Medicine and Health Sciences Commons^™

Isomirmap-Fast, Deterministic, And Exhaustive Mining Of Isomirs From Short Rna-Seq Datasets., Phillipe Loher, Nestoras Karathanasis, Eric R Londin, Paul Bray, Venetia Pliatsika, Aristeidis G. Telonis, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

MOTIVATION: MicroRNA (miRNA) precursor arms give rise to multiple isoforms simultaneously called "isomiRs." IsomiRs from the same arm typically differ by a few nucleotides at either their 5´ or 3´ termini, or both. In humans, the identities and abundances of isomiRs depend on a person's sex, population of origin, race/ethnicity, and on tissue type, tissue state, and disease type/subtype. Moreover, nearly half of the time the most abundant isomiR differs from the miRNA sequence found in public databases. Accurate mining of isomiRs from deep sequencing data is thus important.

RESULTS: We developed isoMiRmap, a fast, standalone, user-friendly mining tool that …

The Transcriptional Trajectories Of Pluripotency And Differentiation Comprise Genes With Antithetical Architecture And Repetitive-Element Content., Aristeidis G. Telonis, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

BACKGROUND: Extensive molecular differences exist between proliferative and differentiated cells. Here, we conduct a meta-analysis of publicly available transcriptomic datasets from preimplantation and differentiation stages examining the architectural properties and content of genes whose abundance changes significantly across developmental time points.

RESULTS: Analysis of preimplantation embryos from human and mouse showed that short genes whose introns are enriched in Alu (human) and B (mouse) elements, respectively, have higher abundance in the blastocyst compared to the zygote. These highly expressed genes encode ribosomal proteins or metabolic enzymes. On the other hand, long genes whose introns are depleted in repetitive elements have …

Machine Learning Approaches Identify Genes Containing Spatial Information From Single-Cell Transcriptomics Data., Phillipe Loher, Nestoras Karathanasis

Computational Medicine Center Faculty Papers

The development of single-cell sequencing technologies has allowed researchers to gain important new knowledge about the expression profile of genes in thousands of individual cells of a model organism or tissue. A common disadvantage of this technology is the loss of the three-dimensional (3-D) structure of the cells. Consequently, the Dialogue on Reverse Engineering Assessment and Methods (DREAM) organized the Single-Cell Transcriptomics Challenge, in which we participated, with the aim to address the following two problems: (a) to identify the top 60, 40, and 20 genes of the Drosophila melanogaster embryo that contain the most spatial information and (b) to …

Consequential Considerations When Mapping Trna Fragments., Aristeidis G Telonis, Phillipe Loher, Yohei Kirino, Phd, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

We examine several of the choices that went into the design of tDRmapper, a recently reported tool for identifying transfer RNA (tRNA) fragments in deep sequencing data, evaluate them in the context of currently available knowledge, and discuss their potential impact on the output that the tool generates.

Beyond The One-Locus-One-Mirna Paradigm: Microrna Isoforms Enable Deeper Insights Into Breast Cancer Heterogeneity., Aristeidis G Telonis, Phillipe Loher, Yi Jing, Eric R Londin, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

Here we describe our study of miRNA isoforms (isomiRs) in breast cancer (BRCA) and normal breast data sets from the Cancer Genome Atlas (TCGA) repository. We report that the full isomiR profiles, from both known and novel human-specific miRNA loci, are particularly rich in information and can distinguish tumor from normal tissue much better than the archetype miRNAs. IsomiR expression is also dependent on the patient's race, exemplified by miR-183-5p, several isomiRs of which are upregulated in triple negative BRCA in white but not black women. Additionally, we find that an isomiR's 5' endpoint and length, but not the genomic …

Targeting The Mrna-Binding Protein Hur Impairs Malignant Characteristics Of Pancreatic Ductal Adenocarcinoma Cells., Masaya Jimbo, Fernando F Blanco, Yu-Hung Huang, Aristeidis G Telonis, Brad A Screnci, Gabriela L Cosma, Vitali Alexeev, Gregory E Gonye, Charles Yeo, Janet A Sawicki, Jordan M Winter, Jonathan Brody, Md

Computational Medicine Center Faculty Papers

Post-transcriptional regulation is a powerful mediator of gene expression, and can rapidly alter the expression of numerous transcripts involved in tumorigenesis. We have previously shown that the mRNA-binding protein HuR (ELAVL1) is elevated in human pancreatic ductal adenocarcinoma (PDA) specimens compared to normal pancreatic tissues, and its cytoplasmic localization is associated with increased tumor stage. To gain a better insight into HuR's role in PDA biology and to assess it as a candidate therapeutic target, we altered HuR expression in PDA cell lines and characterized the resulting phenotype in preclinical models. HuR silencing by short hairpin and small interfering RNAs …

Trna-Derived Short Non-Coding Rna As Interacting Partners Of Argonaute Proteins., Megumi Shigematsu, Yohei Kirino, Phd

Computational Medicine Center Faculty Papers

The advent of next-generation sequencing technologies has not only accelerated findings on various novel non-coding RNA (ncRNA) species but also led to the revision of the biological significance and versatility of fundamental RNA species with canonical function, such as transfer RNAs (tRNAs). Although tRNAs are best known as adapter components of translational machinery, recent studies suggest that tRNAs are not always end products but can further serve as a source for short ncRNAs. In many organisms, various tRNA-derived ncRNA species are produced from mature tRNAs or their precursor transcripts as functional molecules involved in various biological processes beyond translation. In …

What Is Translational Bioinformatics?, Eric R. Londin, Carol I. Barash

Computational Medicine Center Faculty Papers

No abstract provided.

The Emerging Roles Of Gprc5a In Diseases., Honglei Zhou, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

The 'Retinoic Acid-Inducible G-protein-coupled receptors' or RAIG are a group comprising the four orphan receptors GPRC5A, GPRC5B, GPRC5C and GPRC5D. As the name implies, their expression is induced by retinoic acid but beyond that very little is known about their function. In recent years, one member, GPRC5A, has been receiving increasing attention as it was shown to play important roles in human cancers. As a matter of fact, dysregulation of GPRC5A has been associated with several cancers including lung cancer, breast cancer, colorectal cancer, and pancreatic cancer. Here we review the current state of knowledge about the heterogeneity and evolution …

Isomir Expression Profiles In Human Lymphoblastoid Cell Lines Exhibit Population And Gender Dependencies., Phillipe Loher, Eric R Londin, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

For many years it was believed that each mature microRNA (miRNA) existed as a single entity with fixed endpoints and a 'static' and unchangeable primary sequence. However, recent evidence suggests that mature miRNAs are more 'dynamic' and that each miRNA precursor arm gives rise to multiple isoforms, the isomiRs. Here we report on our identification of numerous and abundant isomiRs in the lymphoblastoid cell lines (LCLs) of 452 men and women from five different population groups. Unexpectedly, we find that these isomiRs exhibit an expression profile that is population-dependent and gender-dependent. This is important as it indicates that the LCLs …

Mir-103a-3p Targets The 5' Utr Of Gprc5a In Pancreatic Cells., Honglei Zhou, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

MicroRNAs (miRNAs) are short noncoding RNAs that regulate the expression of their targets in a sequence-dependent manner. For protein-coding transcripts, miRNAs regulate expression levels through binding sites in either the 3' untranslated region (3' UTR) or the amino acid coding sequence (CDS) of the targeted messenger RNA (mRNA). Currently, for the 5' untranslated region (5' UTR) of mRNAs, very few naturally occurring examples exist whereby the targeting miRNA down-regulates the expression of the corresponding mRNA in a seed-dependent manner. Here we describe and characterize two miR-103a-3p target sites in the 5' UTR of GPRC5A, a gene that acts as a …

Nuclear And Mitochondrial Trna-Lookalikes In The Human Genome., Aristeidis G Telonis, Phillipe Loher, Yohei Kirino, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

We are interested in identifying and characterizing loci of the human genome that harbor sequences resembling known mitochondrial and nuclear tRNAs. To this end, we used the known nuclear and mitochondrial tRNA genes (the "tRNA-Reference" set) to search for "tRNA-lookalikes" and found many such loci at different levels of sequence conservation. We find that the large majority of these tRNA-lookalikes resemble mitochondrial tRNAs and exhibit a skewed over-representation in favor of some mitochondrial anticodons. Our analysis shows that the tRNA-lookalikes have infiltrated specific chromosomes and are preferentially located in close proximity to known nuclear tRNAs (z-score ≤ -2.54, P-value ≤ …

The Human Platelet: Strong Transcriptome Correlations Among Individuals Associate Weakly With The Platelet Proteome., Eric R Londin, Eleftheria Hatzimichael, Phillipe Loher, Leonard Edelstein, Chad Shaw, Kathleen Delgrosso, Paolo Fortina, Paul Bray, Steven E. Mckenzie, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

BACKGROUND: For the anucleate platelet it has been unclear how well platelet transcriptomes correlate among different donors or across different RNA profiling platforms, and what the transcriptomes' relationship is with the platelet proteome. We profiled the platelet transcriptome of 10 healthy young males (5 white and 5 black) with no notable clinical history using RNA sequencing and by Affymetrix microarray.

RESULTS: We found that the abundance of platelet mRNA transcripts was highly correlated across the 10 individuals, independently of race and of the employed technology. Our RNA-seq data showed that these high inter-individual correlations extend beyond mRNAs to several categories …

Whole-Exome Sequencing Of Dna From Peripheral Blood Mononuclear Cells (Pbmc) And Ebv-Transformed Lymphocytes From The Same Donor., Eric R Londin, Margaret A Keller, Michael R D'Andrea, Kathleen Delgrosso, Adam Ertel, Saul Surrey, Paolo Fortina

Kimmel Cancer Center Faculty Papers

BACKGROUND: The creation of lymphoblastoid cell lines (LCLs) through Epstein-Barr virus (EBV) transformation of B-lymphocytes can result in a valuable biomaterial for cell biology research and a renewable source of DNA. While LCLs have been used extensively in cellular and genetic studies, the process of cell transformation and expansion during culturing may introduce genomic changes that may impact their use and the interpretation of subsequent genetic findings.

RESULTS: We performed whole exome sequencing on a tetrad family using DNA derived from peripheral blood mononuclear cells (PBMCs) and LCLs from each individual. We generated over 4.7 GB of mappable sequence to …