Medical Genetics Commons^™

Easi-Crispr: A Robust Method For One-Step Generation Of Mice Carrying Conditional And Insertion Alleles Using Long Ssdna Donors And Crispr Ribonucleoproteins., Rolen M Quadros, Hiromi Miura, Donald W Harms, Hisako Akatsuka, Takehito Sato, Tomomi Aida, Ronald Redder, Guy P Richardson, Yutaka Inagaki, Daisuke Sakai, Shannon M Buckley, Parthasarathy Seshacharyulu, Surinder K Batra, Mark A Behlke, Sarah A Zeiner, Ashley M Jacobi, Yayoi Izu, Wallace B Thoreson, Lisa D Urness, Suzanne L Mansour, Masato Ohtsuka, Channabasavaiah B Gurumurthy

Journal Articles: Munroe-Meyer Institute

BACKGROUND: Conditional knockout mice and transgenic mice expressing recombinases, reporters, and inducible transcriptional activators are key for many genetic studies and comprise over 90% of mouse models created. Conditional knockout mice are generated using labor-intensive methods of homologous recombination in embryonic stem cells and are available for only ~25% of all mouse genes. Transgenic mice generated by random genomic insertion approaches pose problems of unreliable expression, and thus there is a need for targeted-insertion models. Although CRISPR-based strategies were reported to create conditional and targeted-insertion alleles via one-step delivery of targeting components directly to zygotes, these strategies are quite inefficient. …

Oriented Clonal Cell Dynamics Enables Accurate Growth And Shaping Of Vertebrate Cartilage., Marketa Kaucka, Tomas Zikmund, Marketa Tesarova, Daniel Gyllborg, Andreas Hellander, Josef Jaros, Jozef Kaiser, Julian Petersen, Bara Szarowska, Phillip T. Newton, Vyacheslav Dyachuk, Lei Li, Hong Qian, Anne-Sofie Johansson, Yuji Mishina, Joshua D. Currie, Elly M. Tanaka, Alek Erickson, A T. Dudley, Hjalmar Brismar, Paul Southam, Enrico Coen, Min Chen, Lee S. Weinstein, Ales Hampl, Ernest Arenas, Andrei S. Chagin, Kaj Fried, Igor Adameyko

Journal Articles: Genetics, Cell Biology & Anatomy

Cartilaginous structures are at the core of embryo growth and shaping before the bone forms. Here we report a novel principle of vertebrate cartilage growth that is based on introducing transversally-oriented clones into pre-existing cartilage. This mechanism of growth uncouples the lateral expansion of curved cartilaginous sheets from the control of cartilage thickness, a process which might be the evolutionary mechanism underlying adaptations of facial shape. In rod-shaped cartilage structures (Meckel, ribs and skeletal elements in developing limbs), the transverse integration of clonal columns determines the well-defined diameter and resulting rod-like morphology. We were able to alter cartilage shape by …

Exome-Based Variant Detection In Core Promoters., Yeong C. Kim, Jian Cui, Jiangtao Luo, Fengxia Xiao, Bradley Downs, San Ming Wang

Journal Articles: Genetics, Cell Biology & Anatomy

Core promoter controls the initiation of transcription. Core promoter sequence change can disrupt transcriptional regulation, lead to impairment of gene expression and ultimately diseases. Therefore, comprehensive characterization of core promoters is essential to understand normal and abnormal gene expression in biomedical studies. Here we report the development of EVDC (Exome-based Variant Detection in Core promoters) method for genome-scale analysis of core-promoter sequence variation. This method is based on the fact that exome sequences contain the sequences not only from coding exons but also from non-coding region including core promoters generated by random fragmentation in exome sequencing process. Using exome data …

Prevalence And Spectrum Of Brca Germline Variants In Mainland Chinese Familial Breast And Ovarian Cancer Patients., Yeong C. Kim, Linli Zhao, Hanwen Zhang, Ye Huang, Jian Cui, Fengxia Xiao, Bradley Downs, San Ming Wang

Journal Articles: Genetics, Cell Biology & Anatomy

Germline mutations in BRCA1 and BRCA2 are the most penetrating genetic predispositions for breast and ovarian cancer, and their presence is largely ethnic-specific. Comprehensive information about the prevalence and spectrum of BRCA mutations has been collected in European and North American populations. However, similar information is lacking in other populations, including the mainland Chinese population despite its large size of 1.4 billion accounting for one fifth of the world's population. Herein, we performed an extensive literature analysis to collect BRCA variants identified from mainland Chinese familial breast and ovarian cancer patients. We observed 137 distinct BRCA1 variants in 409 of …

Exome Screening To Identify Loss-Of-Function Mutations In The Rhesus Macaque For Development Of Preclinical Models Of Human Disease, Adam Cornish, Robert M. Gibbs, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Exome sequencing has been utilized to identify genetic variants associated with disease in humans. Identification of loss-of-function mutations with exome sequencing in rhesus macaques (Macaca mulatta) could lead to valuable animal models of genetic disease. Attempts have been made to identify variants in rhesus macaques by aligning exome data against the rheMac2 draft genome. However, such efforts have been impaired due to the incompleteness and annotation errors associated with rheMac2. We wished to determine whether aligning exome reads against our new, improved rhesus genome, MacaM, could be used to identify high impact, loss-of-function mutations in rhesus macaques that would …

Discovering Distinct Functional Modules Of Specific Cancer Types Using Protein-Protein Interaction Networks., Ru Shen, Xiaosheng Wang, Chittibabu Guda

Journal Articles: Genetics, Cell Biology & Anatomy

Background. The molecular profiles exhibited in different cancer types are very different; hence, discovering distinct functional modules associated with specific cancer types is very important to understand the distinct functions associated with them. Protein-protein interaction networks carry vital information about molecular interactions in cellular systems, and identification of functional modules (subgraphs) in these networks is one of the most important applications of biological network analysis. Results. In this study, we developed a new graph theory based method to identify distinct functional modules from nine different cancer protein-protein interaction networks. The method is composed of three major steps: (i) extracting modules …

Crispr/Cas9-Based Generation Of Knockdown Mice By Intronic Insertion Of Artificial Microrna Using Longer Single-Stranded Dna., Hiromi Miura, Channabasavaiah B. Gurumurthy, Takehito Sato, Masahiro Sato, Masato Ohtsuka

Journal Articles: Genetics, Cell Biology & Anatomy

Knockdown mouse models, where gene dosages can be modulated, provide valuable insights into gene function. Typically, such models are generated by embryonic stem (ES) cell-based targeted insertion, or pronuclear injection, of the knockdown expression cassette. However, these methods are associated with laborious and time-consuming steps, such as the generation of large constructs with elements needed for expression of a functional RNAi-cassette, ES-cell handling, or screening for mice with the desired knockdown effect. Here, we demonstrate that reliable knockdown models can be generated by targeted insertion of artificial microRNA (amiRNA) sequences into a specific locus in the genome [such as intronic …

Gonad: Genome-Editing Via Oviductal Nucleic Acids Delivery System: A Novel Microinjection Independent Genome Engineering Method In Mice., Gou Takahashi, Channabasavaiah B. Gurumurthy, Kenta Wada, Hiromi Miura, Masahiro Sato, Masato Ohtsuka

Journal Articles: Genetics, Cell Biology & Anatomy

Microinjection is considered the gold standard technique for delivery of nucleic acids (NAs; transgenes or genome editing tools such as CRISPR/Cas9 systems) into embryos, for creating genetically modified organisms. It requires sophisticated equipment as well as well-trained and highly skilled personnel to perform the micro-injection technique. Here, we describe a novel and simple microinjection-independent technique, called Genome-editing via Oviductal Nucleic Acids Delivery (GONAD). Using GONAD, we show that NAs (e.g., eGFP mRNA or Cas9 mRNA/sgRNAs) can be effectively delivered to pre-implantation embryos within the intact mouse oviduct by a simple electroporation method, and result in the desired genetic modification in …

One-Step Generation Of Multiple Transgenic Mouse Lines Using An Improved Pronuclear Injection-Based Targeted Transgenesis (I-Pitt)., Masato Ohtsuka, Hiromi Miura, Keiji Mochida, Michiko Hirose, Ayumi Hasegawa, Atsuo Ogura, Ryuta Mizutani, Minoru Kimura, Ayako Isotani, Masahito Ikawa, Masahiro Sato, Channabasavaiah B. Gurumurthy

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: The pronuclear injection (PI) is the simplest and widely used method to generate transgenic (Tg) mice. Unfortunately, PI-based Tg mice show uncertain transgene expression due to random transgene insertion in the genome, usually with multiple copies. Thus, typically at least three or more Tg lines are produced by injecting over 200 zygotes and the best line/s among them are selected through laborious screening steps. Recently, we developed technologies using Cre-loxP system that allow targeted insertion of single-copy transgene into a predetermined locus through PI. We termed the method as PI-based Targeted Transgenesis (PITT). A similar method using PhiC31-attP/B system …

Insertion Of Sequences At The Original Provirus Integration Site Of Mouse Rosa26 Locus Using The Crispr/Cas9 System., Rolen M. Quadros, Donald W. Harms, Masato Ohtsuka, Channabasavaiah B. Gurumurthy

Journal Articles: Genetics, Cell Biology & Anatomy

Targeted transgenic mouse models, where an exogenous gene is inserted into a specified genomic locus to achieve its stable and reliable expression, have been widely used in biomedical research. However, the available methodologies for targeted insertion of sequences require many laborious steps that involve the use of embryonic stem (ES) cells. We recently developed Pronuclear Injection-based Targeted Transgenesis (PITT), a method that uses a recombinase-mediated cassette exchange (RMCE) to enable insertion of sequences at a predetermined genomic locus, such as ROSA26. The PITT technique uses fertilized eggs (instead of ES cells) collected from 'seed mice' that contain the RMCE landing …

Generation Of A Retinoblastoma (Rb)1-Inducible Dominant-Negative (Dn) Mouse Model., Shikha Tarang, Songila M.S.R Doi, Channabasavaiah B. Gurumurthy, Donald W. Harms, Rolen M. Quadros, Sonia M. Rocha-Sanchez

Journal Articles: Genetics, Cell Biology & Anatomy

Retinoblastoma 1 (Rb1) is an essential gene regulating cellular proliferation, differentiation, and homeostasis. To exert these functions, Rb1 is recruited and physically interacts with a growing variety of signaling pathways. While Rb1 does not appear to be ubiquitously expressed, its expression has been confirmed in a variety of hematopoietic and neuronal-derived cells, including the inner ear hair cells (HCs). Studies in transgenic mice demonstrate that complete germline or conditional Rb1 deletion leads to abnormal cell proliferation, followed by massive apoptosis; making it difficult to fully address Rb1's biochemical activities. To overcome these limitations, we developed a tetracycline-inducible TetO-CB-myc6-Rb1 (CBRb) mouse …

Validation Of Simple Sequence Length Polymorphism Regions Of Commonly Used Mouse Strains For Marker Assisted Speed Congenics Screening., Channabasavaiah B. Gurumurthy, Poonam S. Joshi, Scott G. Kurz, Masato Ohtsuka, Rolen M. Quadros, Donald W. Harms, K.C. Kent Lloyd

Journal Articles: Genetics, Cell Biology & Anatomy

Marker assisted speed congenics technique is commonly used to facilitate backcrossing of mouse strains in nearly half the time it normally takes otherwise. Traditionally, the technique is performed by analyzing PCR amplified regions of simple sequence length polymorphism (SSLP) markers between the recipient and donor strains: offspring with the highest number of markers showing the recipient genome across all chromosomes is chosen for the next generation. Although there are well-defined panels of SSLP makers established between certain pairs of mice strains, they are incomplete for most strains. The availability of well-established marker sets for speed congenic screens would enable the …

Assessment Of Artificial Mirna Architectures For Higher Knockdown Efficiencies Without The Undesired Effects In Mice., Hiromi Miura, Hidetoshi Inoko, Masafumi Tanaka, Hirofumi Nakaoka, Minoru Kimura, Channabasavaiah B. Gurumurthy, Masahiro Sato, Masato Ohtsuka

Journal Articles: Genetics, Cell Biology & Anatomy

RNAi-based strategies have been used for hypomorphic analyses. However, there are technical challenges to achieve robust, reproducible knockdown effect. Here we examined the artificial microRNA (amiRNA) architectures that could provide higher knockdown efficiencies. Using transient and stable transfection assays in cells, we found that simple amiRNA-expression cassettes, that did not contain a marker gene (-MG), displayed higher amiRNA expression and more efficient knockdown than those that contained a marker gene (+MG). Further, we tested this phenomenon in vivo, by analyzing amiRNA-expressing mice that were produced by the pronuclear injection-based targeted transgenesis (PITT) method. While we observed significant silencing of the …

De Novo Assembly Of The Chimpanzee Transcriptome From Nextgen Mrna Sequences, Mnirnal D. Maudhoo, Jacob D. Madison, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are the species most closely related to humans. For this reason, it is especially important to have complete and accurate chimpanzee nucleotide and protein sequences to understand how humans evolved their unique capabilities. We provide transcriptome data from four untransformed cell types derived from the reference Pan troglodytes, "Clint", to better annotate the chimpanzee genome and provide empirical validation for proposed gene models of this important species.

FINDINGS: RNA was extracted from primary cells cultured from four tissues: skin, adipose stroma, vascular smooth muscle and skeletal muscle. These four RNA samples …

Motor-Skill Learning Is Dependent On Astrocytic Activity., Ragunathan Padmashri, Anand Suresh, Michael D. Boska, Anna Dunaevsky

Journal Articles: Munroe-Meyer Institute

Motor-skill learning induces changes in synaptic structure and function in the primary motor cortex through the involvement of a long-term potentiation- (LTP-) like mechanism. Although there is evidence that calcium-dependent release of gliotransmitters by astrocytes plays an important role in synaptic transmission and plasticity, the role of astrocytes in motor-skill learning is not known. To test the hypothesis that astrocytic activity is necessary for motor-skill learning, we perturbed astrocytic function using pharmacological and genetic approaches. We find that perturbation of astrocytes either by selectively attenuating IP3R2 mediated astrocyte Ca(2+) signaling or using an astrocyte specific metabolic inhibitor fluorocitrate (FC) results …

A New Rhesus Macaque Assembly And Annotation For Next-Generation Sequencing Analyses, Aleksey V. Zimin, Adam S. Cornish, Mnirnal D. Maudhoo, Robert M. Gibbs, Xiongfei Zhang, Sanjit Pandey, Daniel T. Meehan, Kristin Wipfler, Steven E. Bosinger, Zachary P. Johnson, Gregory K. Tharp, Guillaume Marçais, Michael Roberts, Betsy Ferguson, Howard S. Fox, Todd Treangen, Steven L. Salzberg, James A. Yorke, Robert B. Norgren Jr.

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: The rhesus macaque (Macaca mulatta) is a key species for advancing biomedical research. Like all draft mammalian genomes, the draft rhesus assembly (rheMac2) has gaps, sequencing errors and misassemblies that have prevented automated annotation pipelines from functioning correctly. Another rhesus macaque assembly, CR_1.0, is also available but is substantially more fragmented than rheMac2 with smaller contigs and scaffolds. Annotations for these two assemblies are limited in completeness and accuracy. High quality assembly and annotation files are required for a wide range of studies including expression, genetic and evolutionary analyses.

RESULTS: We report a new de novo assembly of the …

Computational Analysis Of Transcriptional Circuitries In Human Embryonic Stem Cells Reveals Multiple And Independent Networks, Xiaosheng Wang, Chittibabu Guda

Journal Articles: Genetics, Cell Biology & Anatomy

It has been known that three core transcription factors (TFs), NANOG, OCT4, and SOX2, collaborate to form a transcriptional circuitry to regulate pluripotency and self-renewal of human embryonic stem (ES) cells. Similarly, MYC also plays an important role in regulating pluripotency and self-renewal of human ES cells. However, the precise mechanism by which the transcriptional regulatory networks control the activity of ES cells remains unclear. In this study, we reanalyzed an extended core network, which includes the set of genes that are cobound by the three core TFs and additional TFs that also bind to these cobound genes. Our results …

The Genome Of Polymorphonuclear Neutrophils Maintains Normal Coding Sequences, Fengxia Xiao, Yeong C. Kim, Hongxiu Wen, Jiangtao Luo, Pei Xian Chen, Kenneth Cowan, San Ming Wang

Journal Articles: Genetics, Cell Biology & Anatomy

Genetic studies often use genomic DNA from whole blood cells, of which the majority are the polymorphonuclear myeloid cells. Those cells undergo dramatic change of nuclear morphology following cellular differentiation. It remains elusive if the nuclear morphological change accompanies sequence alternations from the intact genome. If such event exists, it will cause a serious problem in using such type of genomic DNA for genetic study as the sequences will not represent the intact genome in the host individuals. Using exome sequencing, we compared the coding regions between neutrophil, which is the major type of polymorphonuclear cells, and CD4+ T cell, …

Heterogeneity Of Functional Properties Of Clone 66 Murine Breast Cancer Cells Expressing Various Stem Cell Phenotypes, Partha Mukhopadhyay, Tracy Farrell, Gayatri Sharma, Timothy R. Mcguire, Barbara O'Kane, J. Graham Sharp

Journal Articles: Genetics, Cell Biology & Anatomy

INTRODUCTION:

Breast cancer grows, metastasizes and relapses from rare, therapy resistant cells with a stem cell phenotype (cancer stem cells/CSCs). However, there is a lack of studies comparing the functions of CSCs isolated using different phenotypes in order to determine if CSCs are homogeneous or heterogeneous.

METHODS:

Cells with various stem cell phenotypes were isolated by sorting from Clone 66 murine breast cancer cells that grow orthotopically in immune intact syngeneic mice. These populations were compared by in vitro functional assays for proliferation, growth, sphere and colony formation; and in vivo limiting dilution analysis of tumorigenesis.

RESULTS:

The proportion of …

Discovery Of Molecular Associations Among Aging, Stem Cells, And Cancer Based On Gene Expression Profiling., Xiaosheng Wang

Journal Articles: Genetics, Cell Biology & Anatomy

The emergence of a huge volume of "omics" data enables a computational approach to the investigation of the biology of cancer. The cancer informatics approach is a useful supplement to the traditional experimental approach. I reviewed several reports that used a bioinformatics approach to analyze the associations among aging, stem cells, and cancer by microarray gene expression profiling. The high expression of aging- or human embryonic stem cell-related molecules in cancer suggests that certain important mechanisms are commonly underlying aging, stem cells, and cancer. These mechanisms are involved in cell cycle regulation, metabolic process, DNA damage response, apoptosis, p53 signaling …

Cytoplasmic Localization Of Alteration/Deficiency In Activation 3 (Ada3) Predicts Poor Clinical Outcome In Breast Cancer Patients., Sameer Mirza, Emad A. Rakha, Alaa Alshareeda, Shakur Mohibi, Xiangshan Zhao, Bryan J. Katafiasz, Jun Wang, Channabasavaiah B. Gurumurthy, Aditya Bele, Ian O. Ellis, Andrew R. Green, Hamid Band, Vimla Band

Journal Articles: Genetics, Cell Biology & Anatomy

Transcriptional activation by estrogen receptor (ER) is a key step to breast oncogenesis. Given previous findings that ADA3 is a critical component of HAT complexes that regulate ER function and evidence that overexpression of other ER coactivators such as SRC-3 is associated with clinical outcomes in breast cancer, the current study was designed to assess the potential significance of ADA3 expression/localization in human breast cancer patients. In this study, we analyzed ADA3 expression in breast cancer tissue specimens and assessed the correlation of ADA3 staining with cancer progression and patient outcome. Tissue microarrays prepared from large series of breast cancer …

Identification Of Potential Synthetic Lethal Genes To P53 Using A Computational Biology Approach, Xiaosheng Wang, Richard Simon

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND:

Identification of genes that are synthetic lethal to p53 is an important strategy for anticancer therapy as p53 mutations have been reported to occur in more than half of all human cancer cases. Although genome-wide RNAi screening is an effective approach to finding synthetic lethal genes, it is costly and labor-intensive.

METHODS:

To illustrate this approach, we identified potentially druggable genes synthetically lethal for p53 using three microarray datasets for gene expression profiles of the NCI-60 cancer cell lines, one next-generation sequencing (RNA-Seq) dataset from the Cancer Genome Atlas (TCGA) project, and one gene expression data from the Cancer …

New Fusion Transcripts Identified In Normal Karyotype Acute Myeloid Leukemia, Hongxiu Wen, Yongjin Li, Sami N. Malek, Yeong C. Kim, Jia Xu, Pei Xian Chen, Fengxia Xiao, Xin Huang, Xianzheng Zhou, Zhenyu Xuan, Shiva Mankala, Guihua Hou, Janet D. Rowley, Michael Q. Zhang, San Ming Wang

Journal Articles: Genetics, Cell Biology & Anatomy

Genetic aberrations contribute to acute myeloid leukemia (AML). However, half of AML cases do not contain the well-known aberrations detectable mostly by cytogenetic analysis, and these cases are classified as normal karyotype AML. Different outcomes of normal karyotype AML suggest that this subgroup of AML could be genetically heterogeneous. But lack of genetic markers makes it difficult to further study this subgroup of AML. Using paired-end RNAseq method, we performed a transcriptome analysis in 45 AML cases including 29 normal karyotype AML, 8 abnormal karyotype AML and 8 AML without karyotype informaiton. Our study identified 134 fusion transcripts, all of …

Mammalian Alteration/Deficiency In Activation 3 (Ada3) Is Essential For Embryonic Development And Cell Cycle Progression., Shakur Mohibi, Channabasavaiah B. Gurumurthy, Alo Nag, Jun Wang, Sameer Mirza, Yousaf Mian, Meghan Quinn, Bryan J. Katafiasz, James D. Eudy, Sanjit Pandey, Chittibabu Guda, Mayumi Naramura, Hamid Band, Vimla Band

Journal Articles: Genetics, Cell Biology & Anatomy

Ada3 protein is an essential component of histone acetyl transferase containing coactivator complexes conserved from yeast to human. We show here that germline deletion of Ada3 in mouse is embryonic lethal, and adenovirus-Cre mediated conditional deletion of Ada3 in Ada3(FL/FL) mouse embryonic fibroblasts leads to a severe proliferation defect which was rescued by ectopic expression of human Ada3. A delay in G(1) to S phase of cell cycle was also seen that was due to accumulation of Cdk inhibitor p27 which was an indirect effect of c-myc gene transcription control by Ada3. We further showed that this defect could be …

Overexpression Of A Novel Cell Cycle Regulator Ecdysoneless In Breast Cancer: A Marker Of Poor Prognosis In Her2/Neu-Overexpressing Breast Cancer Patients., Xiangshan Zhao, Sameer Mirza, Alaa Alshareeda, Ying Zhang, Channabasavaiah B. Gurumurthy, Aditya Bele, Jun Hyun Kim, Shakur Mohibi, Monica Goswami, Subodh M. Lele, William West, Fang Qiu, Ian O. Ellis, Emad A. Rakha, Andrew R. Green, Hamid Band, Vimla Band

Journal Articles: Genetics, Cell Biology & Anatomy

Uncontrolled proliferation is one of the hallmarks of breast cancer. We have previously identified the human Ecd protein (human ortholog of Drosophila Ecdysoneless, hereafter called Ecd) as a novel promoter of mammalian cell cycle progression, a function related to its ability to remove the repressive effects of Rb-family tumor suppressors on E2F transcription factors. Given the frequent dysregulation of cell cycle regulatory components in human cancer, we used immunohistochemistry of paraffin-embedded tissues to examine Ecd expression in normal breast tissue versus tissues representing increasing breast cancer progression. Initial studies of a smaller cohort without outcomes information showed that Ecd expression …

Limitations Of The Rhesus Macaque Draft Genome Assembly And Annotation, Xiongfei Zhang, Joel Goodsell, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

Finished genome sequences and assemblies are available for only a few vertebrates. Thus, investigators studying many species must rely on draft genomes. Using the rhesus macaque as an example, we document the effects of sequencing errors, gaps in sequence and misassemblies on one automated gene model pipeline, Gnomon. The combination of draft genome with automated gene finding software can result in spurious sequences. We estimate that approximately 50% of the rhesus gene models are missing, incomplete or incorrect. The problems identified in this work likely apply to all draft vertebrate genomes annotated with any automated gene model pipeline and thus …

Computational Analysis Of Expression Of Human Embryonic Stem Cell-Associated Signatures In Tumors., Xiaosheng Wang

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: The cancer stem cell model has been proposed based on the linkage between human embryonic stem cells and human cancer cells. However, the evidences supporting the cancer stem cell model remain to be collected. In this study, we extensively examined the expression of human embryonic stem cell-associated signatures including core genes, transcription factors, pathways and microRNAs in various cancers using the computational biology approach.

RESULTS: We used the class comparison analysis and survival analysis algorithms to identify differentially expressed genes and their associated transcription factors, pathways and microRNAs among normal vs. tumor or good prognosis vs. poor prognosis phenotypes …

Microarray-Based Cancer Prediction Using Single Genes., Xiaosheng Wang, Richard Simon

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Although numerous methods of using microarray data analysis for cancer classification have been proposed, most utilize many genes to achieve accurate classification. This can hamper interpretability of the models and ease of translation to other assay platforms. We explored the use of single genes to construct classification models. We first identified the genes with the most powerful univariate class discrimination ability and then constructed simple classification rules for class prediction using the single genes.

RESULTS: We applied our model development algorithm to eleven cancer gene expression datasets and compared classification accuracy to that for standard methods including Diagonal Linear …

Inference Of Cancer-Specific Gene Regulatory Networks Using Soft Computing Rules., Xiaosheng Wang, Osamu Gotoh

Journal Articles: Genetics, Cell Biology & Anatomy

Perturbations of gene regulatory networks are essentially responsible for oncogenesis. Therefore, inferring the gene regulatory networks is a key step to overcoming cancer. In this work, we propose a method for inferring directed gene regulatory networks based on soft computing rules, which can identify important cause-effect regulatory relations of gene expression. First, we identify important genes associated with a specific cancer (colon cancer) using a supervised learning approach. Next, we reconstruct the gene regulatory networks by inferring the regulatory relations among the identified genes, and their regulated relations by other genes within the genome. We obtain two meaningful findings. One …

A Robust Gene Selection Method For Microarray-Based Cancer Classification., Xiaosheng Wang, Osamu Gotoh

Journal Articles: Genetics, Cell Biology & Anatomy

Gene selection is of vital importance in molecular classification of cancer using high-dimensional gene expression data. Because of the distinct characteristics inherent to specific cancerous gene expression profiles, developing flexible and robust feature selection methods is extremely crucial. We investigated the properties of one feature selection approach proposed in our previous work, which was the generalization of the feature selection method based on the depended degree of attribute in rough sets. We compared the feature selection method with the established methods: the depended degree, chi-square, information gain, Relief-F and symmetric uncertainty, and analyzed its properties through a series of classification …