• Title, Summary, Keyword: stable transfection

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Antibody productivity of HBsAg containing both preS2 and S regions expressed in Chinese hamster ovary cells (Chinese hamster ovary세포에서 발현된 pres2 및 S부위 함유 HBsAg의 항체유발능)

  • 정성균;박정민;이상봉;박동우;김동연;김기호;김홍진
    • YAKHAK HOEJI
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    • v.45 no.6
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    • pp.708-714
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    • 2001
  • Many studies have provided evidences that hepatitis B surface antigen (HBsAg) including preS region could be an ideal candidate for a new hepatitis B virus (HBV) vaccine with higher efficacy. We established CHO cell lines, IY-CHO-2 and IY-CHO-11 expressing high levels of HBsAg containing preS2 and S protein by stable transfection method. These cell lines expressed the correct size (about 1 kb in length) of HBsAg mRNA as expected. The purified protein from the culture supernatants of the clones showed the same sizes as those expressed in native hepatitis B virus (24 kDa, 27 kDa, 34 kDa and 36 kDa). Antibody productivity of CHO-derived HBsAg protein at lower dose challenge was higher than the protein containing S region alone expressed in yeast system. These results indicate that CHO-derived HBsAg protein containing preS2 and S region can be effectively used for a better immune response as a HBV vaccine.

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Dual-functionalized calcium nanocomplexes for transfection of cancerous and stem cells: Low molecular weight polycation-mediated colloidal stability and ATP-mediated endosomal release

  • Choi, Yeon Su;Kim, Kyoungnam;Ryu, Kitae;Cho, Hana;Cho, Yong-Yeon;Lee, Joo Young;Lee, Hye Suk;Kim, Byung Gon;Song, Soo Chang;Kang, Han Chang
    • Journal of Industrial and Engineering Chemistry
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    • v.64
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    • pp.300-310
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    • 2018
  • To overcome colloidal instability of calcium phosphate nanoparticles in gene delivery, colloidally stable and endosomolytic $Ca^{2+}-based$ pDNA nanocomplexes (NCs) were designed by a surface coating of biocompatible polycations (PCs; low molecular weight branched polyethyleneimine [bPEI], protamine sulfate and ${\varepsilon}-polylysine$) and the addition of natural and endosomolytic ATP, respectively. Without remarkable cytotoxicity and colloidal instability, $Ca^{2+}/ATP-pDNA/bPEI_{1.8kDa}$ NCs having $[bPEI_{1.8kDa}]=3.6{\mu}g$ showed 5.8-fold and 4.4-fold higher transfection efficiencies than $bPEI_{25kDa}/pDNA$ NCs in HepG2 cells and dental pulp stem cells, respectively. In conclusion, pH-sensitive endosomolytic ATP and $Ca^{2+}-based$ gene complexes could be potentials as effective and safe gene delivery vectors in various cells.

Ectopic expression of Bcl-2 or Bcl-xL suppresses p-fluorophenylalanine-induced apoptosis through blocking mitochondria-dependent caspase cascade in human Jurkat T cells (Jurkat T 세포에 있어서 ρ-fluorophenylalanine에 의해 유도되는 세포자살의 Bcl-2 및 Bcl-xL에 의한 저해 기전)

  • Han, Kyu-Hyun;Oh, Hyun-Ji;Jun, Do-Youn;Kim, Young-Ho
    • Journal of Life Science
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    • v.13 no.1
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    • pp.118-127
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    • 2003
  • $\rho$-Fluorophenylalanine (FPA), a phenylalanine analog, is able to induce apoptotic cell death of human acute leukemia Jurkat T cells. To better understand the mechanism by which FPA induces apoptotic cell death, the effect of ectopic expression of antiapoptotic proteins, Bcl-2 and Bcl-xL, on FPA-induced apoptosis was investigated by employing lurkat T cells transfected with Bcl-2 gene (JT/Bcl-2) or Bcl-xL gene (1/Bcl-xL) and Jurkat T cells transfected with vector (JT/Neo or J/Neo). When Jurkat T cells, JT/Neo or J/Neo, were exposed to FPA at concentrations ranging from 0.63 to 5.0 mM, the cell viability determined by MTT assay declined in a dose-dependent manner. In addition, apoptotic DNA fragmentation along with several apoptotic events such as caspase-8 activation, Bid cleavage, mitochondrial cytochrome c release, caspase-9 activation, caspase-3 activation, and degradation of PARP was induced. However, the FPA-induced cytotoxic effect, activation of caspase-8, and cleavage of Bid were significantly abrogated by ectopic expression of Bcl-2 or Bcl-xL. At the same time, there was marked reduction in the level of cytochrome c release from mitorhondria, caspase-9 activation, caspase-3 activation, and degradation of PARP. These results indicate that caspase-8 activation, Bid cleavage, and mitochondrial cytochrome c release with subsequent activation of the caspase cascade are negatively regulated by Bcl-2 or Bcl-xL, and are thus required for FPA-induced apoptosis in Jurkat T cells

Biochemical Characterization of Recombinant Equine Chorionic Gonadotropin (rec-eCG), Using CHO Cells and PathHunter Parental Cells Expressing Equine Luteinizing Hormone/Chorionic Gonadotropin Receptors (eLH/CGR) (말의 LH/CGR를 발현하는 CHO 세포와 PathHunter Parental 세포에서 유전자 재조합 eCGβ/α의 생화학적 특성)

  • Lee, So-Yun;Byambaragchaa, Munkhzaya;Kim, Jeong-Soo;Seong, Hun-Ki;Kang, Myung-Hwa;Min, Kwan-Sik
    • Journal of Life Science
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    • v.27 no.8
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    • pp.864-872
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    • 2017
  • Equine chorionic gonadotropin (eCG) consists of highly glycosylated ${\alpha}-$ and ${\beta}-subunits$ and is a unique member of the gonadotropin family, because it elicits the response characteristics of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in species other than the horse. To directly assess the biological function of $rec-eCG{\beta}/{\alpha}$, we constructed mammalian expressing vectors of equine luteinizing hormone/chorionic gonadotropin receptors (eLH/CGR). The activity of $rec-eCG{\beta}/{\alpha}$ in vitro assayed in transient transfected CHO-K1 cells and in stably transfected PathHunter Parental cells with eLH/CGR was investigated. $rec-eCG{\beta}/{\alpha}$ was efficiently secreted in the CHO-K1 suspension cell media, and the quantity detected was about 200 mIU/ml from 1 to 7 days after transfection. In the western blot analysis, the $rec-eCG{\beta}/{\alpha}$ protein was broadly identified to be about 40~45 kDa molecular weight. The cAMP stimulation in CHO-K1 cells expressing eLH/CGR was determined to evaluate the activity of $rec-eCG{\beta}/{\alpha}$. The cAMP concentration increased in direct proportion to the concentration of the $rec-eCG{\beta}/{\alpha}$. The $EC_{50}$ value in the transient transfected CHO-K1 cells was $8.1{\pm}6.5ng$. The stable cell lines of eLH/CGR were established in the PathHunter Parental cells expressing ${\beta}-arrestin$. We found that $rec-eCG{\beta}/{\alpha}$ had full LH activity in the PathHunter Parental cells expressing eLH/CGR. The $EC_{50}$ value in transient and stable cells was $5.0{\pm}4.7ng/ml$ and $4.5{\pm}5.2ng/ml$, respectively. These results suggest that $rec-eCG{\beta}/{\alpha}$ has a biological activity in a cell expressing eLH/CGR. These stable cells expressed in PathHunter Parental cells could be useful for elucidating the functional mechanisms of deglycosylated $rec-eCG{\beta}/{\alpha}$ mutants.

Overexpression of RUNX3 Inhibits Malignant Behaviour of Eca109 Cells in Vitro and Vivo

  • Chen, Hua-Xia;Wang, Shuai;Wang, Zhou;Zhang, Zhi-Ping;Shi, Shan-Shan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.4
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    • pp.1531-1537
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    • 2014
  • Runt-related transcription factor 3 (RUNX3) is a tumor suppressor gene whose reduced expression may play an important role in the development and progression of esophageal squamous cell cancer (ESCC). The aim of this study was to investigate the clinical relevance of RUNX3 in ESCC patients and effects of overexpression on biological behaviour of Eca109 cells in vitro and in vivo. Immunohistochemistry was performed to detect the clinical relevance of RUNX3 and lymph node metastasis in 80 ESCC tissues and 40 non-cancerous tissues using the SP method. RT-PCR and Western blotting were applied to assess the RUNX3 level and verify the Eca109 cell line with stable overexpression. Localization of RUNX3 proteins was performed by cell immunofluorescence. CCK-8 and Scrape motility assays were used to determine proliferation and migration and the TUNEL assay to analyze cell apoptosis. Invasive potential was assessed in cell transwell invasion experiments. In nude mice, tumorigenesis in vivo was determined. Results showed decreased expression of RUNX3 in esophageal tissue to be significantly related to lymph node metastasis (LNM) (P<0.01). In addition, construction of a recombinant lentiviral vector and transfection into the human ESCC cell line Eca109 demonstrated that overexpression could inhibit cell proliferation, migration and invasion, and induce apoptosis. The in vivo experiments in mice showed tumorigenicity and invasiveness to be significantly reduced. Taken together, our studies indicate that underexpression of RUNX3 in human ESCC tissue is significantly correlated with progression. Restoration of RUNX3 expression significantly inhibits ESCC cells proliferation, migration, invasion and tumorigenesis.

Bag-1L is a Stress-withstand Molecule Prevents the Downregulation of Mcl-1 and c-Raf Under Control of Heat Shock Proteins in Cisplatin Treated HeLa Cervix Cancer Cells

  • Ozfiliz, Pelin;Arisan, Elif Damla;Coker-Gurkan, Ajda;Obakan, Pinar;Eralp, Tugce Nur;Dinler-Doganay, Gizem;Palavan-Unsal, Narcin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4475-4482
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    • 2014
  • Background: Cisplatin, a DNA damaging agent, induces apoptosis through increasing DNA fragmentation. However, identification of intrinsic resistance molecules against Cisplatin is vital to estimate the success of therapy. Bag-1 (Bcl-2-associated anthanogene) is one anti-apoptotic protein involved in drug resistance impacting on therapeutic efficiency. Elevated levels of this protein are related with increase cell proliferation rates, motility and also cancer development. For this reason, we aimed to understand the role of Bag-1 expression in Cisplatin-induced apoptosis in HeLa cervix cancer cells. Cisplatin decreased cell viability in time- and dose-dependent manner in wt and Bag-1L+HeLa cells. Although, $10{\mu}M$ Cisplatin treatment induced cell death within 24h by activating caspases in wt cells, Bag-1L stable transfection protected cells against Cisplatin treatment. To assess the potential protective role of Bag-1, we first checked the expression profile of interacting anti-apoptotic partners of Bag-1. We found that forced Bag-1L expression prevented Cisplatin-induced apoptosis through acting on Mcl-1 expression, which was reduced after Cisplatin treatment in wt HeLa cells. This mechanism was also supported by the regulation of heat shock protein (Hsp) family members, Hsp90 and Hsp40, which were involved in the regulation Bag-1 interactome including several anti-apoptotic Bcl-2 family members and c-Raf.

Par-4 Modulates Cell Migration through Inhibition of MMP-2 Activity in Human Renal Carcinoma Caki Cells (인간 신장암 Caki세포에서 Par-4에 의한 MMP-2 활성 저해를 통한 세포 이동 조절)

  • Woo, Seon Min;Kwon, Taeg Kyu
    • Journal of Life Science
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    • v.26 no.5
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    • pp.614-619
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    • 2016
  • The prostate-apoptosis-response-gene-4 (Par-4) protein has been identified as an effector of cell death in response to various apoptotic stimuli in prostate cancer cells. We found that overexpression of Par-4 by stable transfection inhibits cell migration and invasion in Caki cells. The expression of various matrix metalloproteinases (MMPs) has been implicated in the invasion and metastasis of cancer cells. In this study, we investigated whether ectopic expression of Par-4 modulates MMP-2 expression and activity in human renal carcinoma Caki cells. We found that overexpression of Par-4 markedly inhibited MMP-2 activity, but not MMP-9 activity. However, loss of the leucine zipper domain of Par-4 (Par-4 ΔLZ#1 and #2) did not inhibit MMP-2 activity. Further, knock-down of Par-4 with the corresponding siRNA resulted in increased invasion and metastasis of renal carcinoma Caki cells. Interestingly, overexpression or knock-down of Par-4 did not affect the expression levels of MMP-2 mRNA. Taken together, our findings suggest that Par-4 may inhibit MMP-2 activity through its post-transcriptional regulation in renal carcinoma Caki cells.

IDH1 Overexpression Induced Chemotherapy Resistance and IDH1 Mutation Enhanced Chemotherapy Sensitivity in Glioma Cells in Vitro and in Vivo

  • Wang, Ju-Bo;Dong, Dan-Feng;Wang, Mao-De;Gao, Ke
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.1
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    • pp.427-432
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    • 2014
  • Isocitrate dehydrogenase (IDH) is of great importance in cell metabolism and energy conversion. IDH mutation in glioma cells is reported to be associated with an increased overall survival. However, effects biological behavior of therapy of gliomas are unclear. Here, we investigated the influence of wild-type and mutated IDH genes on glioma cell biological behavior and response to chemotherapy. Relevant mechanisms were further explored. We designed our study on the background of the IDHR132H mutation. Stable cell lines were constructed by transfection. The CCK-8 method was used to assess cell proliferation, flow cytometry for the cell cycle and cell apoptosis, and the transwell method for cell invasion. Nude mouse models were employed to determine tumorigenesis and sensitivity to chemotherapy. Western blotting was used to detect relevant protein expression levels. We found that overexpression of wild IDH1 gene did not cause changes in the cell cycle, apoptosis and invasion ability. However, it resulted in chemotherapy resistance to a high dose of temozolomide (TMZ) in vivo and in vitro. The IDH1 mutation caused cell cycle arrest in G1 stage and a reduction of proliferation and invasion ability, while raising sensitivity to chemotherapy. This may provide an explanation for the better prognosis of IDH1 mutated glioma patients and the relative worse prognosis of their wild-type IDH1 counterparts. We also expect IDH1 mutations may be optimized as new targets to improve the prognosis of glioma patients.

Expression and Function of GSTA1 in Lung Cancer Cells

  • Pan, Xue-Diao;Yang, Zhou-Ping;Tang, Qi-Ling;Peng, Tong;Zhang, Zheng-Bing;Zhou, Si-Gui;Wang, Gui-Xiang;He, Bing;Zang, Lin-Quan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8631-8635
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    • 2014
  • Glutathione S-transferase A1 (GSTA1) appears to be primarily involved in detoxification processes, but possible roles in lung cancer remain unclear. The objective of this study was to investigate the expression and function of GSTA1 in lung cancer cells. Real-time PCR and Western blotting were performed to assess expression in cancer cell lines and the normal lung cells, then verify the A549 cells line with stable overexpression. Localization of GSTA1 proteins was assessed by cytoimmunofluorescence. Three double-strand DNA oligoRNAs (SiRNAs) were synthesized prior to being transfected into A549 cells with Lipofectamine 2000, and then the most efficient SiRNA was selected. Expression of the GSTA1 gene in the transfected cells was determined by real-time PCR and Western blotting. The viability of the transfected cells were assessed by MTT. Results showed that the mRNA and protein expression of A549 cancer cells was higher than in MRC-5 normal cells. Cytoimmunofluorescence demonstrated GSTA1 localization in the cell cytoplasm and/or membranes. Transfection into A549 cells demonstrated that down-regulated expression could inhibit cell viability. Our data indicated that GSTA1 expression may be a target molecule in early diagnosis and treatment of lung cancer.

Analysis of the Molecular Event of ICAM-1 Interaction with LFA-1 During Leukocyte Adhesion Using a Reconstituted Mammalian Cell Expression Model

  • Han, Weon-Cheol;Kim, Kwon-Seop;Park, Jae-Seung;Hwang, Sung-Yeoun;Moon, Hyung-Bae;Chung, Hun-Taeg;Jun, Chang-Duk
    • Animal cells and systems
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    • v.5 no.3
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    • pp.253-262
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    • 2001
  • Ligand-receptor clustering event is the most important step in leukocyte adhesion and spreading on endothelial cells. Intercellular adhesion molecule-1 (ICAM-1) has been shown to enhance leukocyte adhesion, but the molecular event during the process of adhesion is unclear. To visualize the dynamics of ICAM-1 movement during adhesion, we have engineered stable Chinese hamster ovary cell lines expressing ICAM-1 fused to a green fluorescent protein (IC1_GFP/CHO) and examined them under the fluorescence microscopy. The transfection of IC1_GFP alone in these cells was sufficient to support the adhesion of K562 cells that express $\alpha$L$\beta$2 (LFA-1) integrin stimulated by CBR LFA-1/2 mAb. This phenomenon was mediated by ICAM-1-LFA-1 interactions, as an mAb that specifically inhibits ICAM-1-LFA-1 interaction (RRl/l) completely abolished the adhesion of LFA-1* cells to IC1_ GFP/CHO cells. We found that the characteristic of adhesion was followed almost immediately (~10 min) by the rapid accumulation of ICAM-1 on CHO cells at a tight interface between the two cells. Interestingly, ICI_GFP/CHO cells projected plasma membrane and encircled approximately half surface of LFA-1+ cells, as defined by confocal microscopy. This unusual phenomenon was also confirmed on HUVEC after adhesion of LFA-1* cells. Neither cytochalasin D nor 2,3-butanedione 2-monoxime an inhibitor of myosin light chain kinase blocked LFA-1-mediated ICAM-1 clustering, indicating that actin cytoskeleton and myosin-dependent contractility are not necessary for ICAM-1 clustering. Taken together, we suggest that leukocyte adhesion to endothelial cells induces specialized form of ICAM-1 clustering that is distinct from immunological synapse mediated by T cell interaction with antigen presenting cells.

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