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Luo H, Tang L, Zeng M, Yin R, Ding P, Luo L, Li M. BertSNR: an interpretable deep learning framework for single-nucleotide resolution identification of transcription factor binding sites based on DNA language model. Bioinformatics 2024; 40:btae461. [PMID: 39107889 PMCID: PMC11310455 DOI: 10.1093/bioinformatics/btae461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/07/2024] [Indexed: 08/10/2024] Open
Abstract
MOTIVATION Transcription factors are pivotal in the regulation of gene expression, and accurate identification of transcription factor binding sites (TFBSs) at high resolution is crucial for understanding the mechanisms underlying gene regulation. The task of identifying TFBSs from DNA sequences is a significant challenge in the field of computational biology today. To address this challenge, a variety of computational approaches have been developed. However, these methods face limitations in their ability to achieve high-resolution identification and often lack interpretability. RESULTS We propose BertSNR, an interpretable deep learning framework for identifying TFBSs at single-nucleotide resolution. BertSNR integrates sequence-level and token-level information by multi-task learning based on pre-trained DNA language models. Benchmarking comparisons show that our BertSNR outperforms the existing state-of-the-art methods in TFBS predictions. Importantly, we enhanced the interpretability of the model through attentional weight visualization and motif analysis, and discovered the subtle relationship between attention weight and motif. Moreover, BertSNR effectively identifies TFBSs in promoter regions, facilitating the study of intricate gene regulation. AVAILABILITY AND IMPLEMENTATION The BertSNR source code can be found at https://github.com/lhy0322/BertSNR.
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Affiliation(s)
- Hanyu Luo
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, China
- School of Computer Science, University of South China, Hengyang, Hunan 421001, China
| | - Li Tang
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, China
| | - Min Zeng
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, China
| | - Rui Yin
- Department of Health Outcome and Biomedical Informatics, University of Florida, Gainesville, FL 32611, United States
| | - Pingjian Ding
- Center for Artificial Intelligence in Drug Discovery, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, United States
| | - Lingyun Luo
- School of Computer Science, University of South China, Hengyang, Hunan 421001, China
| | - Min Li
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, China
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Chen Y, Li J, Niu K, Peng Y, Song Q, Feng Q. G-quadruplex is involved in the regulation of BmSGF1 expression in the Silkworm, Bombyx mori. INSECT SCIENCE 2024. [PMID: 38439572 DOI: 10.1111/1744-7917.13334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/19/2023] [Accepted: 12/28/2023] [Indexed: 03/06/2024]
Abstract
Advanced DNA structures, such as the G-quadruplex (G4) and the i-motif, are widely but not randomly present in the genomes of many organisms. A G4 structure was identified in the promoter of the silk gland factor-1 gene (SGF1), which is the main regulatory gene for silk production in Bombyx mori. In this study, a BmSGF1 G4-/- homozygous mutant was generated with the G4 sequence knocked out. The promoter activity of BmSGF1 was lowered in the BmSGF1 G4-/- mutant. Pyridostatin (PDS) stabilized the G4 structure and increased the promoter activity of BmSGF1, whereas anti-sense oligonucleotide (ASO) complementary to the G4 sequence suppressed the promoter activity of BmSGF1. Compared with wild-type larvae, the deletion of the BmSGF1 G4 structure decreased both the expression of BmSGF1 and the fibroin heavy chain gene BmFib-H in the posterior silk gland and the weight of the cocoons. Overall, these results suggest that the promoter G4 structure of BmSGF1 participates in the transcription regulation of the BmSGF1 gene in the silkworm.
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Affiliation(s)
- Yanfei Chen
- School of Biology and Agriculture, Shaoguan University, Shaoguan, China
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jin Li
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Kangkang Niu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yuling Peng
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Qisheng Song
- Division of Plant Science & Technology, University of Missouri, Columbia, Missouri, USA
| | - Qili Feng
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
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Li Y, He Z, Li Z, Lu Y, Xun Q, Xiang L, Zhang M. G-quadruplex formation within the promoter region of HSPB2 and its effect on transcription. Heliyon 2024; 10:e24396. [PMID: 38298658 PMCID: PMC10827768 DOI: 10.1016/j.heliyon.2024.e24396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 02/02/2024] Open
Abstract
G-rich sequences in DNA and RNA tend to fold into stable secondary structures called G-quadruplexes. Except for the telomere region, G-quadruplex-forming sequences are widely present in gene promoters and have been implicated in transcriptional regulation. Single nucleotide polymorphisms (SNPs) can disrupt the G-quadruplex structure of a gene promoter. In this study, we confirmed the promoter of HSPB2, a cancer-related gene, tends to form an unusual DNA secondary structure. The dual luciferase assay revealed that the SNP rs2234704 in the HSPB2 promoter with a single G > A mutation increased the transcriptional activity of the HSPB2 promoter. Circular dichroism and native PAGE revealed that the G-rich strand of the DNA in this promoter preferred to form a parallel G-quadruplex, which could be destabilized by the SNP rs2234704 (G > A) mutation. Furthermore, we found that the SNP rs2234704 (G > A) greatly increased and influenced the overexpression of HSPB2 in breast cancer samples. These results suggest SNP rs2234704 (G > A) may play a role in the occurrence of breast cancer by destroying the G-quadruplex structure and promoting the expression of HSPB2.
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Affiliation(s)
- Ying Li
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jing Medical University, Jining, Shandong, 272000, PR China
| | - Zhichao He
- Medical Equipment Department, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272000, PR China
| | - Zewu Li
- Department of Reproductive Medicine, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272000, PR China
| | - Yan Lu
- Clinical Laboratory Medicine Department, Jining No.1 People's Hospital, Jining, Shandong, 272000, PR China
| | - Qingqing Xun
- School of Clinical Medicine, Jining Medical University, Jining, Shandong, 272000, PR China
| | - Longquan Xiang
- Department of Pathology, Jining No.1 People's Hospital, Jining, Shandong, 272000, PR China
| | - Miaomiao Zhang
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jing Medical University, Jining, Shandong, 272000, PR China
- Department of Pathology, Jining No.1 People's Hospital, Jining, Shandong, 272000, PR China
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Romano F, Di Porzio A, Iaccarino N, Riccardi G, Di Lorenzo R, Laneri S, Pagano B, Amato J, Randazzo A. G-quadruplexes in cancer-related gene promoters: from identification to therapeutic targeting. Expert Opin Ther Pat 2023; 33:745-773. [PMID: 37855085 DOI: 10.1080/13543776.2023.2271168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
INTRODUCTION Guanine-rich DNA sequences can fold into four-stranded noncanonical secondary structures called G-quadruplexes (G4s) which are widely distributed in functional regions of the human genome, such as telomeres and gene promoter regions. Compelling evidence suggests their involvement in key genome functions such as gene expression and genome stability. Notably, the abundance of G4-forming sequences near transcription start sites suggests their potential involvement in regulating oncogenes. AREAS COVERED This review provides an overview of current knowledge on G4s in human oncogene promoters. The most representative G4-binding ligands have also been documented. The objective of this work is to present a comprehensive overview of the most promising targets for the development of novel and highly specific anticancer drugs capable of selectively impacting the expression of individual or a limited number of genes. EXPERT OPINION Modulation of G4 formation by specific ligands has been proposed as a powerful new tool to treat cancer through the control of oncogene expression. Actually, most of G4-binding small molecules seem to simultaneously target a range of gene promoter G4s, potentially influencing several critical driver genes in cancer, thus producing significant therapeutic benefits.
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Affiliation(s)
- Francesca Romano
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Anna Di Porzio
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Nunzia Iaccarino
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | | | | | - Sonia Laneri
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Bruno Pagano
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Jussara Amato
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Antonio Randazzo
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
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Li G, Su G, Wang Y, Wang W, Shi J, Li D, Sui G. Integrative genomic analyses of promoter G-quadruplexes reveal their selective constraint and association with gene activation. Commun Biol 2023; 6:625. [PMID: 37301913 PMCID: PMC10257653 DOI: 10.1038/s42003-023-05015-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 06/05/2023] [Indexed: 06/12/2023] Open
Abstract
G-quadruplexes (G4s) regulate DNA replication and gene transcription, and are enriched in promoters without fully appreciated functional relevance. Here we show high selection pressure on putative G4 (pG4) forming sequences in promoters through investigating genetic and genomic data. Analyses of 76,156 whole-genome sequences reveal that G-tracts and connecting loops in promoter pG4s display lower or higher allele frequencies, respectively, than pG4-flanking regions, and central guanines (Gs) in G-tracts show higher selection pressure than other Gs. Additionally, pG4-promoters produce over 72.4% of transcripts, and promoter G4-containing genes are expressed at relatively high levels. Most genes repressed by TMPyP4, a G4-ligand, regulate epigenetic processes, and promoter G4s are enriched with gene activation histone marks, chromatin remodeler and transcription factor binding sites. Consistently, cis-expression quantitative trait loci (cis-eQTLs) are enriched in promoter pG4s and their G-tracts. Overall, our study demonstrates selective constraint of promoter G4s and reinforces their stimulative role in gene expression.
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Affiliation(s)
- Guangyue Li
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Gongbo Su
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Yunxuan Wang
- Department of Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, 150081, China
| | - Wenmeng Wang
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Jinming Shi
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Dangdang Li
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Guangchao Sui
- College of Life Science, Northeast Forestry University, Harbin, 150040, China.
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Liu M, Yu K, Lian W, Zhou N, Wu C, Bao J. G-Quadruplex Structures as a "Switch" Regulate ATF4 Expression in Ferroptotic HepG2 Cells. ACS Chem Biol 2023; 18:273-284. [PMID: 36722101 DOI: 10.1021/acschembio.2c00615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
G-quadruplex (G4) is a noncanonical structure folded in a widespread manner by guanine-rich tandem repeated sequences. As a key response factor, activating transcription factor 4 (ATF4) has dual functions in managing iron-dependent ferroptosis by regulating amino acid synthesis and antioxidant-related gene expression. In our study, the activity of ATF4 expression was elevated in HepG2 cells induced by erastin. Based on preliminary bioinformatics analyses, the G-tract region, named WT, had high potential to form G4, and it was found that PDS could markedly weaken the increase of ATF4 expression by reducing the sensitivity of HepG2 cells toward erastin. In circular dichroism spectra, WT oligonucleotides showed characteristic molar ellipticity at specific wavelengths of parallel G4 structures, while corresponding single-base mutants possessed a weaker ability to form G4, which were consistent with immunostaining results. In addition, endogenous G4 formed by the WT motif was significantly destroyed in HepG2 cells treated with erastin. After being transfected with WT oligonucleotides, the levels of ATF4 mRNA decreased significantly regardless of being treated with erastin or not. Meanwhile, mutations of G-tracts could advantageously impact the luciferase expression downstream of an ATF4 promoter in reporter assays, manifesting that the decrease of endogenous G4 in the ATF4 promoter was positively associated with the expression enhanced by erastin in HepG2 cells.
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Affiliation(s)
- Miaomiao Liu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610065, China
| | - Kangkang Yu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610065, China
| | - Weishao Lian
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610065, China
| | - Nan Zhou
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610065, China
| | - Chuanfang Wu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610065, China
| | - Jinku Bao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610065, China
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High-throughput techniques enable advances in the roles of DNA and RNA secondary structures in transcriptional and post-transcriptional gene regulation. Genome Biol 2022; 23:159. [PMID: 35851062 PMCID: PMC9290270 DOI: 10.1186/s13059-022-02727-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 07/07/2022] [Indexed: 12/27/2022] Open
Abstract
The most stable structure of DNA is the canonical right-handed double helix termed B DNA. However, certain environments and sequence motifs favor alternative conformations, termed non-canonical secondary structures. The roles of DNA and RNA secondary structures in transcriptional regulation remain incompletely understood. However, advances in high-throughput assays have enabled genome wide characterization of some secondary structures. Here, we describe their regulatory functions in promoters and 3’UTRs, providing insights into key mechanisms through which they regulate gene expression. We discuss their implication in human disease, and how advances in molecular technologies and emerging high-throughput experimental methods could provide additional insights.
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Research Progress on G-Quadruplexes in Human Telomeres and Human Telomerase Reverse Transcriptase (hTERT) Promoter. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:2905663. [PMID: 35707279 PMCID: PMC9192192 DOI: 10.1155/2022/2905663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/19/2022] [Indexed: 12/21/2022]
Abstract
The upregulation telomerase activity is observed in over 85-90% of human cancers and provides an attractive target for cancer therapies. The high guanine content in the telomere DNA sequences and the hTERT promoter can form G-quadruplexes (G4s). Small molecules targeting G4s in telomeres and hTERT promoter could stabilize the G4s and inhibit hTERT expression and telomere extension. Several G4 ligands have shown inhibitory effects in cancer cells and xenograft mouse models, indicating these ligands have a potential for cancer therapies. The current review article describes the concept of the telomere, telomerase, and G4s. Moreover, the regulation of telomerase and G4s in telomeres and hTERT promoter is discussed as well. The summary of the small molecules targeting G4s in telomeric DNA sequences and the hTERT promoter will also be shown.
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Marilovtseva EV, Studitsky VM. Guanine Quadruplexes in Cell Nucleus Metabolism. Mol Biol 2021. [DOI: 10.1134/s0026893321040075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Hori D, Yum JH, Sugiyama H, Park S. Tropylium Derivatives as New Entrants that Sense Quadruplex Structures. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20210123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Daisuke Hori
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Ji Hye Yum
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Yoshida-ushinomiyacho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Soyoung Park
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
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Komůrková D, Svobodová Kovaříková A, Bártová E. G-Quadruplex Structures Colocalize with Transcription Factories and Nuclear Speckles Surrounded by Acetylated and Dimethylated Histones H3. Int J Mol Sci 2021; 22:1995. [PMID: 33671470 PMCID: PMC7922289 DOI: 10.3390/ijms22041995] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/11/2021] [Accepted: 02/15/2021] [Indexed: 12/26/2022] Open
Abstract
G-quadruplexes (G4s) are four-stranded helical structures that regulate several nuclear processes, including gene expression and telomere maintenance. We observed that G4s are located in GC-rich (euchromatin) regions and outside the fibrillarin-positive compartment of nucleoli. Genomic regions around G4s were preferentially H3K9 acetylated and H3K9 dimethylated, but H3K9me3 rarely decorated G4 structures. We additionally observed the variability in the number of G4s in selected human and mouse cell lines. We found the highest number of G4s in human embryonic stem cells. We observed the highest degree of colocalization between G4s and transcription factories, positive on the phosphorylated form of RNA polymerase II (RNAP II). Similarly, a high colocalization rate was between G4s and nuclear speckles, enriched in pre-mRNA splicing factor SC-35. PML bodies, the replication protein SMD1, and Cajal bodies colocalized with G4s to a lesser extent. Thus, G4 structures seem to appear mainly in nuclear compartments transcribed via RNAP II, and pre-mRNA is spliced via the SC-35 protein. However, α-amanitin, an inhibitor of RNAP II, did not affect colocalization between G4s and transcription factories as well as G4s and SC-35-positive domains. In addition, irradiation by γ-rays did not change a mutual link between G4s and DNA repair proteins (G4s/γH2AX, G4s/53BP1, and G4s/MDC1), accumulated into DNA damage foci. Described characteristics of G4s seem to be the manifestation of pronounced G4s stability that is likely maintained not only via a high-order organization of these structures but also by a specific histone signature, including H3K9me2, responsible for chromatin compaction.
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Affiliation(s)
| | | | - Eva Bártová
- Institute of Biophysics of the Czech Academy of Sciences, Department of Molecular Cytology and Cytometry, Královopolská 135, 612 65 Brno, Czech Republic; (D.K.); (A.S.K.)
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Bednářová K, Vorlíčková M, Renčiuk D. Diversity of Parallel Guanine Quadruplexes Induced by Guanine Substitutions. Int J Mol Sci 2020; 21:E6123. [PMID: 32854410 PMCID: PMC7503932 DOI: 10.3390/ijms21176123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/21/2020] [Accepted: 08/22/2020] [Indexed: 01/17/2023] Open
Abstract
Recently, we reported an inhibitory effect of guanine substitutions on the conformational switch from antiparallel to parallel quadruplexes (G4) induced by dehydrating agents. As a possible cause, we proposed a difference in the sensitivity of parallel and antiparallel quadruplexes to the guanine substitutions in the resulting thermodynamic stability. Reports on the influence of guanine substitutions on the biophysical properties of intramolecular parallel quadruplexes are rare. Moreover, such reports are often complicated by the multimerisation tendencies of parallel quadruplexes. To address this incomplete knowledge, we employed circular dichroism spectroscopy (CD), both as stopped-flow-assisted fast kinetics measurements and end-point measurements, accompanied by thermodynamic analyses, based on UV absorption melting profiles, and electrophoretic methods. We showed that parallel quadruplexes are significantly more sensitive towards guanine substitutions than antiparallel ones. Furthermore, guanine-substituted variants, which in principle might correspond to native genomic sequences, distinctly differ in their biophysical properties, indicating that the four guanines in each tetrad of parallel quadruplexes are not equal. In addition, we were able to distinguish by CD an intramolecular G4 from intermolecular ones resulting from multimerisation mediated by terminal tetrad association, but not from intermolecular G4s formed due to inter-strand Hoogsteen hydrogen bond formation. In conclusion, our study indicates significant variability in parallel quadruplex structures, otherwise disregarded without detailed experimental analysis.
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Affiliation(s)
| | | | - Daniel Renčiuk
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic; (K.B.); (M.V.)
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Li M, Alsager JS, Wang Z, Cheng L, Shan B. Epigenetic upregulation of HOXC10 in non-small lung cancer cells. Aging (Albany NY) 2020; 12:16921-16935. [PMID: 32687064 PMCID: PMC7521540 DOI: 10.18632/aging.103597] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/13/2020] [Indexed: 01/24/2023]
Abstract
The homeobox genes (HOX) have emerged as a new family of master regulators of development and cancer. In the current study, we examined the expression and function of HOXC10 in human non-small cell lung cancer (NSCLC). We observed increased expression of HOXC10 in the more aggressive human NSCLC cell line NCI-H23 over the well differentiated A549 cells. To elucidate the expression and function of HOXC10 in NSCLC cells, we employed RT-PCR, immunoblotting, methylation-specific PCR, apoptosis assays, and xenograft model. Overexpression of HOXC10 in A549 cells conveyed increased proliferation, reduced apoptosis, and accelerated tumor growth when transplanted into nude mice. In contrast, siRNA-mediated knockdown of HOXC10 in NCI-H23 cells reduced proliferation and increased apoptosis. Our results further indicated that hypomethylation of the CpG island in the HOXC10 promoter was critical to elevated expression of HOXC10 in NSCLC cells. Lastly, we identified a G-quadruplex in the HOXC10 promoter and its G-quadruplex formation was required for elevated expression of HOXC10 in NSCLC cells. Moreover our results suggest that disruption of G-quadruplex formation can silence HOXC10 expression in NSCLC cells. In summary, we report HOXC10 as a novel tumor promoting oncogene in NSCLC cells.
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Affiliation(s)
- Miao Li
- Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - John Simon Alsager
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99202, USA
| | - Zhaokai Wang
- The First Clinical Department of China Medical University, Shenyang, China
| | - Lin Cheng
- The First Clinical Department of China Medical University, Shenyang, China
| | - Bin Shan
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99202, USA
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The SNAIL1 promoter contains G-quadruplex structures regulating its gene expression and DNA replication. Exp Cell Res 2020; 394:112158. [PMID: 32610184 DOI: 10.1016/j.yexcr.2020.112158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 01/17/2023]
Abstract
SNAIL1 is a key regulator of epithelial-mesenchymal transition (EMT) and its expression is associated with tumor progression and poor clinical prognosis of cancer patients. Compared to the studies of SNAIL1 stability and its transcriptional regulation, very limited knowledge is available regarding effective approaches to directly target SNAIL1. In this study, we revealed the potential regulation of SNAIL1 gene expression by G-quadruplex structures in its promoter. We first revealed that the negative strand of the SNAIL1 promoter contained a multi-G-tract region with high potential of forming G-quadruplex structures. In circular dichroism studies, the oligonucleotide based on this region showed characteristic molar ellipticity at specific wavelengths of G-quadruplex structures. We also utilized native polyacrylamide gel electrophoresis, gel-shift assays, immunofluorescent staining, dimethyl sulfate footprinting and chromatin immunoprecipitation studies to verify the G-quadruplex structures formed by the oligonucleotide. In reporter assays, disruption of G-quadruplex potential increased SNAIL1 promoter-mediated transcription, suggesting that G-quadruplexes played a negative role in SNAIL1 expression. In a DNA synthesis study, we detected G-quadruplex-mediated retardation in the SNAIL1 promoter replication. Consistently, we discovered that the G-quadruplex region of the SNAIL1 promoter is highly enriched for mutations, implicating the clinical relevance of G-quadruplexes to the altered SNAIL1 expression in cancer cells.
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Zhou N, Zhang XB, Chen C, Chen XY, Kang B, He JQ, Gong GZ, Wang YJ, Zhou YW. Cellular context- and protein level-dependent interaction of pluripotency factor OCT4A with multiple octamer motifs of the same target gene. Life Sci 2020; 248:117461. [PMID: 32097665 DOI: 10.1016/j.lfs.2020.117461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/20/2020] [Accepted: 02/20/2020] [Indexed: 10/24/2022]
Abstract
AIMS To compare how OCT4A proteins interact with and regulate multiple OCT4A-octamer motifs (OMs) in different regions of the FOS gene expressed in somatic cancer cells versus pluripotent stem cells. MATERIALS AND METHODS Two FOS reporter gene systems harboring predicted OMs or their mutational counterparts were introduced into HeLa and NCCIT cells with varying OCT4A protein levels. The transcription of dsGFP reflecting FOS expression was quantitated by RT-qPCR, the OCT4A-OMs binding and the correlation between OCT4A and FOS transcription was determined by ChIP-PCR and RNA-Seq, respectively. KEY FINDINGS In NCCIT cells, abundant OCT4A proteins bound to and inhibited OM1 and OM2 at the promoter of the FOS gene. RA-induced OCT4A down-regulation transiently increased FOS transcription. In contrast, in HeLa cells that contain much lower levels of endogenous OCT4A proteins, OCT4A primarily bound to and activate OM1 thereby promoting FOS transcription. OCT4A KO significantly reduced FOS expression. Ectopically introduced OCT4A, at its leaked or induced expression level, promoted FOS transcription by binding to OM2/OM3 or OM1/OM3, respectively. Thus, the interaction of OCT4A proteins with different OMs is cellular context- and protein level-dependent, and such complicated OCT4A binding mode can only be reflected by a dsGFP-based reporter harboring the full-length FOS gene but not by that merely having the FOS promoter. SIGNIFICANCE Our findings unravel an additional layer of regulatory mechanisms that account for the cellular context- and dose-related versatile functions of OCT4A protein, and further underscore the importance of precise modulation of OCT4A in the regenerative medicine and anticancer therapies.
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Affiliation(s)
- Ning Zhou
- Department of Infectious Diseases, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Xiao-Bing Zhang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Cheng Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Xin-Yu Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Bo Kang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Jian-Qin He
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Guo-Zhong Gong
- Department of Infectious Diseases, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Ying-Jie Wang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Yan-Wen Zhou
- Department of Infectious Diseases, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China.
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16
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Yan T, Zhao B, Wu Q, Wang W, Shi J, Li D, Stovall DB, Sui G. Characterization of G-quadruplex formation in the ARID1A promoter. Int J Biol Macromol 2020; 147:750-761. [PMID: 31982538 DOI: 10.1016/j.ijbiomac.2020.01.210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/21/2020] [Accepted: 01/21/2020] [Indexed: 12/22/2022]
Abstract
As a member of the SWI/SNF family, ARID1A plays an essential role in modulating chromatin structure and gene expression. The tumor suppressive function of ARID1A has been well-defined and its downregulation in cancers is attributed to genomic deletion, DNA methylation and microRNA-mediated inhibition. In this study, we demonstrated that the negative strand of a C-rich region in the upstream vicinity of the human ARID1A transcription start site could form G-quadruplexes. Synthesized oligonucleotides based on the sequence of this region exhibited molar ellipticity at specific wavelengths characteristic of G-quadruplex structures in circular dichroism analyses. The formation of G-quadruplexes by these oligonucleotides were also proved by native polyacrylamide gel electrophoresis, DNA synthesis block assays, immunofluorescent staining and dimethyl sulfate footprinting studies. In reporter assays, mutations of the G-quadruplex forming sequence reduced ARID1A promoter-mediated transcription. Transfection of the oligonucleotide with the full length of G-quadruplex motif region, but not its partial sequences or the mutants, could both promote endogenous ARID1A expression and reduce cell proliferation.
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Affiliation(s)
- Ting Yan
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Bo Zhao
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Qiong Wu
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Wenmeng Wang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Jinming Shi
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Dangdang Li
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Daniel B Stovall
- College of Arts and Sciences, Winthrop University, Rock Hill, SC 29733, United States
| | - Guangchao Sui
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China.
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17
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Pradhan P, Srivastava A, Singh J, Biswas B, Saini A, Siddique I, Kumari P, Khan MA, Mishra A, Yadav PK, Kumar S, Bhavesh NS, Venkatraman P, Vivekanandan P, Kundu B. Prion protein transcription is auto-regulated through dynamic interactions with G-quadruplex motifs in its own promoter. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194479. [PMID: 31931179 DOI: 10.1016/j.bbagrm.2019.194479] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 12/26/2019] [Accepted: 12/28/2019] [Indexed: 11/19/2022]
Abstract
Cellular prion protein (PrP) misfolds into an aberrant and infectious scrapie form (PrPSc) that lead to fatal transmissible spongiform encephalopathies (TSEs). Association of prions with G-quadruplex (GQ) forming nucleic acid motifs has been reported, but implications of these interactions remain elusive. Herein, we show that the promoter region of the human prion gene (PRNP) contains two putative GQ motifs (Q1 and Q2) that assume stable, hybrid, intra-molecular quadruplex structures and bind with high affinity to PrP. Here, we investigate the ability of PrP to bind to the quadruplexes in its own promoter. We used a battery of techniques including SPR, NMR, CD, MD simulations and cell culture-based reporter assays. Our results show that PrP auto-regulates its expression by binding and resolving the GQs present in its own promoter. Furthermore, we map this resolvase-like activity to the N-terminal region (residues 23-89) of PrP. Our findings highlight a positive transcriptional-translational feedback regulation of the PRNP gene by PrP through dynamic unwinding of GQs in its promoter. Taken together, our results shed light on a yet unknown mechanism of regulation of the PRNP gene. This work provides the necessary framework for a plethora of studies on understanding the regulation of PrP levels and its implications in prion pathogenesis.
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Affiliation(s)
- Prashant Pradhan
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India
| | - Ankit Srivastava
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India
| | - Jasdeep Singh
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India
| | - Banhi Biswas
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India
| | - Akanksha Saini
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India
| | - Ibrar Siddique
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Pooja Kumari
- Transcription Regulation group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Mohd Asim Khan
- Department of Biochemistry, University of Delhi, South Campus, New Delhi 110021, India
| | - Akhilesh Mishra
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India
| | - Pramod Kumar Yadav
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India
| | - Shivani Kumar
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India
| | - Neel Sarovar Bhavesh
- Transcription Regulation group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Prasanna Venkatraman
- Tata Memorial Centre, Advanced Centre for Treatment, Research and Education in Cancer, Kharghar, Navi Mumbai 410210, India; Homi Bhabha National Institute, 2nd floor, BARC Training School Complex, Anushaktinagar, Mumbai, Maharashtra 400094, India
| | - Perumal Vivekanandan
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India.
| | - Bishwajit Kundu
- Kusuma School of Biological Sciences, IIT Delhi, Hauz Khas, New Delhi 110016, India.
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18
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Ghanei Z, Jamshidizad A, Joupari MD, Shamsara M. Isolation and characterization of breast cancer stem cell-like phenotype by Oct4 promoter-mediated activity. J Cell Physiol 2020; 235:7840-7848. [PMID: 31904128 DOI: 10.1002/jcp.29437] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 12/23/2019] [Indexed: 12/18/2022]
Abstract
Cancer stem cells (CSCs) are a small subset of cancer cells responsible for self-renewal activity, drug resistance, and tumor recurrence. CSCs have been derived from diverse tumors and cell lines. The expression of stemness markers has been identified in CSCs. Oct4 is a well-established transcription factor expressed in stem cells and CSCs. In this study, we isolated and characterized breast CSC-like cells from murine MC4-L2 cells by Oct4 promoter-mediated activity. The MC4-L2 cells were electroporated by a plasmid expressing puromycin resistance (PuroR ) gene from the Oct4 promoter and then selected by puromycin. The isolated cells were named as the MC4-L2puro cells and characterized for CSCs properties. Immunostaining indicated CD44high and CD24high phenotype for the MC4-L2 and MC4-L2puro cells. The enhanced expression of stem cell markers was detected in the puromycin-selected cells compared with the parental cells. Moreover, the isolated cells only grew up in sphere-formed shape in low attachment plates. Serial dilution transplantation in syngeneic mouse models showed increased tumorigenicity of the MC4-L2puro cells, as they induced new tumors when injected into the mammary fat pad as few as 104 cells. In conclusion, we designed a novel genetic construct, which allows the isolation of Oct4-positive cells in a cancer population by a simple selection step in a puromycin-containing medium. Transfection of this construct into the MC4-L2 cells resulted in growing a subpopulation of cells having tumor-initiating cell characteristics. To the best of our knowledge, this is the first report on the isolation of CSC-like cells from the mouse breast cancer MC4-L2 cells.
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Affiliation(s)
- Zahra Ghanei
- Department of Animal Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Abbas Jamshidizad
- Department of Animal Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Morteza Daliri Joupari
- Department of Animal Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Mehdi Shamsara
- Department of Animal Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
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19
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Yett A, Lin LY, Beseiso D, Miao J, Yatsunyk LA. N-methyl mesoporphyrin IX as a highly selective light-up probe for G-quadruplex DNA. J PORPHYR PHTHALOCYA 2019; 23:1195-1215. [PMID: 34385812 PMCID: PMC8356643 DOI: 10.1142/s1088424619300179] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
N-methyl mesoporphyrin IX (NMM) is a water-soluble, non-symmetric porphyrin with excellent optical properties and unparalleled selectivity for G-quadruplex (GQ) DNA. G-quadruplexes are non-canonical DNA structures formed by guanine-rich sequences. They are implicated in genomic stability, longevity, and cancer. The ability of NMM to selectively recognize GQ structures makes it a valuable scaffold for designing novel GQ binders. In this review, we survey the literature describing the GQ-binding properties of NMM as well as its wide utility in chemistry and biology. We start with the discovery of the GQ-binding properties of NMM and the development of NMM-binding aptamers. We then discuss the optical properties of NMM, focusing on the light-switch effect - high fluorescence of NMM induced upon its binding to GQ DNA. Additionally, we examine the affinity and selectivity of NMM for GQs, as well as its ability to stabilize GQ structures and favor parallel GQ conformations. Furthermore, a portion of the review is dedicated to the applications of NMM-GQ complexes as biosensors for heavy metals, small molecules (e.g. ATP and pesticides), DNA, and proteins. Finally and importantly, we discuss the utility of NMM as a probe to investigate the roles of GQs in biological processes.
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Affiliation(s)
- Ariana Yett
- Swarthmore College, Department of Chemistry and Biochemistry, 500 College Ave, Swarthmore, PA 19081, USA
| | - Linda Yingqi Lin
- Swarthmore College, Department of Chemistry and Biochemistry, 500 College Ave, Swarthmore, PA 19081, USA
| | - Dana Beseiso
- Swarthmore College, Department of Chemistry and Biochemistry, 500 College Ave, Swarthmore, PA 19081, USA
| | - Joanne Miao
- Swarthmore College, Department of Chemistry and Biochemistry, 500 College Ave, Swarthmore, PA 19081, USA
| | - Liliya A. Yatsunyk
- Correspondence to: Liliya A. Yatsunyk, Swarthmore College, 500 College Ave, Swarthmore, PA 19081, USA. tel.: 610-328-8558,
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20
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Hou Y, Li F, Zhang R, Li S, Liu H, Qin ZS, Sun X. Integrative characterization of G-Quadruplexes in the three-dimensional chromatin structure. Epigenetics 2019; 14:894-911. [PMID: 31177910 PMCID: PMC6691997 DOI: 10.1080/15592294.2019.1621140] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 05/05/2019] [Accepted: 05/14/2019] [Indexed: 12/14/2022] Open
Abstract
DNA molecules are highly compacted in the eukaryotic nucleus where distal regulatory elements reach their targets through three-dimensional chromosomal interactions. G-quadruplexes, stable four-stranded non-canonical DNA structures, can change local chromatin organization through the exclusion of nucleosomes. However, the relationship between G-quadruplexes and higher-order genome organization remains unknown. Here, we found that G-quadruplexes are significantly enriched at boundaries of topological associated domains (TADs). Architectural protein occupancy, which plays critical roles in the formation of TADs, was highly correlated with the content of G-quadruplexes at TAD boundaries. Moreover, adjacent boundaries containing G-quadruplexes frequently interacted with each other because of the high enrichment of architectural protein binding sites. Similar to CCCTC-binding factor (CTCF) binding sites, G-quadruplexes also showed strong insulation ability in the separation of adjacent regions. Additionally, the insulation ability of CTCF binding sites and TAD boundaries was significantly reinforced by G-quadruplexes. Furthermore, G-quadruplex motifs on different strands were associated with the orientation of CTCF binding sites. These findings suggest a potential role for G-quadruplexes in loop extrusion. The enrichment of transcription factor binding sites (TFBSs) around regulatory elements containing G-quadruplexes led to frequent interactions between regulatory elements containing G-quadruplexes. Intriguingly, more than 99% of G-quadruplexes overlapped with TFBSs. The binding sites of CTCF and cohesin proteins were preferentially located surrounding G-quadruplexes. Accordingly, we proposed a new mechanism of long-distance gene regulation in which G-quadruplexes are involved in distal interactions between enhancers and promoters.
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Affiliation(s)
- Yue Hou
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Fuyu Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Rongxin Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Sheng Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Hongde Liu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - Zhaohui S. Qin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA USA
| | - Xiao Sun
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, China
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21
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Dvoráková Z, Renciuk D, Kejnovská I, Školáková P, Bednárová K, Sagi J, Vorlícková M. i-Motif of cytosine-rich human telomere DNA fragments containing natural base lesions. Nucleic Acids Res 2019; 46:1624-1634. [PMID: 29378012 PMCID: PMC5829569 DOI: 10.1093/nar/gky035] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/15/2018] [Indexed: 12/01/2022] Open
Abstract
i-Motif (iM) is a four stranded DNA structure formed by cytosine-rich sequences, which are often present in functionally important parts of the genome such as promoters of genes and telomeres. Using electronic circular dichroism and UV absorption spectroscopies and electrophoretic methods, we examined the effect of four naturally occurring DNA base lesions on the folding and stability of the iM formed by the human telomere DNA sequence (C3TAA)3C3T. The results demonstrate that the TAA loop lesions, the apurinic site and 8-oxoadenine substituting for adenine, and the 5-hydroxymethyluracil substituting for thymine only marginally disturb the formation of iM. The presence of uracil, which is formed by enzymatic or spontaneous deamination of cytosine, shifts iM formation towards substantially more acidic pH values and simultaneously distinctly reduces iM stability. This effect depends on the position of the damage sites in the sequence. The results have enabled us to formulate additional rules for iM formation.
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Affiliation(s)
- Zuzana Dvoráková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Daniel Renciuk
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Iva Kejnovská
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Petra Školáková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Klára Bednárová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Janos Sagi
- Rimstone Laboratory, RLI, Carlsbad, CA 92010, USA
| | - Michaela Vorlícková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
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22
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Mendes E, Cadoni E, Carneiro F, Afonso MB, Brito H, Lavrado J, Dos Santos DJVA, Vítor JB, Neidle S, Rodrigues CMP, Paulo A. Combining 1,3-Ditriazolylbenzene and Quinoline to Discover a New G-Quadruplex-Interactive Small Molecule Active against Cancer Stem-Like Cells. ChemMedChem 2019; 14:1325-1328. [PMID: 31162877 DOI: 10.1002/cmdc.201900243] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/30/2019] [Indexed: 12/17/2022]
Abstract
Quadruplex nucleic acids are promising targets for cancer therapy. In this study we used a fragment-based approach to create new flexible G-quadruplex (G4) DNA-interactive small molecules with good calculated oral drug-like properties, based on quinoline and triazole heterocycles. G4 melting temperature and polymerase chain reaction (PCR)-stop assays showed that two of these compounds are selective G4 ligands, as they were able to induce and stabilize G4s in a dose- and DNA sequence-dependent manner. Molecular docking studies have suggested plausible quadruplex binding to both the G-quartet and groove, with the quinoline module playing the major role. Compounds were screened for cytotoxicity against four cancer cell lines, where 4,4'-(4,4'-(1,3-phenylene)bis(1H-1,2,3-triazole-4,1-diyl))bis(1-methylquinolin-1-ium) (1 d) showed the greater activity. Importantly, dose-response curves show that 1 d is cytotoxic in the human colon cancer HT-29 cell line enriched in cancer stem-like cells, a subpopulation of cells implicated in chemoresistance. Overall, this study identified a new small molecule as a promising lead for the development of drugs targeting G4 in cancer stem cells.
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Affiliation(s)
- Eduarda Mendes
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
| | - Enrico Cadoni
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
| | - Filipa Carneiro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
| | - Marta B Afonso
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
| | - Hugo Brito
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
| | - João Lavrado
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
| | - Daniel J V A Dos Santos
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
| | - Jorge B Vítor
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal.,Department of Biochemistry & Human Biology, Faculty of Pharmacy, Universidade de Lisboa, 1649 003, Lisbon, Portugal
| | - Stephen Neidle
- School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Cecília M P Rodrigues
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
| | - Alexandra Paulo
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649 003, Lisbon, Portugal
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Asamitsu S, Obata S, Yu Z, Bando T, Sugiyama H. Recent Progress of Targeted G-Quadruplex-Preferred Ligands Toward Cancer Therapy. Molecules 2019; 24:E429. [PMID: 30682877 PMCID: PMC6384606 DOI: 10.3390/molecules24030429] [Citation(s) in RCA: 193] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/07/2023] Open
Abstract
A G-quadruplex (G4) is a well-known nucleic acid secondary structure comprising guanine-rich sequences, and has profound implications for various pharmacological and biological events, including cancers. Therefore, ligands interacting with G4s have attracted great attention as potential anticancer therapies or in molecular probe applications. To date, a large variety of DNA/RNA G4 ligands have been developed by a number of laboratories. As protein-targeting drugs face similar situations, G-quadruplex-interacting drugs displayed low selectivity to the targeted G-quadruplex structure. This low selectivity could cause unexpected effects that are usually reasons to halt the drug development process. In this review, we address the recent research on synthetic G4 DNA-interacting ligands that allow targeting of selected G4s as an approach toward the discovery of highly effective anticancer drugs.
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Affiliation(s)
- Sefan Asamitsu
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
| | - Shunsuke Obata
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
| | - Zutao Yu
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
| | - Toshikazu Bando
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
- Institute for Integrated Cell-Material Science (WPI-iCeMS) Kyoto University, Yoshida-Ushinomiyacho, Sakyo, Kyoto, 606-8501, Japan.
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24
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Zhang X, Zhao B, Yan T, Hao A, Gao Y, Li D, Sui G. G-quadruplex structures at the promoter of HOXC10 regulate its expression. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:1018-1028. [DOI: 10.1016/j.bbagrm.2018.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 09/09/2018] [Accepted: 09/10/2018] [Indexed: 12/16/2022]
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Turturici G, La Fiora V, Terenzi A, Barone G, Cavalieri V. Perturbation of Developmental Regulatory Gene Expression by a G-Quadruplex DNA Inducer in the Sea Urchin Embryo. Biochemistry 2018; 57:4391-4394. [PMID: 30011196 DOI: 10.1021/acs.biochem.8b00551] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The G-quadruplex (G4) is a four-stranded DNA structure identified in vivo in guanine-rich regions located in the promoter of a number of genes. Intriguing evidence suggested that small molecules acting as G4-targeting ligands could potentially regulate multiple cellular processes via either stabilizing or disruptive effects on G4 motifs. Research in this field aims to prove the direct role of G4 ligands and/or structures on a specific biological process in a complex living organism. In this study, we evaluate in vivo the effects of a nickel(II)-salnaphen-like complex, named Nisaln, a potent G4 binder and stabilizer, during embryogenesis of the sea urchin embryo. We describe developmental defects inflicted by Nisaln and correlate them with variation in the expression of several regulatory genes. It is worth mentioning that we show that Nisaln binds a G4 structure in the promoter of hbox12-a, a gene lying at the top of the developmental regulatory hierarchy, inducing overexpression of this gene.
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Affiliation(s)
- Giuseppina Turturici
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF) , University of Palermo , Viale delle Scienze Edificio 16 , 90128 Palermo , Italy
| | - Veronica La Fiora
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF) , University of Palermo , Viale delle Scienze Edificio 16 , 90128 Palermo , Italy
| | - Alessio Terenzi
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF) , University of Palermo , Viale delle Scienze Edificio 16 , 90128 Palermo , Italy
| | - Giampaolo Barone
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF) , University of Palermo , Viale delle Scienze Edificio 16 , 90128 Palermo , Italy
| | - Vincenzo Cavalieri
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF) , University of Palermo , Viale delle Scienze Edificio 16 , 90128 Palermo , Italy
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Myoblast Myogenic Differentiation but Not Fusion Process Is Inhibited via MyoD Tetraplex Interaction. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:7640272. [PMID: 29854094 PMCID: PMC5964432 DOI: 10.1155/2018/7640272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 03/17/2018] [Accepted: 04/04/2018] [Indexed: 12/11/2022]
Abstract
The presence of tetraplex structures in the promoter region of the myogenic differentiation 1 gene (MyoD1) was investigated with a specific tetraplex-binding porphyrin (TMPyP4), to test its influence on the expression of MyoD1 itself and downstream-regulated genes during myogenic differentiation. TMPyP4-exposed C2C12 myoblasts, blocking MyoD1 transcription, proliferated reaching confluence and fused forming elongated structures, resembling myotubes, devoid of myosin heavy chain 3 (MHC) expression. Besides lack of MHC, upon MyoD1 inhibition, other myogenic gene expressions were also affected in treated cells, while untreated control cell culture showed normal myotube formation expressing MyoD1, Myog, MRF4, Myf5, and MHC. Unexpectedly, the myomaker (Mymk) gene expression was not affected upon TMPyP4 exposure during C2C12 myogenic differentiation. At the genomic level, the bioinformatic comparison of putative tetraplex sites found that three tetraplexes in MyoD1 and Myog are highly conserved in mammals, while Mymk and MHC did not show any conserved tetraplexes in the analysed regions. Thus, here, we report for the first time that the inhibition of the MyoD1 promoter function, stabilizing the tetraplex region, affects downstream myogenic genes by blocking their expression, while leaving the expression of Mymk unaltered. These results reveal the existence of two distinct pathways: one leading to cell fusion and one guaranteeing correct myotube differentiation.
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Bartas M, Brázda V, Karlický V, Červeň J, Pečinka P. Bioinformatics analyses and in vitro evidence for five and six stacked G-quadruplex forming sequences. Biochimie 2018; 150:70-75. [PMID: 29733879 DOI: 10.1016/j.biochi.2018.05.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/02/2018] [Indexed: 02/08/2023]
Abstract
Quadruplexes are noncanonical DNA structures that arise in guanine rich loci and have important biological functions. Classically, quadruplexes contain four stacked intramolecular G-tetrads. Surprisingly, although some algorithms allow searching for longer than 4G tracts for quadruplex formation, these have not yet been systematically studied. Therefore, we analyzed the human genome for sequences that are predicted to adopt stacked intramolecular G-tetrads with greater than four stacks. The data provide evidence for numerous G-quadruplexes that contain five or six stacked intramolecular G-tetrads. These sequences are predominantly found in known gene regulatory regions. Electrophoretic mobility assays and circular dichroism spectroscopy indicate that these sequences form quadruplex structures in vitro under physiological conditions. The localization and in vitro stability of these G-quadruplexes indicate their potentially important roles in gene regulation and their potential for therapeutic applications.
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Affiliation(s)
- Martin Bartas
- Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Chittussiho 10, Ostrava, CZ, 71000, Czech Republic
| | - Václav Brázda
- Department of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, The Czech Academy of Sciences, Brno, CZ, 61265, Czech Republic
| | - Václav Karlický
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, Ostrava, CZ, 71000, Czech Republic; Global Change Research Institute CAS, V. V. I., Bělidla 986/4a, Brno, CZ, 60300, Czech Republic
| | - Jiří Červeň
- Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Chittussiho 10, Ostrava, CZ, 71000, Czech Republic
| | - Petr Pečinka
- Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Chittussiho 10, Ostrava, CZ, 71000, Czech Republic.
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