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Journal of Biomedical Science Jul 2023Dysregulating cellular metabolism is one of the emerging cancer hallmarks. Mitochondria are essential organelles responsible for numerous physiologic processes, such as... (Review)
Review
Dysregulating cellular metabolism is one of the emerging cancer hallmarks. Mitochondria are essential organelles responsible for numerous physiologic processes, such as energy production, cellular metabolism, apoptosis, and calcium and redox homeostasis. Although the "Warburg effect," in which cancer cells prefer aerobic glycolysis even under normal oxygen circumstances, was proposed a century ago, how mitochondrial dysfunction contributes to cancer progression is still unclear. This review discusses recent progress in the alterations of mitochondrial DNA (mtDNA) and mitochondrial dynamics in cancer malignant progression. Moreover, we integrate the possible regulatory mechanism of mitochondrial dysfunction-mediated mitochondrial retrograde signaling pathways, including mitochondrion-derived molecules (reactive oxygen species, calcium, oncometabolites, and mtDNA) and mitochondrial stress response pathways (mitochondrial unfolded protein response and integrated stress response) in cancer progression and provide the possible therapeutic targets. Furthermore, we discuss recent findings on the role of mitochondria in the immune regulatory function of immune cells and reveal the impact of the tumor microenvironment and metabolism remodeling on cancer immunity. Targeting the mitochondria and metabolism might improve cancer immunotherapy. These findings suggest that targeting mitochondrial retrograde signaling in cancer malignancy and modulating metabolism and mitochondria in cancer immunity might be promising treatment strategies for cancer patients and provide precise and personalized medicine against cancer.
Topics: Humans; Calcium; Neoplasms; Mitochondria; DNA, Mitochondrial; Reactive Oxygen Species; Tumor Microenvironment
PubMed: 37525297
DOI: 10.1186/s12929-023-00956-w -
The CRISPR Journal Oct 2022While genome editing has been revolutionized by the advent of CRISPR-based nucleases, difficulties in achieving efficient, nuclease-mediated, homology-directed repair...
While genome editing has been revolutionized by the advent of CRISPR-based nucleases, difficulties in achieving efficient, nuclease-mediated, homology-directed repair (HDR) still limit many applications. Commonly used DNA donors such as plasmids suffer from low HDR efficiencies in many cell types, as well as integration at unintended sites. In contrast, single-stranded DNA (ssDNA) donors can produce efficient HDR with minimal off-target integration. In this study, we describe the use of ssDNA phage to efficiently and inexpensively produce long circular ssDNA (cssDNA) donors. These cssDNA donors serve as efficient HDR templates when used with Cas9 or Cas12a, with integration frequencies superior to linear ssDNA (lssDNA) donors. To evaluate the relative efficiencies of imprecise and precise repair for a suite of different Cas9 or Cas12a nucleases, we have developed a modified traffic light reporter (TLR) system (TLR-multi-Cas variant 1 [MCV1]) that permits side-by-side comparisons of different nuclease systems. We used this system to assess editing and HDR efficiencies of different nuclease platforms with distinct DNA donor types. We then extended the analysis of DNA donor types to evaluate efficiencies of fluorescent tag knockins at endogenous sites in HEK293T and K562 cells. Our results show that cssDNA templates produce efficient and robust insertion of reporter tags. Targeting efficiency is high, allowing production of biallelic integrants using cssDNA donors. cssDNA donors also outcompete lssDNA donors in template-driven repair at the target site. These data demonstrate that circular donors provide an efficient, cost-effective method to achieve knockins in mammalian cell lines.
Topics: Humans; CRISPR-Cas Systems; DNA; DNA, Single-Stranded; Endonucleases; Gene Editing; HEK293 Cells; K562 Cells
PubMed: 36070530
DOI: 10.1089/crispr.2022.0058 -
Nature Methods Oct 2021How noncoding DNA determines gene expression in different cell types is a major unsolved problem, and critical downstream applications in human genetics depend on...
How noncoding DNA determines gene expression in different cell types is a major unsolved problem, and critical downstream applications in human genetics depend on improved solutions. Here, we report substantially improved gene expression prediction accuracy from DNA sequences through the use of a deep learning architecture, called Enformer, that is able to integrate information from long-range interactions (up to 100 kb away) in the genome. This improvement yielded more accurate variant effect predictions on gene expression for both natural genetic variants and saturation mutagenesis measured by massively parallel reporter assays. Furthermore, Enformer learned to predict enhancer-promoter interactions directly from the DNA sequence competitively with methods that take direct experimental data as input. We expect that these advances will enable more effective fine-mapping of human disease associations and provide a framework to interpret cis-regulatory evolution.
Topics: Animals; Cell Line; DNA; Databases, Genetic; Epigenesis, Genetic; Gene Expression Regulation; Genome; Genomics; Humans; Machine Learning; Mice; Nerve Net; Quantitative Trait Loci
PubMed: 34608324
DOI: 10.1038/s41592-021-01252-x -
Molecular Cancer Jun 2023Chimeric Antigen Receptor (CAR) T cells are now standard of care (SOC) for some patients with B cell and plasma cell malignancies and could disrupt the therapeutic...
BACKGROUND
Chimeric Antigen Receptor (CAR) T cells are now standard of care (SOC) for some patients with B cell and plasma cell malignancies and could disrupt the therapeutic landscape of solid tumors. However, access to CAR-T cells is not adequate to meet clinical needs, in part due to high cost and long lead times for manufacturing clinical grade virus. Non-viral site directed CAR integration can be accomplished using CRISPR/Cas9 and double-stranded DNA (dsDNA) or single-stranded DNA (ssDNA) via homology-directed repair (HDR), however yields with this approach have been limiting for clinical application (dsDNA) or access to large yields sufficient to meet the manufacturing demands outside early phase clinical trials is limited (ssDNA).
METHODS
We applied homology-independent targeted insertion (HITI) or HDR using CRISPR/Cas9 and nanoplasmid DNA to insert an anti-GD2 CAR into the T cell receptor alpha constant (TRAC) locus and compared both targeted insertion strategies in our system. Next, we optimized post-HITI CRISPR EnrichMENT (CEMENT) to seamlessly integrate it into a 14-day process and compared our knock-in with viral transduced anti-GD2 CAR-T cells. Finally, we explored the off-target genomic toxicity of our genomic engineering approach.
RESULTS
Here, we show that site directed CAR integration utilizing nanoplasmid DNA delivered via HITI provides high cell yields and highly functional cells. CEMENT enriched CAR T cells to approximately 80% purity, resulting in therapeutically relevant dose ranges of 5.5 × 10-3.6 × 10 CAR + T cells. CRISPR knock-in CAR-T cells were functionally comparable with viral transduced anti-GD2 CAR-T cells and did not show any evidence of off-target genomic toxicity.
CONCLUSIONS
Our work provides a novel platform to perform guided CAR insertion into primary human T-cells using nanoplasmid DNA and holds the potential to increase access to CAR-T cell therapies.
Topics: Humans; T-Lymphocytes; DNA; Recombinational DNA Repair; Immunotherapy, Adoptive
PubMed: 37365642
DOI: 10.1186/s12943-023-01799-7 -
Gut Mar 2022Infection by HBV is the main risk factor for hepatocellular carcinoma (HCC) worldwide. HBV directly drives carcinogenesis through integrations in the human genome. This...
OBJECTIVE
Infection by HBV is the main risk factor for hepatocellular carcinoma (HCC) worldwide. HBV directly drives carcinogenesis through integrations in the human genome. This study aimed to precisely characterise HBV integrations, in relation with viral and host genomics and clinical features.
DESIGN
A novel pipeline was set up to perform viral capture on tumours and non-tumour liver tissues from a French cohort of 177 patients mainly of European and African origins. Clonality of each integration event was determined with the localisation, orientation and content of the integrated sequence. In three selected tumours, complex integrations were reconstructed using long-read sequencing or Bionano whole genome mapping.
RESULTS
Replicating HBV DNA was more frequently detected in non-tumour tissues and associated with a higher number of non-clonal integrations. In HCC, clonal selection of HBV integrations was related to two different mechanisms involved in carcinogenesis. First, integration of viral enhancer nearby a cancer-driver gene may lead to a strong overexpression of oncogenes. Second, we identified frequent chromosome rearrangements at HBV integration sites leading to cancer-driver genes () alterations at distance. Moreover, HBV integrations have direct clinical implications as HCC with a high number of insertions develop in young patients and have a poor prognosis.
CONCLUSION
Deep characterisation of HBV integrations in liver tissues highlights new HBV-associated driver mechanisms involved in hepatocarcinogenesis. HBV integrations have multiple direct oncogenic consequences that remain an important challenge for the follow-up of HBV-infected patients.
Topics: Carcinogenesis; Carcinoma, Hepatocellular; Case-Control Studies; Cohort Studies; DNA, Viral; Female; Hepatitis B virus; Humans; Liver Neoplasms; Male; Virus Integration
PubMed: 33563643
DOI: 10.1136/gutjnl-2020-323153 -
Frontiers in Cellular and Infection... 2022The incidence of cancer is high worldwide, and biological factors such as viruses and bacteria play an important role in the occurrence of cancer. , , and other... (Review)
Review
The incidence of cancer is high worldwide, and biological factors such as viruses and bacteria play an important role in the occurrence of cancer. , , and other organisms have been identified as carcinogens. Cancer is a disease driven by the accumulation of genome changes. Viruses can directly cause cancer by changing the genetic composition of the human body, such as cervical cancer caused by DNA integration and liver cancer caused by DNA integration. Recently, bacterial DNA has been found around cancers such as pancreatic cancer, breast cancer and colorectal cancer, and the idea that bacterial genes can also be integrated into the human genome has become a hot topic. In the present paper, we reviewed the latest phenomenon and specific integration mechanism of bacterial DNA into the human genome. Based on these findings, we also suggest three sources of bacterial DNA in cancers: bacterial DNA around human tissues, free bacterial DNA in bacteremia or sepsis, and endogenous bacterial DNA in the human genome. Clarifying the theory that bacterial DNA integrates into the human genome can provide a new perspective for cancer prevention and treatment.
Topics: Female; Humans; DNA, Bacterial; Virus Integration; Carcinogenesis; Uterine Cervical Neoplasms; Genome, Human; DNA, Viral
PubMed: 36310856
DOI: 10.3389/fcimb.2022.996778 -
International Journal of Molecular... Aug 2021species transfer DNA (T-DNA) to plant cells where it may integrate into plant chromosomes. The process of integration is thought to involve invasion and ligation of... (Review)
Review
species transfer DNA (T-DNA) to plant cells where it may integrate into plant chromosomes. The process of integration is thought to involve invasion and ligation of T-DNA, or its copying, into nicks or breaks in the host genome. Integrated T-DNA often contains, at its junctions with plant DNA, deletions of T-DNA or plant DNA, filler DNA, and/or microhomology between T-DNA and plant DNA pre-integration sites. T-DNA integration is also often associated with major plant genome rearrangements, including inversions and translocations. These characteristics are similar to those often found after repair of DNA breaks, and thus DNA repair mechanisms have frequently been invoked to explain the mechanism of T-DNA integration. However, the involvement of specific plant DNA repair proteins and proteins in integration remains controversial, with numerous contradictory results reported in the literature. In this review I discuss this literature and comment on many of these studies. I conclude that either multiple known DNA repair pathways can be used for integration, or that some yet unknown pathway must exist to facilitate T-DNA integration into the plant genome.
Topics: Agrobacterium; Chromosomes, Plant; DNA Repair; DNA, Bacterial; DNA, Plant; Plants; Transformation, Genetic
PubMed: 34445162
DOI: 10.3390/ijms22168458 -
Bioscience Reports Mar 2023Prokaryotes use the adaptive immunity mediated via the Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR associated (CRISPR-Cas) system for protection... (Review)
Review
Prokaryotes use the adaptive immunity mediated via the Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR associated (CRISPR-Cas) system for protection against invading elements such as phages and plasmids. The immunity is achieved by capturing small DNA fragments or spacers from foreign nucleic acids (protospacers) and integrating them into the host CRISPR locus. This step of CRISPR-Cas immunity called 'naïve CRISPR adaptation' requires the conserved Cas1-Cas2 complex and is often supported by variable host proteins that assist in spacer processing and integration. Bacteria that have acquired new spacers become immune to the same invading elements when reinfected. CRISPR-Cas immunity can also be updated by integrating new spacers from the same invading elements, a process called 'primed adaptation'. Only properly selected and integrated spacers are functional in the next steps of CRISPR immunity when their processed transcripts are used for RNA-guided target recognition and interference (target degradation). Capturing, trimming, and integrating new spacers in the correct orientation are universal steps of adaptation to all CRISPR-Cas systems, but some details are CRISPR-Cas type-specific and species-specific. In this review, we provide an overview of the mechanisms of CRISPR-Cas class 1 type I-E adaptation in Escherichia coli as a general model for adaptation processes (DNA capture and integration) that have been studied in detail. We focus on the role of host non-Cas proteins involved in adaptation, particularly on the role of homologous recombination.
Topics: Escherichia coli; CRISPR-Cas Systems; Plasmids; Escherichia coli Proteins; DNA
PubMed: 36809461
DOI: 10.1042/BSR20221198 -
Molecular Microbiology May 2024The site-specific recombination pathway of bacteriophage λ encompasses isoenergetic but highly directional and tightly regulated integrative and excisive reactions that... (Review)
Review
The site-specific recombination pathway of bacteriophage λ encompasses isoenergetic but highly directional and tightly regulated integrative and excisive reactions that integrate and excise the vial chromosome into and out of the bacterial chromosome. The reactions require 240 bp of phage DNA and 21 bp of bacterial DNA comprising 16 protein binding sites that are differentially used in each pathway by the phage-encoded Int and Xis proteins and the host-encoded integration host factor and factor for inversion stimulation proteins. Structures of higher-order protein-DNA complexes of the four-way Holliday junction recombination intermediates provided clarifying insights into the mechanisms, directionality, and regulation of these two pathways, which are tightly linked to the physiology of the bacterial host cell. Here we review our current understanding of the mechanisms responsible for regulating and executing λ site-specific recombination, with an emphasis on key studies completed over the last decade.
Topics: Bacteriophage lambda; Recombination, Genetic; DNA, Viral; Viral Proteins; DNA, Bacterial; Binding Sites; Integration Host Factors
PubMed: 38372210
DOI: 10.1111/mmi.15241 -
Science Advances Jul 2023Transcription factor (TF) IIIC recruits RNA polymerase (Pol) III to most of its target genes. Recognition of intragenic A- and B-box motifs in transfer RNA (tRNA) genes...
Transcription factor (TF) IIIC recruits RNA polymerase (Pol) III to most of its target genes. Recognition of intragenic A- and B-box motifs in transfer RNA (tRNA) genes by TFIIIC modules τA and τB is the first critical step for tRNA synthesis but is mechanistically poorly understood. Here, we report cryo-electron microscopy structures of the six-subunit human TFIIIC complex unbound and bound to a tRNA gene. The τB module recognizes the B-box via DNA shape and sequence readout through the assembly of multiple winged-helix domains. TFIIIC220 forms an integral part of both τA and τB connecting the two subcomplexes via a ~550-amino acid residue flexible linker. Our data provide a structural mechanism by which high-affinity B-box recognition anchors TFIIIC to promoter DNA and permits scanning for low-affinity A-boxes and TFIIIB for Pol III activation.
Topics: Humans; Cryoelectron Microscopy; Transcription Factors, TFIII; Transcription, Genetic; DNA; RNA, Transfer
PubMed: 37418517
DOI: 10.1126/sciadv.adh2019