• Title/Summary/Keyword: Cancer cells

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Pheophytin Content and Fibrinolytic Activity of Silkworm Feces in the Different Larval Stages of Silkworms

  • Ahn, Mi-Young;Ryu, Kang-Sun;Kim, Iksoo;Kim, Jin-Won;Lee, Heui-Sam;Lee, Yong-Ki;Kim, Eun-Sun
    • International Journal of Industrial Entomology and Biomaterials
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    • v.5 no.2
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    • pp.195-199
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    • 2002
  • In order to find potential anticancer agents, we extracted pheophytin in the silkworm feces from various larval stages by water, chloroform and methanol extraction. The cytotoxicity of the pheophytin extracts of various silkworm feces was measured in the CT-26 cells originated from murine metastatic colon cancer, by dye uptake assay. The cytotoxicity of those pheophytins in 2nd, 3rd and 4th instars was better than remaining larval stages. The in vitro anticoagulant and fibyinolytic activities of ethanol extract from varietal mulberry leaves, mulberry branches and silkworm feces and pheophytin extracts from silkworm feces obtained at various larval stages were evaluated in order to find effective therapeutic drugs for the treatment of myocardial and cerebral thrombosis. The fibrinolytic activity was tested using the activated partial thromboplastin time (APTT) and thrombin time (TT) was measured for blood clotting activity. With regards to the fibrinolytic system, ethanol extracts of silkworm feces were better than varietal mulberry leaves and mulberry branches. The pheophytin extracts from 7th days of 5th instar contained the highest percentage of pheophytin and good fibrinolytic activity.

DNA Damage-inducible Phosphorylation of p53 at Ser20 is Required for p53 Stabilization

  • Yang, Dong-Hwa;Rhee, Byung-Kirl;Yim, Tae-Hee;Lee, Hye-Jin;Kim, Jungho
    • Animal cells and systems
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    • v.6 no.3
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    • pp.263-269
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    • 2002
  • The p53 tumor suppressor gene is among the most frequently mutated and studied genes in human cancer, but the mechanisms by which it sur presses tumor formation remain unclear. DNA damage regulates both the protein levels of p53 and its affinity for specific DNA sequences. Stabilization of p53 in response to DNA damage is caused by its dissociation from Mdm2, a downstream target gene of p53 and a protein that targets p53 for degradation in the proteosome. Recent studies have suggested that phosphorylation of human p53 at Ser20 is important for stabilizing p53 in response to DNA damage through disruption of the interaction between Mdm2 and p53. We generated mice with an allele encoding changes at Ser20, known to be essential for p53 accumulation following DNA damage, to enable analyses of p53 stabilization in vivo. Our data showed that the mutant p53 was clearly defective for full stabilization of p53 in response to DNA damage. We concluded that Ser20 phosphorylation is critical for modulating the negative regulation of p53 by Mdm2, probably through phosphorylation-dependent inhibition of p53-Mdm2 interaction in the physiological context.

Identification of a Promoter Motif Involved in Curtovirus Sense-Gene Expression in Transgenic Arabidopsis

  • Hur, Jingyung;Choi, Eunseok;Buckley, Kenneth J.;Lee, Sukchan;Davis, Keith R.
    • Molecules and Cells
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    • v.26 no.2
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    • pp.131-139
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    • 2008
  • Expression of the seven open reading frames (ORFs) of single-stranded DNA Curtoviruses such as Beet curly top virus (BCTV) and Beet severe curly top virus (BSCTV) is driven by a bi-directional promoter. To investigate this bidirectional promoter activity with respect to viral late gene expression, transgenic Arabidopsis plants expressing a GUS reporter gene under the control of either the BCTV or BSCTV bi-directional promoter were constructed. Transgenic plants harboring constructs showed higher expression levels when the promoter of the less virulent BCTV was used than when the promoter of the more virulent BSCTV was used. In transgenic seedlings, the reporter gene constructs were expressed primarily in actively dividing tissues such as root tips and apical meristems. As the transgenic plants matured, reporter gene expression diminished but viral infection of mature transgenic plants restored reporter gene expression, particularly in transgenic plants containing BCTV virion-sense gene promoter constructs. A 30 base pair conserved late element (CLE) motif was identified that was present three times in tandem in the BCTV promoter and once in that of BSCTV. Progressive deletion of these repeats from the BCTV promoter resulted in decreased reporter gene expression, but BSCTV promoters in which one or two extra copies of this motif were inserted did not exhibit increased late gene promoter activity. These results demonstrate that Curtovirus late gene expression by virion-sense promoters depends on the developmental stage of the host plant as well as on the number of CLE motifs present in the promoter.

Metastatic thyroid follicular carcinoma of masticator space (저작근극에서 발생한 전이된 갑상선 여포상암)

  • Gang Tae-In;Heo Min-Suk;An Chang-Hyeon;Choi Mi;Lee Sam-Sun;Choi Soon-Chul;Park Tae-Won
    • Imaging Science in Dentistry
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    • v.32 no.3
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    • pp.175-179
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    • 2002
  • Follicular carcinomas are the second most common form of thyroid cancer, accounting for 10 to 20% of all thyroid cancers. Follicular carcinomas have a propensity to metastasize via the bloodstream, spreading to bone, lungs, liver, and elsewhere. We described the case of a 48-year-old woman who presented with swelling of the left preauricular area, which was a consequence of a metastatic follicular carcinoma of the masticator space. Plain films showed illdefined erosive bony changes from the left condylar head to the mandibular notch. Contrast-enhanced CT images showed a well circumscribed round mass with well enhancement within left masticator space. On MR images, the mass was heterogenously hyperintense to the muscle on T2-weighted images and isointense or hyperintense to the muscle on Tl-weighted images, and showed good enhancement on contrast-enhanced Tl-weighted images. Upon microscopic examination, the metastatic mass was found to be composed of fairly uniform cells forming small follicles containing colloid, showing capsular and vascular invasion.

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Combined Small Cell Carcinoma Associated with Microinvasive Squamous Cell Carcinoma of Bronchial Surface Epithelium - A case report - (기관지표면상피의 미세침윤성 편평세포암과 동반된 혼합성 소세포암종 -1례 보고-)

  • 김윤정;심정원
    • Journal of Chest Surgery
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    • v.29 no.9
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    • pp.1031-1035
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    • 1996
  • International Ass ciation for the Study of Lung Cancer(IASLC) recommended the following classification of small cell lung carcinoma(SCLC) : (1) Small cell carcinoma (2) Mixed small cell/large cell carcinoma (3) Combined small cell carcinoma. Combined small cell carcinomas contain a squamous cell carcinoma or adenocarcinoma component. The prognostic significance of these elements is not known, but since the frequency and extent of non-small cell elements are considerably greater in posttherapy and autopsy tissues, it is possible that the non-SCLC elements are more resistant to therapy than the SCLC cells. Metaplasia & dysplasia of the bronchial surface epithelium are frequently observed in the bronchial biopsy specimens that contain small cell carcinoma of the lung. We report a case of combined small cell carcinoma with squamous element associated with microinvasive squamous cell carcinoma of the bronchial surface epithelium in 68 year old male patient, stage was IIIa. The two lesion are not connected n serial sections.

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Inhibition of MMP-2 and MMP-9 Activities by Limonium tetragonum Extract

  • Bae, Min-Joo;Karadeniz, Fatih;Lee, Seul-Gi;Seo, Youngwan;Kong, Chang-Suk
    • Preventive Nutrition and Food Science
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    • v.21 no.1
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    • pp.38-43
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    • 2016
  • Matrix metalloproteinases (MMPs) are crucial extracellular matrices degrading enzymes that take important roles in metastasis of cancer progression as well as other significant conditions such as oxidative stress and hepatic fibrosis. Natural products are on the rise for their potential to provide remarkable health benefits. In this context, halophytes have been of interest in the nutraceutical field with reported instances of isolation of bioactive compounds. In this study, Limonium tetragonum, an edible halophyte, was studied for its ability to inhibit MMP-2 and -9 using HT1080 fibrosarcoma cells. Results showed that L. tetragonum extract was able to inhibit the enzymatic activity and mRNA expression of MMP-2 and -9 according to gelatin zymography and RT-PCR assays, respectively, but it was not able to significantly change the MMP pathway related factors such as tissue inhibitors of metalloproteinases. Also, Mitogen-activated protein kinases pathway-related protein levels and their phosphorylation were assayed. While the phosphorylated p38 levels were decreased, extracellular signal-regulated kinase and c-Jun N-terminal kinase were not affected by L. tetragonum treatment. In conclusion, it was suggested that L. tetragonum contains substances acting as MMP inhibitors on enzymatic activity rather than intracellular pathway intervention, which could be useful for further utilization of L. tetragonum as a source for anti-MMP agents.

Processed Vietnamese ginseng: Preliminary results in chemistry and biological activity

  • Le, Thi Hong Van;Lee, Seo Young;Kim, Tae Ryong;Kim, Jae Young;Kwon, Sung Won;Nguyen, Ngoc Khoi;Park, Jeong Hill;Nguyen, Minh Duc
    • Journal of Ginseng Research
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    • v.38 no.2
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    • pp.154-159
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    • 2014
  • Background: This study was carried out to investigate the effect of the steaming process on chemical constituents, free radical scavenging activity, and antiproliferative effect of Vietnamese ginseng. Methods: Samples of powdered Vietnamese ginseng were steamed at $120^{\circ}C$ for various times and thei extracts were subjected to chemical and biological studies. Results: Upon steaming, contents of polar ginsenosides, such as Rb1, Rc, Rd, Re, and Rg1, were rapidly decreased, whereas less polar ginsenosides such as Rg3, Rg5, Rk1, Rk3, and Rh4 were increased as reported previously. However, ocotillol type saponins, which have no glycosyl moiety at the C-20 position, were relatively stable on steaming. The radical scavenging activity was increased continuously up to 20 h of steaming. Similarly, the antiproliferative activity against A549 lung cancer cells was also increased. Conclusion: It seems that the antiproliferative activity is closely related to the contents of ginsenoside Rg3, Rg5, and Rk1.

Thiazinogeldanamycin, a New Geldanamycin Derivative Produced by Streptomyces hygroscopicus 17997

  • Ni, Siyang;Wu, Linzhuan;Wang, Hongyuan;Gan, Maoluo;Wang, Yucheng;He, Weiqing;Wang, Yiguang
    • Journal of Microbiology and Biotechnology
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    • v.21 no.6
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    • pp.599-603
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    • 2011
  • A new geldanamycin (GDM) derivative was discovered and isolated from the fermentation broth of Streptomyces hygroscopicus 17997. Its chemical structure was elucidated as thiazinogeldanamycin by LC-MS, sulfur analysis, and NMR. The addition of cysteine to the fermentation medium significantly stimulated the production level of thiazinogeldanamycin, suggesting cysteine as a precursor of thiazinogeldanamycin production. Although showing a decreased cytotoxicity against HepG2 cancer cells, thiazinogeldanamycin exhibited an improved water solubility and photostability. Thiazinogeldanamycin may represent the first natural GDM derivative characterized so far that uses GDM as its precursor. Its appearance also clearly indicates that an appropriate end-point of fermentation is of critical importance for the maximal production of GDM by Streptomyces hygroscopicus 17997.

Binding Specificity of Philyra pisum Lectin to Pathogen-Associated Molecular Patterns, and Its Secondary Structure

  • Park, Byung Tae;Kim, Byung Sun;Park, Heajin;Jeong, Jaehoon;Hyun, Hanbit;Hwang, Hye Seong;Kim, Ha Hyung
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.6
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    • pp.547-551
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    • 2013
  • We recently reported a Philyra pisum lectin (PPL) that exerts mitogenic effects on human lymphocytes, and its molecular characterization. The present study provides a more detailed characterization of PPL based on the results from a monosaccharide analysis indicating that PPL is a glycoprotein, and circular dichroism spectra revealing its estimated ${\alpha}$-helix, ${\beta}$-sheet, ${\beta}$-turn, and random coil contents to be 14.0%, 39.6%, 15.8%, and 30.6%, respectively. These contents are quite similar to those of deglycosylated PPL, indicating that glycans do not affect its intact structure. The binding properties to different pathogen-associated molecular patterns were investigated with hemagglutination inhibition assays using lipoteichoic acid from Gram-positive bacteria, lipopolysaccharide from Gram-negative bacteria, and both mannan and ${\beta}$-1,3-glucan from fungi. PPL binds to lipoteichoic acids and mannan, but not to lipopolysaccharides or ${\beta}$-1,3-glucan. PPL exerted no significant antiproliferative effects against human breast or bladder cancer cells. These results indicate that PPL is a glycoprotein with a lipoteichoic acid or mannan-binding specificity and which contains low and high proportions of ${\alpha}$-helix and ${\beta}$-structures, respectively. These properties are inherent to the innate immune system of P. pisum and indicate that PPL could be involved in signal transmission into Gram-positive bacteria or fungi.

Molecular Cloning and Characterization of Bovine HMGA1 Gene

  • Yu, S.L.;Chung, H.J.;Sang, B.C.;Bhuiyan, M.S.A.;Yoon, D.;Kim, K.S.;Jeon, J.T.;Lee, J.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.11
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    • pp.1662-1669
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    • 2007
  • The high mobility group AT-hook1 (HMGA1) proteins are known to be related to the regulation of gene transcription, replication and promotion of metastatic progression in cancer cells. The loss of expression by disrupting the HMGA1 gene affects insulin signaling and causes diabetes in the mouse. Previously identified single nucleotide polymorphism (SNP) of HMGA1 was significantly associated with fat deposition traits in the pig. In this study, we identified 3,935 bp nucleotide sequences from exon 5 to exon 8 of the bovine HMGA1 gene and its mRNA expression was observed by quantitative real-time PCR. Six single nucleotide polymorphisms in the bovine HMGA1 gene were detected and the allele frequencies of these SNPs were investigated using the PCR-RFLP method in nine cattle breeds including Limousin, Simmental, Brown Swiss, Hereford, Angus, Charolais, Hanwoo, Brahman and Red Chittagong cattle. The map location showed that the bovine HMGA1 gene was also closely located with a previously identified meat quality QTL region indicating this gene is the most likely positional candidate for meat quality traits in cattle.