scholarly journals Treatment of human cells with 5-aza-dC induces formation of PARP1-DNA covalent adducts at genomic regions targeted by DNMT1

2019 ◽  
Author(s):  
Kostantin Kiianitsa ◽  
Nancy Maizels
Keyword(s):  
Dna Adducts ◽  
Cell Killing ◽  
Human Cells ◽  
Response To Treatment ◽  
Hematopoietic Malignancies ◽  
Human Lymphoblast ◽  
Covalent Adducts ◽  
Genomic Regions ◽  
Genomic Locations ◽  
Maintenance Methylation

ABSTRACTThe nucleoside analog 5-aza-2’-deoxycytidine (5-aza-dC) is used to treat some hematopoietic malignancies. The mechanism of cell killing depends upon DNMT1, but is otherwise not clearly defined. Here we show that PARP1 forms covalent DNA adducts in human lymphoblast or fibroblasts treated with 5-aza-dC. Some adducts recovered from 5-aza-dC-treated cells have undergone cleavage by apoptotic caspases 3/7. Mapping of PARP1-DNA adducts, by a new method, “Adduct-Seq”, demonstrates adduct enrichment at CpG-dense genomic locations that are targets of maintenance methylation by DNMT1. Covalent protein-DNA adducts can arrest replication and induce apoptosis, and these results raise the possibility that induction of PARP1-DNA adducts may contribute to cell killing in response to treatment with 5-aza-dC.

scholarly journals Multiple Fates of L1 Retrotransposition Intermediates in Cultured Human Cells

2005 ◽  
Vol 25 (17) ◽  
pp. 7780-7795 ◽  
Author(s):  
Nicolas Gilbert ◽  
Sheila Lutz ◽  
Tammy A. Morrish ◽  
John V. Moran
Keyword(s):  
Genetic Instability ◽  
Noncoding Rnas ◽  
Human Cells ◽  
Genomic Rearrangements ◽  
U6 Snrna ◽  
Human Dna ◽  
Cultured Human Cells ◽  
Repair Pathways ◽  
Genomic Locations ◽  
Host Parasite

ABSTRACT LINE-1 (L1) retrotransposons comprise ∼17% of human DNA, yet little is known about L1 integration. Here, we characterized 100 retrotransposition events in HeLa cells and show that distinct DNA repair pathways can resolve L1 cDNA retrotransposition intermediates. L1 cDNA resolution can lead to various forms of genetic instability including the generation of chimeric L1s, intrachromosomal deletions, intrachromosomal duplications, and intra-L1 rearrangements as well as a possible interchromosomal translocation. The L1 retrotransposition machinery also can mobilize U6 snRNA to new genomic locations, increasing the repertoire of noncoding RNAs that are mobilized by L1s. Finally, we have determined that the L1 reverse transcriptase can faithfully replicate its own transcript and has a base misincorporation error rate of ∼1/7,000 bases. These data indicate that L1 retrotransposition in transformed human cells can lead to a variety of genomic rearrangements and suggest that host processes act to restrict L1 integration in cultured human cells. Indeed, the initial steps in L1 retrotransposition may define a host/parasite battleground that serves to limit the number of active L1s in the genome.

Detection of acrolein and crotonaldehyde DNA adducts in cultured human cells and canine peripheral blood lymphocytes by 32P-postlabeling and nucleotide chromatography

1991 ◽  
Vol 12 (8) ◽  
pp. 1483-1490 ◽  
Author(s):  
Vincent L. Wilson ◽  
Peter G. Foiles ◽  
Fung-Lung Chung ◽  
Andrew C. Povey ◽  
Anthony A. Frank ◽  
...  
Keyword(s):  
Dna Adducts ◽  
Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
Human Cells ◽  
Blood Lymphocytes ◽  
Cultured Human Cells

scholarly journals Impact of tobacco-specific nitrosamine–derived DNA adducts on the efficiency and fidelity of DNA replication in human cells

2018 ◽  
Vol 293 (28) ◽  
pp. 11100-11108 ◽  
Author(s):  
Hua Du ◽  
Jiapeng Leng ◽  
Pengcheng Wang ◽  
Lin Li ◽  
Yinsheng Wang
Keyword(s):  
Dna Replication ◽  
Dna Adducts ◽  
Human Cells

Targeting MHC-linked wild type p53 with TCR mimic single chain diabody for cancer immunotherapy.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 2524-2524
Author(s):  
Suman Paul ◽  
Jacqueline Douglass ◽  
Annika Schaefer ◽  
Emily Han-Chung Hsiue ◽  
Alexander Pearlman ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Surface ◽  
Cancer Immunotherapy ◽  
Cell Killing ◽  
Human Cells ◽  
Wild Type ◽  
Single Chain ◽  
Nsg Mice ◽  
Wild Type P53

2524 Background: Increased tumor suppressor protein p53 expression is observed in a wide range of human cancers. As a result there is intense interest in targeting p53 for cancer therapy. Intracellular p53 is inaccessible to therapeutic antibodies that bind cell surface proteins. However, intracellular proteins including p53 are degraded into peptides that are presented on cell surface in association with HLA class I molecules. Thus p53 peptide-HLA (p53-HLA) complexes can be antibody targets. Methods: Using phage display we identified a novel anti-p53-HLA single chain variable fragment (scFv) clone-43 that recognizes a wild-type p53 10-mer epitope bound to HLA-A*2402. By coupling our clone-43 scFv with an anti-CD3 scFv, we generated a single chain diabody (scDb) designed to activate T-cells against p53-expressing target cells. Results: In-vitro co-culture of clone-43 scDb with donor human T-cells and p53 expressing SIG-M5 cancer cells results in SIG-M5 cell killing and concomitant T-cell interferon gamma (IFNγ) release. In contrast, similar co-culture with SIG-M5 p53-knock out (KO) cells showed no cell killing and minimal IFNγ release demonstrating specificity of clone-43 to p53 expressing cells. Additionally, in-vivo growth of p53 expressing SW480 cancer cell xenografts in NSG mice was completely terminated by clone-43 scDb injections. A major concern for wild-type p53 epitope targeting is potential on-target off-tumor effect on non-cancerous tissue. We observed significant in-vitro clone-43 scDb mediated killing of human HLA-A*24:02 peripheral blood mononuclear cells. To better evaluate effect of clone-43 scDb on non-neoplastic human cells, we engrafted HLA-A*24:02 human CD34+ hematopoietic stem cells into NSG mice to generate a humanized mouse model with circulating mature human CD45+ cells. Clone-43 scDb treatment resulted in selective depletion of circulating human cells while the same cells persisted in mice treated with unrelated control scDb. Conclusions: Our observation that immune targeting of wild-type p53 epitope results in significant off-tumor hematopoietic cell death is contrary to previously published reports and carries important implications for future anti-p53 antibody and vaccine design for cancer immunotherapy.

scholarly journals Lack of Mutagenicity of Acrolein-Induced DNA Adducts in Mouse and Human Cells

2007 ◽  
Vol 67 (24) ◽  
pp. 11640-11647 ◽  
Author(s):  
S.-i. Kim ◽  
G. P. Pfeifer ◽  
A. Besaratinia
Keyword(s):  
Dna Adducts ◽  
Human Cells

scholarly journals Identity-by-descent analyses for measuring population dynamics and selection in recombining pathogens

2016 ◽  
Author(s):  
Lyndal Henden ◽  
Stuart Lee ◽  
Ivo Mueller ◽  
Alyssa Barry ◽  
Melanie Bahlo
Keyword(s):  
Drug Resistance ◽  
Positive Selection ◽  
Whole Genome Sequencing Data ◽  
Population Bottlenecks ◽  
Human Pathogens ◽  
Sequencing Data ◽  
Antimalarial Drug Resistance ◽  
Genomic Regions ◽  
Genomic Locations ◽  
Critical Regions

AbstractIdentification of genomic regions that are identical by descent (IBD) has proven useful for human genetic studies where analyses have led to the discovery of familial relatedness and fine-mapping of disease critical regions. Unfortunately however, IBD analyses have been underutilized inanalysis of other organisms, including human pathogens. This is in part due to the lack of statistical methodologies for non-diploid genomes in addition to the added complexity of multiclonal infections. As such, we have developed an IBD methodology, called isoRelate, for analysis of haploid recombining microorganisms in the presence of multiclonal infections. Using the inferred IBD status at genomic locations, we have also developed a novel statistic for identifying loci under positive selection and propose relatedness networks as a means of exploring shared haplotypes within populations. We evaluate the performance of our methodologies for detecting IBD and selection, including comparisons with existing tools, then perform an exploratory analysis of whole genome sequencing data from a global Plasmodium falciparum dataset of more than 2500 genomes. This analysis identifies Southeast Asia as havingmany highly related isolates, possibly as a result of both reduced transmission from intensified control efforts and population bottlenecks following the emergence of antimalarial drug resistance. Many signals of selection are also identified, most of which overlap genes that are known to be associated with drug resistance, in addition to two novel signals observed in multiple countries that have yet to be explored in detail. Additionally, we investigate relatedness networks over the selected loci and determine that one of these sweeps has spread between continents while the other has arisen independently in different countries. IBD analysis of microorganisms using isoRelate can be used for exploring population structure, positive selection and haplotype distributions, and will be a valuable tool for monitoring disease control and elimination efforts of many diseases.

Sign in / Sign up

Export Citation Format

Share Document