• Title/Summary/Keyword: Gene expressions

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Bayesian Variable Selection in the Proportional Hazard Model

  • Lee, Kyeong-Eun
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.3
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    • pp.605-616
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    • 2004
  • In this paper we consider the proportional hazard models for survival analysis in the microarray data. For a given vector of response values and gene expressions (covariates), we address the issue of how to reduce the dimension by selecting the significant genes. In our approach, rather than fixing the number of selected genes, we will assign a prior distribution to this number. To implement our methodology, we use a Markov Chain Monte Carlo (MCMC) method.

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Identification of Potential Target Genes Involved in Doxorubicin Overproduction Using Streptomyces DNA Microarray Systems

  • Kang, Seung-Hoon;Kim, Eung-Soo
    • 한국생물공학회:학술대회논문집
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    • 2005.04a
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    • pp.82-85
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    • 2005
  • Doxorubicin is a highly-valuable anthracycline-family polyketide drug with a very potent anticancer activity, typically produced by a Gram-positive soil bacterium called Streptomyces peucetius. Thanks to the recent development of Streptomyces genomics-based technologies, the random mutagenesis approach for Streptomyces strain improvement has been switched toward the genomics-based technologies including the application of DNA microarray systems. In order to identify and characterize the genomics-driven potential target genes critical for doxorubincin overproduction, three different types of doxorubicin overproducing strains, a dnrI(doxorubicin-specific positive regulatory gene)-overexpressor, a doxA (gene involved in the conversion from daunorubicin to doxorubicin)-overexpressor, and a recursively-mutated industrial strain, were generated and examined their genomic transcription profiles using Streptomyces DNA microarray systems. The DNA microarray results revealed several potential target genes in S. peucetius genome, whose expressions were significantly either up- or down-regulated comparing with the wild-type strain. A systematic understanding of doxorubicin overproduction at the genomic level presented in this research should lead us a rational design of molecular genetic strain improvement strategy.

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Bayesian Variable Selection in the Proportional Hazard Model with Application to DNA Microarray Data

  • Lee, Kyeon-Eun;Mallick, Bani K.
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2005.09a
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    • pp.357-360
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    • 2005
  • In this paper we consider the well-known semiparametric proportional hazards (PH) models for survival analysis. These models are usually used with few covariates and many observations (subjects). But, for a typical setting of gene expression data from DNA microarray, we need to consider the case where the number of covariates p exceeds the number of samples n. For a given vector of response values which are times to event (death or censored times) and p gene expressions (covariates), we address the issue of how to reduce the dimension by selecting the significant genes. This approach enable us to estimate the survival curve when n < < p. In our approach, rather than fixing the number of selected genes, we will assign a prior distribution to this number. The approach creates additional flexibility by allowing the imposition of constraints, such as bounding the dimension via a prior, which in effect works as a penalty. To implement our methodology, we use a Markov Chain Monte Carlo (MCMC) method. We demonstrate the use of the methodology to diffuse large B-cell lymphoma (DLBCL) complementary DNA(cDNA) data.

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Predicting tissue-specific expressions based on sequence characteristics

  • Paik, Hyo-Jung;Ryu, Tae-Woo;Heo, Hyoung-Sam;Seo, Seung-Won;Lee, Do-Heon;Hur, Cheol-Goo
    • BMB Reports
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    • v.44 no.4
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    • pp.250-255
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    • 2011
  • In multicellular organisms, including humans, understanding expression specificity at the tissue level is essential for interpreting protein function, such as tissue differentiation. We developed a prediction approach via generated sequence features from overrepresented patterns in housekeeping (HK) and tissue-specific (TS) genes to classify TS expression in humans. Using TS domains and transcriptional factor binding sites (TFBSs), sequence characteristics were used as indices of expressed tissues in a Random Forest algorithm by scoring exclusive patterns considering the biological intuition; TFBSs regulate gene expression, and the domains reflect the functional specificity of a TS gene. Our proposed approach displayed better performance than previous attempts and was validated using computational and experimental methods.

Gene Expressions in Bovine Nuclear Transferred Embryos with Mouse Fetal Fibroblast Cell

  • Park, Sang-Hyun;Park, Sang-Wook;Yun, Ji-Yung;Jun, Soon-Hong;Kim, Nam-Hyung
    • Proceedings of the KSAR Conference
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    • 2002.06a
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    • pp.11-11
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    • 2002
  • Interspecies nuclear transfer has been interested to determine ability of oocyte cytoplasm to support reprogramming of somatic cell nuclei of different species. In this study, we investigated developmental ability and mRNA expression patterns of developmentally important genes in bovine reconstructed embryos using a mouse fibroblast cell nucleus. While 20% nuclear transferred embryos with bovine fibroblast developed to morulae/blastocysts, a few(2-5%) nuclear transferred bovine embryos with mouse fibroblast developed to morula. (omitted)

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Expression of Metallothionein mRNA in Diesel Exhaust Particles Treated A549 Cell (디젤분진의 수용성 추출물에 의한 메탈로치오닌 유전자 발현)

  • Park Kwangsik;Moon Chang-Kiu
    • Environmental Analysis Health and Toxicology
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    • v.19 no.1
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    • pp.59-64
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    • 2004
  • Metallothionein gene expression of diesel exhaust particles (DEP) was investigated in human lung epithelial cell line. DEP was collected from diesel motor bus and soluble fraction in water was obtained. Cells, grown to near confluence, were exposed to 5-50 ppm DEP for 6 hours. Regarding the metallothionein gene expressions, MT-1 and MT-2 were induced in the DEP-treated cell by using RT-PCR and real-time PCR. However, MT-3 which is known to be brain specific, and another isoform MT-4 were not expressed in cadmium-treated groups as well as control group. Heavy metal of DEP was also analyzed and Zn was found as the major component of heavy metals in DEP used in this study.

Development of Information Biology (I)

  • Tateno, Yoshio
    • Interdisciplinary Bio Central
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    • v.5 no.1
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    • pp.2.1-2.3
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    • 2013
  • Birth and development of information biology are introduced with its definition and scientific basis. The discipline lives on the two types of nutrition, one is a huge amount of biological data on genomes, gene expressions, proteomes, protein 3D structures, protein networks, and so forth. The other is the method of using them on a computer. The scientific basis of the two is evolution. To collect genome and gene expression data form laboratories in the world, annotate and dissimilate back to researchers worldwide, they built the EMBL database in Europe in 1982, GenBank in USA in 1984 and DNA Data Bank of Japan in 1987. On the other hand, the methods of using and analyzing those data have accordingly been developed. The two aspects advance the discipline further and further.

Gene Expression upon Development of In Vitro Potato Microtuber (감자 기내 소괴경 발달에 따른 유전자 발현)

  • 홍주봉
    • Proceedings of the Botanical Society of Korea Conference
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    • 1987.07a
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    • pp.309-321
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    • 1987
  • Differential gene expressions of patatin, proteinase inhibitor II, PAPI, rbcS and actin in potato microtuber have been examined. Microtubers from the several different stages of development were collected and their protein and mRNA patterns were examined. SDS-PAGE of microtuber proteins revealed that developmental changes in protein should be analogous to that of potatoes grown in the field. The level of patatin mRNA was the highest at the 30th day of development. Proteinse inhibitor IImRNA level was at the highest at the 15th day and decreased thereafter. The levels of PAPI mRNA, rbcS mRNA and actin mRNA were low throughout the time course examined.

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Gene Expression Profiles in Cervical Cancer with Radiation Therapy Alone and Chemo-radiation Therapy (자궁경부암의 방사선치료 및 방사선항암화학 병용치료에 따른 유전자발현 조절양상)

  • Lee Kyu Chan;Kim Meyoung-kon;Kim Jooyoung;Hwang You Jin;Choi Myung Sun;Kim Chul Yong
    • Radiation Oncology Journal
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    • v.21 no.1
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    • pp.54-65
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    • 2003
  • Purpose : To analyze the gene expression Profiles of uterine ceulcal cancer, and its variation after radiation therapy, with or without concurrent chemotherapy, using a CDNA microarray. Materials and Methods :Sixteen patients, 8 with squamous ceil carcinomas of the uterine cervix, who were treated with radiation alone, and the other 8 treated w14h concurrent chemo-radiation, were Included in the study. Before the starling of the treatment, tumor biopsies were carried out, and the second time biopsies were peformed after a radiation dose of 16.2$\~$27 Gy. Three normal cervix tissues were used as a control group. The microarray experiments were peformed with 5 groups of the total RNAs extracted individually and then admixed as control, pre-radiation therapy alone, during-radiation therapy alone, pre-chemoradiation therapy, and during-chemoradlation therapy. The 33P-iabeled CDNAS were synthesized from the total RNAs of each group, by reverse transcription, and then they were hybridized to the CDNA microarray membrane. The gene expression of each microarrays was captured by the intensity of each spot produced by the radioactive isotopes. The pixels per spot were counted with an Arrayguage, and were exported to Microsoft Excel The data were normalized by the Z transformation, and the comparisons were peformed on the Z-ratio values calculated. Results : The expressions of 15 genes, including integrin linked kinase (ILK), CDC28 protein kinase 2, Spry 2, and ERK 3, were increased with the Z-ratio values of over 2.0 for the cervix cancer tissues compared to those for the normal controls. Those genes were involved In cell growth and proliferation, cell cycle control, or signal transduction. The expressions of the other 6 genes, Including G protein coupled receptor kinase 5, were decreased with the Z-ratio values of below -2.0. After the radiation thorapy, most of the genes, with a previously Increase expressions, represented the decreased expression profiles, and the genes, with the Z-ratio values of over 2.0, were cyclic nucleotlde gated channel and 3 Expressed sequence tags (EST). In the concurrent chemo-radiation group, the genes involved in cell growth and proliferation, cell cycle control, and signal transduction were shown to have increased expressions compared to the radiation therapy alone group. The expressions of genes involved in anglogenesis (angiopoietln-2), immune reactions (formyl peptide receptor-iike 1), and DNA repair (CAMP phosphodiesterase) were increased, however, the expression of gene involved In apoptosls (death associated protein kinase) was decreased. Conclusion : The different kinds of genes involved in the development and progression of cervical cancer were identified with the CDNA microarray, and the proposed theory is that the proliferation signal stalls with ILK, and is amplified with Spry 2 and MAPK signaling, and the cellular mitoses are Increased with the increased expression oi Cdc 2 and cell division kinases. After the radiation therapy, the expression profiles demonstrated 4he evidence of the decreased cancer cell proliferation. There was no sigificant difference in the morphological findings of cell death between the radiation therapy aione and the chemo-radiation groups In the second time biopsy specimen, however, the gene expression profiles were markedly different, and the mechanism at the molecular level needs further study.