• Title/Summary/Keyword: MICROENVIRONMENT

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The Role of Complement in the Immunologic Microenvironment of Tumor Cells: Potential Therapeutic Targets

  • Jo, Kyeong Beom;Snape, Alison
    • Microbiology and Biotechnology Letters
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    • v.44 no.4
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    • pp.420-431
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    • 2016
  • The complement system comprises a set of essential molecules that bridge the innate and adaptive immune responses. Research has focused on how the complement system's destructive mechanism could potentially be harnessed for cancer treatment. However, cancer subverts the complement system to avoid immunosurveillance. In addition, a complement-triggered biological mechanism that contributes to cancer growth has been identified. Thus, drugs should be designed to homeostatically maintain a normal concentration of complement. This review explores three types of complement-related anti-cancer drugs: therapeutic antibodies, complement inhibitory drugs, and anti-complement regulatory drugs.

Aluminium increase Iron uptake into Glial cells

  • Cheong, Jae-Hoon;Lim, Sung-Sup;Lee, Choong-Jae
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.293.3-294
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    • 2002
  • In the brain, glial cells serve in the role to sequester metal from the neural microenvironment and therefore play an important role as a cellular deposition site. The central nervous system is highly vulnerable to oxidative stress, and free iron can stimulate oxidative stress by the Fenton reaction. Aluminum may upregulates the transferrin-independent iron uptake system and stimulate oxidative stress. Nramp2. also known as DMT 1. is a 12-transmembrane(TM) domain protein responsible for dietary iron uptake as well as metal ions such as iron. lead, mangamese. zinc. copper, and cobait. (omitted)

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Regulatory T Cells and Infectious Disease

  • Rouse, Barry T.;Sehrawat, Sharvan
    • IMMUNE NETWORK
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    • v.7 no.4
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    • pp.167-172
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    • 2007
  • Various cell types that express regulatory function may influence the pathogenesis of most and perhaps all infections. Some regulatory cells are present at the time of infection whereas others are induced or activated in response to infection. The actual mechanisms by which different types of infections signal regulatory cell responses remain poorly understood. However a most likely mechanism is the creation of a microenvironment that permits the conversion of conventional T cells into cells with the same antigen specificity that have regulatory function. Some possible means by which this can occur are discussed. The relationship between regulatory cells and infections is complex especially with chronic situations. The outcome can either be of benefit to the host or damage the disease control process or in rare instances appears to be a component of a finely balanced relationship between the host and the infecting agent. Manipulating the regulatory cell responses to achieve a favorable outcome of infection remains an unfulfilled objective of therapeutic immunology.

Psoriasis as a T-cell-mediated Immunologic Disease (T 세포 매개 면역질환으로서의 건선)

  • Lew, Wook
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.189-194
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    • 2002
  • Although the exact mechanism responsible for the pathogenesis of psoriasis is unclear, interferon-${\gamma}$ producing type 1 T cells have been reported to play a significant role. Infiltrating activated type 1 T cells in the lesions are believed to be responsible for stimulating keratinocytes, which produce many cytokines and growth factors. The hyperproliferative epidermis is understood to be the result of either the cytokines produced by the intraepidermal T cells or the reactive phenomenon after keratinocyte damage. The microenvironment in psoriatic lesions deviates toward the type 1 status, because of the increased type 1 cytokines and either the decreased or unchanged type 2 cytokines observed in psoriatic lesions. Therefore, this review focused on a T-cell-mediated immunological basis for the current hypothesis of the psoriasis pathogenesis.

Activity of Human Dihydrolipoamide Dehydrogenase Is Reduced by Mutation at Threonine-44 of FAD-binding Region to Valine

  • Kim, Hak-Jung
    • BMB Reports
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    • v.35 no.4
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    • pp.437-441
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    • 2002
  • Dihydrolipoamide dehydrogenase (E3) is a member of the pyridine nucleotide-disulfide oxidoreductase family. Thr residues are highly conserved. They are at the active site disulfide-bond regions of most E3s and other oxidoreductases,. The crystal structure of Azotobacter vinelandii E3 suggests that the hydroxyl group of Thr that are involved in the FAD binding interact with the adenosine phosphate of FAD. However, several prokaryotic E3s have Val instead of Thr. To investigate the meaning and importance of the Thr conservation in many E3s, the corresponding residue, Thr-44, in human E3 was substituted to Val by site-directed mutagenesis. The mutant’s E3 activity showed about a 2.2-fold decrease. Its UV-visible and fluorescence spectra indicated that the mutant might have a slightly different microenvironment at the FAD-binding region.

Life of T Follicular Helper Cells

  • Suh, Woong-Kyung
    • Molecules and Cells
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    • v.38 no.3
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    • pp.195-201
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    • 2015
  • Antibodies are powerful defense tools against pathogens but may cause autoimmune diseases when erroneously directed toward self-antigens. Thus, antibody producing cells are carefully selected, refined, and expanded in a highly regulated microenvironment (germinal center) in the peripheral lymphoid organs. A subset of T cells termed T follicular helper cells (Tfh) play a central role in instructing B cells to form a repertoire of antibody producing cells that provide life-long supply of high affinity, pathogenspecific antibodies. Therefore, understanding how Tfh cells arise and how they facilitate B cell selection and differentiation during germinal center reaction is critical to improve vaccines and better treat autoimmune diseases. In this review, I will summarise recent findings on molecular and cellular mechanisms underlying Tfh generation and function with an emphasis on T cell costimulation.

Correlation between Microvascular Density and Matrix Metalloproteinase 11 Expression in Prostate Cancer Tissues: a Preliminary Study in Thailand

  • Kanharat, Nongnuch;Tuamsuk, Panya
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6639-6643
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    • 2015
  • Background: Prostate cancer is a major concern of public health. Microvascular density (MVD) is one of the prognostic markers for various solid cancers. Matrix metalloproteinase 11 (MMP11) plays an important role in angiogenesis and changes in its expression level are known to be associated with tumor progression and clinical outcome. Aim: To investigate the relationship between MVD and MMP11 expression in prostatic adenocarcinoma tissues. Materials and Methods: The expression levels of MMP11 and MVD were analyzed immunohistochemically for 50 specimens of prostatic adenocarcinoma. Results: MMP11 was mainly expressed in stromal cells but rarely seen in epithelial cells. Mean MVD was $36/mm^2$, and it was correlated significantly only with bone metastases. MVD was also significantly correlated with MMP11 expression (r=0.29, p=0.044). Conclusions: MMP11 may alter the stromal microenvironment of prostate cancer to stimulate tumor angiogenesis.

GSTT1 is Deregulated in Left Colon Tumors

  • Coskunpinar, Ender;Canbay, Emel;Oltulu, Yasemin Musteri;Tiryakioglu, Necip Ozan;Bugra, Dursun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2319-2321
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    • 2014
  • Our aim was to determine GSTT1 expression levels in left colon tumors and paired normal tissue in order to identify specific alterations in GSTT1 mRNA levels. Alterations in GSTT1 expression in twenty-four left-sided colon tumors and paired cancer free tissue were determined by qRT-PCR. Significant fold changes were determined with t-test. When compared with cancer free tissue, left colon cancers showed a significant decrease in GSTT1 expression. However, GSTT1 mRNA levels among different grades increased gradually in correlation with tumor grade. Our results suggest that downregulation of GSTT1 in left-sided colon cancers is an early event and is reversed with cancer progression, probably due to cellular defense mechanisms as a response to changes in the microenvironment.

Cell behavior study using microfluidic chip (마이크로 유체 칩을 이용한 세포행태에 관한 연구)

  • Park, Joong-Yull;Lee, Sang-Hoon
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1450-1454
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    • 2008
  • In the conventional biology, the most of cell studies was carried out by culturing cells in the Petri dish and by investigating cellular behavior under the diverse bio-molecule (cell signalling materials, drugs or etc.) conditions. However, in vivo environments, diverse stimulations including chemical, mechanical and topological environments involved in the proliferation, differentiation and migration of cells and it is almost impossible to provide these conditions with traditional method. We have developed the methods to provide the well defined chemical and mechanical stimulations using microfluidic devices and applied these approaches to the study of environmental effect on cells. In this paper, we will introduce our microfluidic chips to provide microenvironment and its applications using several cells.

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Pulsed Electron Paramagnetic Resonance Application on the Photoinduced Charge Separation of Alkylphenothiazine Derivatives in Molecular Assemblies

  • Kang, Young-Soo;Park, Chan-Young
    • Journal of the Korean Magnetic Resonance Society
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    • v.4 no.2
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    • pp.82-90
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    • 2000
  • Photoinduced charge separation of alkylphenothiazines in molecular assemblies such as positively, negatively and neutrally charged micelle interface results in the paramagnetic phenothiazine cation radical. This was studied as a model system for the light energy conversion into chemical energy. The photoproduced phenothaizne cation radical was identified and its amount was quantized with electron spin resonance (ESR). The microenvironment of photoproduced cation radical was studied with pulsed-ESR. Such a charge separation is enhanced by the optimization of various structural factors of the molecular assemblies. The structural factors of molecular assemblies have focused on the interface charge, interface structure with different headgroups and interfacial perturbation by disolving interface active organic additives.

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