• Title/Summary/Keyword: western blotting

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Neuroendocrine Differentiation in Acquired Resistance to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor

  • Chang, Youjin;Kim, Seon Ye;Choi, Yun Jung;So, Kwang Sup;Rho, Jin Kyung;Kim, Woo Sung;Lee, Jae Cheol;Chung, Jin-Haeng;Choi, Chang-Min
    • Tuberculosis and Respiratory Diseases
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    • v.75 no.3
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    • pp.95-103
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    • 2013
  • Background: Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms. Methods: We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment. Results: Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib. Conclusion: NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.

Purification of TGF-$\beta$ 1 from Human Platelets by an Improved Method (개량된 방법에 의한 사람혈소판으로부터 TGF-$\beta$ 1의 분리)

  • 신충건;김상국;문병조;김평현;전계택;남상욱;김장환;이종원
    • KSBB Journal
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    • v.14 no.1
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    • pp.9-16
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    • 1999
  • Transforming growth factor $\beta$1(TGF-$\beta$1) has potentials to be used as a new therapeutic agent. However, studies with TGF-$\beta$ were hindered by its high cost. In this study, we developed an improved method to purify TGF-$\beta$1 from human platelets, for which four purification steps were used: platelet extraction, gel filtration, cation exchange chromatography, and reverse phase high performance liquid chromatography. After a final step of purification, a pure protein with a molecular weight of 25,000 corresponding to the commercially available TGF-$\beta$1 was obtained, which were confirmed by silver staining and Western blotting after SDS-polyacrylamide gel electrophoresis (SDS-PAGE). It was confirmed by the inhibitory effects of TGF-$\beta$1 on a mink lung epithelial cell line that the purified TGF-$\beta$1 had its biological activity, whose activity is slightly higher than that of the commercially available TGF-$\beta$1. About 3.7$\mug of the purified TGF-$\beta$1 was obtained from 10 units of concentrated human platelets, the final yield of which is about 21%.

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Anti-Inflammatory Effect of Erigeron annuus L. Flower Extract through Heme Oxygenase-1 Induction in RAW264.7 Macrophages (RAW264.7 대식세포에서 Heme Oxygenase-1의 유도에 의한 개망초 (Erigeron annuus L.) 꽃 Methanol 추출물의 항염증 효과)

  • Sung, Mi-Sun;Kim, Young-Hwa;Choi, Young-Min;Ham, Hyeon-Mi;Jeong, Heon-Sang;Lee, Jun-Soo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.11
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    • pp.1507-1511
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    • 2011
  • This study investigated the anti-inflammatory effect of Erigeron annuus L. flower (EAF) methanol extract. We examined the involvement of heme oxygenase-1 (HO-1) in the inhibitory activities of EAF methanol extract on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Cell viability and NO assays were performed. In addition, inducible nitric oxide synthase (iNOS) and HO-1 expressions were detected by Western blotting and blocking HO-1 activity on NO production. EAF methanol extract (25, 50, 100, 200 ${\mu}g$/mL) significantly inhibited LPS-stimulated NO production (p<0.05; 12.82, 9.61, 6.83, 2.52 ${\mu}m$) in a concentration-dependent manner. EAF methanol extract also reduced the expression of iNOS protein. The EAF methanol extract induced the expression of HO-1 in a dose-dependent manner. Blockage of HO-1 activity by zinc protoporphyrin suppressed EAF methanol extract-induced reductions in the production of NO. The present results suggest that EAF methanol extract has a potent anti-inflammatory effect in RAW264.7 macrophages through the induction of HO-1.

Extract from Artemisia annua Linné Induces Apoptosis through the Mitochondrial Signaling Pathway in HepG2 Cells (HepG2 간암세포에서 미토콘드리아 경로를 통한 개똥쑥 추출물의 Apoptosis 유도 효과)

  • Kim, Bo Min;Kim, Guen Tae;Kim, Eun Ji;Lim, Eun Gyeong;Kim, Sang-Yong;Kim, Young Min
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.12
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    • pp.1708-1716
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    • 2016
  • The Akt/mammalian target of the rapamycin (mTOR) pathway is activated in the majority of human cancers. Activation of the Akt/mTOR pathway confers resistance to many types of cancer therapy. In this study, we evaluated the apoptotic effect of ethanol extract of Artemisia annua L. through down-regulation of Akt signal pathways and the mitochondrial pathway in hepato-carcinoma cells (HepG2). A. annua extract is known as a medicinal herb that is effective against cancer. We evaluated anti-proliferative activity by MTT-based viability assay and apoptotic effect by Annexin-V/PI staining, mitochondrial membrane potential (MMP), and caspase-3/7 activity as determined by flow cytometry. A. annua treatment led to loss of MMP, resulting in cytochrome c-inducible activation of caspase-3/7. Treatment with A. annua extract reduced activities of Akt/mTOR/anti-apoptotic proteins (such as Bcl-2 and $Bcl-X_L$), leading to increased activation of tumor suppressor p53 and pro-apoptotic proteins (such as Bax and Bak). We applied LY294002 (inhibitor of Akt) and rapamycin (inhibitor of mTOR) to determine the relationship between signal transduction of proteins associated with apoptosis. LY294002 and rapamycin significantly reduced cell viability and increased apoptosis. These results indicate that Bcl-2 and caspase-3 are key regulators in A. annua extract-induced apoptosis in HepG2 cells and are controlled through the Akt/mTOR signaling pathway.

Biphasic effects of TGFβ1 on BMP9-induced osteogenic differentiation of mesenchymal stem cells

  • Li, Rui-Dong;Deng, Zhong-Liang;Hu, Ning;Liang, Xi;Liu, Bo;Luo, Jin-Yong;Chen, Liang;Yin, Liangjun;Luo, Xiaoji;Shui, Wei;He, Tong-Chuan;Huang, Wei
    • BMB Reports
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    • v.45 no.9
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    • pp.509-514
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    • 2012
  • We have found that the previously uncharacterized bone morphogenetic protein-9 (BMP9) is one of the most osteogenic factors. However, it is unclear if BMP9 cross-talks with $TGF{\beta}1$ during osteogenic differentiation. Using the recombinant BMP9 adenovirus, we find that low concentration of rh$TGF{\beta}1$ synergistically induces alkaline phosphatase activity in BMP9-transduced C3H10T1/2 cells and produces more pronounced matrix mineralization. However, higher concentrations of $TGF{\beta}1$ inhibit BMP9-induced osteogenic activity. Real-time PCR and Western blotting indicate that BMP9 in combination with low dose of $TGF{\beta}1$ potentiates the expression of later osteogenic markers osteopontin, osteocalcin and collagen type 1 (COL1a2), while higher concentrations of $TGF{\beta}1$ decrease the expression of osteopontin and osteocalcin but not COL1a2. Cell cycle analysis reveals that $TGF{\beta}1$ inhibits C3H10T1/2 proliferation in BMP9-induced osteogenesis and restricts the cells in $G_0/G_1$ phase. Our findings strongly suggest that $TGF{\beta}1$ may exert a biphasic effect on BMP9-induced osteogenic differentiation of mesenchymal stem cells.

Biochemical characterization of a novel extracellular pullulan 6-glucanohydrolase from Bacillus circulans S-1

  • Lee, Moon-Jo;Park, Cheon;Park, Joon-Ho;Chung, Kang-Hyun;Nam, Kyung-Soo;Park, Jin-Woo;Kim, Cheorl-Ho
    • Journal of Life Science
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    • v.10 no.3
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    • pp.307-316
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    • 2000
  • Bacillus circulans S-1 extracellular pullulan 6-glucanohydrolase (EP) (EC 3.2.1.41) has been characterized with a purified enzyme of 140 kDa. The N-terminal amino acid sequence of the purified enzyme was P-L-N-M-S-Q-P. The enzyme displayed a temperature optimum of around $60^{\circ}C$ and a pH optimum of around pH 9.0. The enzyme was stable to incubation from pH 4.0 to pH 11.0 at $4^{\circ}C$ for 48h. The presence of substrate allowed the protection of the enzyme from heat inactivation. The activity of the enzyme was stimulated by several metal ions such as Mn2+ and Ca2+. The enzyme had an apparent Km of 7.92 mg/ml for pullulan. The purfied enzyme completely hydrolysed pullulan to maltotriose.

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Effects of Acupuncture at the Sea Point on the Changes of Plasma and Tissue Levels of NO, nNOS, Norepinephrine in Rats (12경맥(經脈)의 오수혈중(五輸穴中) 합혈(合穴) 침자(鍼刺)가 백서(白鼠)의 혈위(穴位) 조직내 NO, nNOS와 조직 및 혈장 Norepinephrine의 변화에 미치는 영향(影響))

  • Kim, Young-Sun;Choi, Dong-Hee;Choi, Tae-Jin;Jang, Ho-Sun;Na, Chang-Su;Shin, Heon-Tae;Lee, Kyoung-In;Kim, Sun-Min;Pyo, Byoung-Sik;Youn, Dae-Hwan
    • Korean Journal of Acupuncture
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    • v.29 no.2
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    • pp.300-314
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    • 2012
  • Objectives : This study is to observe the changes in the expression of neurotransmitters, such as NO, nNOS, and NE, upon the needle insertion to the sea points, which is one of the five transport points. Methods : Needles were inserted into rats, on both left and right sides of all sea points, including the LU5, PC3, HT3, LI11, TE10, SI8, SP9, LR8, KI10, ST36, GB34, and BL40, which are the sea points of five transport points for 12 meridian vessels. After insertion, needles were retained for five minutes. After the retention, blood was drawn via cardiac puncture, and tissues of each point near meridian vessels were extracted to examine the changes in the expression of NO, nNOS and NE. Results : In terms of the effect in NO production, there was a significant decrease only in the LU5 point, whereas there was a significant increase in the TE10 point alone. In terms of the expression of nNOS within tissues, none of the experimental groups showed significant changes based on the results of immunohistochemistry and western blotting. Regarding the formation of norepinephrine within tissues, the HT3, SP9, and KI10 point showed a significant decrease, while the PC3 and LR8 point showed a significant increase. Production of plasma norepinephrine was significantly increased at the TE10, SP9, LR8, GB34, and BL40 point. Conclusions : The effect of needles applied at the sea points of five transport points of 12 meridian vessels on the functions of NO, nNOS, and NE could be observed, and it is considered that the effect of needle stimulation on nervous system disorders could be studied through additional researches based on this one.

Study on Cosmeceutical Activities and Anti-inflammatory Activities of Magnolia biondii Extracts (신이화(辛夷花, Magnoliae Flos)추출물의 화장품약리활성 및 항염증효과에 관한 연구)

  • Kim, Young-Hun;Sung, Ji-Yeon;Seo, Kyo-Seong;Shin, Jae-Cheon;Kim, Byung-So;Yeum, Jeong-Hyun;Lee, Jin-Tae
    • Journal of Life Science
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    • v.22 no.6
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    • pp.730-735
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    • 2012
  • Existing pharmaceutical studies show that Magnolia biondii is effective in treating rhinitis and in reducing cholesterol, given its endogenous, volatile ingredients. The study herein seeks to assess the cosmeceutical activities and anti-inflammatory activities of Magnolia biondii extracts for possible application as cosmetic ingredients. The cosmeceutical and anti-inflammatory activities were investigated using hydroxyl radical scavenging, superoxide dismutase (SOD)-like activity, xanthine oxidase (XO) inhibition, cell viability, nitric oxide (NO) inhibition, and inducible nitric oxide synthase (iNOS) expression by Western blotting. Magnolia biondii extracts were identified to have antioxidant activities in hydroxyl free radical scavenging, SOD-like activity, and XO inhibition. In testing the anti-inflammatory activities of the extracts, NO production was inhibited in a dose-dependent manner. Additionally, in a dose-dependent manner, the Magnolia biondii extracts were able to suppress iNOS expression in LPS-stimulated RAW 264.7 macrophage cells. From these results, Magnolia biondii showed adequate potential for application in cosmetic production and related industries as well as a functional material.

Endoplasmic Reticulum Stress Response and Apoptosis via the CoCl2-Induced Hypoxia in Neuronal Cells (CoCl2 처리로 유도된 hypoxia상태에서 세포자살과 ER stress에 관련된 인자의 발현)

  • Kim, Seon-Hwan;Kwon, Hyon-Jo;Koh, Hyeon-Song;Song, Shi-Hun;Kwon, Ki-Sang;Kwon, O-Yu;Choi, Seung-Won
    • Journal of Life Science
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    • v.20 no.12
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    • pp.1820-1828
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    • 2010
  • Cobalt(II) chloride, a chemical compound with the formula$CoCl_2$, has been widely used in the treatment of anemia, as a chemical agent for the induction of hypoxia in cell cultures, and is known to activate hypoxic signaling. However, excessive exposure to cobalt is associated with several clinical conditions, including asthma, pneumonia, and hematological abnormalities, and can lead to tissue and cellular toxicity. It is also known to induce apoptosis. One of the questions was that of whether $CoCl_2$ might induce apoptosis via endoplasmic reticulum (ER) stress in neurons. To address this question, first, the level of DNA fragmentation was measured for assay of apoptotic rates using $CoCl_2$ with neuron PC12 cells. After confirmation of apoptosis inductions, under the same conditions, the expression levels of ER stress associated factors [ER chaperones Bip, calnexin, ERp72, ERp29, PDI, and ER membrane kinases (IRE1, ATF6, PERK)] were examined by RT-PCR and Western blotting. These results indicated that apoptosis is induced through activation of ER membrane kinases via ER stress. In conclusion, during induction of apoptosis through $CoCl_2$-induced hypoxia in neuron PC12 cells, ER membrane kinase of IRE1 was dominantly up-expressed, and, consecutively, TRAF2, which has been suggested to be one of the links connecting apoptosis and ER stress, was strongly up-expressed.

Enhanced Transduction of Cu,Zn-Superoxide Dismutase with HIV-1 Tat Protein Transduction Domains at Both Termini

  • Eum, Won Sik;Jang, Sang Ho;Kim, Dae Won;Choi, Hee Soon;Choi, Soo Hyun;Kim, So Young;An, Jae Jin;Lee, Sun Hwa;Han, Kyuhyung;Kang, Jung Hoon;Kang, Tae-Cheon;Won, Moo Ho;Cho, Yong Joon;Choi, Jin Hi;Kim, Tae Yoon;Park, Jinseu;Choi, Soo Young
    • Molecules and Cells
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    • v.19 no.2
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    • pp.191-197
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    • 2005
  • The human immunodeficiency virus type 1 (HIV-1) Tat protein transduction domain (PTD) is responsible for highly efficient protein transduction across plasma membranes. In a previous study, we showed that Tat-Cu,Zn-superoxide dismutase (Tat-SOD) can be directly transduced into mammalian cells across the lipid membrane barrier. In this study, we fused the human SOD gene with a Tat PTD transduction vector at its N- and/or C-terminus. The fusion proteins (Tat-SOD, SOD-Tat, Tat-SOD-Tat) were purified from Escherichia coli and their ability to enter cells in vitro and in vivo compared by Western blotting and immunohistochemistry. The transduction efficiencies and biological activities of the SOD fusion protein with the Tat PTD at either terminus were equivalent and lower than the fusion protein with the Tat PTD at both termini. The availability of a more efficient SOD fusion protein provides a powerful vehicle for therapy in human diseases related to this anti-oxidant enzyme and to reactive oxygen species.