1
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Li Q, Dong M, Chen P. Advances in structural-guided modifications of siRNA. Bioorg Med Chem 2024; 110:117825. [PMID: 38954918 DOI: 10.1016/j.bmc.2024.117825] [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: 05/16/2024] [Revised: 06/27/2024] [Accepted: 06/27/2024] [Indexed: 07/04/2024]
Abstract
To date, the US Food and Drug Administration (FDA) has approved six small interfering RNA (siRNA) drugs: patisiran, givosiran, lumasiran, inclisiran, vutrisiran, and nedosiran, serving as compelling evidence of the promising potential of RNA interference (RNAi) therapeutics. The successful implementation of siRNA therapeutics is improved through a combination of various chemical modifications and diverse delivery approaches. The utilization of chemically modified siRNA at specific sites on either the sense strand (SS) or antisense strand (AS) has the potential to enhance resistance to ribozyme degradation, improve stability and specificity, and prolong the efficacy of drugs. Herein, we provide comprehensive analyses concerning the correlation between chemical modifications and structure-guided siRNA design. Various modifications, such as 2'-modifications, 2',4'-dual modifications, non-canonical sugar modifications, and phosphonate mimics, are crucial for the activity of siRNA. We also emphasize the essential strategies for enhancing overhang stability, improving RISC loading efficacy and strand selection, reducing off-target effects, and discussing the future of targeted delivery.
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Affiliation(s)
- Qiang Li
- Department of Medicinal Chemistry, School of Pharmacy, Qingdao University, Qingdao 266021, China; Research and Development Department, NanoPeptide (Qingdao) Biotechnology Ltd., Qingdao, China.
| | - Mingxin Dong
- Department of Medicinal Chemistry, School of Pharmacy, Qingdao University, Qingdao 266021, China.
| | - Pu Chen
- Research and Development Department, NanoPeptide (Qingdao) Biotechnology Ltd., Qingdao, China; Department of Chemical Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, Canada.
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2
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Gangopadhyay S, Das G, Gupta S, Ghosh A, Bagale SS, Roy PK, Mandal M, Harikrishna S, Sinha S, Gore KR. 4'- C-Acetamidomethyl-2'- O-methoxyethyl Nucleic Acid Modifications Improve Thermal Stability, Nuclease Resistance, Potency, and hAgo2 Binding of Small Interfering RNAs. J Org Chem 2024; 89:3747-3768. [PMID: 38394362 DOI: 10.1021/acs.joc.3c02506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
In this study, we designed the 4'-C-acetamidomethyl-2'-O-methoxyethyl (4'-C-ACM-2'-O-MOE) uridine and thymidine modifications, aiming to test them into small interfering RNAs. Thermal melting studies revealed that incorporating a single 4'-C-ACM-2'-O-MOE modification in the DNA duplex reduced thermal stability. In contrast, an increase in thermal stability was observed when the modification was introduced in DNA:RNA hybrid and in siRNAs. Thermal destabilization in DNA duplex was attributed to unfavorable entropy, which was mainly compensated by the enthalpy factor to some extent. A single 4'-C-ACM-2'-O-MOE thymidine modification at the penultimate position of the 3'-end of dT20 oligonucleotides in the presence of 3'-specific exonucleases, snake venom phosphodiesterase (SVPD), demonstrated significant stability as compared to monomer modifications including 2'-O-Me, 2'-O-MOE, and 2'-F. In gene silencing studies, we found that the 4'-C-ACM-2'-O-MOE uridine or thymidine modifications at the 3'-overhang in the passenger strand in combination with two 2'-F modifications exhibited superior RNAi activity. The results suggest that the dual modification is well tolerated at the 3'-end of the passenger strand, which reflects better siRNA stability and silencing activity. Interestingly, 4'-C-ACM-2'-O-MOE-modified siRNAs showed considerable gene silencing even after 96 h posttransfection; it showed that our modification could induce prolonged gene silencing due to improved metabolic stability. Molecular modeling studies revealed that the introduction of the 4'-C-ACM-2'-O-MOE modification at the 3'-end of the siRNA guide strand helps to anchor the strand within the PAZ domain of the hAgo2 protein. The overall results indicate that the 4'-C-ACM-2'-O-MOE uridine and thymidine modifications are promising modifications to improve the stability, potency, and hAgo2 binding of siRNAs.
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Affiliation(s)
- Sumit Gangopadhyay
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Gourav Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Shalini Gupta
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Kolkata, Jadavpur 700032, India
| | - Atanu Ghosh
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Kolkata, Jadavpur 700032, India
| | | | - Pritam Kumar Roy
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Mahitosh Mandal
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - S Harikrishna
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Surajit Sinha
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Kolkata, Jadavpur 700032, India
| | - Kiran R Gore
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
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3
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Sahoo A, Das G, Ghosh A, Shivappa Bagale S, Kumar Choudhary N, Harikrishna S, Sinha S, Gore KR. N 3-Methyluridine and 2'-O-Alkyl/2'-Fluoro-N 3-methyluridine functionalized nucleic acids improve nuclease resistance while maintaining duplex geometry. Bioorg Med Chem 2024; 100:117616. [PMID: 38295488 DOI: 10.1016/j.bmc.2024.117616] [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: 12/06/2023] [Revised: 01/16/2024] [Accepted: 01/26/2024] [Indexed: 02/02/2024]
Abstract
Herein, we report the synthesis of 2'-O-alkyl/2'-fluoro-N3-methyluridine (2'-O-alkyl/2'-F-m3U) phosphoramidites and their incorporation in DNA and RNA oligonucleotides. The duplex binding affinity and base discrimination studies showed that all 2'-O-alkyl/2'-F-m3U modifications significantly decreased the thermal stability and base-pairing discrimination ability. Serum stability study of dT20 with 2'-O-alkyl-m3U modification exhibited excellent nuclease resistance when incubated with 3'-exonucleases (SVPD) or 5'-exonucleases (PDE-II) as compared to m3U, 2'-F, 2'-OMe modified oligonucleotides. MD simulation studies with RNA tetradecamer duplexes illustrated that the m3U and 2'-O-methyl-m3U modifications reduce the duplex stabilities by disrupting the Watson-Crick hydrogen bonding and base-stacking interactions. Further molecular modelling investigations demonstrated that the 2'-O-propyl-m3U modification exhibits steric interactions with amino acid residues in the active site of 3'- and 5'-exonuclease, leading to enhanced stability. These combined data indicate that the 2'-modified-m3U nucleotides can be used as a promising tool to enhance the stability, silencing efficiency, and drug-like properties of antisense/siRNA-based therapeutics.
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Affiliation(s)
- Avijit Sahoo
- Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India
| | - Gourav Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India
| | - Atanu Ghosh
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | | | - Nishant Kumar Choudhary
- Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India
| | - S Harikrishna
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, United States
| | - Surajit Sinha
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Kiran R Gore
- Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
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4
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Zhang H, Vandesompele J, Braeckmans K, De Smedt SC, Remaut K. Nucleic acid degradation as barrier to gene delivery: a guide to understand and overcome nuclease activity. Chem Soc Rev 2024; 53:317-360. [PMID: 38073448 DOI: 10.1039/d3cs00194f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Gene therapy is on its way to revolutionize the treatment of both inherited and acquired diseases, by transferring nucleic acids to correct a disease-causing gene in the target cells of patients. In the fight against infectious diseases, mRNA-based therapeutics have proven to be a viable strategy in the recent Covid-19 pandemic. Although a growing number of gene therapies have been approved, the success rate is limited when compared to the large number of preclinical and clinical trials that have been/are being performed. In this review, we highlight some of the hurdles which gene therapies encounter after administration into the human body, with a focus on nucleic acid degradation by nucleases that are extremely abundant in mammalian organs, biological fluids as well as in subcellular compartments. We overview the available strategies to reduce the biodegradation of gene therapeutics after administration, including chemical modifications of the nucleic acids, encapsulation into vectors and co-administration with nuclease inhibitors and discuss which strategies are applied for clinically approved nucleic acid therapeutics. In the final part, we discuss the currently available methods and techniques to qualify and quantify the integrity of nucleic acids, with their own strengths and limitations.
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Affiliation(s)
- Heyang Zhang
- Laboratory for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
- Leiden Academic Centre for Drug Research, Leiden University, 2333 CC Leiden, The Netherlands
| | - Jo Vandesompele
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Kevin Braeckmans
- Laboratory for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
- Centre for Nano- and Biophotonics, Ghent University, 9000 Ghent, Belgium
| | - Stefaan C De Smedt
- Laboratory for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- Centre for Nano- and Biophotonics, Ghent University, 9000 Ghent, Belgium
| | - Katrien Remaut
- Laboratory for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
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5
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Sato H, Chandela A, Ueno Y. Synthesis and characterization of novel (S)-5'-C-aminopropyl-2'-fluorouridine modified oligonucleotides as therapeutic siRNAs. Bioorg Med Chem 2023; 87:117317. [PMID: 37196425 DOI: 10.1016/j.bmc.2023.117317] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/04/2023] [Accepted: 05/04/2023] [Indexed: 05/19/2023]
Abstract
The lack of stability of natural nucleosides limits their application in small interfering RNA (siRNA)-mediated RNA interference (RNAi). Various chemical modifications have been reported to improve their pharmacokinetic behavior; however, the development of potential candidates is still underway. In this study, we designed and synthesized (S)-5'-C-aminopropyl-2'-fluorouridine (5'-AP-2'-FU) and evaluated the properties of siRNAs containing this analog. A comparative thermodynamic study revealed the enhanced thermal stability of double-stranded RNAs (dsRNAs) containing 5'-AP-2'-FU in a position-specific manner, whereas (S)-5'-C-aminopropyl-2'-O-methyluridine (5'-AP-2'-MoU)-modified dsRNAs exhibited lower melting temperatures. This improved thermal stability of RNA duplexes is attributed to favorable entropy loss, which induces the duplex into an N-type (C3'-endo) conformation and enhances duplex binding in this case. The 5'-AP-2'-FU analog was also suitable for incorporation into the passenger strand to induce gene-silencing activity. Gene knockdown efficacy was comparable to that of unmodified siRNAs, and the best response was observed by introducing 5'-AP-2'-FU near the 3'-terminal end of the passenger strand. In addition, the single-stranded RNAs (ssRNAs) modified with 5'-AP-2'-FU showed strong resistance against decomposition by nucleases when treated with buffer containing bovine serum, which was similar to 5'-AP-2'-MoU.
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Affiliation(s)
- Hitotaka Sato
- United Graduate School of Agricultural Science, Gifu University, Japan
| | - Akash Chandela
- Course of Applied Life Science, Faculty of Applied Biological Sciences, Gifu University, Japan
| | - Yoshihito Ueno
- Department of Life Science and Chemistry, Graduate School of Natural Science and Technology, Gifu University, Japan; Course of Applied Life Science, Faculty of Applied Biological Sciences, Gifu University, Japan; United Graduate School of Agricultural Science, Gifu University, Japan; Center for One Medicine Innovative Translational Research (COMIT), Gifu University Institute for Advanced Study, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
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6
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Das G, Harikrishna S, Gore KR. Influence of Sugar Modifications on the Nucleoside Conformation and Oligonucleotide Stability: A Critical Review. CHEM REC 2022; 22:e202200174. [PMID: 36048010 DOI: 10.1002/tcr.202200174] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/16/2022] [Indexed: 12/15/2022]
Abstract
Ribofuranose sugar conformation plays an important role in the structure and dynamics of functional nucleic acids such as siRNAs, AONs, aptamers, miRNAs, etc. To improve their therapeutic potential, several chemical modifications have been introduced into the sugar moiety over the years. The stability of the oligonucleotide duplexes as well as the formation of stable and functional protein-oligonucleotide complexes are dictated by the conformation and dynamics of the sugar moiety. In this review, we systematically categorise various ribofuranose sugar modifications employed in DNAs and RNAs so far. We discuss different stereoelectronic effects imparted by different substituents on the sugar ring and how these effects control sugar puckering. Using this data, it would be possible to predict the precise use of chemical modifications and design novel sugar-modified nucleosides for therapeutic oligonucleotides that can improve their physicochemical properties.
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Affiliation(s)
- Gourav Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal-721302, India
| | - S Harikrishna
- Department of Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Kiran R Gore
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal-721302, India
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7
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Gangopadhyay S, Gore KR. Advances in siRNA therapeutics and synergistic effect on siRNA activity using emerging dual ribose modifications. RNA Biol 2022; 19:452-467. [PMID: 35352626 PMCID: PMC8973385 DOI: 10.1080/15476286.2022.2052641] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Nucleic acid-based therapeutics that control gene expression have been steadily progressing towards achieving their full clinical potential throughout the last few decades. Rapid progress has been achieved in RNAi-based therapy by optimizing high specificity and gene silencing efficiency using chemically modified siRNAs. Since 2018, four siRNA drugs – patisiran, givosiran, lumasiran, and inclisiran, were approved by the US FDA, providing a testament to the promise of RNAi therapeutics. Despite these promising results, safe and efficient siRNA delivery at the target site remains a major obstacle for efficient siRNA-based therapeutics. In this review, we have outlined the synergistic effects of emerging dual ribose modifications, including 2’,4’- and 2’,5’-modifications, 5’-E/Z-vinylphosphonate, and northern methanocarbacyclic (NMC) modifications that have contributed to drug-like effects in siRNA. These modifications enhance nuclease stability, prolong gene silencing efficiency, improve thermal stability, and exhibit high tissue accumulation. We also highlight the current progress in siRNA clinical trials. This review will help to understand the potential effects of dual ribose modifications and provides alternative ways to use extensive 2’-modifications in siRNA drugs. Moreover, the minimal number of these dual ribose modifications could be sufficient to achieve the desired therapeutic effect. In future, detailed in vivo studies using these dual ribose modifications could help to improve the therapeutic effects of siRNA. Rational design could further open doors for the rapid progress in siRNA therapeutics. ![]() ![]()
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Affiliation(s)
- Sumit Gangopadhyay
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Kiran R Gore
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
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8
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Kajino R, Ueno Y. Synthesis and Properties of Artificial Oligonucleotides Containing Novel Nucleoside Analogs with Cationic Alkyl Sidechains. J SYN ORG CHEM JPN 2021. [DOI: 10.5059/yukigoseikyokaishi.79.1102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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9
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Zhou Y, Lu K, Li Q, Fan C, Zhou C. C4'-Fluorinated Oligodeoxynucleotides: Synthesis, Stability, Structural Studies. Chemistry 2021; 27:14738-14746. [PMID: 34432342 DOI: 10.1002/chem.202102561] [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: 07/14/2021] [Indexed: 11/06/2022]
Abstract
Fluoro-substitution on the ribose moiety (e. g., 2'-F-deoxyribonucleotide) represents a popular way to modulate the ribose conformation and, hence, the structure and function of nucleic acids. In the present study, we synthesized 4'-F-deoxythymidine (4'-F T) and introduced it to oligodeoxyribonucleotides (ODNs). Though scission of the glycosylic bond of 4'-F T followed by strand cleavage occurred to some extent under alkaline conditions, the 4'-F T-modified ODNs were rather stable in neutral buffers. NMR studies showed that like 2'-F-deoxyribonucleoside, 4'-F T exists predominantly in the North conformation not only in the nucleoside form but also in the context of ODN strands. Circular dichroism spectroscopy, thermal denaturing and RNase H1 footprinting studies of 4'-F T-modified ODN/cDNA and ODN/cRNA duplexes indicated that the North conformation tendency of 4'-F T is maintained in the duplexes, leading to a local structural perturbation. Collectively, 4'-F-deoxyribonucleotide structurally resembles the 2'-F-deoxyribonucleotide but imparts less structural perturbation to the duplex than the latter.
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Affiliation(s)
- Yifei Zhou
- State Key Laboratory of Elemento-Organic Chemistry, and Department of Chemical Biology, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Kuan Lu
- State Key Laboratory of Elemento-Organic Chemistry, and Department of Chemical Biology, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Qiang Li
- State Key Laboratory of Elemento-Organic Chemistry, and Department of Chemical Biology, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Chaochao Fan
- State Key Laboratory of Elemento-Organic Chemistry, and Department of Chemical Biology, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Chuanzheng Zhou
- State Key Laboratory of Elemento-Organic Chemistry, and Department of Chemical Biology, College of Chemistry, Nankai University, Tianjin, 300071, China
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10
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Rydzik AM, Balk R, Koegler M, Steinle T, Riether D, Gottschling D. Access to 1'-Amino Carbocyclic Phosphoramidite to Enable Postsynthetic Functionalization of Oligonucleotides. Org Lett 2021; 23:6735-6739. [PMID: 34424724 DOI: 10.1021/acs.orglett.1c02302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We report a synthesis of a carbocyclic, abasic RNA phosphoramidite decorated with an amino functionality. The building block was efficiently incorporated into an RNA oligonucleotide in a site-specific manner, followed by deprotection to a free amino group. The amino moiety could be further derivatized as exemplified with fluorescein N-hydroxysuccinimide ester. Hence, this convertible building block may provide access to a variety of RNA oligonucleotides via postsynthetic amino group functionalization. In particular, providing a vector toward nucleobase replacements.
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Affiliation(s)
- Anna M Rydzik
- Boehringer Ingelheim Pharma GmbH & Co. KG, 88400 Biberach an der Riss, Germany
| | - Regina Balk
- Boehringer Ingelheim Pharma GmbH & Co. KG, 88400 Biberach an der Riss, Germany
| | | | - Tobias Steinle
- Boehringer Ingelheim Pharma GmbH & Co. KG, 88400 Biberach an der Riss, Germany
| | - Doris Riether
- Boehringer Ingelheim Pharma GmbH & Co. KG, 88400 Biberach an der Riss, Germany
| | - Dirk Gottschling
- Boehringer Ingelheim Pharma GmbH & Co. KG, 88400 Biberach an der Riss, Germany
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11
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Liczner C, Duke K, Juneau G, Egli M, Wilds CJ. Beyond ribose and phosphate: Selected nucleic acid modifications for structure-function investigations and therapeutic applications. Beilstein J Org Chem 2021; 17:908-931. [PMID: 33981365 PMCID: PMC8093555 DOI: 10.3762/bjoc.17.76] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 04/14/2021] [Indexed: 12/16/2022] Open
Abstract
Over the past 25 years, the acceleration of achievements in the development of oligonucleotide-based therapeutics has resulted in numerous new drugs making it to the market for the treatment of various diseases. Oligonucleotides with alterations to their scaffold, prepared with modified nucleosides and solid-phase synthesis, have yielded molecules with interesting biophysical properties that bind to their targets and are tolerated by the cellular machinery to elicit a therapeutic outcome. Structural techniques, such as crystallography, have provided insights to rationalize numerous properties including binding affinity, nuclease stability, and trends observed in the gene silencing. In this review, we discuss the chemistry, biophysical, and structural properties of a number of chemically modified oligonucleotides that have been explored for gene silencing.
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Affiliation(s)
- Christopher Liczner
- Department of Chemistry and Biochemistry, Concordia University, Montréal, Québec H4B 1R6, Canada
| | - Kieran Duke
- Department of Chemistry and Biochemistry, Concordia University, Montréal, Québec H4B 1R6, Canada
| | - Gabrielle Juneau
- Department of Chemistry and Biochemistry, Concordia University, Montréal, Québec H4B 1R6, Canada
| | - Martin Egli
- Department of Biochemistry, Vanderbilt Institute of Chemical Biology, and Center for Structural Biology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Christopher J Wilds
- Department of Chemistry and Biochemistry, Concordia University, Montréal, Québec H4B 1R6, Canada
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12
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Gangopadhyay S, Nikam RR, Gore KR. Folate Receptor-Mediated siRNA Delivery: Recent Developments and Future Directions for RNAi Therapeutics. Nucleic Acid Ther 2021; 31:245-270. [PMID: 33595381 DOI: 10.1089/nat.2020.0882] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
RNA interference (RNAi), a gene regulatory process mediated by small interfering RNAs (siRNAs), has made remarkable progress as a potential therapeutic agent against various diseases. However, RNAi is associated with fundamental challenges such as poor systemic delivery and susceptibility to the nucleases. Targeting ligand-bound delivery vehicles has improved the accumulation of drug at the target site, which has resulted in high transfection efficiency and enhanced gene silencing. Recently, folate receptor (FR)-mediated targeted delivery of siRNAs has garnered attention due to their enhanced cellular uptake and high transfection efficiency toward tumor cells. Folic acid (FA), due to its small size, low immunogenicity, high in vivo stability, and high binding affinity toward FRs, has attracted much attention for targeted siRNA delivery. FRs are overexpressed in a large number of tumors, including ovarian, breast, kidney, and lung cancer cells. In this review, we discuss recent advances in FA-mediated siRNA delivery to treat cancers and inflammatory diseases. This review summarizes various FA-conjugated nanoparticle systems reported so far in the literature, including liposome, silica, metal, graphene, dendrimers, chitosan, organic copolymers, and RNA nanoparticles. This review will help in the design and development of potential delivery vehicles for siRNA drug targeting to tumor cells using an FR-mediated approach.
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Affiliation(s)
- Sumit Gangopadhyay
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Rahul R Nikam
- Department of Chemistry, University of Mumbai, Mumbai, India
| | - Kiran R Gore
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
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13
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Nikam RR, Harikrishna S, Gore KR. Synthesis, Structural, and Conformational Analysis of 4′‐
C
‐Alkyl‐2′‐
O
‐Ethyl‐Uridine Modified Nucleosides. European J Org Chem 2021. [DOI: 10.1002/ejoc.202001348] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Rahul R. Nikam
- Department of Chemistry University of Mumbai Mumbai 400098 India
| | - S. Harikrishna
- Center for Structural Biology Vanderbilt University Nashville, Tennessee 37232 United States
| | - Kiran R. Gore
- Department of Chemistry University of Mumbai Mumbai 400098 India
- Department of Chemistry Indian Institute of Technology Kharagpur Kharagpur, West Bengal 721302 India
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14
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Tsuchihira T, Kajino R, Maeda Y, Ueno Y. 4'-C-Aminomethyl-2'-deoxy-2'-fluoroarabinonucleoside increases the nuclease resistance of DNA without inhibiting the ability of a DNA/RNA duplex to activate RNase H. Bioorg Med Chem 2020; 28:115611. [PMID: 32690266 DOI: 10.1016/j.bmc.2020.115611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/19/2020] [Accepted: 06/23/2020] [Indexed: 10/24/2022]
Abstract
An antisense oligonucleotide is expected as an innovative drug for cancer and hereditary diseases. In this paper, we designed and synthesized DNAs containing a novel nucleoside analog, 1-(4-C-aminomethyl-2-deoxy-2-fluoro-β-d-arabinofuranosyl)thymine, and evaluated their properties. It was revealed that the analog slightly decreases the thermal stability of the DNA/RNA duplex but significantly increases the stability of DNA in a buffer containing bovine serum. Furthermore, it turned out that the DNA/RNA duplex containing the analog is a good substrate for Escherichia coli RNase H. Thus, DNAs containing the nucleoside analog would be good candidates for the development of therapeutic antisense oligonucleotides.
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Affiliation(s)
- Tatsuya Tsuchihira
- Graduate School of Natural Science and Technology, Gifu University, Japan
| | - Ryohei Kajino
- Graduate School of Natural Science and Technology, Gifu University, Japan
| | - Yusuke Maeda
- Graduate School of Natural Science and Technology, Gifu University, Japan
| | - Yoshihito Ueno
- Graduate School of Natural Science and Technology, Gifu University, Japan; Faculty of Applied Life Sciences, Gifu University, Japan; Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University, Japan.
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15
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16
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Zhou Y, Zang C, Wang H, Li J, Cui Z, Li Q, Guo F, Yan Z, Wen X, Xi Z, Zhou C. 4'-C-Trifluoromethyl modified oligodeoxynucleotides: synthesis, biochemical studies, and cellular uptake properties. Org Biomol Chem 2020; 17:5550-5560. [PMID: 31112186 DOI: 10.1039/c9ob00765b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Herein, we report the synthesis of 4'-C-trifluoromethyl (4'-CF3) thymidine (T4'-CF3) and its incorporation into oligodeoxynucleotides (ODNs) through solid-supported DNA synthesis. The 4'-CF3 modification leads to a marginal effect on the deoxyribose conformation and a local helical structure perturbation for ODN/RNA duplexes. This type of modification slightly decreases the thermal stability of ODN/RNA duplexes (-1 °C/modification) and leads to improved nuclease resistance. Like the well-known phosphorothioate (PS) modification, heavy 4'-CF3 modifications enable direct cellular uptake of the modified ODNs without any delivery reagents. This work highlights that 4'-CF3 modified ODNs are promising candidates for antisense-based therapeutics, which will, in turn, inspire us to develop more potent modifications for antisense ODNs and siRNAs.
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Affiliation(s)
- Yifei Zhou
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry, Nankai University, Tianjin 300071, China.
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17
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Nikam RR, Gore KR. A mild and convenient approach for selective acetonide cleavage involved in carbohydrate synthesis using PPA-SiO2. J Carbohydr Chem 2020. [DOI: 10.1080/07328303.2019.1708374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Rahul R. Nikam
- Department of Chemistry, University of Mumbai, Mumbai, India
| | - Kiran R. Gore
- Department of Chemistry, University of Mumbai, Mumbai, India
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, India
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18
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Uematsu A, Kajino R, Maeda Y, Ueno Y. Synthesis and characterization of 4'- C-guanidinomethyl-2'- O-methyl-modified RNA oligomers. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2019; 39:280-291. [PMID: 31530080 DOI: 10.1080/15257770.2019.1666277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
This study investigated the synthesis and properties of 4'-C-guanidinomethyl-2'-O-methyluridine and RNAs containing the analog. Thermal and thermodynamic stabilities of double-stranded RNAs (dsRNAs) containing the nucleoside analog were examined. It was found that although the analog decreased the thermal and thermodynamic stabilities of dsRNA, it had base-discrimination ability. The 4'-C-guanidinomethyl modification increased stability of RNAs in a buffer containing serum. Furthermore, small interference RNAs incorporating one analog at the passenger strand still preserved their RNA interference activities. It was suggested that the 4'-guanidinomethyl modification significantly improved cell membrane permeability of RNA. Thus, 4'-C-guanidinomethyl-2'-O-methyl analogs may be useful in improving the properties of therapeutic siRNA molecules.
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Affiliation(s)
- Azusa Uematsu
- Course of Applied Life Science, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Ryohei Kajino
- Course of Applied Life Science, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Yusuke Maeda
- Course of Applied Life Science, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Yoshihito Ueno
- Course of Applied Life Science, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan.,United Graduate School of Agricultural Science, Gifu University, Gifu, Japan.,Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University, Gifu, Japan
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19
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Chernikov IV, Vlassov VV, Chernolovskaya EL. Current Development of siRNA Bioconjugates: From Research to the Clinic. Front Pharmacol 2019; 10:444. [PMID: 31105570 PMCID: PMC6498891 DOI: 10.3389/fphar.2019.00444] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 04/08/2019] [Indexed: 12/12/2022] Open
Abstract
Small interfering RNAs (siRNAs) acting via RNA interference mechanisms are able to recognize a homologous mRNA sequence in the cell and induce its degradation. The main problems in the development of siRNA-based drugs for therapeutic use are the low efficiency of siRNA delivery to target cells and the degradation of siRNAs by nucleases in biological fluids. Various approaches have been proposed to solve the problem of siRNA delivery in vivo (e.g., viruses, cationic lipids, polymers, nanoparticles), but all have limitations for therapeutic use. One of the most promising approaches to solve the problem of siRNA delivery to target cells is bioconjugation; i.e., the covalent connection of siRNAs with biogenic molecules (lipophilic molecules, antibodies, aptamers, ligands, peptides, or polymers). Bioconjugates are "ideal nanoparticles" since they do not need a positive charge to form complexes, are less toxic, and are less effectively recognized by components of the immune system because of their small size. This review is focused on strategies and principles for constructing siRNA bioconjugates for in vivo use.
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Affiliation(s)
- Ivan V Chernikov
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Valentin V Vlassov
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Elena L Chernolovskaya
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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20
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Kajino R, Maeda Y, Yoshida H, Yamagishi K, Ueno Y. Synthesis and Biophysical Characterization of RNAs Containing (R)- and (S)-5′-C-Aminopropyl-2′-O-methyluridines. J Org Chem 2019; 84:3388-3404. [DOI: 10.1021/acs.joc.8b03277] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
| | | | - Hisae Yoshida
- Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, 1 Azanakagawara, Tokusada, Tamuramachi, Koriyama, Fukushima 963-8642, Japan
| | - Kenji Yamagishi
- Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, 1 Azanakagawara, Tokusada, Tamuramachi, Koriyama, Fukushima 963-8642, Japan
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21
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Nawale GN, Bahadorikhalili S, Sengupta P, Kadekar S, Chatterjee S, Varghese OP. 4′-Guanidinium-modified siRNA: a molecular tool to control RNAi activity through RISC priming and selective antisense strand loading. Chem Commun (Camb) 2019; 55:9112-9115. [DOI: 10.1039/c9cc04141a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We present synthesis, biochemical, biophysical and computational evaluation of 4′ gunanidino modified siRNA.
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Affiliation(s)
- Ganesh N. Nawale
- Translational Chemical Biology Laboratory
- Division of Polymer Chemistry
- Department of Chemistry-Ångström
- Uppsala University
- Uppsala
| | - Saeed Bahadorikhalili
- Translational Chemical Biology Laboratory
- Division of Polymer Chemistry
- Department of Chemistry-Ångström
- Uppsala University
- Uppsala
| | - Pallabi Sengupta
- Biomolecular NMR and Drug Design Laboratory
- Department of Biophysics
- Bose Institute
- Kolkata
- India
| | - Sandeep Kadekar
- Translational Chemical Biology Laboratory
- Division of Polymer Chemistry
- Department of Chemistry-Ångström
- Uppsala University
- Uppsala
| | - Subhrangsu Chatterjee
- Biomolecular NMR and Drug Design Laboratory
- Department of Biophysics
- Bose Institute
- Kolkata
- India
| | - Oommen P. Varghese
- Translational Chemical Biology Laboratory
- Division of Polymer Chemistry
- Department of Chemistry-Ångström
- Uppsala University
- Uppsala
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22
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He XY, Wang J, Lu DD, Wang SQ. Synthesis and Antisense Properties of 2'β-F-Arabinouridine Modified Oligonucleotides with 4'- C-OMe Substituent. Molecules 2018; 23:molecules23092374. [PMID: 30227644 PMCID: PMC6225415 DOI: 10.3390/molecules23092374] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 11/16/2022] Open
Abstract
A novel 2′-F,4′-C-OMe–arabinouridine (araU) was successfully synthesized and introduced into oligonucleotides. The oligonucleotide containing 2′-F,4′-C-OMe–araU exhibited improved nuclease resistance and RNA hybridizing selective ability relative to 2′-F–araU. In particular, when 2′-F,4′-C-OMe–araU inserted into C–H⋯F–C bonding-favorable 5′–uridine–purine–3′ steps, the modified oligonucleotide showed remarkable binding affinity and selectivity to RNA complements. Thus, 2′-F,4′-C-OMe–araU has valuable antisense properties and can be used as novel chemical modification for antisense therapeutic strategy.
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Affiliation(s)
- Xiao-Yang He
- Beijing Institute of Radiation Medicine, Beijing 100850, China.
| | - Jing Wang
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Dan-Dan Lu
- Beijing Institute of Radiation Medicine, Beijing 100850, China.
| | - Sheng-Qi Wang
- Beijing Institute of Radiation Medicine, Beijing 100850, China.
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23
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Koizumi K, Maeda Y, Kano T, Yoshida H, Sakamoto T, Yamagishi K, Ueno Y. Synthesis of 4′-C-aminoalkyl-2′-O-methyl modified RNA and their biological properties. Bioorg Med Chem 2018; 26:3521-3534. [DOI: 10.1016/j.bmc.2018.05.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 12/16/2022]
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24
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Nikam RR, Gore KR. Journey of siRNA: Clinical Developments and Targeted Delivery. Nucleic Acid Ther 2018; 28:209-224. [PMID: 29584585 DOI: 10.1089/nat.2017.0715] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Since the evolutionary discovery of RNA interference and its utilization for gene knockdown in mammalian cell, a remarkable progress has been achieved in small interfering RNA (siRNA) therapeutics. siRNA is a promising tool, utilized as therapeutic agent against various diseases. Despite its significant potential benefits, safe, efficient, and target oriented delivery of siRNA is one of the major challenges in siRNA therapeutics. This review covers major achievements in clinical trials and targeted delivery of siRNAs using various targeting ligand-receptor pair. Local and systemically administered siRNA drug candidates at various phases in clinical trials are described in this review. This review also provides a deep insight in development of targeted delivery of siRNA. Various targeting ligand-siRNA pair with complexation and conjugation approaches are discussed in this review. This will help to achieve further optimization and development in targeted delivery of siRNAs to achieve higher gene silencing efficiency with lowest siRNA dose availability.
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Affiliation(s)
| | - Kiran R Gore
- Department of Chemistry, University of Mumbai , Mumbai, India
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25
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Paul A, Kumar A, Nanjunda R, Farahat AA, Boykin DW, Wilson WD. Systematic synthetic and biophysical development of mixed sequence DNA binding agents. Org Biomol Chem 2018; 15:827-835. [PMID: 27995240 DOI: 10.1039/c6ob02390h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
It is now well established that, although only about 5% of the human genome codes for protein, most of the DNA has some function, such as synthesis of specific, functional RNAs and/or control of gene expression. These functional sequences open immense possibilities in both biotechnology and therapeutics for the use of cell-permeable, small molecules that can bind mixed-base pair sequences of DNA for regulation of genomic functions. Unfortunately very few types of modules have been designed to recognize mixed DNA sequences and for progress in targeting specific genes, it is essential to have additional classes of compounds. Compounds that can be rationally designed from established modules and which can bind strongly to mixed base pair DNA sequences are especially attractive. Based on extensive experience in design of minor-groove agents for AT recognition, a small library of compounds with two AT specific binding modules, connected through linkers which can recognize the G·C base pairs, were prepared. The compound-DNA interactions were evaluated with a powerful array of biophysical methods and the results show that some pyridyl-linked compounds bind with the target sequence with sub-nanomolar KD, with very slow dissociation kinetics and 200 times selectivity over the related sequence without a G·C base pair. Interestingly, a set of compounds with AT module connected by different linkers shows cooperative dimer recognition of related sequences. This type of design approach can be expanded to additional modules for recognition of a wide variety of sequences.
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Affiliation(s)
- Ananya Paul
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
| | - Arvind Kumar
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
| | - Rupesh Nanjunda
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA. and Janssen Research and Development, 1400 McKean Rd, Spring House, PA 19477, USA
| | - Abdelbasset A Farahat
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA. and Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - David W Boykin
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
| | - W David Wilson
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
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26
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Harikrishna S, Pradeepkumar PI. Probing the Binding Interactions between Chemically Modified siRNAs and Human Argonaute 2 Using Microsecond Molecular Dynamics Simulations. J Chem Inf Model 2017; 57:883-896. [DOI: 10.1021/acs.jcim.6b00773] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- S. Harikrishna
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai−400076, India
| | - P. I. Pradeepkumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai−400076, India
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27
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Ghodke PP, Harikrishna S, Pradeepkumar PI. Synthesis and Polymerase-Mediated Bypass Studies of the N2-Deoxyguanosine DNA Damage Caused by a Lucidin Analogue. J Org Chem 2015; 80:2128-38. [DOI: 10.1021/jo502627b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Pratibha P. Ghodke
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - S. Harikrishna
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - P. I. Pradeepkumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
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28
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Gore KR, Harikrishna S, Pradeepkumar PI. Influence of 2'-fluoro versus 2'-O-methyl substituent on the sugar puckering of 4'-C-aminomethyluridine. J Org Chem 2013; 78:9956-62. [PMID: 24016294 DOI: 10.1021/jo4012333] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Herein, we report the synthesis of 4'-C-aminomethyl-2'-deoxy-2'-fluorouridine, a therapeutically appealing RNA modification. Conformational analysis by DFT calculations and molecular dynamics simulations using trinucleotide model systems revealed that modified sugar adopts C3'-endo conformation. In this conformer, a weak intramolecular C-H···F H-bond between the hydrogen atom of the 4'-C-CH2 group and the F atom at the 2' position is observed. Comparative studies with unmodified, 2'-fluoro-, 2'-O-methyl-, and 4'-C-aminomethyl-2'-O-methyluridine showed the chemical nature of 2'-substituent dictates the sugar puckering of 2',4'-modified nucleotides.
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Affiliation(s)
- Kiran R Gore
- Department of Chemistry, Indian Institute of Technology Bombay , Mumbai 400076, India
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29
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Nawale GN, Gore KR, Höbartner C, Pradeepkumar PI. Incorporation of 4'-C-aminomethyl-2'-O-methylthymidine into DNA by thermophilic DNA polymerases. Chem Commun (Camb) 2013; 48:9619-21. [PMID: 22908130 DOI: 10.1039/c2cc35222b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The dual modified nucleotide 4'-C-aminomethyl-2'-O-methylthymidine 5'-triphosphate was synthesized and enzymatically incorporated into DNA by the thermophilic DNA polymerases Pfu and Therminator III. The dual ribose modification imparted increased exonuclease resistance to DNA compared to the well-known 2'-O-methyl modification.
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Affiliation(s)
- Ganesh N Nawale
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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30
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Deleavey GF, Damha MJ. Designing chemically modified oligonucleotides for targeted gene silencing. ACTA ACUST UNITED AC 2012; 19:937-54. [PMID: 22921062 DOI: 10.1016/j.chembiol.2012.07.011] [Citation(s) in RCA: 423] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 06/28/2012] [Accepted: 07/02/2012] [Indexed: 02/07/2023]
Abstract
Oligonucleotides (ONs), and their chemically modified mimics, are now routinely used in the laboratory as a means to control the expression of fundamentally interesting or therapeutically relevant genes. ONs are also under active investigation in the clinic, with many expressing cautious optimism that at least some ON-based therapies will succeed in the coming years. In this review, we will discuss several classes of ONs used for controlling gene expression, with an emphasis on antisense ONs (AONs), small interfering RNAs (siRNAs), and microRNA-targeting ONs (anti-miRNAs). This review provides a current and detailed account of ON chemical modification strategies for the optimization of biological activity and therapeutic application, while clarifying the biological pathways, chemical properties, benefits, and limitations of oligonucleotide analogs used in nucleic acids research.
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Affiliation(s)
- Glen F Deleavey
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, QC H3A 0B8, Canada.
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31
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Ghanty U, Fostvedt E, Valenzuela R, Beal PA, Burrows CJ. Promiscuous 8-alkoxyadenosines in the guide strand of an siRNA: modulation of silencing efficacy and off-pathway protein binding. J Am Chem Soc 2012; 134:17643-52. [PMID: 23030736 DOI: 10.1021/ja307102g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
8-Alkoxyadenosines have the potential to exist in anti or syn conformations around the glycosidic bond when paired opposite to U or G in the complementary strands, thereby placing the sterically demanding 8-alkoxy groups in the major or minor groove, respectively, of duplex RNA. These modified bases were used as "base switches" in the guide strands of an siRNA to prevent off-pathway protein binding during delivery via placement of the alkoxy group in the minor groove, while maintaining significant RNAi efficacy by orienting the alkoxy group in the major groove. 8-Alkoxyadenosine phosphoramidites were synthesized and incorporated into the guide strand of caspase 2 siRNA at four different positions: two in the seed region, one at the cleavage junction, and another nearer to the 3'-end of the guide strand. Thermal stabilities of the corresponding siRNA duplexes showed that U is preferred over G as the base-pairing partner in the complementary strand. When compared to the unmodified positive control siRNAs, singly modified siRNAs knocked down the target mRNA efficiently and with little or no loss of efficacy. Doubly modified siRNAs were found to be less effective and lose their efficacy at low nanomolar concentrations. SiRNAs singly modified at positions 6 and 10 of the guide strand were found to be effective in blocking binding to the RNA-dependent protein kinase PKR, a cytoplasmic dsRNA-binding protein implicated in sequence-independent off-target effects.
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Affiliation(s)
- Uday Ghanty
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, USA
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32
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Bramsen JB, Kjems J. Development of Therapeutic-Grade Small Interfering RNAs by Chemical Engineering. Front Genet 2012; 3:154. [PMID: 22934103 PMCID: PMC3422727 DOI: 10.3389/fgene.2012.00154] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 07/31/2012] [Indexed: 12/25/2022] Open
Abstract
Recent successes in clinical trials have provided important proof of concept that small interfering RNAs (siRNAs) indeed constitute a new promising class of therapeutics. Although great efforts are still needed to ensure efficient means of delivery in vivo, the siRNA molecule itself has been successfully engineered by chemical modification to meet initial challenges regarding specificity, stability, and immunogenicity. To date, a great wealth of siRNA architectures and types of chemical modification are available for promoting safe siRNA-mediated gene silencing in vivo and, consequently, the choice of design and modification types can be challenging to individual experimenters. Here we review the literature and devise how to improve siRNA performance by structural design and specific chemical modification to ensure potent and specific gene silencing without unwarranted side-effects and hereby complement the ongoing efforts to improve cell targeting and delivery by other carrier molecules.
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Affiliation(s)
- Jesper B Bramsen
- Interdisciplinary Nanoscience Center, Department of Molecular Biology and Genetics, Aarhus University Aarhus C, Denmark
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