• Title/Summary/Keyword: Human Embryonic Stem Cells

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Role of Gremlin-1 in Cancer

  • Park, Sin-Aye
    • Biomedical Science Letters
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    • v.24 no.4
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    • pp.285-291
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    • 2018
  • Gremlin-1 (GREM1) has been defined as an antagonist of bone morphogenetic proteins (BMPs), particularly during embryonic development and tissue differentiation. However, recent studies have shown that GREM1 has BMPs-dependent or -independent functions in diverse human diseases. GREM1 plays a key role in the process of organ fibrosis, including lungs, kidneys, and so on. The GREM1-induced fibrosis typically promotes the development of other diseases, such as pulmonary hypertension, renal inflammation, and diabetic nephropathy. More recently, considerable evidence has been reported showing that GREM1 is involved in the promotion and/or progression of tumors in vitro and in vivo. It also performs an oncogenic role in the maintenance of cancer stem cells. Although GREM1 is known to function in a variety of diseases, here we focus on the role of GREM1 in cancer, and suggest GREM1 as a potential therapeutic target in certain types of cancer.

EMPAS: Electron Microscopy Screening for Endogenous Protein Architectures

  • Kim, Gijeong;Jang, Seongmin;Lee, Eunhye;Song, Ji-Joon
    • Molecules and Cells
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    • v.43 no.9
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    • pp.804-812
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    • 2020
  • In cells, proteins form macromolecular complexes to execute their own unique roles in biological processes. Conventional structural biology methods adopt a bottom-up approach starting from defined sets of proteins to investigate the structures and interactions of protein complexes. However, this approach does not reflect the diverse and complex landscape of endogenous molecular architectures. Here, we introduce a top-down approach called Electron Microscopy screening for endogenous Protein ArchitectureS (EMPAS) to investigate the diverse and complex landscape of endogenous macromolecular architectures in an unbiased manner. By applying EMPAS, we discovered a spiral architecture and identified it as AdhE. Furthermore, we performed screening to examine endogenous molecular architectures of human embryonic stem cells (hESCs), mouse brains, cyanobacteria and plant leaves, revealing their diverse repertoires of molecular architectures. This study suggests that EMPAS may serve as a tool to investigate the molecular architectures of endogenous macromolecular proteins.

Isolation of Mouse Ig Heavy and Light Chain Genomic DNA Clones, and Construction of Gene Knockout Vector for the Generation of Humanized Xenomouse (인간 단클론 항체 생산용 Humanized Xenomouse 제작의 기초 소재인 생쥐 Ig 중사슬 및 경사슬 Genomic DNA 클론의 확보 및 유전자 적중 벡터의 제작)

  • Lee, Hee-kyung;Cha, Sang-hoon
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.233-241
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    • 2002
  • Background: Monoclonal antibodies (mAb) of rodent origin are produced with ease by hybridoma fusion technique, and have been successfully used as therapeutic reagents for humans after humanization by genetic engineering. However, utilization of these antibodies for therapeutic purpose has been limited by the fact that they act as immunogens in human body causing undesired side effects. So far, there have been several attempts to produce human mAbs for effective in vivo diagnostic or therapeutic reagents including the use of humanized xenomouse that is generated by mating knockout mice which lost Ig heavy and light chain genes by homologous recombination and transgenic mice having both human Ig heavy and light gene loci in their genome. Methods: Genomic DNA fragments of mouse Ig heavy and light chain were obtained from a mouse brain ${\lambda}$ genomic library by PCR screening and cloned into a targeting vector with ultimate goal of generating Ig knockout mouse. Results: Through PCR screening of the genomic library, three heavy chain and three light chain Ig gene fragments were identified, and restriction map of one of the heavy chain gene fragments was determined. Then heavy chain Ig gene fragments were subcloned into a targeting vector. The resulting construct was introduced into embryonic stem cells. Antibiotic selection of transfected cells is under the progress. Conclusion: Generation of xenomouse is particularly important in medical biotechnology. However, this goal is not easily achieved due to the technical difficulties as well as huge financial expenses. Although we are in the early stage of a long-term project, our results, at least, partially contribute the successful generation of humanized xenomouse in Korea.

Synthesis, characterization, and toxicity of multi-walled carbon nanotubes functionalized with 4-hydroxyquinazoline

  • Tahermansouri, Hasan;Mirosanloo, Atieh;Keshel, Saeed Heidari;Gardaneh, Mossa
    • Carbon letters
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    • v.17 no.1
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    • pp.45-52
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    • 2016
  • The attachment of 2-aminobenzamide to carboxylated multi-wall carbon nanotubes (MWCNTs)-COOH was achieved through the formation of amide bonds. Then, the functionalized MWCNTs, MWCNT-amide, were treated by phosphoryl chloride to produce MWCNT-quin. The products were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, thermogravimetric analysis, derivative thermogravimetric, steady-state fluorescence spectroscopy, and solubility testing. MWCNT-quin showed photo-electronic properties, which is due to the attachment of the 4-hydroxyquinazoline groups to them as proved by steady-state fluorescence spectroscopy. This suggests intramolecular interactions between the tubes and the attached 4-hydroxyquinazoline. The toxicity of the samples was evaluated in human embryonic kidney HEK293 and human breast cancer SKBR3 cell lines, and the viable cell numbers were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) after the cells were cultured for 24 h. Cellular investigations showed that the modified MWCNTs, particularly MWCNT-quin, have considerably significant toxic impact on SKBR3 as compared to HEK293 at the concentration of 5 µg/mL.