clearly conclude its signaling pathways. The purpose of this study is to determine the role of the signal protein of Akt/ERK1/2 and MAPK by CDDP-induced apoptosis in ovarian cancer cells (SKOV3). As a result, the number of apoptosis increased according to the TUNEL assay, and flow cytometric analysis confirmed that the percentage of sub-G1 early apoptosis was 8.73% higher than the control. The PARP and caspase-3 activity that appeared in the process of apoptosis was increased and the Bcl-2 expression was decreased. It was verified that the Akt and ERK1/2 activity was decreased, and p38 and JNK activity increased in a time dependent fashion. In conclusion, these results demonstrate that cisplatin inhibits the proliferation of ovarian cancer cells by inhibiting Akt activity and induces apoptosis by modulating the MAPK signaling pathway. However, a decrease in the ERK1/2 activity by CDDP was the opposite result to the result shown from the HeLa cells. For this reason, further research on signaling pathways is necessary. These results are expected to be useful for ovarian cancer treatment strategies targeting the MAPK pathway.

• Radiation Oncology Journal
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• v.28 no.2
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• pp.91-98
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• 2010

Purpose: Troglitazone (TRO), a PPAR-$\gamma$ agonist, can reduce heat shock protein (HSP) 70 and increase the antioxidant enzymes, such as superoxide dismutase (SOD) and catalase, which might affect thermal sensitivity. Here, we investigated whether TRO modifies thermal sensitivity in uterine cervical cancer cells, which is most commonly treated by hyperthermia (HT). Materials and Methods: HeLa cells were treated with $5{\mu}M$ TRO for 24 hours before HT at $42^{\circ}C$ for 1 hour. Cell survival was analyzed by clonogenic assay. The expression of HSPs was analyzed by Western blot. SOD and catalase activity was measured and reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate and dihydroethidium. Results: The decreased cell survival by HT was increased by preincubation with TRO before HT. Expression of HSP 70 was increased by HT however, it was not decreased by preincubation with TRO before HT. The decreased Bcl-2 expression by HT was increased by preincubation with TRO. SOD and catalase activity was increased by 1.2 and 1.3 times,respectively with TRO. Increased ROS by HT was decreased by preincubation with TRO. Conclusion: TRO decreases thermal sensitivity through increased SOD and catalase activity, as well as scavenging ROS in HeLa cells.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4685-4688
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• 2013

We aimed to investigate the mechanism and effects of autophagy on cisplatin (DDP)-induced apoptosis in human gastric cancer cell line SGC7901. After SGC7901 cells were treated with DDP and/or chloroquine, cell proliferation was measured using MTT assay; cell apoptosis was determined by flow cytometry; autophagy and apotosis-related proteins expression were detected by Western blot; and quantitative analysis of autophagy after monodansylcadaverine (MDC) staining was performed using fluorescence microscopy. We found after treatment with 5 mg/L DDP for 24 h, the rates of cell apoptosis were ($21.07{\pm}2.12$)%. Autophagy, characterized by an increase in the number of autophagic vesicles and the level of LC3-II protein was observed in cells treated with DDP. After inhibition of autophagy by chloroquine, the rates of cell apoptosis were increased to ($30.16{\pm}3.54$)%, and the level of Caspase-3 and P53 protein were increased, and Bcl-2 protein was decreased. Therefore, autophagy protects human gastric cancer cell line SGC7901 against DDP-induced apoptosis, inhibition of autophagy can promote apoptosis, and combination therapy with DDP and chloroquine may be a promising therapeutic strategy for gastric cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.491-495
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• 2016

Background: Small B-cell non-Hodgkins lymphoma (NHL) is difficult to be distinguished from non-neoplastic reactive processes using conventional haematoxylin-eosin (HE) staining due to different interpretations among pathologists with diagnosis based on morphologic features. Ancillary examinations such as immunohistochemical (IHC) staining are essential. However, negative or doubtful results are still sometimes obtained due to unsatisfactory tissue processing or IHC technique. The polymerase chain reaction (PCR) as a molecular diagnostic technique is very sensitive and specific. Clonality detection of heavy chain immunoglobulin (IgH) gene rearrangement has been widely used to establish diagnosis of B-cell NHL. Aims: To elaborate interobserver variation in small B-cell NHL diagnosis based on morphologic features only and to confirm sensitivity and specificity of the PCR technique as an ancillary method. Materials and Methods: A toptal of 28 samples of small B cell NHL and suspicious lymphoma were interpreted by 3 pathologists in Sardjito General Hospital based on their morphology only. The reliability of assessment and the coefficient of interobserver agreement were calculated by Fleiss kappa statistics. Interpretation results were confirmed with IHC staining (CD20, CD3, Bcl2). PCR was performed to analyze the clonality of IgH gene rearrangement. Results: Interobserver agreement in morphologic evalution of small B cell NHL and chronic lymphadenitis revealed kappa coefficient 0.69 included in the substantial agreement category. The cases were divided into 3 groups based on morphology and IHC results; lymphoma, reactive process and undetermined group. PCR analysis showed 90% sensitivity and 60% specificity. Conclusions: The present study revealed a substantial agreement among pathologists in small B-cell NHL diagnosis. For difficult cases, PCR is useful as complementary method to morphologic and IHC examinations to establish definitive diagnosis.

• Journal of Korean Neurosurgical Society
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• v.38 no.3
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• pp.215-220
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• 2005

Objective : Many researchers believe that the hypothermia shows neuro-protective effect on brain injury. To understand the molecular mechanism of the hypothermic treatment, this study investigated its effects on the expression of cell death or survival related proteins such as p53, Bcl-2 and Bax in the rat traumatic brain injury[TBI] model. Methods : Twenty rats [Spraque Dawley, $200{\sim}250g$] were subjected to the brain injury of moderate severity [$2.4{\sim}2.6atm$] using the fluid percussion injury device and five rats were received only same surgery as controls. During 30minutes after the brain injury, the hypothermia group was maintained the body temperature around $34^{\circ}C$ while the control group were maintained that of $36^{\circ}C$. Five rats in each group were sacrificed 12h or 24h after brain injury and their brain sections was analyzed for physical damages by H-E stains and the extent of apoptosis by TUNEL assay and immunohistochemical stains. The tissue damage after TBI was mainly observed in the ipsilateral cortex and partly in the hippocampus. Results : Apoptosis was observed by TUNEL assay and the Bax protein was detected in both sample which harvested 12h and 24h after TBI. In the hypothermia treatment group, tissue damage and apoptosis were reduced in HE stains and TUNEL assay. In hypothermia treatment group rat shows more expression of the Bcl-2 protein and shows less expression of the Bax protein, at both 12h and 24h after TBI. Conclusion : These results show that the hypothermia treatment is an effective treatment after TBI, by reducing the apoptotic process. Therefore, it could be suggested that hypothermia has a high therapeutic value for treating tissue damages after TBI.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9997-10001
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• 2014

Background: Curdione, one of the major components of Curcuma zedoaria, has been reported to possess various biological activities. It thus might be a candidate anti-flammatory and cancer chemopreventive agent. However, the precise molecular mechanisms of action of curdione on cancer cells are still unclear. In this study, we investigated the effect of curdione on breast cancer. Materials and Methods: Xenograft nude mice were used to detect the effect of curdione on breast cancer in vivo; we also tested the effect of curdione on breast cancer in vitro by MTT, Flow cytometry, JC-I assay, and western blot. Results: Firstly, we found that curdione significantly suppressed tumor growth in a xenograft nude mouse breast tumor model in a dose-dependent manner. In addition, curdione treatment inhibited cell proliferation and induced cell apoptosis. Moreover, after curdione treatment, increase of impaired mitochondrial membrane potential occurred in a concentration dependent manner. Furthermore, the expression of apoptosis-related proteins including cleaved caspase-3, caspase-9 and Bax was increased in curdione treatment groups, while the expression of the anti-apoptotic Bcl-2 was decreased. Inhibitors of caspase-3 were used to confirm that curdione induced apoptosis. Conclusions: Overall, our observations first suggested that curdione inhibited the proliferation of breast cancer cells by inducing apoptosis. These results might provide some molecular basis for the anti-cancer activity of curdione.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.413-417
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• 2015

Recently, we isolated HY253, a novel decahydrofluorene analog with a molecular structure of 7,8a-divinyl-2,4a,4b,5,6,7,8,8a,9,9a-decahydro-1H-fluorene-2,4a,4b,9a-tetraol from the roots of Aralia continentalis, which is known as Dokwhal (獨活), a traditional medicinal herb. Moreover, we previously reported its cytotoxic activity on cancer cell proliferation in human lung cancer A549 and cervical cancer HeLa cells. The current study aimed to evaluate its detailed molecular mechanisms in cell cycle arrest and apoptotic induction in human hepatocellular carcinoma HepG2 cells. Flow cytometric analysis of HepG2 cells treated with $60{\mu}M$ HY253 revealed appreciable cell cycle arrest at the G1 phase via inhibition of Rb phosphorylation and down-regulation of cyclin D1. Furthermore, using western blots, we found that up-regulation of cyclin-dependent kinase inhibitors, such as p21^CIP1 and p27^KIP1, was associated with this G₁ phase arrest. Moreover, TUNEL assay and immunoblottings revealed apoptotic induction in HepG2 cells treated with $60{\mu}M$ HY253 for 24 h, which is associated with cytochrome c release from mitochondria, via down-regulation of anti-apoptotic Bcl-2 protein, which in turn resulted in activation of caspase-9 and -3, and proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). Accordingly, we suggest that HY253 may be a potent chemotherapeutic hit compound for treating human liver cancer cells via up-regulation and activation of the p53 gene.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.495-498
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• 2006

Purpose: Trichoblastic fibroma originates from hair germ layer tumor which is a benign tumor mixture of epidermal and mesodermal factor. Trichoblastic fibroma was found only in adults and showed equal occurrence rate between men and women. Since it is a rare tumor, we report a case of a trichoblastic fibroma which developed on the right cheek. Methods: A 72 year-old male was treated with excisional operation 17 years ago due to a solitary tumor that developed on the same site. He returned to the hospital with an asymptomatic mass which have been increasing in size for the last 3 months. Results: In computerized tomography, a size of $2.7{\times}2.3{\times}0.8cm$ tumor was found in the subcutaneous tissue layer. Grossly, the mass was well-circumscribed, smooth-surfaced and flesh colored, and was lobulated and fragile. Pathologic observation showed diverse shaped and sized tumor cell nests and fibrocellular stroma consisting basophilic cells in dermal and subdermal layers. Immunohistopathologic staining showed positive reaction on pancytokeratin, CK-5/6, and bcl-2. Conclusion: By having no connection to the epidermis, and being positioned in the dermal and epidermal layers, typical pathologic findings make it possible to differentiate this tumor with basal cell carcinoma. This lesion is not clear whether it is a local recurrence or not, and it is necessary to observe a new recurrence in the future.

• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.146-161
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• 2005

Objectives : This study investigated neuroprotective effects of Polygoni Multiflori Radix on cerebral ischemia of hyperlipidemic rats. Methods : Effects of Polygoni Multiflori Radix were evaluated with changes of infarct size after He focal cerebral ischemia induced by the middle cerebral artery occlusion, changes of pyramidal neurons and expressions of Bax and Bcl-2 apoptosis regulating factors after global cerebral ischemia, and changes of serum lipid revels after cerebral ischemia. Results & Conclusions : Results obtained were as follows; 1. Polygoni Multiflori Radix did net reduce the focal cerebral infarct size induced by the middle cerebral artery occlusion under both hyperlipidemic and normal-lipid conditions. 2. Polygoni Multiflori Radix significantly reduced the increase of neuronal cell death in CAl region of hippocampus induced by the global cerebral ischemia under both hyperlipidemic and normal-lipid conditions. 3. Polygoni Multiflori Radix significantly reduced the increase of Bax expression in the CAl region of the hippocampus induced by global cerebral ischemia under both hyperlipidemic and normal-lipid conditions. 4. Polygoni Multiflori Radix significantly increased Bc1-2 expression in the CA1 region of the hippocampus after global cerebral ischemia under normal-lipid condition, but was not effective on that under hyperlipidemic condition. 5. Polygoni Multiflori Radix was not effective on serum total-cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride levels under normal-lipid conditions, irrespective of focal cerebral infarct or global cerebral ischemia. 6. Polygoni Multiflori Radix significantly reduced the increase of serum total-cholesterol and triglyceride levels, and increased serum LDL-cholesterol level under hyperlipidemic conditions, irrespective of foc31 cerebral infarct or global cerebral ischemia.