Progress toward an amplifiable metabolic label for DNA: conversion of 4-thiothymidine (4sT) to 5-methyl-2′-deoxycytidine and synthesis of a 4sT phosphorodiamidate prodrug

2018 ◽  
Vol 96 (7) ◽  
pp. 636-645
Author(s):  
Adam K. Hedger ◽  
Marlies E. Oomen ◽  
Victor Liu ◽  
Michael P. Moazami ◽  
Nicholas Rhind ◽  
...  
Keyword(s):  
High Throughput ◽  
Mammalian Cells ◽  
High Throughput Sequencing ◽  
Base Pairing ◽  
Nucleotide Analogue ◽  
Metabolic Label ◽  
Cellular Dna

The ability to metabolically label DNA in a way that produces a latent change from one nucleobase to another would create a signal that can be amplified by PCR — this in turn would allow studies of newly synthesized DNA using high-throughput sequencing. To function as an amplifiable metabolic label, a nucleotide analogue would need to be taken up by cells and incorporated into cellular DNA; after purification of DNA, it could be converted into a different nucleobase with a different base pairing pattern. We selected 4-thiothymidine (4sT) as a candidate metabolic label: 4sT is readily taken up by a large number of polymerases in vitro, and we present a method that allows 4sT to be converted into 5-methyl-2′-deoxycytidine (5mC) after incorporation into DNA. Encouraged by these results, we treated cells with 4sT nucleoside; however, we found that 4sT is not incorporated into DNA in bacterial, yeast, or mammalian cells to useful levels under the conditions we tested. A phosphorodiamidate prodrug of 4sTMP was successfully synthesized but did not measurably improve incorporation into cellular DNA.

scholarly journals Construction of High Content Nanobody Library in Mammalian Cells by Linear-double-stranded DNA Based Strategies

2020 ◽  
Author(s):  
Yanjie Zhao ◽  
Weijun Su ◽  
Shuai Li
Keyword(s):  
Cell Lines ◽  
High Throughput ◽  
Mammalian Cells ◽  
High Throughput Sequencing ◽  
Full Length ◽  
Expression Cassette ◽  
Cultured Cell ◽  
Double Stranded Dna ◽  
Novel Methods

AbstractHere, we developed two novel methods to construct high content nanobody library in mammalian cells. For the first method, we employed a linear-double-stranded DNA based AND-gate (LBAG) strategy. Upstream- and downstream-linear-double-stranded DNAs (ldsDNAs), containing identical overlapping sequences, were co-transfected into cultured cell lines to conduct AND-gate calculation to form intact nanobody expression cassette. For the second method, we generated full-length nanobody expression ldsDNA by in vitro ligation of restrict cut up- and down-stream ldsDNAs. Then the ldsDNAs were directly transfected into mammalian cells to express nanobody library. Both methods generated over a million different nanobody sequences as revealed by high-throughput sequencing (HTS).

scholarly journals Selection of aptamers against triple negative breast cancer cells using high throughput sequencing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Débora Ferreira ◽  
Joaquim Barbosa ◽  
Diana A. Sousa ◽  
Cátia Silva ◽  
Luís D. R. Melo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
High Throughput ◽  
Triple Negative Breast Cancer ◽  
High Throughput Sequencing ◽  
Triple Negative ◽  
Metastatic Breast ◽  
Target Cells ◽  
Cancer Tissue ◽  
Surface Receptors

AbstractTriple-negative breast cancer is the most aggressive subtype of invasive breast cancer with a poor prognosis and no approved targeted therapy. Hence, the identification of new and specific ligands is essential to develop novel targeted therapies. In this study, we aimed to identify new aptamers that bind to highly metastatic breast cancer MDA-MB-231 cells using the cell-SELEX technology aided by high throughput sequencing. After 8 cycles of selection, the aptamer pool was sequenced and the 25 most frequent sequences were aligned for homology within their variable core region, plotted according to their free energy and the key nucleotides possibly involved in the target binding site were analyzed. Two aptamer candidates, Apt1 and Apt2, binding specifically to the target cells with $$K_{d}$$ K d values of 44.3 ± 13.3 nM and 17.7 ± 2.7 nM, respectively, were further validated. The binding analysis clearly showed their specificity to MDA-MB-231 cells and suggested the targeting of cell surface receptors. Additionally, Apt2 revealed no toxicity in vitro and showed potential translational application due to its affinity to breast cancer tissue sections. Overall, the results suggest that Apt2 is a promising candidate to be used in triple-negative breast cancer treatment and/or diagnosis.

scholarly journals CDK10 Regulates Gastric Cancer Metastasis By Inhibiting lncRNA-C5ORF42-5 Via Phosphorylation Level of AKT/ERK

2021 ◽  
Author(s):  
Zi-Jian Deng ◽  
Dong-Wen Chen ◽  
Xi-Jie Chen ◽  
Jia-Ming Fang ◽  
Liang Xv ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Cell Line ◽  
High Throughput ◽  
Cancer Metastasis ◽  
High Throughput Sequencing ◽  
Gastric Cancer Cells ◽  
Related Proteins

Abstract Background: Gastric cancer is the fourth most common malignant disease. Both CDK10 and long noncoding RNAs (lncRNAs) have been found to exert biological functions in multiple cancers. However, it is still unclear whether CDK10 represses tumor progression in gastric cancer by reducing potential targeting lncRNAs.Methods: The functions of CDK10 and lncRNA-C5ORF42-5 in proliferation, invasion and migration were assessed by MTS assays, colony formation assays, cell cycle and apoptosis assays, Transwell assays, wound healing assays and animal experiments. We used high-throughput sequencing to confirm the existence of lncRNA-C5ORF42-5 and quantitative real-time PCR was used to evaluate lncRNA expression. Then, with RNA-seq sequencing as well as GO function and KEGG enrichment analysis, we identified the signaling pathways in which lncRNA-C5ORF42-5 was involved in gastric cancer. Finally, western blotting was used to identify the genes regulated by lncRNA-C5ORF42-5.Results: Our results showed that CDK10 is expressed at relatively low levels in gastric cancer cell lines and inhibits the progression of gastric cancer cells both in vitro and in vivo. Next, based on high-throughput sequencing, we identified a novel lncRNA, lncRNA-C5ORF42-5, in the stable CDK10-overexpressing cell line compared with the CDK-knockdown cell line and their controls. Additionally, we confirmed that lncRNA-C5ORF42-5 acts as an oncogene to promote metastasis in gastric cancer in vitro and in vivo. We then ascertained that lncRNA-C5ORF42-5 is a major contributor to the function of CDK10 in gastric cancer metastasis by upregulating lncRNA-C5ORF42-5 to reverse the effects of CDK10 overexpression. Finally, we explored the mechanism by which lncRNA-C5ORF42-5 overexpression affects gastric cancer cells to elucidate whether lncRNA-C5ORF42-5 may increase the activity of the SMAD pathway of BMP signaling and promote the expression of EMT-related proteins, such as E-cadherin. Additionally, overexpression of lncRNA-C5ORF42-5 affected the phosphorylation levels of AKT and ERK.Conclusion: Our findings suggest that CDK10 overexpression represses gastric cancer tumor progression by reducing lncRNA-C5ORF42-5 and hindering activation of the related proteins in metastatic signaling pathways, which provides new insight into developing effective therapeutic strategies in the treatment of metastatic gastric cancer.

CTNND1 to mediate bone metastasis of triple-negative breast cancer via regulating CXCR4.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e13045-e13045
Author(s):  
Chang Gong ◽  
Qun Lin ◽  
Xiaolin Fang ◽  
Wenguo Jiang ◽  
Jun Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Bone Metastasis ◽  
High Throughput ◽  
Triple Negative Breast Cancer ◽  
High Throughput Sequencing ◽  
Triple Negative ◽  
Mtor Pathway ◽  
Tissue Samples

e13045 Background: Compared to lumial breast cancer, the proporation of triple-negative breast cancer (TNBC) with bone metastases (BMs) is relatively low and few data focusing on the mechanism of the BMs in TNBC are available, Here, we screened that CTNND1 was associated with BMs of TNBC by integrating high-throughput sequencing, and further investigated the role of CTNND1 in BMs of TNBC in vitro. Methods: TNBC tissue samples with only BMs (n = 6) and without any metastasis (n = 10) were tested using high-throughput sequencing and 11 differentially expressed relative genes were identified. We then quantified these 11 genes in normal breast tissue samples (n = 26), TNBC tissue samples with only BMs (n = 10), TNBC tissue samples without any metastasis (n = 88) as well as luminal tissue samples with BMs（n = 10）through qPCR and immunohistochemical staining (IHC). The effects of knocking down CTNND1 on the interaction between TNBC cells and osteoblasts were examined by cell adhesion, transwell migration and matrigel invasion assays. To explorethe role of CTNND1 in mediating bone metastasis in TNBC, we used RNA-sequencing to find out the relative downstream gene CXCR4 and PI3K-AKT-mTOR pathway and verified it in vitro by Western Blotting. Results: Combining our high-throughput sequencing data, qPCR and IHC in clinical tissue samples, we verified that CTNND1 was decreased in TNBC patients with bone metastasis compared to normal tissue and luminal tissue with BMs. Knocking down of CTNND1 in TNBC cells including MDA-MB-231, MDA-MB-468 and BT549 weakened cells adhesion, but facilitated cells migration and invasion. Mechanically, knocking down of CTNND1 upregulated CXCR4 via activating PI3K-AKT-mTOR pathway in TNBC but not luminal and HER2- positive breast cancer cells lines. Conclusions: CTNND1 mediates bone metastasis in triple-negative breast cancer via regulating CXCR4.CTNND1 may serve as a potential predictor of bone metastasis for TNBC patients.

scholarly journals T cell neoepitope discovery in colorectal cancer by high throughput profiling of somatic mutations in expressed genes

Gut ◽  
2015 ◽  
Vol 66 (3) ◽  
pp. 454-463 ◽  
Author(s):  
Daniele Mennonna ◽  
Cristina Maccalli ◽  
Michele C Romano ◽  
Claudio Garavaglia ◽  
Filippo Capocefalo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Cell Epitope ◽  
Patient Specific ◽  
Cancer Genes ◽  
Healthy Donors

ObjectivePatient-specific (unique) tumour antigens, encoded by somatically mutated cancer genes, generate neoepitopes that are implicated in the induction of tumour-controlling T cell responses. Recent advancements in massive DNA sequencing combined with robust T cell epitope predictions have allowed their systematic identification in several malignancies.DesignWe undertook the identification of unique neoepitopes in colorectal cancers (CRCs) by using high-throughput sequencing of cDNAs expressed by standard cancer cell cultures, and by related cancer stem/initiating cells (CSCs) cultures, coupled with a reverse immunology approach not requiring human leukocyte antigen (HLA) allele-specific epitope predictions.ResultsSeveral unique mutated antigens of CRC, shared by standard cancer and related CSC cultures, were identified by this strategy. CD8+and CD4+T cells, either autologous to the patient or derived from HLA-matched healthy donors, were readily expanded in vitro by peptides spanning different cancer mutations and specifically recognised differentiated cancer cells and CSC cultures, expressing the mutations. Neoepitope-specific CD8+T cell frequency was also increased in a patient, compared with healthy donors, supporting the occurrence of clonal expansion in vivo.ConclusionsThese results provide a proof-of-concept approach for the identification of unique neoepitopes that are immunogenic in patients with CRC and can also target T cells against the most aggressive CSC component.

scholarly journals Elucidation of Insertion Elements Carried on Plasmids andIn VitroConstruction of Shuttle Vectors from the Toxic Cyanobacterium Planktothrix

2014 ◽  
Vol 80 (16) ◽  
pp. 4887-4897 ◽  
Author(s):  
Guntram Christiansen ◽  
Alexander Goesmann ◽  
Rainer Kurmayer
Keyword(s):  
Homologous Recombination ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Gene Clusters ◽  
Content Type ◽  
Shuttle Vectors ◽  
Is Element ◽  
Toxic Cyanobacterium ◽  
Is Elements

ABSTRACTSeveral gene clusters that are responsible for toxin synthesis in bloom-forming cyanobacteria have been found to be associated with transposable elements (TEs). In particular, insertion sequence (IS) elements were shown to play a role in the inactivation or recombination of the genes responsible for cyanotoxin synthesis. Plasmids have been considered important vectors of IS element distribution to the host. In this study, we aimed to elucidate the IS elements propagated on the plasmids and the chromosome of the toxic cyanobacteriumPlanktothrix agardhiiNIVA-CYA126/8 by means of high-throughput sequencing. In total, five plasmids (pPA5.5, pPA14, pPA50, pPA79, and pPA115, of 5, 6, 50, 79, and 120 kbp, respectively) were elucidated, and two plasmids (pPA5.5, pPA115) were found to propagate full IS element copies. Large stretches of shared DNA information between plasmids were constituted of TEs. Two plasmids (pPA5.5, pPA14) were used as candidates to engineer shuttle vectors (named pPA5.5SV and pPA14SV, respectively)in vitroby PCR amplification and the subsequent transposition of the Tn5 cattransposon containing the R6Kγ origin of replication ofEscherichia coli. While pPA5.5SV was found to be fully segregated, pPA14SV consistently co-occurred with its wild-type plasmid even under the highest selective pressure. Interestingly, the Tn5 cattransposon became transferred by homologous recombination into another plasmid, pPA50. The availability of shuttle vectors is considered to be of relevance in investigating genome plasticity as a consequence of homologous recombination events. Combining the potential of high-throughput sequencing andin vitroproduction of shuttle vectors makes it simple to produce species-specific shuttle vectors for many cultivable prokaryotes.

scholarly journals Implementation of High-Throughput Sequencing (HTS) in Aptamer Selection Technology

2020 ◽  
Vol 21 (22) ◽  
pp. 8774
Author(s):  
Natalia Komarova ◽  
Daria Barkova ◽  
Alexander Kuznetsov
Keyword(s):  
Nucleic Acid ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Combinatorial Libraries ◽  
Structure And Function ◽  
Huge Number ◽  
Systematic Evolution ◽  
And Function ◽  
Exponential Enrichment

Aptamers are nucleic acid ligands that bind specifically to a target of interest. Aptamers have gained in popularity due to their high potential for different applications in analysis, diagnostics, and therapeutics. The procedure called systematic evolution of ligands by exponential enrichment (SELEX) is used for aptamer isolation from large nucleic acid combinatorial libraries. The huge number of unique sequences implemented in the in vitro evolution in the SELEX process imposes the necessity of performing extensive sequencing of the selected nucleic acid pools. High-throughput sequencing (HTS) meets this demand of SELEX. Analysis of the data obtained from sequencing of the libraries produced during and after aptamer isolation provides an informative basis for precise aptamer identification and for examining the structure and function of nucleic acid ligands. This review discusses the technical aspects and the potential of the integration of HTS with SELEX.

scholarly journals Molecular Fitness Landscapes from High-Coverage Sequence Profiling

2019 ◽  
Vol 48 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Celia Blanco ◽  
Evan Janzen ◽  
Abe Pressman ◽  
Ranajay Saha ◽  
Irene A. Chen
Keyword(s):  
High Throughput ◽  
Large Scale ◽  
High Throughput Sequencing ◽  
Fitness Landscape ◽  
Complete Sequence ◽  
Fitness Landscapes ◽  
Future Research ◽  
High Coverage

The function of fitness (or molecular activity) in the space of all possible sequences is known as the fitness landscape. Evolution is a random walk on the fitness landscape, with a bias toward climbing hills. Mapping the topography of real fitness landscapes is fundamental to understanding evolution, but previous efforts were hampered by the difficulty of obtaining large, quantitative data sets. The accessibility of high-throughput sequencing (HTS) has transformed this study, enabling large-scale enumeration of fitness for many mutants and even complete sequence spaces in some cases. We review the progress of high-throughput studies in mapping molecular fitness landscapes, both in vitro and in vivo, as well as opportunities for future research. Such studies are rapidly growing in number. HTS is expected to have a profound effect on the understanding of real molecular fitness landscapes.

scholarly journals Characterization of Intracellular Growth RegulatoricgRby Utilizing Transcriptomics To Identify Mediators of Pathogenesis in Shigella flexneri

2013 ◽  
Vol 81 (9) ◽  
pp. 3068-3076 ◽  
Author(s):  
Carolyn R. Morris ◽  
Christen L. Grassel ◽  
Julia C. Redman ◽  
Jason W. Sahl ◽  
Eileen M. Barry ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Sequencing ◽  
Diarrheal Disease ◽  
Intracellular Growth ◽  
Bioinformatics Analyses ◽  
Content Type ◽  
Regulatory Pathways

ABSTRACTShigellaspecies Gram-negative bacteria which cause a diarrheal disease, known as shigellosis, by invading and destroying the colonic mucosa and inducing a robust inflammatory response. With no vaccine available, shigellosis annually kills over 600,000 children in developing countries. This study demonstrates the utility of combining high-throughput bioinformatic methods within vitroandin vivoassays to provide new insights into pathogenesis. Comparisons ofin vivoandin vitrogene expression identified genes associated with intracellular growth. Additional bioinformatics analyses identified genes that are present inS. flexneriisolates but not in the three otherShigellaspecies. Comparison of these two analyses revealed nine genes that are differentially expressed during invasion and that are specific toS. flexneri. One gene, a DeoR family transcriptional regulator with decreased expression during invasion, was further characterized and is now designatedicgR, forintracellulargrowthregulator. Deletion oficgRcaused no difference in growthin vitrobut resulted in increased intracellular replication in HCT-8 cells. Furtherin vitroandin vivostudies using high-throughput sequencing of RNA transcripts (RNA-seq) of an isogenic ΔicgRmutant identified 34 genes that were upregulated under both growth conditions. This combined informatics and functional approach has allowed the characterization of a gene and pathway previously unknown inShigellapathogenesis and provides a framework for further identification of novel virulence factors and regulatory pathways.

scholarly journals Integrated analysis of RNA-binding protein complexes using in vitro selection and high-throughput sequencing and sequence specificity landscapes (SEQRS)

Methods ◽  
2017 ◽  
Vol 118-119 ◽  
pp. 171-181 ◽  
Author(s):  
Tzu-Fang Lou ◽  
Chase A. Weidmann ◽  
Jordan Killingsworth ◽  
Traci M. Tanaka Hall ◽  
Aaron C. Goldstrohm ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Sequencing ◽  
In Vitro Selection ◽  
Rna Binding ◽  
Protein Complexes ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Integrated Analysis ◽  
Sequence Specificity
Sign in / Sign up

Export Citation Format

Share Document