scholarly journals Long-read isoform sequencing reveals survival-associated splicing in breast cancer

2020 ◽  
Author(s):  
Diogo F.T. Veiga ◽  
Alex Nesta ◽  
Yuqi Zhao ◽  
Anne Deslattes Mays ◽  
Richie Huynh ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Patient Survival ◽  
Protein Localization ◽  
Data Sets ◽  
Protein Coding ◽  
Subtype Specificity ◽  
Cancer Subtype ◽  
Long Read ◽  
And Function ◽  
Novel Isoforms

SummaryTumors display widespread transcriptome alterations, but the full repertoire of isoform-level alternative splicing in cancer is not known. We developed a long-read RNA sequencing and analytical platform that identifies and annotates full-length isoforms, and infers tumor-specific splicing events. Application of this platform to breast cancer samples vastly expands the known isoform landscape of breast cancer, identifying thousands of previously unannotated isoforms of which ~30% impact protein coding exons and are predicted to alter protein localization and function, including of the breast cancer-associated genes ESR1 and ERBB2. We performed extensive cross-validation with -omics data sets to support transcription and translation of novel isoforms. We identified 3,059 breast tumor-specific splicing events, including 35 that are significantly associated with patient survival. Together, our results demonstrate the complexity, cancer subtype-specificity, and clinical relevance of novel isoforms in breast cancer that are only annotatable by LR-seq, and provide a rich resource of immuno-oncology therapeutic targets.

scholarly journals Regulation of Breast Cancer and Bone Metastasis by MicroRNAs

2013 ◽  
Vol 35 ◽  
pp. 369-387 ◽  
Author(s):  
S. Vimalraj ◽  
P. J. Miranda ◽  
B. Ramyakrishna ◽  
N. Selvamurugan
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Bone Metastasis ◽  
Cancer Progression ◽  
Human Breast ◽  
Protein Coding ◽  
Regulate Gene Expression ◽  
Complex Process ◽  
And Function

Breast cancer progression including bone metastasis is a complex process involving numerous changes in gene expression and function. MicroRNAs (miRNAs) are small endogenous noncoding RNAs that regulate gene expression by targeting protein-coding mRNAs posttranscriptionally, often affecting a number of gene targets simultaneously. Alteration in expression of miRNAs is common in human breast cancer, possessing with either oncogenic or tumor suppressive activity. The expression and the functional role of several miRNAs (miR-206, miR-31, miR-27a/b, miR-21, miR-92a, miR-205, miR-125a/b, miR-10b, miR-155, miR-146a/b, miR-335, miR-204, miR-211, miR-7, miR-22, miR-126, and miR-17) in breast cancer has been identified. In this review we summarize the experimentally validated targets of up- and downregulated miRNAs and their regulation in breast cancer and bone metastasis for diagnostic and therapeutic purposes.

scholarly journals Nanopore Sequencing Resolves Elusive Long Tandem-Repeat Regions in Mitochondrial Genomes

2021 ◽  
Vol 22 (4) ◽  
pp. 1811
Author(s):  
Liina Kinkar ◽  
Robin Gasser ◽  
Bonnie Webster ◽  
David Rollinson ◽  
D. Littlewood ◽  
...  
Keyword(s):  
Structural Variation ◽  
Mitochondrial Genomes ◽  
Nanopore Sequencing ◽  
Coding Region ◽  
High Coverage ◽  
Protein Coding ◽  
Oxford Nanopore ◽  
Long Read ◽  
Genomic Dnas ◽  
And Function

Long non-coding, tandem-repetitive regions in mitochondrial (mt) genomes of many metazoans have been notoriously difficult to characterise accurately using conventional sequencing methods. Here, we show how the use of a third-generation (long-read) sequencing and informatic approach can overcome this problem. We employed Oxford Nanopore technology to sequence genomic DNAs from a pool of adult worms of the carcinogenic parasite, Schistosoma haematobium, and used an informatic workflow to define the complete mt non-coding region(s). Using long-read data of high coverage, we defined six dominant mt genomes of 33.4 kb to 22.6 kb. Although no variation was detected in the order or lengths of the protein-coding genes, there was marked length (18.5 kb to 7.6 kb) and structural variation in the non-coding region, raising questions about the evolution and function of what might be a control region that regulates mt transcription and/or replication. The discovery here of the largest tandem-repetitive, non-coding region (18.5 kb) in a metazoan organism also raises a question about the completeness of some of the mt genomes of animals reported to date, and stimulates further explorations using a Nanopore-informatic workflow.

scholarly journals Long-read cDNA sequencing identifies functional pseudogenes in the human transcriptome

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Robin-Lee Troskie ◽  
Yohaann Jafrani ◽  
Tim R. Mercer ◽  
Adam D. Ewing ◽  
Geoffrey J. Faulkner ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Open Reading Frames ◽  
Cdna Sequencing ◽  
Protein Coding ◽  
Dynamic Component ◽  
Gene Copies ◽  
Long Read ◽  
Normal Human ◽  
Reading Frames ◽  
Transcriptional Landscape

AbstractPseudogenes are gene copies presumed to mainly be functionless relics of evolution due to acquired deleterious mutations or transcriptional silencing. Using deep full-length PacBio cDNA sequencing of normal human tissues and cancer cell lines, we identify here hundreds of novel transcribed pseudogenes expressed in tissue-specific patterns. Some pseudogene transcripts have intact open reading frames and are translated in cultured cells, representing unannotated protein-coding genes. To assess the biological impact of noncoding pseudogenes, we CRISPR-Cas9 delete the nucleus-enriched pseudogene PDCL3P4 and observe hundreds of perturbed genes. This study highlights pseudogenes as a complex and dynamic component of the human transcriptional landscape.

scholarly journals Common and rare genetic variants that could contribute to severe otitis media in an Australian Aboriginal population

2021 ◽  
Author(s):  
Sarra E Jamieson ◽  
Michaela Fakiola ◽  
Dave Tang ◽  
Elizabeth Scaman ◽  
Genevieve Syn ◽  
...  
Keyword(s):  
Hair Cell ◽  
Otitis Media ◽  
Genetic Risk ◽  
Transforming Growth Factor ◽  
Rare Variants ◽  
Protein Coding ◽  
Gene Sets ◽  
Growth Factor Signalling ◽  
Rare Genetic Variants ◽  
And Function

Abstract Background Our goal was to identify genetic risk factors for severe otitis media (OM) in Aboriginal Australians. Methods Illumina ® Omni2.5 BeadChip and imputed data were compared between 21 children with severe OM (multiple episodes chronic suppurative OM and/or perforations or tympanic sclerosis) and 370 individuals without this phenotype, followed by FUnctional Mapping and Annotation (FUMA). Exome data filtered for common (EXaC_all≥0.1) putative deleterious variants influencing protein coding (CADD-scaled scores ≥ 15) were used to compare 15 severe OM cases with 9 mild cases (single episode of acute OM recorded over ≥ 3 consecutive years). Rare (ExAC_all≤0.01) such variants were filtered for those present only in severe OM. Enrichr was used to determine enrichment of genes contributing to pathways/processes relevant to OM. Results FUMA analysis identified two plausible genetic risk loci for severe OM: NR3C1 (Pimputed_1000G=3.62x10 -6) encoding the glucocorticoid receptor, and NREP (Pimputed_1000G=3.67x10 -6) encoding neuronal regeneration related protein. Exome analysis showed: (i) association of severe OM with variants influencing protein coding (CADD-scaled ≥ 15) in a gene-set (GRXCR1, CDH23, LRP2, FAT4, ARSA, EYA4) enriched for Mammalian Phenotype Level 4 abnormal hair cell stereociliary bundle morphology and related phenotypes; (ii) rare variants influencing protein coding only seen in severe OM provided gene-sets enriched for “abnormal ear” (LMNA, CDH23, LRP2, MYO7A, FGFR1), integrin interactions, transforming growth factor signalling, and cell projection phenotypes including hair cell stereociliary bundles and cilium assembly. Conclusions This study highlights interacting genes and pathways related to cilium structure and function that may contribute to extreme susceptibility to OM in Aboriginal Australian children.

scholarly journals Expression and Function of C1orf132 Long-Noncoding RNA in Breast Cancer Cell Lines and Tissues

2021 ◽  
Vol 22 (13) ◽  
pp. 6768
Author(s):  
Afsaneh Malekzadeh Shafaroudi ◽  
Ali Sharifi-Zarchi ◽  
Saeid Rahmani ◽  
Nahid Nafissi ◽  
Seyed Javad Mowla ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Noncoding Rna ◽  
Breast Cancer Cell Lines ◽  
Mcf7 Cells ◽  
Migration Ability ◽  
Mesenchymal Transition ◽  
Migration Assay ◽  
And Function ◽  
Distal Promoter

miR-29b2 and miR-29c play a suppressive role in breast cancer progression. C1orf132 (also named MIR29B2CHG) is the host gene for generating both microRNAs. However, the region also expresses longer transcripts with unknown functions. We employed bioinformatics and experimental approaches to decipher C1orf132 expression and function in breast cancer tissues. We also used the CRISPR/Cas9 technique to excise a predicted C1orf132 distal promoter and followed the behavior of the edited cells by real-time PCR, flow cytometry, migration assay, and RNA-seq techniques. We observed that C1orf132 long transcript is significantly downregulated in triple-negative breast cancer. We also identified a promoter for the longer transcripts of C1orf132 whose functionality was demonstrated by transfecting MCF7 cells with a C1orf132 promoter-GFP construct. Knocking-out the promoter by means of CRISPR/Cas9 revealed no alterations in the expression of the neighboring genes CD46 and CD34, while the expression of miR-29c was reduced by half. Furthermore, the promoter knockout elevated the migration ability of the edited cells. RNA sequencing revealed many up- and downregulated genes involved in various cellular pathways, including epithelial to mesenchymal transition and mammary gland development pathways. Altogether, we are reporting here the existence of an additional/distal promoter with an enhancer effect on miR-29 generation and an inhibitory effect on cell migration.

scholarly journals The Secreted Protein C10orf118 Is a New Regulator of Hyaluronan Synthesis Involved in Tumour-Stroma Cross-Talk

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1105
Author(s):  
Ilaria Caon ◽  
Maria Luisa D’Angelo ◽  
Barbara Bartolini ◽  
Elena Caravà ◽  
Arianna Parnigoni ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Patient Survival ◽  
Breast Tumour ◽  
Surrounding Area ◽  
Uncharacterized Protein ◽  
Stromal Fibroblasts ◽  
Tumour Cell Lines ◽  
Cell Niche ◽  
Hyaluronan Synthase 2 ◽  
Ncbi Blast

Interaction between cancer cells and their microenvironment is central in defining the fate of cancer development. Tumour cells secrete signals (cytokines, chemokines, growth factors) that modify the surrounding area, while the niche supplies structures and activities necessary for tumour maintenance and growth. Hyaluronan (HA) is a glycosaminoglycan that constitute cancer cell niche and is known to influence tumour functions such as proliferation, migration and neoangiogenesis. The knowledge of the factors regulating HA synthesis and size is crucial in understanding the mechanisms sustaining tumour development. Here we show that a yet uncharacterized protein secreted by breast tumour cell lines, named c10orf118 (accession number NM_018017 in NCBI/BLAST, and Q7z3E2 according to the Uniprot identifier), with a predicted length of 898 amino acids, can induce the secretion of HA by stromal fibroblasts through the up-regulation of the hyaluronan synthase 2 gene (HAS2). Intracellularly, this protein is localized in the Golgi apparatus with a possible role in vesicle maturation and transport. The expression of c10orf118 was verified in breast cancer patient specimens and was found to be associated with the presence of estrogen receptor that characterizes a good patient survival. We suggest c10orf118 as a new player that influences the HA amount in breast cancer microenvironment and is associated with low aggressiveness of cancer.

scholarly journals Genome sequences of human cytomegalovirus strain TB40/E variants propagated in fibroblasts and epithelial cells

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Ahmed Al Qaffas ◽  
Salvatore Camiolo ◽  
Mai Vo ◽  
Alexis Aguiar ◽  
Amine Ourahmane ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Cytomegalovirus ◽  
Viral Entry ◽  
Sequence Data ◽  
Laboratory Strain ◽  
Serial Passage ◽  
Wild Type Virus ◽  
Protein Coding ◽  
Genetic Changes ◽  
Long Read

AbstractThe advent of whole genome sequencing has revealed that common laboratory strains of human cytomegalovirus (HCMV) have major genetic deficiencies resulting from serial passage in fibroblasts. In particular, tropism for epithelial and endothelial cells is lost due to mutations disrupting genes UL128, UL130, or UL131A, which encode subunits of a virion-associated pentameric complex (PC) important for viral entry into these cells but not for entry into fibroblasts. The endothelial cell-adapted strain TB40/E has a relatively intact genome and has emerged as a laboratory strain that closely resembles wild-type virus. However, several heterogeneous TB40/E stocks and cloned variants exist that display a range of sequence and tropism properties. Here, we report the use of PacBio sequencing to elucidate the genetic changes that occurred, both at the consensus level and within subpopulations, upon passaging a TB40/E stock on ARPE-19 epithelial cells. The long-read data also facilitated examination of the linkage between mutations. Consistent with inefficient ARPE-19 cell entry, at least 83% of viral genomes present before adaptation contained changes impacting PC subunits. In contrast, and consistent with the importance of the PC for entry into endothelial and epithelial cells, genomes after adaptation lacked these or additional mutations impacting PC subunits. The sequence data also revealed six single noncoding substitutions in the inverted repeat regions, single nonsynonymous substitutions in genes UL26, UL69, US28, and UL122, and a frameshift truncating gene UL141. Among the changes affecting protein-coding regions, only the one in UL122 was strongly selected. This change, resulting in a D390H substitution in the encoded protein IE2, has been previously implicated in rendering another viral protein, UL84, essential for viral replication in fibroblasts. This finding suggests that IE2, and perhaps its interactions with UL84, have important functions unique to HCMV replication in epithelial cells.

scholarly journals Comprehensive identification of transposable element insertions using multiple sequencing technologies

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chong Chu ◽  
Rebeca Borges-Monroy ◽  
Vinayak V. Viswanadham ◽  
Soohyun Lee ◽  
Heng Li ◽  
...  
Keyword(s):  
Transposable Element ◽  
Structure And Function ◽  
Endogenous Retroviruses ◽  
Whole Genome Sequencing Data ◽  
Whole Genome ◽  
Sequencing Data ◽  
Short Read ◽  
Sequencing Technologies ◽  
Long Read ◽  
And Function

AbstractTransposable elements (TEs) help shape the structure and function of the human genome. When inserted into some locations, TEs may disrupt gene regulation and cause diseases. Here, we present xTea (x-Transposable element analyzer), a tool for identifying TE insertions in whole-genome sequencing data. Whereas existing methods are mostly designed for short-read data, xTea can be applied to both short-read and long-read data. Our analysis shows that xTea outperforms other short read-based methods for both germline and somatic TE insertion discovery. With long-read data, we created a catalogue of polymorphic insertions with full assembly and annotation of insertional sequences for various types of retroelements, including pseudogenes and endogenous retroviruses. Notably, we find that individual genomes have an average of nine groups of full-length L1s in centromeres, suggesting that centromeres and other highly repetitive regions such as telomeres are a significant yet unexplored source of active L1s. xTea is available at https://github.com/parklab/xTea.

Sign in / Sign up

Export Citation Format

Share Document