• 제목/요약/키워드: Growth suppression

검색결과 661건 처리시간 0.025초

Apigenin과 대사물 isovitexin에 의한 인체 대장암세포의 세포활성 억제효과에 있어서의 EGR-1의 역할 연구 (Involvement of Early Growth Response Gene 1 (EGR-1) in Growth Suppression of the Human Colonic Tumor Cells By Apigenin and Its Derivative Isovitexin)

  • 문유석;최뢰광;양현
    • 생명과학회지
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    • 제17권1호
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    • pp.110-115
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    • 2007
  • Tumor suppressor 유전자로알려진 early growth response gene 1 (EGR-1)에 있어 항산화 천연물인 apigenin과 그대사물인 isovitexin에 의한 장관 상피성 종양세포에 대하여 항종양 역할을 규명하였다. Apigenin 과 isovitexin은 대장암세포에서의 EGR-1 단백질의 발현을 9-12시간의 노출에 의해 농도 의존적으로 증가하였다. 또한 신호전달측면에서 이런 apigenin에 의한 EGR-1 유전자의 유도가 U0126 화합물에 의해 완벽하게 저해 받는 것으로 보아 ERK1/2 MAP kinase pathway의 이 신호전달계에서의 관여를 보여주었다. 본 연구에서 apigenin에 의해 농도 의존적으로 대장암세포의 세포활성의 저해를 MTT assay를 통해 보였고, 또한 EGR-1 siRNA를 transfectien한 세포의 경우 이런 apigenin에 의한 세포활성의 저해효과를 완화하였다. 따라서 apigenin에 의한 항종암세포 세포활성 억제에 있어 EGR-1의 중요성을 보여 준다. 이런 EGR-1에 의해 유도되는 유전자중 대표적으로 NAG-1 유전자의 경우 apigenin과 isovitexin에 의해 24-48시간에 발현이 증가하였다. 결론적으로 암세포 증식억제활성이 있고 apoptosis 유도효과가 있는 NAG-1의 유도에 의해 대장암 세포의 세포활성이 억제된 것으로 의미되고 향후 apigenin 유도의 NAG-1유전자에 의한 암세포증식의 억제기전에 대한 명확한 연구가 요구된다.

Enhancing Resistance of Red Pepper to Phytophthora Blight Diseases by Seed Treatment with Plant Growth Promoting Rhizobacteria

  • M. Rajkumar;Lee, Kui-Jae;Lee, Wang-Hyu
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.95.1-95
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    • 2003
  • Plant growth promoting rhizobacteria (PGPR) have been shown to suppress phytopthora blight. This suppression has been related to both microbial antagonism and induced resistance. The PGPR isolates were screened by dual culture plate method and most of the isolates were showed varying levels of antagonism. Among the PGPR isolates pyoverdin, pyochelin and salicylic acid producing strains showed the maximum inhibition of mycelial growth of Phytopkhora capsici and increased plant growth promotion in red pepper. PGPR isolates further analysed for its ability to induce production of defence related enzymes and chemicals. The activities such as Phenyle alanin ammonia Iyase (PAL), Peroxidase (PO), Polyphenol oxidase (PPO) and accumulation of phenolics were observed in PGPR pretreated red pepper plants challenged with Phytopkhora capsici. The present study shows that an addition of direct antagonism and plant growth promotion, induction of defense related enzymes involved to enhance resistance against invasion of P. capsici in red pepper.

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Biocontrol Effect of Gliocladium virens G1 and Soil Amendment on Astragal Stem Rot Caused by Rhizoctonia solani

  • Chung, Bong-Koo;Yun, Kyung-Ho
    • Mycobiology
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    • 제28권4호
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    • pp.180-184
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    • 2000
  • In order to find an environment-friendly method to suppress astragal stem rot caused by the isolates of Rhizoctonia solani AG 1 and AG 4, we tested an antagonistic fungus Gliocladium virens G1 was evaluated as a biocontrol agent and estimated inorganic compounds and organic materials were tested for their effect of the disease suppression. G. virens G1 effectively inhibited mycelial growth in a dual culture and caused mycelial lysis in the culture filtrate. No adverse effect was observed when examined for seed germination and seedling growth. Promoted seedling growth was observed with the seed treatment. Seeds of astragal plant were germinated higher in the sterile soil than the natural soil. Of 14 inorganics tested, alum, aluminum sulfate and calcium oxide significantly suppressed the mycelial growth and sclerotial germination. Milled pine bark and oak sawdust also suppressed the mycelial growth. Soil amended with 1% of G. virens G1 composted with pine bark (w/v) significantly controlled astragal stem rot in the glasshouse experiments.

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Anti-Helicobacter pylori Activity of Bifidobacterium spp.

  • Bae, Eun-Ah;Kim, Dong-Hyun;Han, Myung-Joo
    • Journal of Microbiology and Biotechnology
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    • 제10권4호
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    • pp.532-534
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    • 2000
  • The inhibitory effects of different Bifidobacterium spp. on the growth of Helicobacter pylori (HP) were investigated. A significant suppression of HP growth occurred only when HP was inoculated onto a petri dish containing 0.1 mg/ml of Bifidobacterium spp. When HP was separately cultured with B. breve K-110, B. catenulatum K-309, B magnum K-311, B. magnum K-321, and B. cuniculi K-513, the urease activity was also inhibited by these Bifidobacterium spp. Therefore, it appears that these Bifidobacterium spp. excrete a heat-labile inhibitory component for HP growth into the culture medium. Although most organic acids produced by the Bifidobacterium spp. inhibited the growth of HP, the HP growth was not inhibited by the physiological concentrations of organic acids produced in bifidobacteria-cultured media. Accordingly, these results suggest that some Bifidobacterium spp. may produce antibiotic-like compounds (bacteriocins).

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Deer Antler Extract Selectively Suppresses Hyphal Growth in Dimorphic Fungus, Candida albicans

  • Park, Hyun-Sook;Jeon, Gil-Ja;Choi, Won-Ja
    • Journal of Microbiology and Biotechnology
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    • 제8권3호
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    • pp.291-294
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    • 1998
  • Transfer of Candida albicans grown in Sabouraud medium to the RPMI medium induces the transition from a nonpathogenic yeast form to a pathogenic hyphal form. This transition was severely inhibited in a dose-dependent manner when deer antler extract was added to the RPMI medium in a nontoxic range (up to $500{\mu}g$). In that range, deer antler extract inhibited the hyphal transition and cell growth, whereas no effect was observed on the yeast growth. When hydrophobic or hydrophilic fractions were prepared by detergent-solubilization of deer antler extract, the hydrophobic fraction showed a large degree of inhibition of the hyphal growth in Candida albicans. Neither fraction affected the growth in the yeast form. The pattern of chitin localization in the culture of the yeast form grown in RPMI in the presence of deer antler extract was confirmed by calcofluor staining and this exhibited strongly the suppression of hyphal transition.

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Transferrin-Conjugated Liposome/IL-12 pDNA Complexes for Cancer Gene Therapy in Mice

  • Joo, Soo-Yeon;Kim, Jin-Seok;Park, Heon-Joo;Choi, Eun-Kyung
    • Macromolecular Research
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    • 제13권4호
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    • pp.293-296
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    • 2005
  • Transferrin ($T_{f}$) has been used as a targeting ligand for delivering liposome/interleukin-12 (IL-12) pDNA complexes to cancer cells mostly due to the greater number of transferrin receptors ($T_{f}R$) found on tumor cells than on normal cells. $T_{f}$ was conjugated to liposomes via the reaction of MPB-PE with thiol groups of $T_{f}$ introduced by a heterobifunctional cross-linking agent, N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP). Four days after C26 inoculation when the tumor volume reached ${\sim}100mm^{3}$, tumor-bearing Balb/c mice were injected intravenously with $T_{f}-liposome/IL-12 pDNA$complexes twice a week for 3 weeks. Significant suppression of tumor growth was achieved in the group treated with the $T_{f}-liposome/IL-12 pDNA$ complexes, with a dose of $10{\mu}g$ of IL-12 pDNA showing the highest suppression effect among the tested doses. Similar results were obtained when the therapy was initiated one day after tumor inoculation, although in this case $30{\mu}g$ IL-12 pDNA/$T_{f}-liposome$ complexes showed a significant suppression of tumor growth between 19 and 23 days after tumor inoculation. This result indicates that the transferrin receptor-targeted liposomal system is an efficient delivery agent of therapeutic genes, such as IL-12, in mice and that its potential clinical use warrants further research investigation.

Biological Control of Phytopathogenic Fungi by Bacillus amyloliquefaciens 7079; Suppression Rates are Better Than Popular Chemical Fungicides

  • CHUNG SOOHEE;KIM SANG-DAL
    • Journal of Microbiology and Biotechnology
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    • 제15권5호
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    • pp.1011-1021
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    • 2005
  • Rhizobacteria are actively sought for the substitution of chemical fertilizers and pathogen control agents in environment-friendly sustainable agriculture. To be successfully commercialized in the current Korean market as agriculture biomaterials, microbial agents should exhibit both properties of plant growth promotion and pathogen control. That is, the organism must be a phytostimulator as well as a biocontrol agent. These criteria and the survival rate of a rhizobacterium, Bacillus amyloliquefaciens 7079, in the soil system were investigated to evaluate the suitability for future commercialization. B. amyloliquefaciens 7079-treated seedlings showed $22.8\%$ maximum increase in leaf-length growth, compared with water-treated controls, showing the phytostimulating property. The disease suppression rates of Phytophthora-blight of peppers and Fusarium-wilt of tomatoes by B. amyloliquefaciens 7079 were 1.5 and 2.2 times better, respectively, than by three popular chemical fungicides used in actual agricultural practices to control the respective pathogens. Survival of B. amyloliquefaciens 7079 on the rhizoplane and in the rhizosphere was favorable up to 50 days in the soil system employed. These positive properties show that B. amyloliquefaciens 7079 is likely to be a suitable candidate for commercialization to market as agricultural biomaterials.

Influence of Antibiotics on Shoot Regeneration and Agrobacteium Suppression Using Cotyledonary Node in Korean Soybean Cultivars

  • Kim, Kyung-Hee;Lee, Jae-Eun;Kwon, Young-Up;Lee, Byung-Moo
    • 한국작물학회지
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    • 제54권3호
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    • pp.307-313
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    • 2009
  • Mature dry seeds of Korean cultivars, Daepungkong, Muhankong, Myeongjunamulkong, Somyeongkong, Sowonkong, Jinpumkong, and Pungsannamulkong were used. The influence of antibiotics on elimination of Agrobacterium growth and shoot regeneration was estimated with cotyledonary node. Cefotaxime and timentin at the concentration of 250 and 500 mg/l suppressed Agrobacterium, especially cefotaxime was an efficient antibiotic to suppress Agrobacterium in all cultivars. While carbenicillin and timentin at the concentration of 50 and 100 mg/l were not sufficient to control the development of Agrobacterium, respectively. Cefotaxime and timentin represented high shoot formation rates compared with carbenicillin. Carbenicillin at low concentrations did not effectively suppress Agrobacterium and also had no effect on shoot development. Cefotaxime at the concentration of 250 mg/l showed maximum frequency of shoot regeneration in cvs. Somyeongkong and Sowonkong. Furthermore, on medium containing cefotaxime, shoot was more quickly formed than the other antibiotics. The use of cefotaxime was very useful for elimination of Agrobacterium growth with cotyledonary node of Korean soybean cultivars.

CTRP9 Regulates Growth, Differentiation, and Apoptosis in Human Keratinocytes through TGFβ1-p38-Dependent Pathway

  • Jung, Tae Woo;Park, Hyung Sub;Choi, Geum Hee;Kim, Daehwan;Lee, Taeseung
    • Molecules and Cells
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    • 제40권12호
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    • pp.906-915
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    • 2017
  • Impairment of wound healing is a common problem in individuals with diabetes. Adiponectin, an adipocyte-derived cytokine, has many beneficial effects on metabolic disorders such as diabetes, obesity, hypertension, and dyslipidemia. C1q/TNF-Related Protein 9 (CTRP9), the closest paralog of adiponectin, has been reported to have beneficial effects on wound healing. In the current study, we demonstrate that CTRP9 regulates growth, differentiation, and apoptosis of HaCaT human keratinocytes. We found that CTRP9 augmented expression of transforming growth factor beta 1 ($TGF{\beta}1$) by transcription factor activator protein 1 (AP-1) binding activity and phosphorylation of p38 in a dose-dependent manner. Furthermore, siRNA-mediated suppression of $TGF{\beta}1$ reversed the increase in p38 phosphorylation induced by CTRP9. siRNA-mediated suppression of $TGF{\beta}1$ or p38 significantly abrogated the effects of CTRP9 on cell proliferation and differentiation while inducing apoptosis, implying that CTRP9 stimulates wound recovery through a $TGF{\beta}1$-dependent pathway in keratinocytes. Furthermore, intravenous injection of CTRP9 via tail vein suppressed mRNA expression of Ki67 and involucrin whereas it augmented $TGF{\beta}1$ mRNA expression and caspase 3 activity in skin of type 1 diabetes animal models. In conclusion, our results suggest that CTRP9 has suppressive effects on hyperkeratosis, providing a potentially effective therapeutic strategy for diabetic wounds.