• Title/Summary/Keyword: c-myc expression

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Production of Red-spotted Grouper Nervous Necrosis Virus (RGNNV) Capsid Protein Using Saccharomyces cerevisiae Surface Display (Saccharomyces cerevisiae 표면 발현을 이용한 붉바리 신경괴사 바이러스 외피단백질의 생산)

  • Park, Mirye;Suh, Sung-Suk;Hwang, Jinik;Kim, Donggiun;Park, Jongbum;Chung, Young-Jae;Lee, Taek-Kyun
    • Journal of Life Science
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    • v.24 no.9
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    • pp.995-1000
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    • 2014
  • The studies of marine viruses in terms of viral isolation and detection have been limited due to the high mutation rate and genetic diversity of marine viruses. Of the modern methods currently used to detect marine viruses, serological methods based on enzyme-linked immunosorbent assay (ELISA) are the most common. They depend largely on the quality of the antibodies and on highly purified suitable antigens. Recently, a new experimental system for using viral capsid protein as an antigen has been developed using the yeast surface display (YSD) technique. In the present study, the capsid protein gene of the red-spotted grouper nervous necrosis virus (RGNNV) was expressed and purified via YSD and HA-tagging systems, respectively. Two regions of the RGNNV capsid protein gene, RGNNV1 and RGNNV2, were individually synthesized and subcloned into a yeast expression vector, pCTCON. The expressions of each RGNNV capsid protein in the Saccharomyces cerevisiae strain EBY100 were indirectly detected by flow cytometry with fluorescently labeled antibodies, while recognizing the C-terminal c-myc tags encoded by the display vector. The expressed RGNNV capsid proteins were isolated from the yeast surface through the cleavage of the disulfide bond between the Aga1 and Aga2 proteins after ${\beta}$-mercaptoethanol treatment, and they were directly detected by Western blot using anti-HA antibody. These results indicated that YSD and HA-tagging systems could be applicable to the expressions and purification of recombinant RGNNV capsid proteins.

Mechanism of Action of Nigella sativa on Human Colon Cancer Cells: the Suppression of AP-1 and NF-κB Transcription Factors and the Induction of Cytoprotective Genes

  • Elkady, Ayman I;Hussein, Rania A;El-Assouli, Sufian M
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7943-7957
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    • 2015
  • Background and Aims: Colorectal cancer is one of the leading causes of death in the world. The aim of this study was to investigate the growth-suppression potentiality of a crude saponin extract (CSENS) prepared from medicinal herb, Nigella sativa, on human colon cancer cells, HCT116. Materials and Methods: HCT116 cells were subjected to increasing doses of CSENS for 24, 48 and 72 h, and then harvested and assayed for cell viability by WST-1. Flow cytometry analyses, cell death detection ELISA, fluorescent stains (Hoechst 33342 and acridine orange/ethidium bromide), DNA laddering and comet assays were carried out to confirm the apoptogenic effects of CSENS. Luciferase reporter gene assays, quantitative reverse transcription-polymerase chain reaction and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells. Results: The results demonstrated that CSENS inhibited proliferation and induced apoptosis. Apoptosis was confirmed by flow cytometry analyses, while CSENS-treated cells exhibited morphological hallmarks of apoptosis including cell shrinkage, irregularity in cellular shape, cellular detachment and chromatin condensation. Biochemical signs of apoptosis, such as DNA degradation, were observed by comet assay and gel electrophoresis. The pro-apoptotic effect of CSENS was caspase-3-independent and associated with increase of the Bax/Bcl-2 ratio. CSENS treatment down-regulated transcriptional and DNA-binding activities of NF-${\kappa}B$ and AP-1 proteins, associated with down-regulation of their target oncogenes, c-Myc, cyclin D1 and survivin. On the other hand, CSENS up-regulated transcriptional and DNA-binding activities of Nrf2 and expression of cytoprotective genes. In addition, CSENS modulated the expression levels of ERK1/2 MAPK, p53 and p21. Conclusions: These findings suggest that CSENS may be a valuable agent for treatment of colon cancer.

Effects of n-3 Fatty Acids on Proliferation of Human Breast Cancer Cells in Relatino to Lipid Peroxidation and Oncogene Expression (n-3 지방산이 유방암세포의 증시과 지질과산화 및 Oncogene 발현에 미치는 영향)

  • 조성희
    • Journal of Nutrition and Health
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    • v.30 no.8
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    • pp.987-994
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    • 1997
  • To investigate the effects of n-3 fatty acids on breast cancer, MDA-MB231 human breast cancer cells were cultured in the presence of $\alpha$-linolenic (LNA), eicosapentaenoic(EPA), and docosahexaenoic acid (DHA) at a concentration of 0.5$\mu\textrm{g}$/ml in serum -free IMM medium. Cell growth was monitored and thiobarbituric acid reactive substances (TBARS), $\alpha$-tocopherol contents, and oncogene expression were measured. To compare the effects of n-3 fatty acids with other types of fatty acid, steraic (STA), olieic(OA). linoleic acid(LA) were used. After one day , cell growth was retarded most highly when DHA was in the medium. Cellular TBARS level measured after three days of culture was the highest with DHA in the medium and was also increased by LNA and EPA, compared with STA, OA and LA. Alpha-tocoopherol contents of cells were decreased by DHA but only modestly. There was non significant difference in $\alpha$-tocopherol contents in cells cultured in the presence of the other fatty acids. northern blot hybridization carried out with cells cultured during 24 hours showed that levels of erbB-2 mRNA were not altered by six different fatty acids in the medium but those of c-myc were transiently decreased in the early period by both n-6 and n-3 polyunsaturated fatty acids. The level of tumor suppressor gen p53 mRNA , however, was increased by DHA with time. It is concluded that the cytotoxicity of lipid peroxide and increased expression of tumor suppressor gene p53 are at least partly responsible for the inhibitory effect of DHA on growth of breast cancer cells.

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Modification of ERα by UFM1 Increases Its Stability and Transactivity for Breast Cancer Development

  • Yoo, Hee Min;Park, Jong Ho;Kim, Jae Yeon;Chung, Chin Ha
    • Molecules and Cells
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    • v.45 no.6
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    • pp.425-434
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    • 2022
  • The post-translational modification (e.g., phosphorylation) of estrogen receptor α (ERα) plays a role in controlling the expression and subcellular localization of ERα as well as its sensitivity to hormone response. Here, we show that ERα is also modified by UFM1 and this modification (ufmylation) plays a crucial role in promoting the stability and transactivity of ERα, which in turn promotes breast cancer development. The elevation of ufmylation via the knockdown of UFSP2 (the UFM1-deconjugating enzyme in humans) dramatically increases ERα stability by inhibiting ubiquitination. In contrast, ERα stability is decreased by the prevention of ufmylation via the silencing of UBA5 (the UFM1-activating E1 enzyme). Lys171 and Lys180 of ERα were identified as the major UFM1 acceptor sites, and the replacement of both Lys residues by Arg (2KR mutation) markedly reduced ERα stability. Moreover, the 2KR mutation abrogated the 17β-estradiol-induced transactivity of ERα and the expression of its downstream target genes, including pS2, cyclin D1, and c-Myc; this indicates that ERα ufmylation is required for its transactivation function. In addition, the 2KR mutation prevented anchorage-independent colony formation by MCF7 cells. Most notably, the expression of UFM1 and its conjugating machinery (i.e., UBA5, UFC1, UFL1, and UFBP1) were dramatically upregulated in ERα-positive breast cancer cell lines and tissues. Collectively, these findings implicate a critical role attributed to ERα ufmylation in breast cancer development by ameliorating its stability and transactivity.

Potentiation of Anticancer Effect of Artesunate by Combination with Nonsteroidal Anti-inflammatory Drugs on Human Cancer Cells (Artesunate와 비스테로이드소염제 NSAID의 병용 처리에 의한 항암 활성 증강)

  • Moon, Hyun-Jung;Kang, Chi-Dug;Kim, Sun-Hee
    • Journal of Life Science
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    • v.31 no.10
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    • pp.873-884
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    • 2021
  • The purpose of present study is to investigate the role of artesunate (ART) in enhancing anticancer effect of nonsteroidal anti-inflammatory drug (NSAID) on human cancer cells, and we elucidate a possible molecular mechanism of this combination effect. We showed that the combined effect of ART with NSAID such as celecoxib (CCB) or dimethyl-CCB (DMC) in various type of human cancer cells. After ART treatment, the expression of p62, nuclear factor erythroid 2-like 2 (NRF2) and cancer stemness (CS)-related proteins including CD44, CD133, aldehyde dehydrogenase 1 (ALDH1), octamer-binding transcription factor 4 (Oct4), mutated p53 (mutp53) and c-Myc was down-regulated. ART induced autophagy as reduction of the autophagy receptor p62, which was associated with up-regulation of activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP), and simultaneous down-regulation of NRF2 and CS-related proteins was occurred in the human cancer cells. These results indicate a possibility that ART activates autophagy through ATF4-CHOP cascade leading to down-regulation of CS-related proteins and subsequently eradicated cancer stem cells. In addition, co-treatment with ART and imatinib was more effective than either drug alone on growth inhibition and apoptosis induction of cancer cells. In conclusion, induction of autophagy-dependent cell death by ART might play a critical role in mediating the synergistic effect of drug combination (ART/NSAID and ART/imatinib). Therefore, ART could be a promising candidate as a chemosensitizer to enhance the anticancer effects of NSAID and imatinib.

Immunoregulatory Action of OGAPI (오가피의 면역조절작용)

  • Kim Nam Seok;Kwon Jin;Koh Ha Young;Choi Dong Seong;Oh Chan Ho
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.5
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    • pp.1337-1342
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    • 2004
  • The purpose of this research was to investigate the immunoregulatory effect and the leukemia cell apoptosis of EtOH extract of OGAPI(OGP). The proliferation of cultured splenocytes, thymocytes and mesenteric lymph node cells were enhanced by the addition of OGP. Splenic and thymic T lymphocytes, especially TH and Tc cells were significantly increased in OGP-administered mice. OGP markedly increased the production of γ-interferon in mice serum and accelerated the phagocytic activity in peritoneal macrophages. OGP treatment enhanced the apoptosis of L1210 mouse leukemia and Jurkat, Molt4 human leukemia cells, and increased the expression of apoptosis-related ICE, c-myc, p53 gene in Jurkat cell. These results suggest that OGP have an immunoregulatory action and anti-cancer activity.

Growth Inhibitory Activity of Honokiol through Cell-cycle Arrest, Apoptosis and Suppression of Akt/mTOR Signaling in Human Hepatocellular Carcinoma Cells

  • Hong, Ji-Young;Park, Hyen Joo;Bae, KiHwan;Kang, Sam Sik;Lee, Sang Kook
    • Natural Product Sciences
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    • v.19 no.2
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    • pp.155-159
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    • 2013
  • Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has exhibited a potential anti-proliferative activity in human cancer cells. However, the growth inhibitory activity against hepatocellular carcinoma cells and the underlying molecular mechanisms has been poorly determined. The present study was designed to examine the anti-proliferative effect of honokiol in SK-HEP-1 human hepatocellular cancer cells. Honokiol exerted anti-proliferative activity with cell-cycle arrest at the G0/G1 phase and sequential induction of apoptotic cell death. The cell-cycle arrest was well correlated with the down-regulation of checkpoint proteins including cyclin D1, cyclin A, cyclin E, CDK4, PCNA, retinoblastoma protein (Rb), and c-Myc. The increase of sub-G1 peak by the higher concentration of honokiol ($75{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by decreased expression of Bcl-2, Bid, and caspase-9. Hohokiol was also found to attenuate the activation of signaling proteins in the Akt/mTOR and ERK pathways. These findings suggest that the anti-proliferative effect of honokiol was associated in part with the induction of cell-cycle arrest, apoptosis, and dow-nregulation of Akt/mTOR signaling pathways in human hepatocellular cancer cells.

Melatonin inhibits glycolysis in hepatocellular carcinoma cells by downregulating mitochondrial respiration and mTORC1 activity

  • Lee, Seunghyeong;Byun, Jun-Kyu;Kim, Na-Young;Jin, Jonghwa;Woo, Hyein;Choi, Yeon-Kyung;Park, Keun-Gyu
    • BMB Reports
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    • v.55 no.9
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    • pp.459-464
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    • 2022
  • Various mechanisms have been suggested to explain the chemopreventive and tumor-inhibitory effects of melatonin. Despite the growing evidence supporting melatonin-induced mitochondrial dysfunction, it remains largely unknown how this phenomenon modulates metabolic reprogramming in cancer cells. The aim of our study was to identify the mechanism underlying the anti-proliferative and apoptotic effects of melatonin, which is known to inhibit glycolysis. We analyzed the time-dependent effects of melatonin on mitochondrial respiration and glycolysis in liver cancer cells. The results showed that from a cell bioenergetic point of view, melatonin caused an acute reduction in mitochondrial respiration, however, increased reactive oxygen species production, thereby inhibiting mTORC1 activity from an early stage post-treatment without affecting glycolysis. Nevertheless, administration of melatonin for a longer time reduced expression of c-Myc protein, thereby suppressing glycolysis via downregulation of HK2 and LDHA. The data presented herein suggest that melatonin suppresses mitochondrial respiration and glycolysis simultaneously in HCC cells, leading to anti-cancer effects. Thus, melatonin can be used as an adjuvant agent for therapy of liver cancer.

Vitamin C promotes the early reprogramming of fetal canine fibroblasts into induced pluripotent stem cells

  • Sang Eun Kim;Jun Sung Lee;Keon Bong Oh;Jeong Ho Hwang
    • Journal of Animal Reproduction and Biotechnology
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    • v.38 no.4
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    • pp.199-208
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    • 2023
  • Background: Canine induced pluripotent stem cells (iPSCs) are an attractive source for veterinary regenerative medicine, disease modeling, and drug development. Here we used vitamin C (Vc) to improve the reprogramming efficiency of canine iPSCs, and its functions in the reprogramming process were elucidated. Methods: Retroviral transduction of Oct4, Sox2, Klf4, c-Myc (OSKM), and GFP was employed to induce reprogramming in canine fetal fibroblasts. Following transduction, the culture medium was subsequently replaced with ESC medium containing Vc to determine the effect on reprogramming activity. Results: The number of AP-positive iPSC colonies dramatically increased in culture conditions supplemented with Vc. Vc enhanced the efficacy of retrovirus transduction, which appears to be correlated with enhanced cell proliferation capacity. To confirm the characteristics of the Vc-treated iPSCs, the cells were cultured to passage 5, and pluripotency markers including Oct4, Sox2, Nanog, and Tra-1-60 were observed by immunocytochemistry. The expression of endogenous pluripotent genes (Oct4, Nanog, Rex1, and telomerase) were also verified by PCR. The complete silencing of exogenously transduced human OSKM factors was observed exclusively in canine iPSCs treated with Vc. Canine iPSCs treated with Vc are capable of forming embryoid bodies in vitro and have spontaneously differentiated into three germ layers. Conclusions: Our findings emphasize a straightforward method for enhancing the efficiency of canine iPSC generation and provide insight into the Vc effect on the reprogramming process.

The Effect of the Injinhotang Extract on the Hepatocarcinogenesis Induced by N-Nitrosodiethylamine and Carbon Tetrachloride in Rats (N-Nitrosodiethylamine과 사염화탄소로 유발된 흰쥐의 간암발생에 대한 인진호탕 추출액의 효과)

  • Yoon, Jung-Sik;Kim, Jeong-Sang
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.4
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    • pp.436-441
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    • 2009
  • In order to examine the effect of Injinhotang extract on the hepatocarcinogenesis induced by N-nitrosodiethylamine (NDEA) and carbon tetrachloride ($CCl_4$) in 8 week-old rats. Experimental rats were subdivided into three groups; normal group (Nor), hepatic cancer inducing control group (Con), and control group administered Injinhotang extract 260 mg/kg/day (IJH). The body weight decreased significantly (p<0.05) in the Con compared with the Nor. The body weight of IJH group more increased than Con. Rats intoxicated with NDEA had significantly (p<0.05) increased levels of serum AST, ALT, LDH, ALP, and AFP. On the contrary, group treated with Injinhotang extract had inhibited levels of serum AST, ALT, LDH, ALP, and AFP. The bcl-2 mRNA expression levels in rat liver were more increased in the IJH than Con, but these levels of c-myc mRNA were more decreased in the IJH than Con. Also, cytoplasmic vacuolizations in the liver of NDEA-administrated rats were inhibited by the treatment of Injinhotang extract. These results suggest that administration of Injinhotang extract suppresses or retards NDEA and $CCl_4$-induced hepatocarcinogenesis in rats.