• Title/Summary/Keyword: genomic pattern

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Suppressed DNA Repair Mechanisms in Rheumatoid Arthritis

  • Lee, Sang-Heon;Firestein, Gary S
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.208-216
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    • 2002
  • Background: Reactive oxygen and nitrogen are produced by rheumatoid arthritis (RA) synovial tissue and can induce mutations in key genes. Normally, this process is prevented by a DNA mismatch repair (MMR) system that maintains sequence fidelity. Key members of the MMR system include MutS${\alpha}$ (comprised of hMSH2 and hMSH6), which can sense and repair single base mismatches and 8-oxoguanine, and MutS${\beta}$ (comprised of hMSH2 and hMSH3), which repairs longer insertion/deletion loops. Methods: To provide further evidence of DNA damage, we analyzed synovial tissues for microsatellite instability (MSI). MSI was examined by PCR on genomic DNA of paired synovial tissue and peripheral blood cells (PBC) of RA patients using specific primer sequences for 5 key microsatellites. Results: Surprisingly, abundant MSI was observed in RA synovium compared with osteoarthritis (OA) tissue. Western blot analysis of the same tissues for the expression of MMR proteins demonstrated decreased hMSH6 and increased hMSH3 in RA synovium. To evaluate potential mechanisms of MMR regulation in arthritis, fibroblast-like synoviocytes (FLS) were isolated from synovial tissues and incubated with the nitric oxide donor S-nitroso-N-acetylpenicillamine (SNAP). Western blot analysis demonstrated constitutive expression of hMSH2, 3 and 6 in RA and OA FLS. When FLS were cultured with SNAP, the RA synovial pattern of MMR expression was reproduced (high hMSH3, low hMSH6). Conclusion: Therefore, oxidative stress can relax the DNA MMR system in RA by suppressing hMSH6. Decreased hMSH6 can subsequently interfere with repair of single base mutations, which is the type observed in RA. We propose that oxidative stress not only creates DNA adducts that are potentially mutagenic, but also suppresses the mechanisms that limit the DNA damage.

Establishment of Highly Tumorigenic Human Gastric Carcinoma Cell Lines from Xenograft Tumors in Mice

  • Song, Kyung-A;Park, Jihyun;Kim, Ha-Jung;Kang, Myung Soo;Kim, Sun Young
    • Biomedical Science Letters
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    • v.23 no.3
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    • pp.238-250
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    • 2017
  • Patient's primary tumor-derived tumor cell lines likely represent ideal tools for human tumor biology in vitro and in vivo. Here, we describe eight human gastric carcinoma cell lines derived from established tumors in vivo upon subcutaneous transplantation of primary gastric carcinoma specimens in BALB/c nude mice. These xenografted gastric tumor cell lines (GTX) displayed close similarity with primary gastric tumor tissues in their in vivo growth pattern and genomic alterations. GTX-085 cells were resistant to cisplatin, while GTX-087 was the most sensitive cell line. GTX-085 was the only cell line showing a metastatic potential. Epithelial cell adhesion molecule (EPCAM) expression was especially strong in all tissue samples, as well as in cell cultures. GTX-139, the largest tumor graft obtained after injection, displayed distinct expression of CD44v6, fibroblast growth factor receptor 2 (FGFR2), and prominin 1 (PROM1, also known as CD133). In summary, we established eight xenograft gastric cancer cell lines from gastric cancer patient tissues, with their histological and molecular features consistent with those of the primary tumors. The established GTX cell lines will enable future studies of their responses to various treatments for gastric cancer.

Differential Localisation of PARP-1 N-Terminal Fragment in PARP-1+/+ and PARP-1-/- Murine Cells

  • Rajiah, Ida Rachel;Skepper, Jeremy
    • Molecules and Cells
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    • v.37 no.7
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    • pp.526-531
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    • 2014
  • Human PARP family consists of 17 members of which PARP-1 is a prominent member and plays a key role in DNA repair pathways. It has an N-terminal DNA-binding domain (DBD) encompassing the nuclear localisation signal (NLS), central automodification domain and C-terminal catalytic domain. PARP-1 accounts for majority of poly-(ADP-ribose) polymer synthesis that upon binding to numerous proteins including PARP itself modulates their activity. Reduced PARP-1 activity in ageing human samples and its deficiency leading to telomere shortening has been reported. Hence for cell survival, maintenance of genomic integrity and longevity presence of intact PARP-1 in the nucleus is paramount. Although localisation of full-length and truncated PARP-1 in PARP-1 proficient cells is well documented, subcellular distribution of PARP-1 fragments in the absence of endogenous PARP-1 is not known. Here we report the differential localisation of PARP-1 Nterminal fragment encompassing NLS in PARP-$1^{+/+}$ and PARP-$1^{-/-}$ mouse embryo fibroblasts by live imaging of cells transiently expressing EGFP tagged fragment. In PARP-$1^{+/+}$ cells the fragment localises to the nuclei presenting a granular pattern. Furthermore, it is densely packaged in the midsections of the nucleus. In contrast, the fragment localises exclusively to the cytoplasm in PARP-$1^{-/-}$ cells. Flourescence intensity analysis further confirmed this observation indicating that the N-terminal fragment requires endogenous PARP-1 for its nuclear transport. Our study illustrates the trafficking role of PARP-1 independently of its enzymatic activity and highlights the possibility that full-length PARP-1 may play a key role in the nuclear transport of its siblings and other molecules.

Whole Genomic Expression Analysis of Rat Liver Epithelial Cells in Response to Phenytoin

  • Kim, Ji-Hoon;Kim, Seung-Jun;Yeon, Jong-Pil;Yeom, Hye-Jung;Jung, Jin-Wook;Oh, Moon-Ju;Park, Joon-Suk;Kang, Kyung-Sun;Hwang, Seung-Yong
    • Molecular & Cellular Toxicology
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    • v.2 no.2
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    • pp.120-125
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    • 2006
  • Phenytoin is an anti-epileptic. It works by slowing down impulses in the brain that cause seizures. The recent microarray technology enables us to understand possible mechanisms of genes related to compounds which have toxicity in biological system. We have studied that the effect of a compound related to hepatotoxin in vitro system using a rat whole genome microarray. In this study, we have used a rat liver epithelial cell line WB-F344 and phenytoin as a hepatotoxin. WB-F344 was treated with phenytoin for 1 to 24 hours. Total RNA was isolated at times 1, 6 and 24h following treatment of phenytoin, and hybridized to the microarray containing about 22,000 rat genes. After analysis with clustering methods, we have identified a total of 1,455 differentially expressed genes during the time course. Interestingly, about 1,049 genes exhibited differential expression pattern in response to phenytoin in early time. Therefore, the identification of genes associated with phenytoin in early response may give important insights into various toxicogenomic studies in vitro system.

Low Level of TERC Gene Amplification between Chronic Myeloid Leukaemia Patients Resistant and Respond to Imatinib Mesylate Treatment

  • Mohamad Ashari, Zaidatul Shakila;Sulong, Sarina;Hassan, Rosline;Husin, Azlan;Sim, Goh Ai;Wahid, S. Fadilah Abdul
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.4
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    • pp.1863-1869
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    • 2014
  • The amplification of telomerase component (TERC) gene could play an important role in generation and treatment of haematological malignancies. This present study was aimed to investigate copy number amplification status of TERC gene in chronic myeloid leukaemia (CML) patients who were being treated with imatinib mesylate (IM). Genomic DNA was extracted from peripheral blood of CML-IM Resistant (n=63), CML-IM Respond (n=63) and healthy individuals (n=30). TERC gene copy number predicted (CNP) and copy number calculated (CNC) were determined based on $Taqman^{(R)}$ Copy Number Assay. Fluorescence in situ hybridization (FISH) analysis was performed to confirm the normal signal pattern in C4 (calibrator) for TERC gene. Nine of CML patients showed TERC gene amplification (CNP=3), others had 2 CNP. A total of 17 CML patients expressed CNC>2.31 and the rest had 2.31>CNC>1.5. TERC gene CNP value in healthy individuals was 2 and their CNC value showed in range 1.59-2.31. The average CNC TERC gene copy number was 2.07, 1.99 and 1.94 in CML-IM Resistant patients, CML-IM Respond and healthy groups, respectively. No significant difference of TERC gene amplification observed between CML-IM Resistant and CML-IM Respond patients. Low levels of TERC gene amplification might not have a huge impact in haematological disorders especially in terms of resistance towards IM treatment.

Optimum Condition of Polymerase Chain Reaction Techniques for Randomly Amplified Polymorphic DNA of Strawberry (딸기의 RAPD를 위한 PCR의 최적조건)

  • 양덕춘;최성민;강태진;이미애;송남현;민병훈
    • Korean Journal of Plant Resources
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    • v.14 no.1
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    • pp.65-70
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    • 2001
  • This study was performed to select marker which can identify genetic variation between mother plant and in vitro cultured plantlets of strawberry by PCR using random primer. When 'Yeobong' DNA extracted was treated with proteinase-K and RNase-H, clear DNA bands were shown. The optimal condition for RAPD in strawberry was to use 50ng of template DNA, 10pmol of primer,37oC of annealing temperature, and 45 cycles of PCR. After establishing above PCR optimal condition, RAPD pattern was investigated by using UBC primers. PCR was performed, and 46 of 90 primers produced PCR product showing 158 total bands. GC content was compared between the primers forming bands and no bands. The GC content showing bands was average 67.4%, whereas primers showing no bands 58%.

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Molecular cloning, expression and characterization of a squalene synthase gene from grain amaranth (Amaranthus cruentus L.)

  • Park, Young-Jun;Nemoto, Kazuhiro;Matsushima, Kenichi;Um, Han-Yong;Choi, Jung-Hoon;Oh, Chan-sung;Nishikawa, Tomotaro
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.89-89
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    • 2017
  • A gene encoding squalene synthase from grain amaranth was cloned and characterized. The full-length cDNA was 1805-bp long and contained a 1248-bp open reading frame encoding a protein of 416 amino acids with a molecular mass of 47.6 kDa. Southern blot analysis revealed that the A. cruentus genome contained a single copy of the gene. Comparison of the cDNA and genomic sequences indicated that the amaranth SQS gene had 12 introns and 13 exons. All of the exons contributed to the coding sequence. The predicted amino acid sequence of the SQS cDNA shared high homology with those of SQSs from several other plants. It contained conserved six domains that are believed to represent crucial regions of the active site. We conducted qRT-PCR analyses to examine the expression pattern of the SQS gene in seeds at different developmental stages and in several tissues. The amaranth SQS gene was low levels of SQS transcripts at the initial stage of seed development, but the levels increased rapidly at the mid-late developmental stages before declining at the late developmental stage. These findings showed that the amaranth SQS is a late-expressed gene that is rapidly expressed at the mid-late stage of seed development. In addition, we observed that the SQS mRNA levels in stems and roots increased rapidly during the four- to six-leaf stage of development. Therefore, our results showed that the expression levels of SQS in stem and root tissues are significantly higher than those in leaf tissues. In present study provides useful information about the molecular characterization of the SQS clone isolated from grain amaranth. Finally, a basic understanding of these characteristics will contribute to further studies on the amaranth SQS.

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Breeding of the native vegetables using the biotechnology

  • Iwamoto, Yuzuri
    • Proceedings of the Korean Society of Plant Biotechnology Conference
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    • 2005.11a
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    • pp.106-111
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    • 2005
  • For breeding of a new rootstock for eggplant production, somatic hybrids between two species, Solanum integrifolium and S. sanitwongsei were obtained through protoplast fusion. The former species has been commonly used for rootstock for eggplant production in Japan. Eggplants on these rootstocks are more productive than ungrafted plants, but are susceptible to bacterial wilt caused Ralstonia solanacearum. While the latter species is resistant, the growth of eggplants on this rootstock is rather slow and low yield. Protoplast of both species were isolated from cotyledons, and inactivated with iodoacetamide or UV-irradiation, then fused electrically. The fused products were then cultured. Regenerated plantlets were then transplanted on soil then maintained in a green house. The plants were classified into four groups. Those in the first group showed morphological characters intermediate of the parentalspecies. The plants bore fruit with viable seeds. The plants showed a chromosome number of 2n=48, the sum of those of the parental species, and are suggested to be symmetric fusion products. While plants in the other groupswas less vigorous and showed chromosome number 2n= 68 to 72 suggesting asymmetric fusion products by genomic in situ hybridization(GISH). Isozyme pattern of shikimate dehydrogenase (SKDH; EC 1.1.1.25), isocitrate dehydrogenase (IDH; EC 1.1.1.41) and phosphoglucomutase (PGM; EC 2.7.5.1) showed that 24 regenerated plants in three groups were somatic hybrids. Analysis of random amplified polymorphic DNA (RAPD) showed that 43 S. integrifolium-specific and 57 S. sanitwongsei-specific bands were all found in 24 plants. Both somatic hybrids and its S1 plants were found to be resistant to bacterial wilt, and eggplant grafted these plants using for rootstocks were more productive than grafted mother plants. Now, S1 progenies are used for commercial eggplant production in Osaka Prefecture.

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Genetic Diversity Measured by RAPDs in Korean Barley Germplasm Pools

  • Kim Hong-Sik;Park Kwang-Geun;Baek Seong-Bum;Kim Jung-Gon;Nam Jung-Hyun
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.2
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    • pp.131-141
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    • 2005
  • Molecular-based genetic diversity for a set of 141 accessions of Korean barley cultivars and 24 accessions of foreign exotic cultivars were analyzed using random amplified polymorphic DNAs (RAPDs). Different level of genetic variability was observed with 30 random decamer primers in the Korean barley varieties and breeding lines which were preliminarily classified by morphological (hulled & hulless barley) and end-use (malting barley) and/or by the released periods. A total of 74 RAPD bands were scored, and the number of bands per primer varied from 1 to 7 with an average of 2.74. The hulled barley pool had one more marker genotype per primer than the hulless barley pool. The polymorphic information content (PIC) values based on the band pattern frequencies among genotypes varied depending on genetic pools where mean PICs of hulled, hulless and malting barleys were 0.62, 0.57, and 0.43, respectively. Certain genomic loci amplified by opR04, opF01, opB05, and opC13 were highly polymorphic with PIC>0.8. Patterns and temporal trends of genetic diversity assessed over the period from 1970s to 1990s had a tendency to increase, and in particular, this upward slant was quite clear and significant for the hulless barley pool. In the cluster analysis using genetic similarity matrix calculated from RAPD profiles, two major groups and several small subgroups were classified. Major grouping of materials was not affected by the presence of the husk but by their genetic background and the spike-row type. The validity of information on the genetic diversity and relationships between genotypes will have been reviewed to predict their yield potential.

Comparative Analysis of Transgene Copy Numbers and Expression Characteristics across Multiple Transgenic Marine Medaka Oryzias dancena Strains carrying the β-Actin Promoter-Driven GFP Reporter

  • Cho, Young Sun;Lee, Sang Yoon;Vu, Nguyen Thanh;Kim, Dong Soo;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.18 no.2
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    • pp.183-193
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    • 2015
  • Several transgenic marine medaka Oryzias dancena strains harboring a green fluorescent protein (GFP) reporter construct regulated by an endogenous ${\beta}$-actin promoter were established and their expression characteristics in relation to transgene copy numbers were examined in 21 transgene genotypes. Most of the transgenic strains displayed transgene insertion patterns typical of microinjection-mediated introduction of foreign DNA into fish embryos, characterized by the random integration of multiple transgene copies (ranging from 1 - 282 copies per cell), often accompanied by the formation of concatemer(s), as assessed by genomic Southern blot hybridization analysis and qPCR. Transgenic strains showed ubiquitous and continued temporal and spatial expression patterns of the transgenic GFP during most of their life cycle, from the embryonic stage to adulthood, enabling assessment of the expression pattern of the endogenous ${\beta}$-actin gene. However, a comparative evaluation of transgene copy numbers and expression levels showed that copy number-dependent expression, the stability of the ubiquitous distribution and expression efficiency per transgene copy varied among the transgenic strains. Fluorescence expression levels were positively correlated with absolute transgene copy numbers, whereas the expression efficiency per transgene copy was inversely related to the number of transgene integrant copies. Data from this study will guide the selection of potentially desirable transgenic strains with ubiquitous expression of a fluorescent transgene, not only in this marine medaka species but also in other related model fish species.