• Tuberculosis and Respiratory Diseases
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• 제75권1호
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• pp.9-17
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• 2013

Background: In cancer cells, autophagy is generally induced as a pro-survival mechanism in response to treatment-associated genotoxic and metabolic stress. Thus, concurrent autophagy inhibition can be expected to have a synergistic effect with chemotherapy on cancer cell death. Monensin, a polyether antibiotic, is known as an autophagy inhibitor, which interferes with the fusion of autophagosome and lysosome. There have been a few reports of its effect in combination with anticancer drugs. We performed this study to investigate whether erlotinib, an epidermal growth factor receptor inhibitor, or rapamycin, an mammalian target of rapamycin (mTOR) inhibitor, is effective in combination therapy with monensin in non-small cell lung cancer cells. Methods: NCI-H1299 cells were treated with rapamycin or erlotinib, with or without monensin pretreatment, and then subjected to growth inhibition assay, apoptosis analysis by flow cytometry, and cell cycle analysis on the basis of the DNA contents histogram. Finally, a Western blot analysis was done to examine the changes of proteins related to apoptosis and cell cycle control. Results: Monensin synergistically increases growth inhibition and apoptosis induced by rapamycin or erlotinib. The number of cells in the sub-$G_1$ phase increases noticeably after the combination treatment. Increase of proapoptotic proteins, including bax, cleaved caspase 3, and cleaved poly(ADP-ribose) polymerase, and decrease of anti-apoptotic proteins, bcl-2 and bcl-xL, are augmented by the combination treatment with monensin. The promoters of cell cycle progression, notch3 and skp2, decrease and p21, a cyclin-dependent kinase inhibitor, accumulates within the cell during this process. Conclusion: Our findings suggest that concurrent autophagy inhibition could have a role in lung cancer treatment.

• IMMUNE NETWORK
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• 제2권1호
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• pp.60-64
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• 2002

Background: Chemotherapy with 5-fluorouracil (5-FU) has been one of the mainstay in breast cancer treatment. The effects of high dose 5-FU on cell cycle regulation were studied in breast caner cells. Methods: A breast cancer cell line MCF-7 was used. Protein expressions of G1/S cyclins, $p21^{Waf1/Cip1}$, cdk2, E2F1 and retinoblastoma were tested by western blot analysis. Immunoprecipitation and immune complex kinase assay were done for the assessment of E2F1/RB interacton and the activity of cdk2 respectively. Results: $p21^{Waf1/Cip1}$ expression was barely detectable in control cells. With addition of 5-FU level of $p21^{Waf1/Cip1}$ were induced and cyclin D3 level was decreased as cell growth decreases. In accordance with increased expression of $p21^{Waf1/Cip1}$, cyclin E-associated cdk2 kinase activity was reduced. Retinoblastoma protein (RB) became dephosphorylated and E2F-1 binding activity with RB was increased. Conclusion: In this situation of high concentration of 5-FU breast cancer cells tend to be G1/S cell cycle arrested. Overexpression of $p21^{Waf1/Cip1}$ and dephosphorylation of RB may mediate the effectss of 5-FU by inhibiting E2F-1 activity, which contributes to G1/S cell cycle arrest. These results could be an indicating landmark for further study of high dose chemotherapy with 5-FU.

• Toxicological Research
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• 제17권
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• pp.59-69
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• 2001

Arsenic exposure is associated with several human diseases, including cancers, atherosclerosis, hypertension, and cerebrovascular diseases. In cultured cells, arsenite, an inorganic arsenic com-pound, was demonstrated to interfere with many physiological functions, such as enhancement of oxidative stress, delay of cell cycle progression, and induction of structural and numerical changes of chromosomes. The objective of this study is to investigate the effects of arsenic exposure on gene expression profiles by colorimetric cDNA microarray technique. HFW (normal human diploid skin fibroblasts), CL3 (human lung adenocarcinoma cell line), and HaCaT (immortalized human keratinocyte cell line) were treated with 5 $\mu\textrm{M}$ or 10 $\mu\textrm{M}$ sodium arsenite for 6 or 16 h, respectively. By a dual-color detection system, the expression profile of arsenite-treated cultures was compared to that of control cultures. Several genes expressed differentially were identified on the microarray membranes. For example, MDM2, SWI/SNF, ubiquitin specific protease 4, MAP3K11, RecQ protein-like 5, and Ribosomal protein Ll0a were consistently induced in all three cell types by arsenite, whereas prohibitin, cyclin D1, nucleolar protein 1, PCNA, Nm23, and immediate early protein (ETR101) were apparently inhibited. The present results suggest that arsenite insults altered the expression of several genes participating in cellular responses to DNA damage, stress, transcription, and cell cycle arrest.

• Molecules and Cells
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• 제39권9호
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• pp.654-662
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• 2016

Almost all eukaryotic proteins are subject to post-translational modifications during mitosis and cell cycle, and in particular, reversible phosphorylation being a key event. The recent use of high-throughput experimental analyses has revealed that more than 70% of all eukaryotic proteins are regulated by phosphorylation; however, the mechanism of dephosphorylation, counteracting phosphorylation, is relatively unknown. Recent discoveries have shown that many of the protein phosphatases are involved in the temporal and spatial control of mitotic events, such as mitotic entry, mitotic spindle assembly, chromosome architecture changes and cohesion, and mitotic exit. This implies that certain phosphatases are tightly regulated for timely dephosphorylation of key mitotic phosphoproteins and are essential for control of various mitotic processes. This review describes the physiological and pathological roles of mitotic phosphatases, as well as the versatile role of various protein phosphatases in several mitotic events.

• Journal of Ginseng Research
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• 제20권2호
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• pp.149-153
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• 1996

Studies were Performed to determine whether the water fraction of Panax ginseng Protected radiation damage to hair medullar cells of N:GP(s) mice after in vivo irradiation with $^{60}Co{\;}{\gamma}-rays$. The hair follicles in the middle of the growth cycle were analysed 3 days after 3 Gy irradiation for the changes in the number of cells in the forming medulla of the hair in the region just above the germinal matrix of the growing (anagen) hair follicle. The radioprotective effect of ginseng was compared with the irradiation control. The medullar cell count per unit length ($100{\;}\mu\textrm{m}$) of hair follicle was higher in the pretreated-groups of ginseng, both oral (2 mg/ml of drinking water, p<0.05) and intraperitoneal (0.3 mg/head, p<0.001) treatments, than the irradiation control. These data suggested that the water fraction of Panax ginseng may reduce cell damages on the body surface caused by ${\gamma}-rays$.

• 대한치과보철학회지
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• 제59권4호
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• pp.379-394
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• 2021

목적: 이전 연구에서 치은섬유아세포 혹은 성견 구개 연조직에 trichloroacetic acid (TCA)를 적용하는 것이 세포주기진행 유전자 발현의 변화를 일으키는 것으로 밝혀졌다. 이에 따라 본 연구에서는, hydrophobically modified glycol chitosan (HGC)기반의 나노방출제어시스템을 이용한 TCA 및 상피세포성장인자(EGF)의 순차적 방출시스템에서 이 효과를 검증하기 위하여 다양한 세포주기진행 유전자들의 발현을 규명하였다. 재료 및 방법: TCA와 EGF를 담지하는 HGC기반 나노방출제어시스템을 제작하였다. 실험군은 대조군(CON); TCA-담지형 나노방출제어시스템 투여군(EXP1); TCA- 및 EGF-담지형 나노방출제어시스템 투여군(EXP2)으로 정의되었다. 24시간 및 48시간 배양 시 37개 세포주기 유전자들의 발현을 분석하였다. 영향인자로서의 유전자 및 상관관계에 대해서도 분석하였다. 결과: Cyclins (CCNDs), cell division cycles (CDCs), cyclin-dependent kinases (CDKs), E2F transcription factors (E2Fs), extracellular signal-regulated kinases (ERKs)와 같은 다수의 유전자들과 기타 다른 세포주기 유전자들의 발현이 EXP1과 EXP2에서 상향조절되었다. E2F4, E2F5, GADD45G와 같은 세포주기차단 유전자들의 발현도 상향조절되었으나, 또다른 세포주기차단 유전자인 SMAD4의 발현은 하향조절되었다. 다중회귀분석에서 CCNA2, CDK4 그리고 ANAPC4가 ERK 유전자 발현에 가장 영향력 있는 유전자로 선정되었다. 결론: HGC기반 순차적 나노방출제어시스템을 이용한 TCA 및 EGF의 적용은 다양한 세포주기진행 유전자들의 발현을 상향조절함이 밝혀졌고, 이를 토대로 한 구강연조직증대시스템 개발의 가능성이 확보되었다.

• 전력전자학회논문지
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• 제13권6호
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• pp.469-475
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• 2008

본 논문에서는 소형 PEM(Proton Exchange Membrane) 연료전지 스택의 마이크로프로세서를 이용한 제어에 관하여 소개한다. 연료전지 제어의 핵심 기술인 스택 내부의 수분 관리는 부하에 의해 요구되는 연료와 온도에 따른 냉각용 공기의 유량을 적절하게 조절하고, 잉여수분을 스택으로부터 배출시킴으로써 성취된다. 이러한 주변장치(BOS: Balance of Stack)의 제어는 시스템의 안정적인 운전을 좌우하는 중요한 요소이기 때문에 이를 정확하게 제어하는 것이 매우 중요하다. 본 연구에서는 최적 운전조건에서 공기유량과 퍼지주기를 측정하고 이를 바탕으로 BOS를 제어함으로써 BOS의 소비전력을 최소화하여 연료 효율을 향상시킬 수 있었으며, 이를 실험을 통해 검증하였다. 마이크로프로세서를 이용하여 개발된 제어기는 시스템의 운전 안정성을 향상시켜 소형 연료전지 스택의 제어에 널리 사용될 것으로 기대된다.

• Journal of Plant Biotechnology
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• 제36권1호
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• pp.7-12
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• 2009

본 실험은 음나무 배발생 세포의 증식 및 체세포배 발달을 위한 액체 현탁 배양조건의 확립을 위해 수행되었다. 배발생 세포의 생장율은 접종 밀도가 증가할수록 감소하였다. 배발생 세포의 증식에 가장 효과적인 접종 밀도는 0.1 g/100 ml 로서 이 농도에서 세포의 생장율이 가장 높았다. 배양기간에 따른 배발생 세포의 생장 패턴 및 세포 주기 (G1, S, G2/M) 분석 결과, 세포의 생장은 배양 5일 후부터 증가가 시작되어 15일 까지 급격히 생장하였으며 그 이후에는 점차 감소하였다. 배양 기간 별 세포 주기 (cell cycle)의 변화가 명확하게 관찰되어 배양 5일째 5기는 초기의 5.5% 에서 11.7%로 두 배정도 증가하였으며, 배양 15일 이후부터는 다시 초기의 세포 주기로 되돌아가면서 안정화되는 것으로 나타났다. 따라서 음나무 배발생 세포의 현탁배양은 15일의 주기로 배양하는 것이 증식에 가장 효과적인 것으로 생각되었다. 한편 배발생 세포에서 체세포배의 유도는 배양초기의 접종 밀도가 중요한 것으로 나타났다. 0.5 g/L 의 낮은 밀도로 접종 시에는 65% 이상의 어뢰형 배가 유도된 반면 접종 밀도가 높아질수록 어뢰형으로의 배발달은 급격히 감소하였다. 초기의 접종 밀도가 증가할수록 특히 어뢰형 배의 발달은 지연되었으나 구형 및 심장형 배의 유도는 초기 접종밀도에 영향을 받지 않았다. 이상의 실험결과로 음나무 액체 배양 시 초기 접종 밀도를 조절함으로써 배발생 캘러스의 증식 및 체세포배를 효과적으로 유도할 수 있었으며 이는 체세포배 생산을 위한 배양 기간의 단축이 가능함을 보여주는 결과이다.

• Journal of Acupuncture Research
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• 제19권2호
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• pp.28-38
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• 2002

Objective : This study is aimed to investigate the effects of bee venom and purified bee venom on cell death in synovial cell line. Methods : It was evaluated by using MTT assay, morphological method, flow cytometry, immunocytochemistry analysis, RT-PCR. Results : The result obtained is as follows. 1. The MTT assay demonstrated that synovial cell viability was significantly inhibitted dose-dependently by treatment with BV and PBV in comparison with control. And the inhibitory effect of BV and PBV was almost same. 2. The morphologic study demonstrated that synovial cell showed apoptotic body resulted from apoptosis after treatment with BV and PBV for 6 hours using microscope. 3. The Flow cytometry demonstrated that apoptosis of synovial cell treated with BV and PBV was related with stop of cell cycle in stage of G0/G1. 4. Immunocytochemistry assay demonstrated that COX-II and iNOS were slightly expressed by treatment with BV and PBV in comparison with control group. 5. RT-PCR analysis demonstrated that COX-II were almost down-regulated by high dose treatment with BV and PBV in comparison with control group. iNOS were well down-regulated by treatment with $5{\mu}g/ml$ BV and PBV whereas it was well expressed in control group. Conclusion : These results suggest that bee venom and purified bee venom have significant effect on cell death in synovial cell line and further study is needed in vivo.

• 동의생리병리학회지
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• 제17권6호
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• pp.1383-1392
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• 2003

Apoptosis is a morphologically and biochemically district form of cell death that occurs in many different cell types in a wide variety of organisms. Albizzia julibrissin belonging the family Leguminosae has been used for the treatment of contusion, sore throat, amnesia, and insomnia in oriental traditional medicine. This study investigates whether the water extract of A. julibrissin induce apoptotic cell death in Jurkat T-acute lymphoblastic leukemia (ALL) cells. Jurkat cells were increased inhibitions of cell viability in a concentration-dependent manner by A. julibrissin. This herbal medicine also caused apoptosis as measured by cell morphology and DNA fragmentation. The capability of A. julibrissin to induce apoptosis was associated with proteolytic cleavage of specific target proteins such as poly (ADP-ribose)polymerase (PARP) and beta-catenin proteins suggesting the possible involvement of caspases. Our result showed that Bcl-2 and Bax protein levels were not changed in all A. julibrissin-treated groups compared to control group. These results suggest that A. julibrissin-mediated apoptosis is independent with Bcl-2 related signaling pathway in this cells. The purpose of the present study is also to investigate the Effect of A. julibrissin on cell cycle progression. Our results showed that G1 checkpoint related gene products (cyclin D1, cyclin dependent kinase 4, retinoblastoma, E2F1) were decreased in their protein levels in a dose-dependent manners after treatment of the extract. These results indicate that the increase of apoptotic cell death by A. julibrissin may be due to the inhibition of cell cycle progression in wild type p53-lacking Jurkat cells.