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Sadat SMA, Vakili MR, Abd-El Hafeez SI, Paladino M, Hall DG, Weinfeld M, Lavasanifar A. Synergistic Nanomedicine Delivering Topoisomerase I Toxin (SN-38) and Inhibitors of Polynucleotide Kinase 3'-Phosphatase (PNKP) for Enhanced Treatment of Colorectal Cancer. Mol Pharm 2024. [PMID: 38785196 DOI: 10.1021/acs.molpharmaceut.4c00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Inhibitors of a DNA repair enzyme known as polynucleotide kinase 3'-phosphatase (PNKP) are expected to show synergistic cytotoxicity in combination with topoisomerase I (TOP1) inhibitors in cancer. In this study, the synergistic cytotoxicity of a novel inhibitor of PNKP, i.e., A83B4C63, with a potent TOP1 inhibitor, i.e., SN-38, against colorectal cancer cells was investigated. Polymeric micelles (PMs) for preferred tumor delivery of A83B4C63, developed through physical encapsulation of this compound in methoxy poly(ethylene oxide)-poly(α-benzyl carboxylate-ε-caprolactone) (mPEO-b-PBCL) micelles, were combined with SN-38 in free or PM form. The PM form of SN-38 was prepared through chemical conjugation of SN-38 to the functional end group of mPEO-b-PBCL and further assembly of mPEO-b-PBCL-SN-38 in water. Moreover, mixed micelles composed of mPEO-b-PBCL and mPEO-b-PBCL-SN-38 were used to co-load A83B4C63 and SN-38 in the same nanoformulation. The loading content (% w/w) of the SN-38 and A83B4C63 to mPEO-b-PBCL in the co-loaded formulation was 7.91 ± 0.66 and 16.13 ± 0.11% (w/w), respectively, compared to 15.67 ± 0.34 (% w/w) and 23.06 ± 0.63 (% w/w) for mPEO-b-PBCL micelles loading individual drugs. Notably, the average diameter of PMs co-encapsulating both SN-38 and A83B4C63 was larger than that of PMs encapsulating either of these compounds alone but still lower than 60 nm. The release of A83B4C63 from PMs co-encapsulating both drugs was 76.36 ± 1.41% within 24 h, which was significantly higher than that of A83B4C63-encapsulated micelles (42.70 ± 0.72%). In contrast, the release of SN-38 from PMs co-encapsulating both drugs was 44.15 ± 2.61% at 24 h, which was significantly lower than that of SN-38-conjugated PMs (74.16 ± 3.65%). Cytotoxicity evaluations by the MTS assay as analyzed by the Combenefit software suggested a clear synergy between PM/A83B4C63 (at a concentration range of 10-40 μM) and free SN-38 (at a concentration range of 0.001-1 μM). The synergistic cytotoxic concentration range for SN-38 was narrowed down to 0.1-1 or 0.01-1 μM when combined with PM/A83B4C63 at 10 or 20-40 μM, respectively. In general, PMs co-encapsulating A83B4C63 and SN-38 at drug concentrations within the synergistic range (10 μM for A83B4C63 and 0.05-1 μM for SN-38) showed slightly less enhancement of SN-38 anticancer activity than a combination of individual micelles, i.e., A83B4C63 PMs + SN-38 PMs at the same molar concentrations. This was attributed to the slower release of SN-38 from the SN-38 and A83B4C63 co-encapsulated PMs compared to PMs only encapsulating SN-38. Cotreatment of cells with TOP1 inhibitors and A83B4C63 formulation enhanced the expression level of γ-HA2X, cleaved PARP, caspase-3, and caspase-7 in most cases. This trend was more consistent and notable for PMs co-encapsulating both A83B4C63 and SN-38. The overall result from the study shows a synergy between PMs of SN-38 and A83B4C63 as a mixture of two PMs for individual drugs or PMs co-encapsulating both drugs.
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Affiliation(s)
- Sams M A Sadat
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - Mohammad Reza Vakili
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - Sara I Abd-El Hafeez
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
- Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut 71515, Egypt
| | - Marco Paladino
- Department of Chemistry, Faculty of Science, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - Dennis G Hall
- Department of Chemistry, Faculty of Science, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - Michael Weinfeld
- Department of Oncology, Cross Cancer Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - Afsaneh Lavasanifar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
- Department of Chemical and Material Engineering, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
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Ertay A, Ewing RM, Wang Y. Synthetic lethal approaches to target cancers with loss of PTEN function. Genes Dis 2023; 10:2511-2527. [PMID: 37533462 PMCID: PMC7614861 DOI: 10.1016/j.gendis.2022.12.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 02/05/2023] Open
Abstract
Phosphatase and tensin homolog (PTEN) is a tumour suppressor gene and has a role in inhibiting the oncogenic AKT signalling pathway by dephosphorylating phosphatidylinositol 3,4,5-triphosphate (PIP3) into phosphatidylinositol 4,5-bisphosphate (PIP2). The function of PTEN is regulated by different mechanisms and inactive PTEN results in aggressive tumour phenotype and tumorigenesis. Identifying targeted therapies for inactive tumour suppressor genes such as PTEN has been challenging as it is difficult to restore the tumour suppressor functions. Therefore, focusing on the downstream signalling pathways to discover a targeted therapy for inactive tumour suppressor genes has highlighted the importance of synthetic lethality studies. This review focuses on the potential synthetic lethality genes discovered in PTEN-inactive cancer types. These discovered genes could be potential targeted therapies for PTEN-inactive cancer types and may improve the treatment response rates for aggressive types of cancer.
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Affiliation(s)
- Ayse Ertay
- Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Rob M. Ewing
- Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Yihua Wang
- Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
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Gohil D, Sarker AH, Roy R. Base Excision Repair: Mechanisms and Impact in Biology, Disease, and Medicine. Int J Mol Sci 2023; 24:14186. [PMID: 37762489 PMCID: PMC10531636 DOI: 10.3390/ijms241814186] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Base excision repair (BER) corrects forms of oxidative, deamination, alkylation, and abasic single-base damage that appear to have minimal effects on the helix. Since its discovery in 1974, the field has grown in several facets: mechanisms, biology and physiology, understanding deficiencies and human disease, and using BER genes as potential inhibitory targets to develop therapeutics. Within its segregation of short nucleotide (SN-) and long patch (LP-), there are currently six known global mechanisms, with emerging work in transcription- and replication-associated BER. Knockouts (KOs) of BER genes in mouse models showed that single glycosylase knockout had minimal phenotypic impact, but the effects were clearly seen in double knockouts. However, KOs of downstream enzymes showed critical impact on the health and survival of mice. BER gene deficiency contributes to cancer, inflammation, aging, and neurodegenerative disorders. Medicinal targets are being developed for single or combinatorial therapies, but only PARP and APE1 have yet to reach the clinical stage.
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Affiliation(s)
- Dhara Gohil
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, USA;
| | - Altaf H. Sarker
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA;
| | - Rabindra Roy
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, USA;
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Zika Virus Induces Mitotic Catastrophe in Human Neural Progenitors by Triggering Unscheduled Mitotic Entry in the Presence of DNA Damage While Functionally Depleting Nuclear PNKP. J Virol 2022; 96:e0033322. [PMID: 35412344 PMCID: PMC9093132 DOI: 10.1128/jvi.00333-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Vertical transmission of Zika virus (ZIKV) leads with high frequency to congenital ZIKV syndrome (CZS), whose worst outcome is microcephaly. However, the mechanisms of congenital ZIKV neurodevelopmental pathologies, including direct cytotoxicity to neural progenitor cells (NPC), placental insufficiency, and immune responses, remain incompletely understood. At the cellular level, microcephaly typically results from death or insufficient proliferation of NPC or cortical neurons. NPC replicate fast, requiring efficient DNA damage responses to ensure genome stability. Like congenital ZIKV infection, mutations in the polynucleotide 5′-kinase 3′-phosphatase (PNKP) gene, which encodes a critical DNA damage repair enzyme, result in recessive syndromes often characterized by congenital microcephaly with seizures (MCSZ). We thus tested whether there were any links between ZIKV and PNKP. Here, we show that two PNKP phosphatase inhibitors or PNKP knockout inhibited ZIKV replication. PNKP relocalized from the nucleus to the cytoplasm in infected cells, colocalizing with the marker of ZIKV replication factories (RF) NS1 and resulting in functional nuclear PNKP depletion. Although infected NPC accumulated DNA damage, they failed to activate the DNA damage checkpoint kinases Chk1 and Chk2. ZIKV also induced activation of cytoplasmic CycA/CDK1 complexes, which trigger unscheduled mitotic entry. Inhibition of CDK1 activity inhibited ZIKV replication and the formation of RF, supporting a role of cytoplasmic CycA/CDK1 in RF morphogenesis. In brief, ZIKV infection induces mitotic catastrophe resulting from unscheduled mitotic entry in the presence of DNA damage. PNKP and CycA/CDK1 are thus host factors participating in ZIKV replication in NPC, and pathogenesis to neural progenitor cells. IMPORTANCE The 2015–2017 Zika virus (ZIKV) outbreak in Brazil and subsequent international epidemic revealed the strong association between ZIKV infection and congenital malformations, mostly neurodevelopmental defects up to microcephaly. The scale and global expansion of the epidemic, the new ZIKV outbreaks (Kerala state, India, 2021), and the potential burden of future ones pose a serious ongoing risk. However, the cellular and molecular mechanisms resulting in microcephaly remain incompletely understood. Here, we show that ZIKV infection of neuronal progenitor cells results in cytoplasmic sequestration of an essential DNA repair protein itself associated with microcephaly, with the consequent accumulation of DNA damage, together with an unscheduled activation of cytoplasmic CDK1/Cyclin A complexes in the presence of DNA damage. These alterations result in mitotic catastrophe of neuronal progenitors, which would lead to a depletion of cortical neurons during development.
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de Paiva IM, Vakili MR, Soleimani AH, Tabatabaei Dakhili SA, Munira S, Paladino M, Martin G, Jirik FR, Hall DG, Weinfeld M, Lavasanifar A. Biodistribution and Activity of EGFR Targeted Polymeric Micelles Delivering a New Inhibitor of DNA Repair to Orthotopic Colorectal Cancer Xenografts with Metastasis. Mol Pharm 2022; 19:1825-1838. [PMID: 35271294 PMCID: PMC9175178 DOI: 10.1021/acs.molpharmaceut.1c00918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The disruption of polynucleotide kinase/phosphatase (PNKP) in colorectal cancer (CRC) cells deficient in phosphatase and tensin homolog (PTEN) is expected to lead to the loss of cell viability by a process known as synthetic lethality. In previous studies, we have reported on the encapsulation of a novel inhibitor of PNKP, namely, A83B4C63, in polymeric micelles and its activity in slowing the growth of PTEN-deficient CRC cells as well as subcutaneous xenografts. In this study, to enhance drug delivery and specificity to CRC tumors, the surface of polymeric micelles carrying A83B4C63 was modified with GE11, a peptide targeting epidermal growth factor receptor (EGFR) overexpressed in about 70% of CRC tumors. Using molecular dynamics (MD) simulations, we assessed the binding site and affinity of GE11 for EGFR. The GE11-modified micelles, tagged with a near-infrared fluorophore, showed enhanced internalization by EGFR-overexpressing CRC cells in vitro and a trend toward increased primary tumor homing in an orthotopic CRC xenograft in vivo. In line with these observations, the GE11 modification of polymeric micelles was shown to positively contribute to the improved therapeutic activity of encapsulated A83B4C63 against HCT116-PTEN-/- cells in vitro and that of orthotopic CRC xenograft in vivo. In conclusion, our results provided proof of principle evidence for the potential benefit of EGFR targeted polymeric micellar formulations of A83B4C63 as monotherapeutics for aggressive and metastatic CRC tumors but at the same time highlighted the need for the development of EGFR ligands with improved physiological stability and EGFR binding.
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Affiliation(s)
- Igor Moura de Paiva
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2EZ, Canada
| | - Mohammad Reza Vakili
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2EZ, Canada
| | - Amir Hasan Soleimani
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2EZ, Canada
| | | | - Sirazum Munira
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2EZ, Canada
| | - Marco Paladino
- Department of Chemistry, Faculty of Science, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | | | | | - Dennis G Hall
- Department of Chemistry, Faculty of Science, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Michael Weinfeld
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 1Z2, Canada
| | - Afsaneh Lavasanifar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2EZ, Canada.,Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB T6G 2H5, Canada
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Sadat SMA, Wuest M, Paiva IM, Munira S, Sarrami N, Sanaee F, Yang X, Paladino M, Binkhathlan Z, Karimi-Busheri F, Martin GR, Jirik FR, Murray D, Gamper AM, Hall DG, Weinfeld M, Lavasanifar A. Nano-Delivery of a Novel Inhibitor of Polynucleotide Kinase/Phosphatase (PNKP) for Targeted Sensitization of Colorectal Cancer to Radiation-Induced DNA Damage. Front Oncol 2022; 11:772920. [PMID: 35004293 PMCID: PMC8733593 DOI: 10.3389/fonc.2021.772920] [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: 09/09/2021] [Accepted: 11/24/2021] [Indexed: 12/29/2022] Open
Abstract
Inhibition of the DNA repair enzyme polynucleotide kinase/phosphatase (PNKP) increases the sensitivity of cancer cells to DNA damage by ionizing radiation (IR). We have developed a novel inhibitor of PNKP, i.e., A83B4C63, as a potential radio-sensitizer for the treatment of solid tumors. Systemic delivery of A83B4C63, however, may sensitize both cancer and normal cells to DNA damaging therapeutics. Preferential delivery of A83B4C63 to solid tumors by nanoparticles (NP) was proposed to reduce potential side effects of this PNKP inhibitor to normal tissue, particularly when combined with DNA damaging therapies. Here, we investigated the radio-sensitizing activity of A83B4C63 encapsulated in NPs (NP/A83) based on methoxy poly(ethylene oxide)-b-poly(α-benzyl carboxylate-ε-caprolactone) (mPEO-b-PBCL) or solubilized with the aid of Cremophor EL: Ethanol (CE/A83) in human HCT116 colorectal cancer (CRC) models. Levels of γ-H2AX were measured and the biodistribution of CE/A83 and NP/A83 administered intravenously was determined in subcutaneous HCT116 CRC xenografts. The radio-sensitization effect of A83B4C63 was measured following fractionated tumor irradiation using an image-guided Small Animal Radiation Research Platform (SARRP), with 24 h pre-administration of CE/A83 and NP/A83 to Luc+/HCT116 bearing mice. Therapeutic effects were analyzed by monitoring tumor growth and functional imaging using Positron Emission Tomography (PET) and [18F]-fluoro-3’-deoxy-3’-L:-fluorothymidine ([18F]FLT) as a radiotracer for cell proliferation. The results showed an increased persistence of DNA damage in cells treated with a combination of CE/A83 or NP/A83 and IR compared to those only exposed to IR. Significantly higher tumor growth delay in mice treated with a combination of IR and NP/A83 than those treated with IR plus CE/A83 was observed. [18F]FLT PET displayed significant functional changes for tumor proliferation for the drug-loaded NP. This observation was attributed to the higher A83B4C63 levels in the tumors for NP/A83-treated mice compared to those treated with CE/A83. Overall, the results demonstrated a potential for A83B4C63-loaded NP as a novel radio-sensitizer for the treatment of CRC.
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Affiliation(s)
- Sams M A Sadat
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Melinda Wuest
- Department of Oncology, Cross Cancer Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Igor M Paiva
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Sirazum Munira
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Nasim Sarrami
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Forughalsadat Sanaee
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Xiaoyan Yang
- Department of Oncology, Cross Cancer Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Marco Paladino
- Department of Chemistry, Faculty of Science, University of Alberta, Edmonton, AB, Canada
| | - Ziyad Binkhathlan
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Feridoun Karimi-Busheri
- Department of Oncology, Cross Cancer Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Gary R Martin
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Frank R Jirik
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada.,Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - David Murray
- Department of Oncology, Cross Cancer Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Armin M Gamper
- Department of Oncology, Cross Cancer Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Dennis G Hall
- Department of Chemistry, Faculty of Science, University of Alberta, Edmonton, AB, Canada
| | - Michael Weinfeld
- Department of Oncology, Cross Cancer Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Afsaneh Lavasanifar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Department of Chemical and Material Engineering, University of Alberta, Edmonton, AB, Canada
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Pi J, Xiong Y, Liu C, Liao J, Liu J, Li C, Fu W, Zhao T. A Nomogram Model to Predict Recurrence of Non-Muscle Invasive Bladder Urothelial Carcinoma After Resection Based on Clinical Parameters and Immunohistochemical Markers. J INVEST SURG 2021; 35:1186-1194. [PMID: 34913802 DOI: 10.1080/08941939.2021.2017080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE This study aims to establish a nomogram model by combining traditional clinical parameters with immunohistochemical markers to predict the recurrence of non-muscle invasive bladder urothelial carcinoma (NMIBUC) after resection. METHODS In total, 504 patients were included in this study. Of these patients, 353 underwent transurethral resection of bladder tumor (TURBT) in the Yongchuan Hospital of Chongqing Medical University and were identified as a training cohort. Univariate and multivariate Cox regression analyses were used to determine the risk factors associated with recurrence in the training cohort and to establish a nomogram model. A total of 151 patients who were hospitalized in the Second Affiliated Hospital of Chongqing Medical University (validation cohort) were used for further validation. The calibration curve was generated for internal and external model validation. The clinical practicability of this model was further verified by comparing the consistency index (C-index) among various models. RESULTS The mean follow-up time of the training cohort was 45.6 months (range 4-90). In total, 146 patients relapsed in training cohort. After univariate analysis, multivariate analysis further confirmed tumor grade (p=.034), immediate postoperative instillation therapy (p=.025), Ki67 (p=.047), P53 (p=.038) and CK20 (p=.049) as independent risk factors for recurrence, and these factors were included in the nomogram model. The model more accurately predicted recurrence compared with other models based on the highest C-index of 0.82 (95% CI, 0.78-0.86) in the training cohort and 0.80 (95% CI, 0.77-0.83) in the validation cohort. CONCLUSIONS This proposed nomogram model based on traditional clinical parameters and immunohistochemical markers can more accurately predict postoperative recurrence in patients with NMIBUC.
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Affiliation(s)
- Jiangchuan Pi
- Department of Urology, The Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
| | - Yongjiang Xiong
- Department of Urology, The Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
| | - Chuan Liu
- Department of Urology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
| | - Juan Liao
- Department of Urology, The Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
| | - Jiaji Liu
- Department of Urology, The Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
| | - Chuan Li
- Department of Urology, The Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
| | - Wenyu Fu
- Department of Urology, The Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
| | - Tao Zhao
- Department of Urology, The Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
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Discovery of potential inhibitors targeting the kinase domain of polynucleotide kinase/phosphatase (PNKP): Homology modeling, virtual screening based on multiple conformations, and molecular dynamics simulation. Comput Biol Chem 2021; 94:107517. [PMID: 34456161 DOI: 10.1016/j.compbiolchem.2021.107517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/11/2021] [Accepted: 05/16/2021] [Indexed: 12/15/2022]
Abstract
In recent years, the level of interest has been increased in developing the DNA-repair inhibitors, to enhance the cytotoxic effects in the treatment of cancers. Polynucleotide kinase/phosphatase (PNKP) is a critical human DNA repair enzyme that repairs DNA strand breaks by catalyzing the restoration of 5'-phosphate and 3'-hydroxyl termini that are required for subsequent processing by DNA ligases and polymerases. PNKP is the only protein that repairs the 3'-hydroxyl group and 5'-phosphate group, which depicts PNKP as a potential therapeutic target. Besides, PNKP is the only DNA-repair enzyme that contains the 5'-kinase activity, therefore, targeting this kinase domain would motivate the development of novel PNKP-specific inhibitors. However, there are neither crystal structures of human PNKP nor the kinase inhibitors reported so far. Thus, in this present study, a sequential molecular docking-based virtual screening with multiple PNKP conformations integrating homology modeling, molecular dynamics simulation, and binding free energy calculation was developed to discover novel PNKP kinase inhibitors, and the top-scored molecule was finally submitted to molecular dynamics simulation to reveal the binding mechanism between the inhibitor and PNKP. Taken together, the current study could provide some guidance for the molecular docking based-virtual screening of novel PNKP kinase inhibitors.
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Base excision repair and its implications to cancer therapy. Essays Biochem 2021; 64:831-843. [PMID: 32648895 PMCID: PMC7588666 DOI: 10.1042/ebc20200013] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 12/15/2022]
Abstract
Base excision repair (BER) has evolved to preserve the integrity of DNA following cellular oxidative stress and in response to exogenous insults. The pathway is a coordinated, sequential process involving 30 proteins or more in which single strand breaks are generated as intermediates during the repair process. While deficiencies in BER activity can lead to high mutation rates and tumorigenesis, cancer cells often rely on increased BER activity to tolerate oxidative stress. Targeting BER has been an attractive strategy to overwhelm cancer cells with DNA damage, improve the efficacy of radiotherapy and/or chemotherapy, or form part of a lethal combination with a cancer specific mutation/loss of function. We provide an update on the progress of inhibitors to enzymes involved in BER, and some of the challenges faced with targeting the BER pathway.
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10
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A synthetically lethal nanomedicine delivering novel inhibitors of polynucleotide kinase 3'-phosphatase (PNKP) for targeted therapy of PTEN-deficient colorectal cancer. J Control Release 2021; 334:335-352. [PMID: 33933518 DOI: 10.1016/j.jconrel.2021.04.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 11/21/2022]
Abstract
Phosphatase and TENsin homolog deleted on chromosome 10 (PTEN) is a major tumor-suppressor protein that is lost in up to 75% of aggressive colorectal cancers (CRC). The co-depletion of PTEN and a DNA repair protein, polynucleotide kinase 3'-phosphatase (PNKP), has been shown to lead to synthetic lethality in several cancer types including CRC. This finding inspired the development of novel PNKP inhibitors as potential new drugs against PTEN-deficient CRC. Here, we report on the in vitro and in vivo evaluation of a nano-encapsulated potent, but poorly water-soluble lead PNKP inhibitor, A83B4C63, as a new targeted therapeutic for PTEN-deficient CRC. Our data confirmed the binding of A83B4C63, as free or nanoparticle (NP) formulation, to intracellular PNKP using the cellular thermal shift assay (CETSA), in vitro and in vivo. Dose escalating toxicity studies in healthy CD-1 mice, based on measurement of animal weight changes and biochemical blood analysis, revealed the safety of both free and nano-encapsulated A83B4C63, at assessed doses of ≤50 mg/kg. Nano-carriers of A83B4C63 effectively inhibited the growth of HCT116/PTEN-/- xenografts in NIH-III nude mice following intravenous (IV) administration, but not that of wild-type HCT116/PTEN+/+ xenografts. This was in contrast to IV administration of A83B4C63 solubilized with the aid of Cremophor EL: Ethanol (CE), which led to similar tumor growth to that of formulation excipients (NP or CE without drug) or 5% dextrose. This observation was attributed to the higher levels of A83B4C63 delivered to tumor tissue by its NP formulation. Our data provide evidence for the success of NPs of A83B4C63, as novel synthetically lethal nano-therapeutics in the treatment of PTEN-deficient CRC. This research also highlights the potential of successful application of nanomedicine in the drug development process.
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Sadat SMA, Vakili MR, Paiva IM, Weinfeld M, Lavasanifar A. Development of Self-Associating SN-38-Conjugated Poly(ethylene oxide)-Poly(ester) Micelles for Colorectal Cancer Therapy. Pharmaceutics 2020; 12:pharmaceutics12111033. [PMID: 33138058 PMCID: PMC7694018 DOI: 10.3390/pharmaceutics12111033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 10/25/2020] [Accepted: 10/26/2020] [Indexed: 12/24/2022] Open
Abstract
The clinical use of 7-ethyl-10-hydroxy-camptothecin (SN-38), which is the active metabolite of irinotecan, has been hampered because of its practical water-insolubility. In this study, we successfully synthesized two self-associating SN-38-polymer drug conjugates to improve the water-solubility of SN-38, while retaining its anticancer activity. The polymeric micellar SN-38 conjugates were composed of either methoxy-poly(ethylene oxide)-block-poly(α-benzyl carboxylate-ε-caprolactone) conjugated to SN-38 at the PBCL end (mPEO-b-PBCL/SN-38) or mPEO-block-poly(α-carboxyl-ε-caprolactone) attached to SN-38 from the pendent-free carboxyl site (mPEO-b-PCCL/SN-38). The chemical structure of block copolymers was confirmed by 1H NMR. The physicochemical characterizations of their self-assembled structures including size, surface charge, polydispersity, critical micellar concentration, conjugation content and efficiency, morphology, kinetic stability, and in vitro release of SN-38 were compared between the two formulations. In vitro anticancer activities were evaluated by measuring cellular cytotoxicity and caspase activation by MTS and Caspase-Glo 3/7 assays, respectively. The hemolytic activity of both micellar structures against rat red blood cells was also measured. The results showed the formation of SN-38-polymeric micellar conjugates at diameters < 50 nm with a narrow size distribution and sustained release of SN-38 for both structures. The loading content of SN-38 in mPEO-b-PBCL and mPEO-b-PCCL were 11.47 ± 0.10 and 12.03 ± 0.17 (% w/w), respectively. The mPEO-b-PBCL/SN-38, end-capped micelles were kinetically more stable than mPEO-b-PCCL/SN-38. The self-assembled mPEO-b-PBCL/SN-38 and mPEO-b-PCCL/SN-38 micelles resulted in significantly higher cytotoxic effects than irinotecan against human colorectal cancer cell lines HCT116, HT-29, and SW20. The CRC cells were found to be 70-fold to 330-fold more sensitive to micellar SN-38 than irinotecan, on average. Both SN-38-incorporated micelles showed two-fold higher caspase-3/7 activation levels than irinotecan. The mPEO-b-PBCL/SN-38 micelles were not hemolytic, but mPEO-b-PCCL/SN-38 showed some hemolysis. The overall results from this study uphold mPEO-b-PBCL/SN-38 over mPEO-b-PCCL/SN-38 micellar formulation as an effective delivery system of SN-38 that warrants further preclinical investigation.
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Affiliation(s)
- Sams M. A. Sadat
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2E1, Canada; (S.M.A.S.); (I.M.P.)
| | - Mohammad Reza Vakili
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2E1, Canada; (S.M.A.S.); (I.M.P.)
- Correspondence: (M.R.V.); (A.L.); Tel.: +1-5879204349 (M.R.V.); +1-7804922742 (A.L.); Fax: +1-7804921217 (M.R.V.); +1-7804921217 (A.L.)
| | - Igor M. Paiva
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2E1, Canada; (S.M.A.S.); (I.M.P.)
| | - Michael Weinfeld
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R7, Canada;
- Department of Experimental Oncology, Cross Cancer Institute, Edmonton, AB T6G 1Z2, Canada
| | - Afsaneh Lavasanifar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2E1, Canada; (S.M.A.S.); (I.M.P.)
- Department of Chemical and Material Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
- Correspondence: (M.R.V.); (A.L.); Tel.: +1-5879204349 (M.R.V.); +1-7804922742 (A.L.); Fax: +1-7804921217 (M.R.V.); +1-7804921217 (A.L.)
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12
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Yang B, Zhang B, Cao Z, Xu X, Huo Z, Zhang P, Xiang S, Zhao Z, Lv C, Meng M, Zhang G, Dong L, Shi S, Yang L, Zhou Q. The lipogenic LXR-SREBF1 signaling pathway controls cancer cell DNA repair and apoptosis and is a vulnerable point of malignant tumors for cancer therapy. Cell Death Differ 2020; 27:2433-2450. [PMID: 32144382 PMCID: PMC7370224 DOI: 10.1038/s41418-020-0514-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/23/2020] [Accepted: 02/03/2020] [Indexed: 01/13/2023] Open
Abstract
Cancer cells are defective in DNA repair, so they experience increased DNA strand breaks, genome instability, gene mutagenesis, and tumorigenicity; however, multiple classic DNA repair genes and pathways are strongly activated in malignant tumor cells to compensate for the DNA repair deficiency and gain an apoptosis resistance. The mechanisms underlying this phenomenon in cancer are unclear. We speculate that a key DNA repair gene or signaling pathway in cancer has not yet been recognized. Here, we show that the lipogenic liver X receptor (LXR)-sterol response element binding factor-1 (SREBF1) axis controls the transcription of a key DNA repair gene polynucleotide kinase/phosphatase (PNKP), thereby governing cancer cell DNA repair and apoptosis. Notably, the PNKP levels were significantly reduced in 95% of human pancreatic cancer (PC) patients, particularly deep reduction for sixfold in all of the advanced-stage PC cases. PNKP is also deficient in three other types of cancer that we examined. In addition, the expression of LXRs and SREBF1 was significantly reduced in the tumor tissues from human PC patients compared with the adjacent normal tissues. The newly identified LXR-SREBF1-PNKP signaling pathway is deficient in PC, and the defect in the pathway contributes to the DNA repair deficiency in the cancer. Strikingly, further diminution of the vulnerable LXR-SREBF1-PNKP signaling pathway using a small molecule triptonide, a new LXR antagonist identified in this investigation, at a concentration of 8 nM robustly activated tumor-suppressor p53 and readily elevated cancer cell DNA strand breaks over an apoptotic threshold, and selectively induced PC cell apoptosis, resulting in almost complete elimination of tumors in xenograft mice without obvious complications. Our findings provide new insight into DNA repair and apoptosis in cancer, and offer a new platform for developing novel anticancer therapeutics.
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Affiliation(s)
- Bo Yang
- Department of General Surgery, The Third Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- The First People's Hospital of Changzhou, Changzhou, 213003, P. R. China
| | - Bin Zhang
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Center of Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China
- Suzhou Institute of Systems Medicine, Suzhou, 215123, China
| | - Zhifei Cao
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
- Department of Pathology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
| | - Xingdong Xu
- Department of General Surgery, The People's Hospital of China, Three Gorges University, Yichang, 443000, P. R. China
- The First People's Hospital of Yichang, Yichang, 443000, P. R. China
| | - Zihe Huo
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Pan Zhang
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Shufen Xiang
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Zhe Zhao
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Chunping Lv
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Mei Meng
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Gaochuan Zhang
- Department of Bioinformatics, College of Basic Medical Science, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Liang Dong
- Department of Pathology, College of Basic Medical Science, Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Shucheng Shi
- Department of General Surgery, The Third Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- The First People's Hospital of Changzhou, Changzhou, 213003, P. R. China
| | - Lan Yang
- Department of General Surgery, The Third Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215123, P. R. China
- The First People's Hospital of Changzhou, Changzhou, 213003, P. R. China
| | - Quansheng Zhou
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
- State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
- Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
- 2011 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
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13
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Paiva I, Mattingly S, Wuest M, Leier S, Vakili MR, Weinfeld M, Lavasanifar A, Wuest F. Synthesis and Analysis of 64Cu-Labeled GE11-Modified Polymeric Micellar Nanoparticles for EGFR-Targeted Molecular Imaging in a Colorectal Cancer Model. Mol Pharm 2020; 17:1470-1481. [DOI: 10.1021/acs.molpharmaceut.9b01043] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Igor Paiva
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
| | - Stephanie Mattingly
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Melinda Wuest
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Canada
| | - Samantha Leier
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Mohammad Reza Vakili
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
| | - Michael Weinfeld
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Afsaneh Lavasanifar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
- Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Frank Wuest
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Canada
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14
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Abstract
A snapshot of noteworthy recent developments in the patent literature of relevance to pharmaceutical and medical research and development.
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