1
|
Stachelska-Wierzchowska A, Wierzchowski J. Chemo-Enzymatic Generation of Highly Fluorescent Nucleoside Analogs Using Purine-Nucleoside Phosphorylase. Biomolecules 2024; 14:701. [PMID: 38927104 DOI: 10.3390/biom14060701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/08/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
Chemo-enzymatic syntheses of strongly fluorescent nucleoside analogs, potentially applicable in analytical biochemistry and cell biology are reviewed. The syntheses and properties of fluorescent ribofuranosides of several purine, 8-azapurine, and etheno-purine derivatives, obtained using various types of purine nucleoside phosphorylase (PNP) as catalysts, as well as α-ribose-1-phosphate (r1P) as a second substrate, are described. In several instances, the ribosylation sites are different to the canonical purine N9. Some of the obtained ribosides show fluorescence yields close to 100%. Possible applications of the new analogs include assays of PNP, nucleoside hydrolases, and other enzyme activities both in vitro and within living cells using fluorescence microscopy.
Collapse
Affiliation(s)
| | - Jacek Wierzchowski
- Department of Physics and Biophysics, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland
| |
Collapse
|
2
|
Martínez-Puente DH, Pérez-Trujillo JJ, Zavala-Flores LM, García-García A, Villanueva-Olivo A, Rodríguez-Rocha H, Valdés J, Saucedo-Cárdenas O, Montes de Oca-Luna R, Loera-Arias MDJ. Plasmid DNA for Therapeutic Applications in Cancer. Pharmaceutics 2022; 14:pharmaceutics14091861. [PMID: 36145609 PMCID: PMC9503848 DOI: 10.3390/pharmaceutics14091861] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/30/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Recently, the interest in using nucleic acids for therapeutic applications has been increasing. DNA molecules can be manipulated to express a gene of interest for gene therapy applications or vaccine development. Plasmid DNA can be developed to treat different diseases, such as infections and cancer. In most cancers, the immune system is limited or suppressed, allowing cancer cells to grow. DNA vaccination has demonstrated its capacity to stimulate the immune system to fight against cancer cells. Furthermore, plasmids for cancer gene therapy can direct the expression of proteins with different functions, such as enzymes, toxins, and cytotoxic or proapoptotic proteins, to directly kill cancer cells. The progress and promising results reported in animal models in recent years have led to interesting clinical results. These DNA strategies are expected to be approved for cancer treatment in the near future. This review discusses the main strategies, challenges, and future perspectives of using plasmid DNA for cancer treatment.
Collapse
Affiliation(s)
| | - José Juan Pérez-Trujillo
- Histology Department, Faculty of Medicine, Universidad Autonoma de Nuevo Leon (UANL), Monterrey 64460, Mexico
| | - Laura Mireya Zavala-Flores
- Department of Molecular Genetics, Northeast Biomedical Research Center (CIBIN) of IMSS, Nuevo Leon Delegation, Monterrey 64720, Mexico
| | - Aracely García-García
- Histology Department, Faculty of Medicine, Universidad Autonoma de Nuevo Leon (UANL), Monterrey 64460, Mexico
| | - Arnulfo Villanueva-Olivo
- Histology Department, Faculty of Medicine, Universidad Autonoma de Nuevo Leon (UANL), Monterrey 64460, Mexico
| | - Humberto Rodríguez-Rocha
- Histology Department, Faculty of Medicine, Universidad Autonoma de Nuevo Leon (UANL), Monterrey 64460, Mexico
| | - Jesús Valdés
- Departamento de Bioquímica, CINVESTAV-México, Av. IPN 2508, Colonia San Pedro Zacatenco, Mexico City 07360, Mexico
| | - Odila Saucedo-Cárdenas
- Histology Department, Faculty of Medicine, Universidad Autonoma de Nuevo Leon (UANL), Monterrey 64460, Mexico
| | - Roberto Montes de Oca-Luna
- Histology Department, Faculty of Medicine, Universidad Autonoma de Nuevo Leon (UANL), Monterrey 64460, Mexico
- Correspondence: (R.M.d.O.-L.); (M.d.J.L.-A.); Tel.: +52-81-8329-4195 (R.M.d.O.-L. & M.d.J.L.-A.)
| | - María de Jesús Loera-Arias
- Histology Department, Faculty of Medicine, Universidad Autonoma de Nuevo Leon (UANL), Monterrey 64460, Mexico
- Correspondence: (R.M.d.O.-L.); (M.d.J.L.-A.); Tel.: +52-81-8329-4195 (R.M.d.O.-L. & M.d.J.L.-A.)
| |
Collapse
|
3
|
Microbial cytosine deaminase is a programmable anticancer prodrug mediating enzyme: antibody, and gene directed enzyme prodrug therapy. Heliyon 2022; 8:e10660. [PMID: 36164544 PMCID: PMC9508425 DOI: 10.1016/j.heliyon.2022.e10660] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/26/2022] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
Cytosine deaminase (CDA) is a non-mammalian enzyme with powerful activity in mediating the prodrug 5-fluorcytosine (5-FC) into toxic drug 5-fluorouracil (5-FU), as an alternative directed approach for the traditional chemotherapies and radiotherapies of cancer. This enzyme has been frequently reported and characterized from various microorganisms. The therapeutic strategy of 5-FC-CDA involves the administration of CDA followed by the prodrug 5-FC injection to generate cytotoxic 5-FU. The antiproliferative activity of CDA-5-FC elaborates from the higher activity of uracil pathway in tumor cells than normal ones. The main challenge of the therapeutic drug 5-FU are the short half-life, lack of selectivity and emergence of the drug resistance, consistently to the other chemotherapies. So, mediating the 5-FU to the tumor cells by CDA is one of the most feasible approaches to direct the drug to the tumor cells, reducing its toxic effects and improving their pharmacokinetic properties. Nevertheless, the catalytic efficiency, stability, antigenicity and targetability of CDA-5-FC, are the major challenges that limit the clinical application of this approach. Thus, exploring the biochemical properties of CDA from various microorganisms, as well as the approaches for localizing the system of CDA-5-FC to the tumor cells via the antibody directed enzyme prodrug therapy (ADEPT) and gene directed prodrug therapy (GDEPT) were the objectives of this review. Finally, the perspectives for increasing the therapeutic efficacy, and targetability of the CDA-5-FC system were described.
Collapse
|
4
|
Against the Resilience of High-Grade Gliomas: Gene Therapies (Part II). Brain Sci 2021; 11:brainsci11080976. [PMID: 34439595 PMCID: PMC8393930 DOI: 10.3390/brainsci11080976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/12/2021] [Accepted: 07/19/2021] [Indexed: 12/29/2022] Open
Abstract
Introduction: High-grade gliomas (HGGs) still have a high rate of recurrence and lethality. Gene therapies were projected to overcome the therapeutic resilience of HGGs, due to the intrinsic genetic heterogenicity and immune evasion pathways. The present literature review strives to provide an updated overview of the novel gene therapies for HGGs treatment, highlighting evidence from clinical trials, molecular mechanisms, and future perspectives. Methods: An extensive literature review was conducted through PubMed/Medline and ClinicalTrials.gov databases, using the keywords “high-grade glioma,” “glioblastoma,” and “malignant brain tumor”, combined with “gene therapy,” “oncolytic viruses,” “suicide gene therapies,” “tumor suppressor genes,” “immunomodulatory genes,” and “gene target therapies”. Only articles in English and published in the last 15 years were chosen, further screened based on best relevance. Data were analyzed and described according to the PRISMA guidelines. Results: Viruses were the most vehicles employed for their feasibility and transduction efficiency. Apart from liposomes, other viral vehicles remain largely still experimental. Oncolytic viruses and suicide gene therapies proved great results in phase I, II preclinical, and clinical trials. Tumor suppressor, immunomodulatory, and target genes were widely tested, showing encouraging results especially for recurrent HGGs. Conclusions: Oncolytic virotherapy and suicide genes strategies are valuable second-line treatment options for relapsing HGGs. Immunomodulatory approaches, tumor suppressor, and target genes therapies may implement and upgrade standard chemoradiotherapy. Future research aims to improve safety profile and prolonging therapeutic effectiveness. Further clinical trials are needed to assess the efficacy of gene-based therapies.
Collapse
|
5
|
Acosta J, Pérez E, Sánchez-Murcia PA, Fillat C, Fernández-Lucas J. Molecular Basis of NDT-Mediated Activation of Nucleoside-Based Prodrugs and Application in Suicide Gene Therapy. Biomolecules 2021; 11:biom11010120. [PMID: 33477716 PMCID: PMC7831932 DOI: 10.3390/biom11010120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 11/16/2022] Open
Abstract
Herein we report the first proof for the application of type II 2′-deoxyribosyltransferase from Lactobacillus delbrueckii (LdNDT) in suicide gene therapy for cancer treatment. To this end, we first confirm the hydrolytic ability of LdNDT over the nucleoside-based prodrugs 2′-deoxy-5-fluorouridine (dFUrd), 2′-deoxy-2-fluoroadenosine (dFAdo), and 2′-deoxy-6-methylpurine riboside (d6MetPRib). Such activity was significantly increased (up to 30-fold) in the presence of an acceptor nucleobase. To shed light on the strong nucleobase dependence for enzymatic activity, different molecular dynamics simulations were carried out. Finally, as a proof of concept, we tested the LdNDT/dFAdo system in human cervical cancer (HeLa) cells. Interestingly, LdNDT/dFAdo showed a pronounced reduction in cellular viability with inhibitory concentrations in the low micromolar range. These results open up future opportunities for the clinical implementation of nucleoside 2′-deoxyribosyltransferases (NDTs) in cancer treatment.
Collapse
Affiliation(s)
- Javier Acosta
- Applied Biotechnology Group, European University of Madrid, c/ Tajo s/n, Villaviciosa de Odón, 28670 Madrid, Spain; (J.A.); (E.P.)
| | - Elena Pérez
- Applied Biotechnology Group, European University of Madrid, c/ Tajo s/n, Villaviciosa de Odón, 28670 Madrid, Spain; (J.A.); (E.P.)
| | - Pedro A. Sánchez-Murcia
- Division of Physiological Chemistry, Otto-Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/III, A-8010 Graz, Austria;
| | - Cristina Fillat
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain;
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 08036 Barcelona, Spain
| | - Jesús Fernández-Lucas
- Division of Physiological Chemistry, Otto-Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/III, A-8010 Graz, Austria;
- Grupo de Investigación en Ciencias Naturales y Exactas, GICNEX, Universidad de la Costa, CUC, Calle 58 # 55-66 Barranquilla, Colombia
- Correspondence:
| |
Collapse
|
6
|
Kim GS, Hwang KA, Choi KC. A promising therapeutic strategy for metastatic gestational trophoblastic disease: Engineered anticancer gene-expressing stem cells to selectively target choriocarcinoma. Oncol Lett 2019; 17:2576-2582. [PMID: 30867726 DOI: 10.3892/ol.2019.9911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 09/19/2018] [Indexed: 12/31/2022] Open
Abstract
Gestational trophoblastic disease (GTD) is an unusual disease occurring in pregnancy that originates from abnormal trophoblastic cells and comprises a group of diseases with different properties of invasion, metastasis and recurrence. The GTD group includes hydatidiform moles and gestational trophoblastic neoplasms (GTNs), with GTNs being divided into invasive moles, choriocarcinoma, placental site trophoblastic tumors and epithelioid trophoblastic tumors. The present review focuses on current effective treatments for GTD, including conventional and novel promising direct enzyme prodrug therapies (DEPTs). Conventional therapies, such as chemotherapy and hysterectomy, are currently used in a clinical setting; however, the use of diverse DEPTs, including antibody-DEPT and gene-DEPT is also being attempted to cure GTNs. In addition, gene delivery tools using genetically engineered neural stem cells (NSCs) are presently being examined for the treatment of GTNs. The tumor-tropism of NSCs by chemoattractant factors is a unique characteristic of these cells and can serve as a vehicle to deliver anticancer agents. Previous studies have demonstrated that injection with NSC-expressing suicide genes into xenograft animal models has a significant inhibitory effect on tumor growth. Stem cells can be genetically engineered to express anticancer genes, which migrate to the metastatic sites and selectively target cancer cells, and are considered to effectively target metastatic GTNs. However, the safety issue of stem cell therapy, such as tumorigenesis, remains a challenge. Novel therapies comprising a combination of conventional and novel promising treatments are anticipated to be definitive treatments for metastasized and/or recurrent patients with GTNs.
Collapse
Affiliation(s)
- Gyu-Sik Kim
- Laboratory of Biochemistry and Immunology, College of Veterinary Medicine, Chungbuk National University, Cheongju, North Chungcheong 28644, Republic of Korea
| | - Kyung-A Hwang
- Laboratory of Biochemistry and Immunology, College of Veterinary Medicine, Chungbuk National University, Cheongju, North Chungcheong 28644, Republic of Korea
| | - Kyung-Chul Choi
- Laboratory of Biochemistry and Immunology, College of Veterinary Medicine, Chungbuk National University, Cheongju, North Chungcheong 28644, Republic of Korea
| |
Collapse
|
7
|
Parker WB, Sorscher EJ. Use of E. coli Purine Nucleoside Phosphorylase in the Treatment of Solid Tumors. Curr Pharm Des 2017; 23:CPD-EPUB-86774. [PMID: 29119917 PMCID: PMC6224313 DOI: 10.2174/1381612823666171109101851] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND The selective expression of non-human genes in tumor tissue to activate non-toxic compounds (Gene Directed Prodrug Enzyme Therapy, GDEPT) is a novel strategy designed for killing tumor cells in patients with little or no systemic toxicity. Numerous non-human genes have been evaluated, but none have yet been successful in the clinic. METHODS Unlike human purine nucleoside phosphorylase (PNP), E. coli PNP accepts adenine containing nucleosides as substrates, and is therefore able to selectively activate non-toxic purine analogs in tumor tissue. Various in vitro and in vivo assays have been utilized to evaluate E. coli PNP as a potential activating enzyme. RESULTS We and others have demonstrated excellent in vitro and in vivo anti-tumor activity with various GDEPT strategies utilizing E. coli PNP to activate purine nucleoside analogs. A phase I clinical trial utilizing recombinant adenoviral vector for delivery of E. coli PNP to solid tumors followed by systemic administration of fludarabine phosphate (NCT01310179; IND# 14271) has recently been completed. In this trial, significant anti-tumor activity was demonstrated with negligible toxicity related to the therapy. The mechanism of cell kill (inhibition of RNA and protein synthesis) is distinct from all currently used anticancer drugs and all experimental compounds under development. The approach has demonstrated excellent ability to kill neighboring tumor cells that do not express E. coli PNP, is active against non-proliferating and proliferating tumors cells (as well as tumor stem cells, stroma), and is therefore very effective against solid tumors with a low growth fraction. CONCLUSION The unique attributes distinguish this approach from other GDEPT strategies and are precisely those required to mediate significant improvements in antitumor therapy.
Collapse
|
8
|
Han W, Li W, Zhang X, Du Z, Liu X, Zhao X, Wen X, Wang G, Hu JF, Cui J. Targeted breast cancer therapy by harnessing the inherent blood group antigen immune system. Oncotarget 2017; 8:15034-15046. [PMID: 28122343 PMCID: PMC5362465 DOI: 10.18632/oncotarget.14746] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 01/10/2017] [Indexed: 12/25/2022] Open
Abstract
Cancer gene therapy has attracted increasing attention for its advantages over conventional therapy in specific killing of tumor cells. Here, we attempt to prove a novel therapeutic approach that targets tumors by harnessing the blood antigen immune response system, which is inherently present in patients with breast cancers. Breast cancer MDA-MB-231 cells expressed blood group H antigen precursor. After ectopic expression of blood group A glycosyltransferase, we found that the H precursor was converted into the group A antigen, appearing on the surface of tumor cells. Incubation with group B plasma from breast cancer patients activated the antigen-antibody-complement cascade and triggered tumor cell killing. Interestingly, expression of blood A antigen also reduced tumorigenesis in breast cancer cells by inhibiting cell proliferation, migration, and tumor sphere formation. Cell cycle analysis revealed that cancer cells were paused at S phase due to the activation of cell cycle regulatory genes. Furthermore, pro-apoptotic genes were unregulated by the A antigen, including BAX, P21, and P53, while the anti-apoptotic BCL2 was down regulated. Importantly, we showed that extracellular HMGB1 and ATP, two critical components of the immunogenic cell death pathway, were significantly increased in the blood A antigen-expressing tumor cells. Collectively, these data suggest that blood antigen therapy induces specific cancer cell killing by activating the apoptosis and immunogenic cell death pathways. Further translational studies are thereby warranted to apply this approach in cancer immuno-gene therapy.
Collapse
Affiliation(s)
- Wei Han
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| | - Wei Li
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| | - Xiaoying Zhang
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| | - Zhonghua Du
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| | - Xiaoliang Liu
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| | - Xin Zhao
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| | - Xue Wen
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| | - Guanjun Wang
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| | - Ji-Fan Hu
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China.,Stanford University Medical School, Palo Alto Veterans Institute for Research, Palo Alto, CA 94304, USA
| | - Jiuwei Cui
- Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130021, China
| |
Collapse
|
9
|
Mooney R, Abdul Majid A, Batalla J, Annala AJ, Aboody KS. Cell-mediated enzyme prodrug cancer therapies. Adv Drug Deliv Rev 2017; 118:35-51. [PMID: 28916493 DOI: 10.1016/j.addr.2017.09.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/15/2017] [Accepted: 09/06/2017] [Indexed: 02/08/2023]
Abstract
Cell-directed gene therapy is a promising new frontier for the field of targeted cancer therapies. Here we discuss the current pre-clinical and clinical use of cell-mediated enzyme prodrug therapy (EPT) directed against solid tumors and avenues for further development. We also discuss some of the challenges encountered upon translating these therapies to clinical trials. Upon sufficient development, cell-mediated enzyme prodrug therapy has the potential to maximize the distribution of therapeutic enzymes within the tumor environment, localizing conversion of prodrug to active drug at the tumor sites thereby decreasing off-target toxicities. New combinatorial possibilities are also promising. For example, when combined with viral gene-delivery vehicles, this may result in new hybrid vehicles that attain heretofore unmatched levels of therapeutic gene expression within the tumor.
Collapse
|
10
|
Hatefi A, Karjoo Z, Nomani A. Development of a Recombinant Multifunctional Biomacromolecule for Targeted Gene Transfer to Prostate Cancer Cells. Biomacromolecules 2017; 18:2799-2807. [PMID: 28806522 DOI: 10.1021/acs.biomac.7b00739] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The objective of this study was to genetically engineer a fully functional single chain fusion peptide composed of motifs from diverse biological and synthetic origins that can perform multiple tasks including DNA condensation, cell targeting, cell transfection, particle shielding from immune system and effective gene transfer to prostate tumors. To achieve the objective, a single chain biomacromolecule (vector) consisted of four repeatative units of histone H2A peptide, fusogenic peptide GALA, short elastin-like peptide, and PC-3 cell targeting peptide was designed. To examine the functionality of each motif in the vector sequence, it was characterized in terms of size and zeta potential by Zetasizer, PC-3 cell targeting and transfection by flowcytometry, IgG induction by immunogenicity assay, and PC-3 tumor transfection by quantitative live animal imaging. Overall, the results of this study showed the possibility of using genetic engineering techniques to program various functionalities into one single chain vector and create a multifunctional nonimmunogenic biomacromolecule for targeted gene transfer to prostate cancer cells. This proof-of-concept study is a significant step forward toward creating a library of vectors for targeted gene transfer to any cancer cell type at both in vitro and in vivo levels.
Collapse
Affiliation(s)
- Arash Hatefi
- Department of Pharmaceutics, Rutgers The State University of New Jersey , Piscataway, New Jersey 08854, United States.,Rutgers Cancer Institute of New Jersey , New Brunswick, New Jersey 08903, United States
| | - Zahra Karjoo
- Department of Pharmaceutics, Rutgers The State University of New Jersey , Piscataway, New Jersey 08854, United States
| | - Alireza Nomani
- Department of Pharmaceutics, Rutgers The State University of New Jersey , Piscataway, New Jersey 08854, United States
| |
Collapse
|
11
|
Orozco Rodriguez JM, Nesrini M, Christiansen LS, Knecht W. Expression of tomato thymidine kinase 1 by means of the baculovirus expression vector system. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2017; 35:691-698. [PMID: 27906616 DOI: 10.1080/15257770.2016.1139126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Tomato thymidine kinase 1 (ToTK1) is a deoxyribonucleoside kinase (dNK) that has been subject to study because of its potential to phosphorylate the nucleoside analogue 3-azido-2,3-dideoxythymidine (azidothymidine, AZT) equally well as its natural substrate thymidine (dThd). The combination of ToTK1 and AZT has been tested in two animal studies for its efficiency and use in suicide gene therapy for malignant glioma. The determination of the 3D structure of ToTK1 might shed light on the structure-function relationships of nucleoside activation by this enzyme and thereby show routes toward further improvement of ToTK1 and other TK1-like dNKs for suicide gene therapy. Here we report the successful expression of both full-length ToTK1 and a C-terminal truncated ToTK1 in Spodoptera frugiperda and Trichoplusia ni insect cells using the baculovirus expression vector system. This constitutes a further step on the road to determine the 3D structure of the first TK1 of plant origin, but also an enzyme with great potential for dNK-mediated suicide gene therapy.
Collapse
Affiliation(s)
| | - Mohamad Nesrini
- a Department of Biology and Lund Protein Production Platform , Lund University , Lund , Sweden
| | | | - Wolfgang Knecht
- a Department of Biology and Lund Protein Production Platform , Lund University , Lund , Sweden
| |
Collapse
|
12
|
Bezborodova OA, Nemtsova ER, Gevorkov AR, Boyko AV, Venediktova JB, Alekseenko IV, Kostina MB, Monastyrskaya GS, Sverdlov ED, Khmelevskiy EV, Yakubovskaya RI. Antitumor efficacy of combined gene and radiotherapy in animals. DOKL BIOCHEM BIOPHYS 2016; 470:345-348. [PMID: 27817015 DOI: 10.1134/s1607672916050112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Indexed: 11/22/2022]
Abstract
Antitumor efficacy of the combined suicide gene therapy and radiotherapy was studied on the model of CT26 murine colon adenocarcinoma. CMV-FCU1-IRES-mGM-CSF-pGL3 construct with PEG-PEI-TAT (FCU1-mGM/5-FC) block copolymer as a vector was used for intratumoral administration. Tumors were irradiated with a single 5 Gy dose. The efficacy was evaluated according to the grade of tumor growth inhibition (T/C) and lifespan of the animals. Pronounced antitumor activity of the combined use of FCU1-mGM/5-FC system with radiotherapy on the background of prolonged lifespan and the synergism of the applied methods was revealed.
Collapse
Affiliation(s)
- O A Bezborodova
- National Medical Research Radiological Center (NMRRC), Ministry of Healthcare of the Russian Federation, Obninsk, Kaluga oblast, Russia.
| | - E R Nemtsova
- National Medical Research Radiological Center (NMRRC), Ministry of Healthcare of the Russian Federation, Obninsk, Kaluga oblast, Russia
| | - A R Gevorkov
- National Medical Research Radiological Center (NMRRC), Ministry of Healthcare of the Russian Federation, Obninsk, Kaluga oblast, Russia
| | - A V Boyko
- National Medical Research Radiological Center (NMRRC), Ministry of Healthcare of the Russian Federation, Obninsk, Kaluga oblast, Russia
| | - J B Venediktova
- National Medical Research Radiological Center (NMRRC), Ministry of Healthcare of the Russian Federation, Obninsk, Kaluga oblast, Russia
| | - I V Alekseenko
- Institute of Molecular Genetics, Russian Academy of Sciences, pl. Akademika Kurchatova 46, Moscow, 123182, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - M B Kostina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - G S Monastyrskaya
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - E D Sverdlov
- Institute of Molecular Genetics, Russian Academy of Sciences, pl. Akademika Kurchatova 46, Moscow, 123182, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - E V Khmelevskiy
- National Medical Research Radiological Center (NMRRC), Ministry of Healthcare of the Russian Federation, Obninsk, Kaluga oblast, Russia
| | - R I Yakubovskaya
- National Medical Research Radiological Center (NMRRC), Ministry of Healthcare of the Russian Federation, Obninsk, Kaluga oblast, Russia
| |
Collapse
|
13
|
Sato T, Yanagisawa T. [The engineered thymidylate kinase (TMPK)/azidothymidine (AZT)-axis offers efficient bystander cell killing effect for suicide gene therapy for cancer]. Nihon Yakurigaku Zasshi 2016; 147:326-9. [PMID: 27301304 DOI: 10.1254/fpj.147.326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
14
|
Progress and problems with the use of suicide genes for targeted cancer therapy. Adv Drug Deliv Rev 2016; 99:113-128. [PMID: 26004498 DOI: 10.1016/j.addr.2015.05.009] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 02/19/2015] [Accepted: 05/14/2015] [Indexed: 12/16/2022]
Abstract
Among various gene therapy methods for cancer, suicide gene therapy attracts a special attention because it allows selective conversion of non-toxic compounds into cytotoxic drugs inside cancer cells. As a result, therapeutic index can be increased significantly by introducing high concentrations of cytotoxic molecules to the tumor environment while minimizing impact on normal tissues. Despite significant success at the preclinical level, no cancer suicide gene therapy protocol has delivered the desirable clinical significance yet. This review gives a critical look at the six main enzyme/prodrug systems that are used in suicide gene therapy of cancer and familiarizes readers with the state-of-the-art research and practices in this field. For each enzyme/prodrug system, the mechanisms of action, protein engineering strategies to enhance enzyme stability/affinity and chemical modification techniques to increase prodrug kinetics and potency are discussed. In each category, major clinical trials that have been performed in the past decade with each enzyme/prodrug system are discussed to highlight the progress to date. Finally, shortcomings are underlined and areas that need improvement in order to produce clinical significance are delineated.
Collapse
|
15
|
Guan X. Metabolic Activation and Drug Targeting. Drug Deliv 2016. [DOI: 10.1002/9781118833322.ch17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
16
|
Wierzchowski J, Antosiewicz JM, Shugar D. 8-Azapurines as isosteric purine fluorescent probes for nucleic acid and enzymatic research. MOLECULAR BIOSYSTEMS 2015; 10:2756-74. [PMID: 25124808 DOI: 10.1039/c4mb00233d] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The 8-azapurines, and their 7-deaza and 9-deaza congeners, represent a unique class of isosteric (isomorphic) analogues of the natural purines, frequently capable of substituting for the latter in many biochemical processes. Particularly interesting is their propensity to exhibit pH-dependent room-temperature fluorescence in aqueous medium, and in non-polar media. We herein review the physico-chemical properties of this class of compounds, with particular emphasis on the fluorescence emission properties of their neutral and/or ionic species, which has led to their widespread use as fluorescent probes in enzymology, including enzymes involved in purine metabolism, agonists/antagonists of adenosine receptors, mechanisms of catalytic RNAs, RNA editing, etc. They are also exceptionally useful fluorescent probes for analytical and clinical applications in crude cell homogenates.
Collapse
Affiliation(s)
- Jacek Wierzchowski
- Department of Biophysics, University of Varmia & Masuria, Oczapowskiego 4, 10-719 Olsztyn, Poland.
| | | | | |
Collapse
|
17
|
Alekseenko IV, Snezhkov EV, Chernov IP, Pleshkan VV, Potapov VK, Sass AV, Monastyrskaya GS, Kopantzev EP, Vinogradova TV, Khramtsov YV, Ulasov AV, Rosenkranz AA, Sobolev AS, Bezborodova OA, Plyutinskaya AD, Nemtsova ER, Yakubovskaya RI, Sverdlov ED. Therapeutic properties of a vector carrying the HSV thymidine kinase and GM-CSF genes and delivered as a complex with a cationic copolymer. J Transl Med 2015; 13:78. [PMID: 25880666 PMCID: PMC4359447 DOI: 10.1186/s12967-015-0433-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 02/10/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Gene-directed enzyme prodrug therapy (GDEPT) represents a technology to improve drug selectivity for cancer cells. It consists of delivery into tumor cells of a suicide gene responsible for in situ conversion of a prodrug into cytotoxic metabolites. Major limitations of GDEPT that hinder its clinical application include inefficient delivery into cancer cells and poor prodrug activation by suicide enzymes. We tried to overcome these constraints through a combination of suicide gene therapy with immunomodulating therapy. Viral vectors dominate in present-day GDEPT clinical trials due to efficient transfection and production of therapeutic genes. However, safety concerns associated with severe immune and inflammatory responses as well as high cost of the production of therapeutic viruses can limit therapeutic use of virus-based therapeutics. We tried to overcome this problem by using a simple nonviral delivery system. METHODS We studied the antitumor efficacy of a PEI (polyethylenimine)-PEG (polyethylene glycol) copolymer carrying the HSVtk gene combined in one vector with granulocyte-macrophage colony-stimulating factor (GM-CSF) cDNA. The system HSVtk-GM-CSF/PEI-PEG was tested in vitro in various mouse and human cell lines, ex vivo and in vivo using mouse models. RESULTS We showed that the HSVtk-GM-CSF/PEI-PEG system effectively inhibited the growth of transplanted human and mouse tumors, suppressed metastasis and increased animal lifespan. CONCLUSIONS We demonstrated that appreciable tumor shrinkage and metastasis inhibition could be achieved with a simple and low toxic chemical carrier - a PEI-PEG copolymer. Our data indicate that combined suicide and cytokine gene therapy may provide a powerful approach for the treatment of solid tumors and their metastases.
Collapse
Affiliation(s)
- Irina V Alekseenko
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Sq. 2, Moscow, 123182, Russia.
| | - Eugene V Snezhkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
| | - Igor P Chernov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
| | - Victor V Pleshkan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Sq. 2, Moscow, 123182, Russia.
| | - Victor K Potapov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
| | - Alexander V Sass
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
| | - Galina S Monastyrskaya
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
| | - Eugene P Kopantzev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
| | - Tatyana V Vinogradova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
| | - Yuri V Khramtsov
- Institute of Gene Biology, Russian Academy of Sciences, ul. Vavilova, 34/5, Moscow, 119334, Russia.
| | - Alexey V Ulasov
- Institute of Gene Biology, Russian Academy of Sciences, ul. Vavilova, 34/5, Moscow, 119334, Russia.
| | - Andrey A Rosenkranz
- Institute of Gene Biology, Russian Academy of Sciences, ul. Vavilova, 34/5, Moscow, 119334, Russia.
- Moscow State University, Biological Faculty, ul. Leninskiye Gory, 1-12, Moscow, 119234, Russia.
| | - Alexander S Sobolev
- Institute of Gene Biology, Russian Academy of Sciences, ul. Vavilova, 34/5, Moscow, 119334, Russia.
- Moscow State University, Biological Faculty, ul. Leninskiye Gory, 1-12, Moscow, 119234, Russia.
| | - Olga A Bezborodova
- Moscow Hertsen Research Institute of Oncology, Russian Ministry of Health Care, 2nd Botkinskiy proezd 3, Moscow, 125284, Russia.
| | - Anna D Plyutinskaya
- Moscow Hertsen Research Institute of Oncology, Russian Ministry of Health Care, 2nd Botkinskiy proezd 3, Moscow, 125284, Russia.
| | - Elena R Nemtsova
- Moscow Hertsen Research Institute of Oncology, Russian Ministry of Health Care, 2nd Botkinskiy proezd 3, Moscow, 125284, Russia.
| | - Raisa I Yakubovskaya
- Moscow Hertsen Research Institute of Oncology, Russian Ministry of Health Care, 2nd Botkinskiy proezd 3, Moscow, 125284, Russia.
| | - Eugene D Sverdlov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia.
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Sq. 2, Moscow, 123182, Russia.
| |
Collapse
|
18
|
Slot Christiansen L, Munch-Petersen B, Knecht W. Non-Viral Deoxyribonucleoside Kinases--Diversity and Practical Use. J Genet Genomics 2015; 42:235-48. [PMID: 26059771 DOI: 10.1016/j.jgg.2015.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/04/2015] [Accepted: 01/05/2015] [Indexed: 12/30/2022]
Abstract
Deoxyribonucleoside kinases (dNKs) phosphorylate deoxyribonucleosides to their corresponding monophosphate compounds. dNks also phosphorylate deoxyribonucleoside analogues that are used in the treatment of cancer or viral infections. The study of the mammalian dNKs has therefore always been of great medical interest. However, during the last 20 years, research on dNKs has gone into non-mammalian organisms. In this review, we focus on non-viral dNKs, in particular their diversity and their practical applications. The diversity of this enzyme family in different organisms has proven to be valuable in studying the evolution of enzymes. Some of these newly discovered enzymes have been useful in numerous practical applications in medicine and biotechnology, and have contributed to our understanding of the structural basis of nucleoside and nucleoside analogue activation.
Collapse
Affiliation(s)
| | - Birgitte Munch-Petersen
- Department of Biology, Lund University, Lund 22362, Sweden; Department of Science, Systems and Models, Roskilde University, Roskilde 4000, Denmark
| | - Wolfgang Knecht
- Department of Biology, Lund University, Lund 22362, Sweden; Lund Protein Production Platform, Lund University, Lund 22362, Sweden.
| |
Collapse
|
19
|
Vande Voorde J, Balzarini J, Liekens S. Mycoplasmas and cancer: focus on nucleoside metabolism. EXCLI JOURNAL 2014; 13:300-22. [PMID: 26417262 PMCID: PMC4464442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 02/19/2014] [Indexed: 11/26/2022]
Abstract
The standard of care for patients suffering cancer often includes treatment with nucleoside analogues (NAs). NAs are internalized by cell-specific nucleobase/nucleoside transporters and, after enzymatic activation (often one or more phosphorylation steps), interfere with cellular nucleo(s)(t)ide metabolism and DNA/RNA synthesis. Therefore, their efficacy is highly dependent on the expression and activity of nucleo(s)(t)ide-metabolizing enzymes, and alterations thereof (e.g. by down/upregulated expression or mutations) may change the susceptibility to NA-based therapy and/or confer drug resistance. Apart from host cell factors, several other variables including microbial presence may determine the metabolome (i.e. metabolite concentrations) of human tissues. Studying the diversity of microorganisms that are associated with the human body has already provided new insights in several diseases (e.g. diabetes and inflammatory bowel disease) and the metabolic exchange between tissues and their specific microbiota was found to affect the bioavailability and toxicity of certain anticancer drugs, including NAs. Several studies report a preferential colonization of tumor tissues with some mycoplasma species (mostly Mycoplasma hyorhinis). These prokaryotes are also a common source of cell culture contamination and alter the cytostatic activity of some NAs in vitro due to the expression of nucleoside-catabolizing enzymes. Mycoplasma infection may therefore bias experimental work with NAs, and their presence in the tumor microenvironment could be of significance when optimizing nucleoside-based cancer treatment.
Collapse
Affiliation(s)
- Johan Vande Voorde
- Rega Institute for Medical Research, KU Leuven, Minderbroedersstraat 10, blok x - bus 1030, B-3000 Leuven, Belgium
| | - Jan Balzarini
- Rega Institute for Medical Research, KU Leuven, Minderbroedersstraat 10, blok x - bus 1030, B-3000 Leuven, Belgium
| | - Sandra Liekens
- Rega Institute for Medical Research, KU Leuven, Minderbroedersstraat 10, blok x - bus 1030, B-3000 Leuven, Belgium
| |
Collapse
|
20
|
Abstract
Early-stage clinical trials of oncolytic virotherapy have reported the safety of several virus platforms, and viruses from three families have progressed to advanced efficacy trials. In addition, preclinical studies have established proof-of-principle for many new genetic engineering strategies. Thus, the virotherapy field now has available a diverse collection of viruses that are equipped to address unmet clinical needs owing to improved systemic administration, greater tumour specificity and enhanced oncolytic efficacy. The current key challenge for the field is to develop viruses that replicate with greater efficiency within tumours while achieving therapeutic synergy with currently available treatments.
Collapse
|
21
|
Kwiatkowska A, Nandhu MS, Behera P, Chiocca EA, Viapiano MS. Strategies in gene therapy for glioblastoma. Cancers (Basel) 2013; 5:1271-305. [PMID: 24202446 PMCID: PMC3875940 DOI: 10.3390/cancers5041271] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 10/15/2013] [Indexed: 01/01/2023] Open
Abstract
Glioblastoma (GBM) is the most aggressive form of brain cancer, with a dismal prognosis and extremely low percentage of survivors. Novel therapies are in dire need to improve the clinical management of these tumors and extend patient survival. Genetic therapies for GBM have been postulated and attempted for the past twenty years, with variable degrees of success in pre-clinical models and clinical trials. Here we review the most common approaches to treat GBM by gene therapy, including strategies to deliver tumor-suppressor genes, suicide genes, immunomodulatory cytokines to improve immune response, and conditionally-replicating oncolytic viruses. The review focuses on the strategies used for gene delivery, including the most common and widely used vehicles (i.e., replicating and non-replicating viruses) as well as novel therapeutic approaches such as stem cell-mediated therapy and nanotechnologies used for gene delivery. We present an overview of these strategies, their targets, different advantages, and challenges for success. Finally, we discuss the potential of gene therapy-based strategies to effectively attack such a complex genetic target as GBM, alone or in combination with conventional therapy.
Collapse
Affiliation(s)
- Aneta Kwiatkowska
- Department of Neurosurgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | | | | | | | | |
Collapse
|
22
|
Vande Voorde J, Liekens S, Balzarini J. Mycoplasma hyorhinis-encoded purine nucleoside phosphorylase: kinetic properties and its effect on the cytostatic potential of purine-based anticancer drugs. Mol Pharmacol 2013; 84:865-75. [PMID: 24068428 DOI: 10.1124/mol.113.088625] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A mycoplasma-encoded purine nucleoside phosphorylase (designated PNPHyor) has been cloned and characterized for the first time. Efficient phosphorolysis of natural 6-oxopurine and 6-aminopurine nucleosides was observed, with adenosine the preferred natural substrate (Km = 61 µM). Several cytostatic purine nucleoside analogs proved to be susceptible to PNPHyor-mediated phosphorolysis, and a markedly decreased or increased cytostatic activity was observed in Mycoplasma hyorhinis-infected human breast carcinoma MCF-7 cell cultures (MCF-7.Hyor), depending on the properties of the released purine base. We demonstrated an ∼10-fold loss of cytostatic activity of cladribine in MCF-7.Hyor cells and observed a rapid and complete phosphorolysis of this drug when it was exposed to the supernatant of mycoplasma-infected cells. This conversion (inactivation) could be prevented by a specific PNP inhibitor. These findings correlated well with the high efficiency of PNPHyor-catalyzed phosphorolysis of cladribine to its less toxic base 2-chloroadenine (Km = 80 µM). In contrast, the cytostatic activity of nucleoside analogs carrying a highly toxic purine base and being a substrate for PNPHyor, but not human PNP, was substantially increased in MCF-7.Hyor cells (∼130-fold for fludarabine and ∼45-fold for 6-methylpurine-2'-deoxyriboside). Elimination of the mycoplasma from the tumor cell cultures or selective inhibition of PNPHyor by a PNP inhibitor restored the cytostatic activity of the purine-based nucleoside drugs. Since several studies suggest a high and preferential colonization or association of tumor tissue in cancer patients with different prokaryotes (including mycoplasmas), the data presented here may be of relevance for the optimization of purine nucleoside-based anticancer drug treatment.
Collapse
|
23
|
Current world literature. Curr Opin Pediatr 2012; 24:770-9. [PMID: 23146873 DOI: 10.1097/mop.0b013e32835af8de] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|