1
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Kruspe S, Dickey DD, Urak KT, Blanco GN, Miller MJ, Clark KC, Burghardt E, Gutierrez WR, Phadke SD, Kamboj S, Ginader T, Smith BJ, Grimm SK, Schappet J, Ozer H, Thomas A, McNamara JO, Chan CH, Giangrande PH. Rapid and Sensitive Detection of Breast Cancer Cells in Patient Blood with Nuclease-Activated Probe Technology. Mol Ther Nucleic Acids 2017; 8:542-557. [PMID: 28918054 PMCID: PMC5577414 DOI: 10.1016/j.omtn.2017.08.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 08/07/2017] [Indexed: 02/07/2023]
Abstract
A challenge for circulating tumor cell (CTC)-based diagnostics is the development of simple and inexpensive methods that reliably detect the diverse cells that make up CTCs. CTC-derived nucleases are one category of proteins that could be exploited to meet this challenge. Advantages of nucleases as CTC biomarkers include: (1) their elevated expression in many cancer cells, including cells implicated in metastasis that have undergone epithelial-to-mesenchymal transition; and (2) their enzymatic activity, which can be exploited for signal amplification in detection methods. Here, we describe a diagnostic assay based on quenched fluorescent nucleic acid probes that detect breast cancer CTCs via their nuclease activity. This assay exhibited robust performance in distinguishing breast cancer patients from healthy controls, and it is rapid, inexpensive, and easy to implement in most clinical labs. Given its broad applicability, this technology has the potential to have a substantive impact on the diagnosis and treatment of many cancers.
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Affiliation(s)
- Sven Kruspe
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - David D Dickey
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Kevin T Urak
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA; Molecular & Cellular Biology Program, University of Iowa, Iowa City, IA, USA
| | - Giselle N Blanco
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Matthew J Miller
- Medical Scientist Training Program, University of Iowa, Iowa City, IA, USA
| | - Karen C Clark
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, USA
| | - Elliot Burghardt
- Medical Scientist Training Program, University of Iowa, Iowa City, IA, USA
| | - Wade R Gutierrez
- Medical Scientist Training Program, University of Iowa, Iowa City, IA, USA
| | - Sneha D Phadke
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Sukriti Kamboj
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Timothy Ginader
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA; Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, USA
| | - Brian J Smith
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA; Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, USA
| | - Sarah K Grimm
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, USA
| | - James Schappet
- Institute for Clinical and Translational Science, University of Iowa, Iowa City, IA, USA
| | - Howard Ozer
- Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Alexandra Thomas
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA; Department of Hematology & Oncology, Wake Forest, Winston Salem, NC, USA
| | - James O McNamara
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA; Molecular & Cellular Biology Program, University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, USA; Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, USA
| | - Carlos H Chan
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, USA; Department of Surgery, University of Iowa, Iowa City, IA, USA.
| | - Paloma H Giangrande
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA; Molecular & Cellular Biology Program, University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, USA; Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, USA; Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA; Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA, USA; Environmental Health Sciences Research Center, University of Iowa, Iowa City, IA, USA.
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2
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Giangrande PH, Kruspe S, Dickey DD, Kamboj S, Clark KC, Urak K, Burghardt E, Smith B, Thomas A, McNamara JO. Abstract P1-01-14: Nuclease-activated oligonucleotide probes for detection of breast cancer circulating tumor cells (CTCs): Early clinical results. Cancer Res 2017. [DOI: 10.1158/1538-7445.sabcs16-p1-01-14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction:
A challenge for CTC-based diagnostic tests has been the development of methods with sufficient sensitivity to detect low levels of CTCs. Expense, accuracy and complexity have also limited clinical uptake of CTCs. To overcome these limitations we explored detecting CTCs by measuring their nuclease activity with nuclease-activated probes. We present the development of a rapid and highly-sensitive CTC detection assay based on probes that are selectively digested (activated) by target nucleases expressed in breast cancer cells.
Methods:
Nuclease activity in samples from women with Stage IV breast cancer and healthy donors was determined and correlated with clinical data. Patients seen at University of Iowa Clincis were eligible for this IRB-approved study. Blood samples were processed using microfilter (ScreenCell) units for CTC enrichment and converted into cell lysates that were examined by means of three different chemically-optimized oligonucleotide probes. CTC-derived nuclease activity was quantified using a fluorometer. The presence of CTCs was confirmed using established CTC detection methods (e.g. RT-PCR, immunohistostaining).
Results:
Sensitivity of the probe assay was 5 cancer cells in buffer solution and ~200 cancer cells in 1 mL of healthy donor blood. The final study cohort included 28 breast cancer patients and 10 healthy donors. The averaged signal intensities from patient samples were significantly higher compared to the healthy donor control group, presumably arising from CTCs in the blood. Statistical analysis further reveald short incubations in the assay (<20 min) to be optimal. From an ROC analysis we obtained AUC values of 0.8821, 0.8103 and 0.9356 for the three different probes. The oligonucleotide probe being the best predictor of disease yielded 100% sensitivity in the patient samples with a specificity of 70%. The dsDNA 20 minute probe was correlated negatively with tumors being ER+/PR+ (p=0.03). The 2'f-RNA 0 minute probe correlated significantly with HER2- tumors (p=0.04). In this smaller series other trends were also suggested.
Conclusion:
We describe a novel diagnostic for the detection of CTCs that could overcome limitations of CTC detection assays and could provide a robust diagnostic tool for breast cancer. Future clinical assays derived from this technology could require minimal training and infrastructure and might be developed into a point-of-care testing format.
Citation Format: Giangrande PH, Kruspe S, Dickey DD, Kamboj S, Clark KC, Urak K, Burghardt E, Smith B, Thomas A, McNamara JO. Nuclease-activated oligonucleotide probes for detection of breast cancer circulating tumor cells (CTCs): Early clinical results [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-01-14.
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Affiliation(s)
- PH Giangrande
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - S Kruspe
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - DD Dickey
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - S Kamboj
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - KC Clark
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - K Urak
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - E Burghardt
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - B Smith
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - A Thomas
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
| | - JO McNamara
- University of Iowa, Internal Medicine, Iowa City, IA; University of Iowa, Genetics Program, Iowa City, IA; University of Iowa, MCB Program, Iowa City, IA; University of Iowa, Biostatistics, Iowa City, IA
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3
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Steines B, Dickey DD, Bergen J, Excoffon KJ, Weinstein JR, Li X, Yan Z, Abou Alaiwa MH, Shah VS, Bouzek DC, Powers LS, Gansemer ND, Ostedgaard LS, Engelhardt JF, Stoltz DA, Welsh MJ, Sinn PL, Schaffer DV, Zabner J. CFTR gene transfer with AAV improves early cystic fibrosis pig phenotypes. JCI Insight 2016; 1:e88728. [PMID: 27699238 DOI: 10.1172/jci.insight.88728] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The physiological components that contribute to cystic fibrosis (CF) lung disease are steadily being elucidated. Gene therapy could potentially correct these defects. CFTR-null pigs provide a relevant model to test gene therapy vectors. Using an in vivo selection strategy that amplifies successful capsids by replicating their genomes with helper adenovirus coinfection, we selected an adeno-associated virus (AAV) with tropism for pig airway epithelia. The evolved capsid, termed AAV2H22, is based on AAV2 with 5 point mutations that result in a 240-fold increased infection efficiency. In contrast to AAV2, AAV2H22 binds specifically to pig airway epithelia and is less reliant on heparan sulfate for transduction. We administer AAV2H22-CFTR expressing the CF transmembrane conductance regulator (CFTR) cDNA to the airways of CF pigs. The transduced airways expressed CFTR on ciliated and nonciliated cells, induced anion transport, and improved the airway surface liquid pH and bacterial killing. Most gene therapy studies to date focus solely on Cl- transport as the primary metric of phenotypic correction. Here, we describe a gene therapy experiment where we not only correct defective anion transport, but also restore bacterial killing in CFTR-null pig airways.
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Affiliation(s)
- Benjamin Steines
- Department of Internal Medicine.,Molecular and Cellular Biology Program, and.,Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - David D Dickey
- Department of Internal Medicine.,Molecular and Cellular Biology Program, and
| | - Jamie Bergen
- Departments of Chemical and Biomolecular Engineering, Bioengineering, The Helen Wills Neuroscience Institute, Molecular and Cellular Biology, University of California, Berkeley, California, USA
| | | | - John R Weinstein
- Departments of Chemical and Biomolecular Engineering, Bioengineering, The Helen Wills Neuroscience Institute, Molecular and Cellular Biology, University of California, Berkeley, California, USA
| | - Xiaopeng Li
- Department of Internal Medicine.,Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | | | - Mahmoud H Abou Alaiwa
- Department of Internal Medicine.,Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Viral S Shah
- Department of Internal Medicine.,Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | | | | | | | - Lynda S Ostedgaard
- Department of Internal Medicine.,Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | | | - David A Stoltz
- Department of Internal Medicine.,Molecular and Cellular Biology Program, and.,Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Michael J Welsh
- Department of Internal Medicine.,Molecular and Cellular Biology Program, and.,Molecular Physiology and Biophysics
| | - Patrick L Sinn
- Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.,Howard Hughes Medical Institute, and
| | - David V Schaffer
- Departments of Chemical and Biomolecular Engineering, Bioengineering, The Helen Wills Neuroscience Institute, Molecular and Cellular Biology, University of California, Berkeley, California, USA
| | - Joseph Zabner
- Department of Internal Medicine.,Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
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4
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Dickey DD, Giangrande PH, Thiel WH. 744. Optimizing Conditions for Aptamer Folding Using a High-Throughput Aptamer Fluorescence Binding and Internalization (AFBI) Assay. Mol Ther 2016. [DOI: 10.1016/s1525-0016(16)33552-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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5
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Dickey DD, Kruspe S, Urak KT, Thiel WH, Clark KC, Burghardt E, Dassie JP, Thomas A, McNamara JO, Giangrande PH. 263. Nuclease-Activated Oligonucleotide Probes for the Rapid and Robust Detection of Breast Cancer Circulating Tumor Cells (CTCs). Mol Ther 2016. [DOI: 10.1016/s1525-0016(16)33072-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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6
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Abstract
RNA aptamers are single-stranded RNA oligos that represent a powerful emerging technology with potential for treating numerous diseases. More recently, cell-targeted RNA aptamers have been developed for delivering RNA interference (RNAi) modulators (siRNAs and miRNAs) to specific diseased cells (e.g., cancer cells or HIV infected cells) in vitro and in vivo. However, despite initial promising reports, the broad application of this aptamer delivery technology awaits the development of methods that can verify and confirm delivery of aptamers to the cytoplasm of target cells where the RNAi machinery resides. We recently developed a functional assay (RIP assay) to confirm cellular uptake and subsequent cytoplasmic release of an RNA aptamer which binds to a cell surface receptor expressed on prostate cancer cells (PSMA). To assess cytoplasmic delivery, the aptamer was chemically conjugated to saporin, a ribosome inactivating protein toxin that is toxic to cells only when delivered to the cytoplasm (where it inhibits the ribosome) by a cell-targeting ligand (e.g., aptamer). Here, we describe the chemistry used to conjugate the aptamer to saporin and discuss a gel-based method to verify conjugation efficiency. We also detail an in vitro functional assay to confirm that the aptamer retains function following conjugation to saporin and describe a cellular assay to measure aptamer-mediated saporin-induced cytotoxicity.
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Affiliation(s)
- David D Dickey
- Department of Internal Medicine, University of Iowa, 375 Newton Rd, 5202 MERF, Iowa City, IA, 52242, USA
| | - Gregory S Thomas
- Department of Internal Medicine, University of Iowa, 375 Newton Rd, 5202 MERF, Iowa City, IA, 52242, USA
| | - Justin P Dassie
- Department of Internal Medicine, University of Iowa, 375 Newton Rd, 5202 MERF, Iowa City, IA, 52242, USA
| | - Paloma H Giangrande
- Department of Internal Medicine, University of Iowa, 375 Newton Rd, 5202 MERF, Iowa City, IA, 52242, USA.
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, 52242, USA.
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7
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Dickey DD, Giangrande PH. Oligonucleotide aptamers: A next-generation technology for the capture and detection of circulating tumor cells. Methods 2015; 97:94-103. [PMID: 26631715 DOI: 10.1016/j.ymeth.2015.11.020] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/20/2015] [Accepted: 11/25/2015] [Indexed: 01/17/2023] Open
Abstract
A critical challenge for treating cancer is the early identification of those patients who are at greatest risk of developing metastatic disease. The number of circulating tumor cells (CTCs) in cancer patients has recently been shown to be a valuable (and non-invasively accessible) diagnostic indicator of the state of metastatic disease. CTCs are rare cancer cells found in the blood circulation of cancer patients believed to provide a means of diagnosing the likelihood for metastatic spread and assessing response to therapy in advanced, as well as early stage disease settings. Numerous technical efforts have been made to reliably detect and quantify CTCs, but the development of a universal assay has proven quite difficult. Notable challenges for developing a broadly useful CTC-based diagnostic assay are the development of easy-to-operate methods that (1) are sufficiently sensitive to reliably detect the small number of CTCs that are present in the circulation and (2) can capture the molecular heterogeneity of tumor cells. In this review, we describe recent progress towards the application of synthetic oligonucleotide aptamers as promising, novel, robust tools for the isolation and detection of CTCs. Advantages and challenges of the aptamer approach are also discussed.
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Affiliation(s)
- David D Dickey
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, United States
| | - Paloma H Giangrande
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, United States; Department of Radiation Oncology, University of Iowa, Iowa City, IA 52242, United States.
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8
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Thiel WH, Esposito CL, Dickey DD, Dassie JP, Long ME, Adam J, Streeter J, Schickling B, Takapoo M, Flenker KS, Klesney-Tait J, de Franciscis V, Miller FJ, Giangrande PH. 61. Vascular Smooth Muscle Cell RNA Aptamers for the Treatment of Cardiovascular Disease. Mol Ther 2015. [DOI: 10.1016/s1525-0016(16)33666-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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9
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Sanders PN, Koval OM, Jaffer OA, Prasad AM, Businga TR, Scott JA, Hayden PJ, Luczak ED, Dickey DD, Allamargot C, Olivier AK, Meyerholz DK, Robison AJ, Winder DG, Blackwell TS, Dworski R, Sammut D, Wagner BA, Buettner GR, Pope RM, Miller FJ, Dibbern ME, Haitchi HM, Mohler PJ, Howarth PH, Zabner J, Kline JN, Grumbach IM, Anderson ME. CaMKII is essential for the proasthmatic effects of oxidation. Sci Transl Med 2014; 5:195ra97. [PMID: 23884469 DOI: 10.1126/scitranslmed.3006135] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Increased reactive oxygen species (ROS) contribute to asthma, but little is known about the molecular mechanisms connecting increased ROS with characteristic features of asthma. We show that enhanced oxidative activation of the Ca(2+)/calmodulin-dependent protein kinase (ox-CaMKII) in bronchial epithelium positively correlates with asthma severity and that epithelial ox-CaMKII increases in response to inhaled allergens in patients. We used mouse models of allergic airway disease induced by ovalbumin (OVA) or Aspergillus fumigatus (Asp) and found that bronchial epithelial ox-CaMKII was required to increase a ROS- and picrotoxin-sensitive Cl(-) current (ICl) and MUC5AC expression, upstream events in asthma progression. Allergen challenge increased epithelial ROS by activating NADPH oxidases. Mice lacking functional NADPH oxidases due to knockout of p47 and mice with epithelial-targeted transgenic expression of a CaMKII inhibitory peptide or wild-type mice treated with inhaled KN-93, an experimental small-molecule CaMKII antagonist, were protected against increases in ICl, MUC5AC expression, and airway hyperreactivity to inhaled methacholine. Our findings support the view that CaMKII is a ROS-responsive, pluripotent proasthmatic signal and provide proof-of-concept evidence that CaMKII is a therapeutic target in asthma.
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Affiliation(s)
- Philip N Sanders
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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10
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Dickey DD, Excoffon KJDA, Young KR, Parekh KR, Zabner J. Hoechst increases adeno-associated virus-mediated transgene expression in airway epithelia by inducing the cytomegalovirus promoter. J Gene Med 2012; 14:366-73. [PMID: 22610695 DOI: 10.1002/jgm.2632] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND In airway epithelia, the kinetics of recombinant adeno-associated virus (AAV) transgene expression is slow. This has negative practical implications for research, as well as for translation into therapy. The DNA minor groove-binding agent Hoechst-33342 has been shown to enhance AAV transgene expression. In the present study, we investigated the mechanism of Hoechst-related augmentation of AAV-mediated transgene expression. METHODS We investigated the effect of Hoechst-33342 on HT1080, COS-7, mouse and human airway epithelia transduced with different AAV serotypes encoding enhanced green fluorescent protein (eGFP). We exposed cells to increasing concentrations of Hoechst-33342 at different time points. We evaluated the effect on second-strand DNA synthesis using AAV with a self-complementary genome. We also investigated the effect on expression from transfected plasmids with and without AAV2 inverted terminal repeats (ITRs). RESULTS We found that Hoechst-33342 significantly accelerated AAV transgene expression for all serotypes tested. Hoechst-33342 only had an effect when the treatment was given during or after transduction, even 120 days post-transduction, suggesting an effect on transgene expression regulation. Hoechst-33342 increased transgene expression when cells were transduced with a self-complementary AAV with the cytomegalovirus promoter, although there was no effect on cells transduced with conventional single-stranded AAV encoding the Rous sarcoma virus promoter. Finally, Hoechst-33342 increases gene expression from transfected plasmids regardless of the presence of AAV2 ITRs. CONCLUSIONS Hoechst dramatically augments and accelerates AAV-mediated transgene expression in airway epithelia without altering AAV-mediated gene transfer. Hoechst activation of the cytomegalovirus promoter is seen in plasmids, although it is drastically enhanced in the context of AAV.
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Affiliation(s)
- David D Dickey
- Department of Internal Medicine and Molecular and Cellular Biology Program, Roy J, Lucille A. Carver College of Medicine, University of Iowa, IA, USA
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11
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Dickey DD, Excoffon KJDA, Koerber JT, Bergen J, Steines B, Klesney-Tait J, Schaffer DV, Zabner J. Enhanced sialic acid-dependent endocytosis explains the increased efficiency of infection of airway epithelia by a novel adeno-associated virus. J Virol 2011; 85:9023-30. [PMID: 21697483 PMCID: PMC3165813 DOI: 10.1128/jvi.05154-11] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 06/08/2011] [Indexed: 11/20/2022] Open
Abstract
We previously used directed evolution in human airway epithelia to create adeno-associated virus 2.5T (AAV2.5T), a highly infectious chimera of AAV2 and AAV5 with one point mutation (A581T). We hypothesized that the mechanism for its increased infection may be a higher binding affinity to the surface of airway epithelia than its parent AAV5. Here, we show that, like AAV5, AAV2.5T, uses 2,3N-linked sialic acid as its primary receptor; however, AAV2.5T binds to the apical surface of human airway epithelia at higher levels and has more receptors than AAV5. Furthermore, its binding affinity is similar to that of AAV5. An alternative hypothesis is that AAV2.5T interaction with 2,3N-linked sialic acid may instead be required for cellular internalization. Consistent with this, AAV2.5T binds but fails to be internalized by CHO cells that lack surface expression of sialic acid. Moreover, whereas AAV2.5T binds similarly to human (rich in 2,3N-linked sialic acid) and pig airway epithelia (2,6N-linked sialic acid), significantly more virus was internalized by human airway. Subsequent transduction correlated with the level of internalized rather than surface-bound virus. We also found that human airway epithelia internalized significantly more AAV2.5T than AAV5. These data suggest that AAV2.5T has evolved to utilize specific 2,3N-linked sialic acid residues on the surface of airway epithelia that mediate rapid internalization and subsequent infection. Thus, sialic acid serves as not just an attachment factor but is also required for AAV2.5T internalization, possibly representing an important rate-limiting step for other viruses that use sialic acids.
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Affiliation(s)
- David D. Dickey
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | | | - James T. Koerber
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720-1462
| | - Jamie Bergen
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720-1462
| | - Benjamin Steines
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Julia Klesney-Tait
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - David V. Schaffer
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720-1462
| | - Joseph Zabner
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
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12
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Excoffon KJDA, Koerber JT, Dickey DD, Murtha M, Keshavjee S, Kaspar BK, Zabner J, Schaffer DV. Directed evolution of adeno-associated virus to an infectious respiratory virus. Proc Natl Acad Sci U S A 2009; 106:3865-70. [PMID: 19237554 PMCID: PMC2646629 DOI: 10.1073/pnas.0813365106] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Indexed: 12/25/2022] Open
Abstract
Respiratory viruses evolve to maintain infectivity levels that permit spread yet prevent host and virus extinction, resulting in surprisingly low infection rates. Respiratory viruses harnessed as gene therapy vectors have illustrated this limitation. We used directed evolution in an organotypic human airway model to generate a highly infectious adeno-associated virus. This virus mediated gene transfer more than 100-fold better than parental strains and corrected the cystic fibrosis epithelial Cl(-) transport defect. Thus, under appropriate selective pressures, viruses can evolve to be more infectious than observed in nature, a finding that holds significant implications for designing vectors for gene therapy and for understanding emerging pathogens.
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Affiliation(s)
| | - James T. Koerber
- Departments of Chemical Engineering and Bioengineering and The Helen Willis Neuroscience Institute, University of California, 278 Stanley Hall, Berkeley, CA 94720
| | - David D. Dickey
- Department of Internal Medicine, University of Iowa, 440 EMRB, Iowa City, IA 52241
| | - Matthew Murtha
- Department of Pediatrics and Children's Research Institute, The Research Institute at Nationwide Children's Hospital and Ohio State University, Columbus, OH 43205; and
| | - Shaf Keshavjee
- Department of Surgery, University of Toronto, Division of Thoracic Surgery, Toronto General Hospital, 200 Elizabeth Street, 9N-946, Toronto, ON, Canada M5G 2C4
| | - Brian K. Kaspar
- Department of Pediatrics and Children's Research Institute, The Research Institute at Nationwide Children's Hospital and Ohio State University, Columbus, OH 43205; and
| | - Joseph Zabner
- Department of Internal Medicine, University of Iowa, 440 EMRB, Iowa City, IA 52241
| | - David V. Schaffer
- Departments of Chemical Engineering and Bioengineering and The Helen Willis Neuroscience Institute, University of California, 278 Stanley Hall, Berkeley, CA 94720
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