• Title/Summary/Keyword: Survival proteins

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Prognostic Significance of Overexpression of EZH2 and H3k27me3 Proteins in Gastric Cancer

  • He, Long-Jun;Cai, Mu-Yan;Xu, Guo-Liang;Li, Jian-Jun;Weng, Zi-Jin;Xu, Da-Zhi;Luo, Guang-Yu;Zhu, Sen-Lin;Xie, Dan
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3173-3178
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    • 2012
  • The enhancer of zeste homolog 2 (EZH2) methyl transferase and histone 3 lysine 27 (H3K27me3) protein can repress gene transcription, and their aberrant expression has been observed in various human cancers. This study determined their expression levels in gastric cancer tissues with reference to clinicopathological features and patient survival. We collected 117 gastric cancer and corresponding normal tissues for immunohistochemistry analysis. In gastric cancers, 82/117 (70.1%) were positive for EZH2 and 66/117 (56.4%) for H3K27me3 proteins in contrast to only 5.41% and 7.25% of normal gastric mucosa specimens, respectively. Kaplan-Meier survival data showed the average overall and disease-free survival of EZH2 high expression patients was 25.2 and 20.2 months, respectively, shorter than that with EZH2 low expression (40.5 and 35.9 months). The average overall survival and disease-free survival of high H3K27me3 expression patients was 23.4 and 17.4 months, shorter than without H3K27me3 expression (37.6 and 34.5 months). The average overall survival and disease-free survival of patients with both EZH2 and H3K27me3 expression was 18.8 and 12.9 months, respectively, shorter than that with either alone (34.7 and 31.2 months) or with low levels of both (43.9 and 39.9 months). Multivariate Cox regression analysis showed that H3K27me3 and EZH2 expression, tumor size differentiation and clinical stage were all independent prognostic factors for predicting patient survival. This study demonstrated that detection of both EZH2 and H3K27me3 proteins can predict poor survival of gastric cancer patients, superior to single protein detection. In addition, H3K27me3 and EZH2 protein expression could predict lymph node metastasis.

Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity

  • Park, Chang-Jin;Seo, Young-Su
    • The Plant Pathology Journal
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    • v.31 no.4
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    • pp.323-333
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    • 2015
  • As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

Responses of Pseudomonas sp. DJ-12 to Pollutant Stresses of Benzoate and 4-Chlorobenzoate

  • Ko, Yeon-Ja;Park, Sang-Ho;Park, Yong-Keun;Kim, Chi-Kyung
    • Journal of Microbiology and Biotechnology
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    • v.9 no.4
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    • pp.422-428
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    • 1999
  • Aromatic hydrocarbons can be utilized as carbon and energy sources by some microorganisms at lower concentrations. However, they can also act as stresses to these organisms at higher concentrations. Pseudomonas sp. DJ-12 is capable of degrading 0.5 mM concentration of benzoate and 4-chlorobenzoate (4CBA). In this study, the exposure of Pseudomonas sp. DJ-12 to the pollutant stresses of benzoate and 4CBA at various concentrations was comparatively studied for its cellular responses, including survival tolerance, degradability of the aromatics, and morphological changes. Pseudomonas sp. DJ-12 utilized 0.5 to 1.0mM benzoate and 4CBA as carbon and energy sources for growth. However, the organism could not degrade the aromatics at concentrations of 3 mM or higher, resulting in reduced cell viability due to the destruction of the cell envelopes. Pseudomonas sp. DJ-12 cells produced stress-shock proteins such as DnaK and GroEL when treated with benzoate and 4CBA at concentrations of 0.5mM, or higher as sublethal dosage; Yet, there were differing responses between the cells treated with either benzoate or 4CBA. 4CBA affected the degradability of the cells more critically than benzoate. The DnaK and GroEL stress-shock proteins were produced either by 1mM benzoate with 5 min treatment or by higher concentrations after 10min. The proteins were also induced by 0.5mM 4CBA, however, it needed at least 20min treatment or longer. These results indicate that the chlorination of benzoate increased the recalcitrance of the pollutant aromatics and changed the conditions to lower concentrations and longer treatment times for the production of stress-shock proteins. of stress-shock proteins produced by the aromatics at sublethal concentrations functioned interactively between the aromatics for survival tolerance to lethal concentrations.

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Comprehensive Proteome Analysis of the Excretory/Secretory Proteins of Toxoplasma gondii

  • Lee, Won-Kyu;Ahn, Hye-Jin;Baek, Je-Hyun;Lee, Chong-Heon;Yu, Yeon Gyu;Nam, Ho-Woo
    • Bulletin of the Korean Chemical Society
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    • v.35 no.10
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    • pp.3071-3076
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    • 2014
  • Proteomic analyses of the excretory/secretory proteins from the RH strain of Toxoplasma gondii have been performed to understand their functions in the host-parasite interaction. A total of 34 proteins were identified from LC/MS/MS analysis and their abundance was estimated by spectral counting methods. Among them, 8 species of micronemal proteins (MICs), 2 species of rhoptry proteins (ROPs), and 6 species of dense granular proteins (GRAs) were confirmed. Besides these, 18 species of protein were newly identified, and their cellular functions were estimated from sequence analysis. The three most abundant of the 34 identified extractor/secretory proteins-GRA1, GRA7 and GRA2-were confirmed to be highly expressed in T. gondii using the spectral count method. This phenomenon is another demonstration of the importance of GRA proteins for the penetration and survival of T. gondii.

Radioprotective Effects of Ginseng Proteins (인삼단백질의 방사선 방어작용)

  • 김춘미;한규선
    • YAKHAK HOEJI
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    • v.29 no.5
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    • pp.246-252
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    • 1985
  • Ginseng proteins were isolated and partially purified to obtain two fractions, namely GI and GII. Radioprotective effects of these fractions were examined on $\gamma$-ray irradiated ICR mice by observing 30-day survival rates after irradiation. Also investigated were the effects of GI fraction on the recovery of radiation damage. As the results, the GI fraction showed strong protection against radiation indicated by the increment of 30-day survival rates, while the GII fraction did not. The GI fraction enhanced the recovery of body and splenic weights and increased the amount of DNA in liver significantly. It also helped to recover the damage done on erythrocytes by increasing the number to normal in short period, however, it had no effect on the recovery of leukocyte counts.

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How to improve the survival rate of implants after radiotherapy for head and neck cancer?

  • Zheng, Min;Li, Li;Tang, Yaling;Liang, Xin-Hua
    • Journal of Periodontal and Implant Science
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    • v.44 no.1
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    • pp.2-7
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    • 2014
  • Implants have been widely used in restorative treatment for patients who have undergone head and neck cancer surgery. With the development of combination treatment of head and neck cancer, radiotherapy has been a common means of therapy. However, it could induce various changes in hard and soft tissues and reduce the success and survival rate of the implants. Some research, using either animal models or clinical studies, have shown that certain strategies could be used for improving the survival rate of implants. In this review, we discussed the changes in both hard and soft tissues, which may reduce the survival rate of the implants, and the proposed methods for improving the survival rate of patients after radiotherapy.

Autocrine prostaglandin E2 signaling promotes promonocytic leukemia cell survival via COX-2 expression and MAPK pathway

  • Shehzad, Adeeb;Lee, Jaetae;Lee, Young Sup
    • BMB Reports
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    • v.48 no.2
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    • pp.109-114
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    • 2015
  • The COX-2/$PGE_2$ pathway has been implicated in the occurrence and progression of cancer. The underlying mechanisms facilitating the production of COX-2 and its mediator, $PGE_2$, in cancer survival remain unknown. Herein, we investigated $PGE_2$-induced COX-2 expression and signaling in HL-60 cells following menadione treatment. Treatment with $PGE_2$ activated anti-apoptotic proteins such as Bcl-2 and Bcl-xL while reducing pro-apoptotic proteins, thereby enhancing cell survival. $PGE_2$ not only induced COX-2 expression, but also prevented casapse-3, PARP, and lamin B cleavage. Silencing and inhibition of COX-2 with siRNA transfection or treatment with indomethacin led to a pronounced reduction of the extracellular levels of $PGE_2$, and restored the menadione- induced cell death. In addition, pretreatment of cells with the MEK inhibitor PD98059 and the PKA inhibitor H89 abrogated the $PGE_2$-induced expression of COX-2, suggesting involvement of the MAPK and PKA pathways. These results demonstrate that $PGE_2$ signaling acts in an autocrine manner, and specific inhibition of $PGE_2$ will provide a novel approach for the treatment of leukemia.

Hypoxic Microenvironmental Control of Stress Protein and Erythropoietin Gene Expression

  • Beak, Sun-Hee;Han, Mi-Young;Lee, Seung-Hoon;Choi, Eun-Mi;Park, Young-Mee
    • BMB Reports
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    • v.32 no.2
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    • pp.112-118
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    • 1999
  • The presence of hypoxic cells in solid tumors has long been considered a problem in cancer treatment such as in radiation therapy or treatment with some anticancer drugs. It has been suggested that hypoxic cells are involved in the development of a more aggressive phenotype and contribute to metastasis. In this study, as an attempt to understand how tumor cells adapt to hypoxic stress, we investigated the regulation of the hypoxia-induced expression of proteins that control essential processes of tumor cell survival and angiogenesis. We first examined whether hypoxia induces stress protein gene expression of murine solid tumor RIF cells. We also examined hypoxia-induced changes in angiogenic gene expression in these cells. Finally, we investigated the association of the elevated levels of stress proteins with the regulation of hypoxia-induced angiogenic gene expression. Results demonstrated that hypoxia induced the expression of the erythropoietin (EPO) gene and at least two major members of stress proteins, heat shock protein 70 (HSP70) and 25 (HSP25) in RIF tumor cells. Evidence that the expression of EPO gene was greatly potentiated in TR cells suggested that the elevated levels of HSPs may play an important role in the regulation of the hypoxia-induced EPO gene expression. One of the RIF variant cell lines, TR, displays elevated levels of HSPs constitutively. Taken together, our results suggest that a hypoxic tumor microenvironment may promote the survival and malignant progression of the tumor cells by temporarily increasing the level of stress proteins and expressing angiogenic genes. We suspect that stress proteins may be associated with the increase of the angiogenic potential of tumor cells under hypoxia.

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Correlation of Overexpression of Nestin with Expression of Epithelial-Mesenchymal Transition-Related Proteins in Gastric Adenocarcinoma

  • Liu, Jin-Kai;Chen, Wan-Cheng;Ji, Xiao-Zhen;Zheng, Wen-Hong;Han, Wei;An, Jing
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.2777-2783
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    • 2015
  • Background: Nestin is associated with neoplastic transformation. However, the mechanisms by which nestin contributes regarding invasion and malignancy of gastric adenocarcinoma (GAC) remain unknown. Recent studies have shown that the epithelial-mesenchymal transition (EMT) is important in invasion and migration of cancer cells. In the present study, we aimed to investigate the expression of nestin and its correlation with EMT-related proteins in GAC. Materials and Methods: The expression of nestin and EMT-related proteins was examined in GAC specimens and cell lines by immunohistochemistry and Western blotting. Clinicopathological features and survival outcomes were retrospectively analyzed. Results: Positive nestin immunostaining was most obviously detected in the cytoplasm, nucleus or both cytoplasm and nucleus of tumor cells in 19.2% (24/125) of GAC tissues, which was significantly higher than that in normal gastric mucosa tissues (1.7%, 1/60) (p=0.001). Nestin expression was closely related to several clinicopathological factors and EMT-related proteins (E-cadherin, vimentin and Snail) and displayed a poor prognosis. Interestingly, simultaneous cytoplasmic and nuclear nestin expression correlated with EMT-related proteins (E-cadherin, vimentin and Snail) (p<0.05) and lymph node metastasis (p=0.041) and a shorter survival time (p<0.05), but this was not the case with cytoplasmic or nuclear nestin expression. Conclusions: Nestin, particularly expression in both cytoplasm and nucleus, might be involved in regulating EMT and malignant progression in GAC, with potential as an unfavorable indicator in tumor diagnosis and a target for clinical therapy.

Cross-talk between STAT6 and Ras/MAPK Pathway for the IL-4-mediated T Cell Survival

  • So, Eui-Young;Jang, Ji-Young;Lee, Choong-Eun
    • BMB Reports
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    • v.34 no.6
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    • pp.578-583
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    • 2001
  • As a prototypic Thl vs Th2 cytokine, IFN-$\gamma$ and IL-4 activate distinct STAT proteins, STAT1 and STATE, respectively. In cytokine-producing Jurkat T cells, IL-4 is effectively rescued from cell death that is induced by dexamethasone, but IFN-$\gamma$ failed to do so. Since the Ras/MAPK pathway is known to play an important role in cytokine-induced cell survival, we investigated the mechanism of T cell survival through the analysis of functional cross-talk between Ras/MAPK and distinct STAT proteins that are activated by IL-4 and IFN-$\gamma$. Although IL-4 and IFN-$\gamma$ each induced the activation of STATE and STATI. in Jurkat T cells, respectively, only IL-4 was capable of inducing MAPK. Along with tyrosine kinase inhibitors, MEK/MAPK inhibitors also caused a significant suppression of the IL-4-induced STATE activity. This suggests a positive regulation of STATE by MAPK during IL-4 signal transduction. Furthermore, transfection studies with dominant active (da) vs dominant negative (dn) Ras revealed that daRas, but not dnRas, selectively up-regulated the expression and activity of STATE with a concomitant increase in MAPK activity. These results, therefore, suggest that there is a functional cross-talk between the Ras/MAPK and Jak/STAT6 pathways, which may have a role in the IL-4-induced T cell survival.

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