• Title/Summary/Keyword: BECN

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Hepatitis B virus X Protein Promotes Liver Cancer Progression through Autophagy Induction in Response to TLR4 Stimulation

  • Juhee Son;Mi-Jeong Kim;Ji Su Lee;Ji Young Kim;Eunyoung Chun;Ki-Young Lee
    • IMMUNE NETWORK
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    • v.21 no.5
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    • pp.37.1-37.17
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    • 2021
  • Hepatitis B virus X (HBx) protein has been reported as a key protein regulating the pathogenesis of HBV-induced hepatocellular carcinoma (HCC). Recent evidence has shown that HBx is implicated in the activation of autophagy in hepatic cells. Nevertheless, the precise molecular and cellular mechanism by which HBx induces autophagy is still controversial. Herein, we investigated the molecular and cellular mechanism by which HBx is involved in the TRAF6-BECN1-Bcl-2 signaling for the regulation of autophagy in response to TLR4 stimulation, therefore influencing the HCC progression. HBx interacts with BECN1 (Beclin 1) and inhibits the association of the BECN1-Bcl-2 complex, which is known to prevent the assembly of the pre-autophagosomal structure. Furthermore, HBx enhances the interaction between VPS34 and TRAF6-BECN1 complex, increases the ubiquitination of BECN1, and subsequently enhances autophagy induction in response to LPS stimulation. To verify the functional role of HBx in liver cancer progression, we utilized different HCC cell lines, HepG2, SK-Hep-1, and SNU-761. HBx-expressing HepG2 cells exhibited enhanced cell migration, invasion, and cell mobility in response to LPS stimulation compared to those of control HepG2 cells. These results were consistently observed in HBx-expressed SK-Hep-1 and HBx-expressed SNU-761 cells. Taken together, our findings suggest that HBx positively regulates the induction of autophagy through the inhibition of the BECN1-Bcl-2 complex and enhancement of the TRAF6-BECN1-VPS34 complex, leading to enhance liver cancer migration and invasion.

Lack of Altered BECN1 Gene Expression in Iranian Patients with Acute Myeloid Leukemia

  • Keyvan, Ladan;Bidoki, Seyed Kazem;Abdollahi, Davood Zare;Mansouri, Neda;Hashemi, Mehrdad;Tabatabaei, SA Mortazavi;Fardmanesh, Hediyeh;Meimandi, Mansour;Ayatollahi, Seyed Majid;Movafagh, Abolfazl
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.12
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    • pp.5173-5177
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    • 2016
  • Acute myeloid leukemia (AML), one of the most prevalent leukemia types in adults, demonstrates great heterogeneity in molecular and clinical terms. Hence, there is a necessity to the mechanisms involved in AML generation in order to determine optimal treatment. This cross sectional study aimed to assess changes in BECN1 gene expression in with blood samples from 30 AML patients, compared with samples from 15 healthy persons. RNA was extracted and cDNA was synthesized and Real Time PCR applied to determine BECN1 gene expression. The results showed no significant differences in BECN1 gene expression between patients with AML and normal controls (P > 0.05). It appears that expression of BECN1 does not play a significant role in genesis of AML leukemia.

An Effective BECN Typed QoS Guaranteeing Mechanism in Optical Burst Switching Networks (광 버스트 교환망에서 BECN 방식의 효과적인 QoS 보장 방법)

  • Choi Young-Bok
    • The KIPS Transactions:PartC
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    • v.13C no.4 s.107
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    • pp.441-446
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    • 2006
  • In recent years, WDM networks have received much attention as the Internet backbone networks because of the explosive growth of the Internet IP-based traffic. The Optical Burst Switching (OBS) has been proposed as an effective optical switching technology in the WDM networks. The OBS has the advantages in 1) the high usage rate of the bandwidth, and 2) no necessity of optical buffer. However, the OBS has the burst-contention problem in the networks. The deflection routing is proposed as one of means to solve this problem. In this paper, we propose a new routing method to minimize burst loss in the deflection routing based networks. In addition, we propose a QoS control method using a new routing algorithm. Finally, we show the variety of the proposed methods by computer simulations.

A BECN Typed Deflection Routing for QoS Guaranteed Optical Burst Switching (OBS 네트워크에서 QoS를 보장을 위한 BECN 방식의 우회 라우팅)

  • Choi Young-Bok;Roh Seok-Jo
    • Proceedings of the IEEK Conference
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    • 2004.06a
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    • pp.241-244
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    • 2004
  • In recent years, WDM networks have received much attention as the Internet backbone networks because of the explosive growth of the Internet IP-based traffic. The Optical Burst Switching (OBS) has been proposed as an effective optical switching technology in the WDM networks. OBS has the advantages in 1) the high usage rate of the bandwidth, and 2) no necessity of optical buffer. However OBS has the burst-contention problem in the networks. The deflection routing is proposed as one of means to solve this problem. In this paper, we propose a new routing method of using deflection routing. In addition. we propose a QoS/CoS control method using a new routing algorithm. Finally, we show the variety of the proposed methods by computer simulations.

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Congestion Control of ABR Traffic in ATM Network (ATM망에서 ABR 트래픽의 폭주제어 방법)

  • Chae, Gi-Jun;Do, In-Sil
    • The Transactions of the Korea Information Processing Society
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    • v.2 no.6
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    • pp.927-936
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    • 1995
  • ATM Forum has defined a new service class for data applications called Available Bit Rate(ABR) Service, which has highly bursty traffic and unpredictable burst size. It is desirable that we reduce the probability of retrans mission of packets by minimizing the loss of cells because the traffic is much more sensitive to loss than delay. The Forum has also selected the Rate-Based Control for the ABR service and proposed EPRCA as the control mechanism for the service. This paper proposes the combination of EPRCA and the other feedb ack control mechanisms such as BECN and BP. The combined control mechanism control ABR traffic more efficiently and the simulation results show that the network performance can be improved by choosing the appropriate parameters.

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Bioinformatics Analysis of Autophagy and Mitophagy Markers Associated with Delayed Cerebral Ischemia Following Subarachnoid Hemorrhage

  • Youn, Dong Hyuk;Kim, Bong Jun;Hong, Eun Pyo;Jeon, Jin Pyeong
    • Journal of Korean Neurosurgical Society
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    • v.65 no.2
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    • pp.236-244
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    • 2022
  • Objective : To evaluate the interactions among differentially expressed autophagy and mitophagy markers in subarachnoid hemorrhage (SAH) patients with delayed cerebral ischemia (DCI). Methods : The expression data of autophagy and mitophagy-related makers in the cerebrospinal fluid (CSF) cells was analyzed by real-time reverse transcription-polymerase chain reaction and Western blotting. The markers included death-associated protein kinase (DAPK)-1, BCL2 interacting protein 3 like (BNIP3L), Bcl-1 antagonist X, phosphatase and tensin homolog-induced kinase (PINK), Unc-51 like autophagy activating kinase 1, nuclear dot protein 52, and p62. In silico functional analyses including gene ontology enrichment and the protein-protein interaction network were performed. Results : A total of 56 SAH patients were included and 22 (38.6%) of them experienced DCI. The DCI patients had significantly increased mRNA levels of DAPK1, BNIP3L, and PINK1, and increased expression of BECN1 compared to the non-DCI patients. The most enriched biological process was the positive regulation of autophagy, followed by the response to mitochondrial depolarization. The molecular functions ubiquitin-like protein ligase binding and ubiquitin-protein ligase binding were enriched. In the cluster of cellular components, Lewy bodies and the phagophore assembly site were enriched. BECN1 was the most connected gene among the differentially expressed markers related to autophagy and mitophagy in the development of DCI. Conclusion : Our study may provide novel insight into mitochondrial dysfunction in DCI pathogenesis.

Primary Malignant Pericardial Mesothelioma(PMPM) -A case Report (심낭의 원발성 악성 중피종 -1례 보고-)

  • 손상태;전순호
    • Journal of Chest Surgery
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    • v.30 no.4
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    • pp.432-436
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    • 1997
  • Primary malignant pericardial mesothelioma(PMPM) is more rare than heart tumor, and the term of mcsothelioma was first used by Adami in 1910, although the lesion was Hrst descripted by Wagner in 1870. Most of 1:le reported 40 cascs have becn diagnosed on autopsy. Antemortem diagnosis are rarely reported with only 40 cases in the world. According to Cohen, its incidence in 500,000 autopsies were 2.2. An analysis of the recent review shows that an antemortem diagnosis was made in only 19∼25% of total cases. This report co sist of a case of our experience of PMPM.

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Raloxifene Induces Autophagy-Dependent Cell Death in Breast Cancer Cells via the Activation of AMP-Activated Protein Kinase

  • Kim, Dong Eun;Kim, Yunha;Cho, Dong-Hyung;Jeong, Seong-Yun;Kim, Sung-Bae;Suh, Nayoung;Lee, Jung Shin;Choi, Eun Kyung;Koh, Jae-Young;Hwang, Jung Jin;Kim, Choung-Soo
    • Molecules and Cells
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    • v.38 no.2
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    • pp.138-144
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    • 2015
  • Raloxifene is a selective estrogen receptor modulator (SERM) that binds to the estrogen receptor (ER), and exhibits potent anti-tumor and autophagy-inducing effects in breast cancer cells. However, the mechanism of raloxifene-induced cell death and autophagy is not well-established. So, we analyzed mechanism underlying death and autophagy induced by raloxifene in MCF-7 breast cancer cells. Treatment with raloxifene significantly induced death in MCF-7 cells. Raloxifene accumulated GFP-LC3 puncta and increased the level of autophagic marker proteins, such as LC3-II, BECN1, and ATG12-ATG5 conjugates, indicating activated autophagy. Raloxifene also increased autophagic flux indicators, the cleavage of GFP from GFP-LC3 and only red fluorescence-positive puncta in mRFP-GFP-LC3-expressing cells. An autophagy inhibitor, 3-methyladenine (3-MA), suppressed the level of LC3-II and blocked the formation of GFP-LC3 puncta. Moreover, siRNA targeting BECN1 markedly reversed cell death and the level of LC3-II increased by raloxifene. Besides, raloxifene-induced cell death was not related to cleavage of caspases-7, -9, and PARP. These results indicate that raloxifene activates autophagy-dependent cell death but not apoptosis. Interestingly, raloxifene decreased the level of intracellular adenosine triphosphate (ATP) and activated the AMPK/ULK1 pathway. However it was not suppressed the AKT/mTOR pathway. Addition of ATP decreased the phosphorylation of AMPK as well as the accumulation of LC3-II, finally attenuating raloxifene-induced cell death. Our current study demonstrates that raloxifene induces autophagy via the activation of AMPK by sensing decreases in ATP, and that the overactivation of autophagy promotes cell death and thereby mediates the anti-cancer effects of raloxifene in breast cancer cells.

Effects of coating Condition on Adhesive strength Ti$_{x}$N Films Prepared by the DC Magetron Sputtering Method (DC magnetron Sputtering 법으로 제작한 Ti$_{x}$N 박막의 밀착력에 미치는 코팅조건의 영향)

  • 김학동;조성석
    • Journal of the Korean institute of surface engineering
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    • v.31 no.1
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    • pp.34-44
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    • 1998
  • Stainless steel is being used widely lor various purposes due to its good corrosion resistance. There has becn much research to produce colored stainless sterl by several methods. In this experiment, we coated TixN film on the SUS304 substrate with thc DC magnetron sputtering system and studied the internal structurc and adhesive strength of the films as a function of the coating conditions. Before lhe specimen was coated, a sputter etching was very effective in removing the$\delta$ Fe(BCC) phase as well as the contaminant and oxide layer as well as increasing rotghness. Five-stage failure mode appeared with increased scratch load with the TIN films coated on the SUS304 in this manner ; tensile failure-,conformal failure-,buckling failure->chipping failurc and spalling Failure. When the failure was terminated at the initial stage, the film will have good adhesion. But, if syalling failure has occurred at the initial scratch, then the adhesion will be poor. The interlayer between thc coated film and thc substratc was homogeneously adhcsive when the $\gamma'-Fe_4N$ phase wasn't detected in the XRD analysis and the adhesive strength only was reduced by surPace defects. But, when the ,$\gamma'-Fe_4N$N phasc was detected in the XRD analysis, the adhesive strength was very poor.

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High-dose lipopolysaccharide induced autophagic cell death in bovine mammary alveolar cells

  • Park, Jin-Ki;Yeo, Joon Mo;Cho, Kwanghyun;Park, Hyun-Jung;Lee, Won-Young
    • Journal of Animal Reproduction and Biotechnology
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    • v.37 no.3
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    • pp.169-175
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    • 2022
  • Bovine mammary epithelial (MAC-T) cells are commonly used to study mammary gland development and mastitis. Lipopolysaccharide is a major bacterial cell membrane component that can induce inflammation. Autophagy is an important regulatory mechanism participating in the elimination of invading pathogens. In this study, we evaluated the mechanism underlying bacterial mastitis and mammary cell death following lipopolysaccharide treatment. After 24 h of 50 ㎍/mL lipopolysaccharide treatment, a significant decrease in the proliferation rate of MAC-T cells was observed. However, no changes were observed upon treatment of MAC-T cells with 10 ㎍/mL of lipopolysaccharide for up to 48 h. Thus, upon lipopolysaccharide treatment, MAC-T cells exhibit dose-dependent effects of growth inhibition at 10 ㎍/mL and death at 50 ㎍/mL. Treatment of MAC-T cells with 50 ㎍/mL lipopolysaccharide also induced the expression of autophagy-related genes ATG3, ATG5, ATG10, ATG12, MAP1LC3B, GABARAP-L2, and BECN1. The autophagy-related LC3A/B protein was also expressed in a dose-dependent manner upon lipopolysaccharide treatment. Based on these results, we suggest that a high dose of bacterial infection induces mammary epithelial cell death related to autophagy signals.