1
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Tang C, Xie AX, Liu EM, Kuo F, Kim M, DiNatale RG, Golkaram M, Chen YB, Gupta S, Motzer RJ, Russo P, Coleman J, Carlo MI, Voss MH, Kotecha RR, Lee CH, Tansey W, Schultz N, Hakimi AA, Reznik E. Immunometabolic coevolution defines unique microenvironmental niches in ccRCC. Cell Metab 2023; 35:1424-1440.e5. [PMID: 37413991 PMCID: PMC10603615 DOI: 10.1016/j.cmet.2023.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 03/10/2023] [Accepted: 06/06/2023] [Indexed: 07/08/2023]
Abstract
Tumor cell phenotypes and anti-tumor immune responses are shaped by local metabolite availability, but intratumoral metabolite heterogeneity (IMH) and its phenotypic consequences remain poorly understood. To study IMH, we profiled tumor/normal regions from clear cell renal cell carcinoma (ccRCC) patients. A common pattern of IMH transcended all patients, characterized by correlated fluctuations in the abundance of metabolites and processes associated with ferroptosis. Analysis of intratumoral metabolite-RNA covariation revealed that the immune composition of the microenvironment, especially the abundance of myeloid cells, drove intratumoral metabolite variation. Motivated by the strength of RNA-metabolite covariation and the clinical significance of RNA biomarkers in ccRCC, we inferred metabolomic profiles from the RNA sequencing data of ccRCC patients enrolled in 7 clinical trials, and we ultimately identifyied metabolite biomarkers associated with response to anti-angiogenic agents. Local metabolic phenotypes, therefore, emerge in tandem with the immune microenvironment, influence ongoing tumor evolution, and are associated with therapeutic sensitivity.
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Affiliation(s)
- Cerise Tang
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Medicine, New York, NY, USA
| | - Amy X Xie
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Biochemistry, Structural Biology, Cell Biology, Developmental Biology and Molecular Biology Graduate Program, Weill Cornell Medicine, New York, NY, USA
| | - Eric Minwei Liu
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Fengshen Kuo
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Minsoo Kim
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Renzo G DiNatale
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Mahdi Golkaram
- Illumina, Inc., 5200 Illumina Way, San Diego, CA 92122, USA
| | - Ying-Bei Chen
- Department of Pathology, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sounak Gupta
- Department of Pathology, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Robert J Motzer
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Paul Russo
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Jonathan Coleman
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Maria I Carlo
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Martin H Voss
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ritesh R Kotecha
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Chung-Han Lee
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Wesley Tansey
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Nikolaus Schultz
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - A Ari Hakimi
- Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| | - Ed Reznik
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Marie-Josée and Henry R. Kravis Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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2
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Zhang H, Hunter MV, Chou J, Quinn JF, Zhou M, White RM, Tansey W. BayesTME: An end-to-end method for multiscale spatial transcriptional profiling of the tissue microenvironment. Cell Syst 2023; 14:605-619.e7. [PMID: 37473731 PMCID: PMC10368078 DOI: 10.1016/j.cels.2023.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 03/09/2023] [Accepted: 06/09/2023] [Indexed: 07/22/2023]
Abstract
Spatial variation in cellular phenotypes underlies heterogeneity in immune recognition and response to therapy in cancer and many other diseases. Spatial transcriptomics holds the potential to quantify such variation, but existing analysis methods are limited by their focus on individual tasks such as spot deconvolution. We present BayesTME, an end-to-end Bayesian method for analyzing spatial transcriptomics data. BayesTME unifies several previously distinct analysis goals under a single, holistic generative model. This unified approach enables BayesTME to deconvolve spots into cell phenotypes without any need for paired single-cell RNA-seq. BayesTME then goes beyond spot deconvolution to uncover spatial expression patterns among coordinated subsets of genes within phenotypes, which we term spatial transcriptional programs. BayesTME achieves state-of-the-art performance across myriad benchmarks. On human and zebrafish melanoma tissues, BayesTME identifies spatial transcriptional programs that capture fundamental biological phenomena such as bilateral symmetry and tumor-associated fibroblast and macrophage reprogramming. BayesTME is open source.
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Affiliation(s)
- Haoran Zhang
- Department of Computer Science, University of Texas at Austin, Austin, TX 78712, USA
| | - Miranda V Hunter
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Jacqueline Chou
- Department of Physiology, Biophysics, & Systems Biology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Jeffrey F Quinn
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Mingyuan Zhou
- McCombs School of Business, University of Texas at Austin, Austin, TX 78712, USA
| | - Richard M White
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Wesley Tansey
- Computational Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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3
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Sudarshan M, Puli A, Tansey W, Ranganath R. DIET: Conditional independence testing with marginal dependence measures of residual information. Proc Mach Learn Res 2023; 206:10343-10367. [PMID: 37681192 PMCID: PMC10484293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Conditional randomization tests (CRTs) assess whether a variable x is predictive of another variable y , having observed covariates z . CRTs require fitting a large number of predictive models, which is often computationally intractable. Existing solutions to reduce the cost of CRTs typically split the dataset into a train and test portion, or rely on heuristics for interactions, both of which lead to a loss in power. We propose the decoupled independence test (DIET), an algorithm that avoids both of these issues by leveraging marginal independence statistics to test conditional independence relationships. DIET tests the marginal independence of two random variables: F x ∣ z ( x ∣ z ) and F y ∣ z ( y ∣ z ) where F ⋅ ∣ z ( ⋅ ∣ z ) is a conditional cumulative distribution function (CDF) for the distribution p ( ⋅ ∣ z ) . These variables are termed "information residuals." We give sufficient conditions for DIET to achieve finite sample type-1 error control and power greater than the type-1 error rate. We then prove that when using the mutual information between the information residuals as a test statistic, DIET yields the most powerful conditionally valid test. Finally, we show DIET achieves higher power than other tractable CRTs on several synthetic and real benchmarks.
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Affiliation(s)
| | | | - Wesley Tansey
- Computational Oncology Memorial Sloan Kettering Cancer Center
| | - Rajesh Ranganath
- Computer Science, New York University
- Data Science, New York University
- Population Health at Langone Health, New York University
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Freeman BA, Jaro S, Park T, Keene S, Tansey W, Reznik E. MIRTH: Metabolite Imputation via Rank-Transformation and Harmonization. Genome Biol 2022; 23:184. [PMID: 36050754 PMCID: PMC9438248 DOI: 10.1186/s13059-022-02738-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/23/2022] [Indexed: 12/12/2022] Open
Abstract
Out of the thousands of metabolites in a given specimen, most metabolomics experiments measure only hundreds, with poor overlap across experimental platforms. Here, we describe Metabolite Imputation via Rank-Transformation and Harmonization (MIRTH), a method to impute unmeasured metabolite abundances by jointly modeling metabolite covariation across datasets which have heterogeneous coverage of metabolite features. MIRTH successfully recovers masked metabolite abundances both within single datasets and across multiple, independently-profiled datasets. MIRTH demonstrates that latent information about otherwise unmeasured metabolites is embedded within existing metabolomics data, and can be used to generate novel hypotheses and simplify existing metabolomic workflows.
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Affiliation(s)
- Benjamin A Freeman
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Sophie Jaro
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, USA.,Electrical Engineering Department, The Cooper Union, New York, USA
| | - Tricia Park
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Sam Keene
- Electrical Engineering Department, The Cooper Union, New York, USA
| | - Wesley Tansey
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, USA.
| | - Ed Reznik
- Computational Oncology, Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, USA.
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5
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Tansey W, Tosh C, Blei DM. A Bayesian model of dose-response for cancer drug studies. Ann Appl Stat 2022. [DOI: 10.1214/21-aoas1485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Wesley Tansey
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center
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Affiliation(s)
- Wesley Tansey
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Victor Veitch
- Department of Statistics, Columbia University, New York, NY
| | - Haoran Zhang
- Department of Computer Science, University of Texas at Austin, TX
| | - Raul Rabadan
- Department of Systems Biology, Columbia University Medical Center, New York, NY
| | - David M. Blei
- Departments of Computer Science and Statistics, Columbia University, New York, NY
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7
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Loper JH, Lei L, Fithian W, Tansey W. Smoothed nested testing on directed acyclic graphs. Biometrika 2021. [DOI: 10.1093/biomet/asab041] [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: 11/13/2022] Open
Abstract
Summary
We consider the problem of multiple hypothesis testing when there is a logical nested structure to the hypotheses. When one hypothesis is nested inside another, the outer hypothesis must be false if the inner hypothesis is false. We model the nested structure as a directed acyclic graph, including chain and tree graphs as special cases. Each node in the graph is a hypothesis and rejecting a node requires also rejecting all of its ancestors. We propose a general framework for adjusting node-level test statistics using the known logical constraints. Within this framework, we study a smoothing procedure that combines each node with all of its descendants to form a more powerful statistic. We prove that a broad class of smoothing strategies can be used with existing selection procedures to control the familywise error rate, false discovery exceedance rate, or false discovery rate, so long as the original test statistics are independent under the null. When the null statistics are not independent, but are derived from positively correlated normal observations, we prove control for all three error rates when the smoothing method is an arithmetic averaging of the observations. Simulations and an application to a real biology dataset demonstrate that smoothing leads to substantial power gains.
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Affiliation(s)
- J H Loper
- Department of Neuroscience, Columbia University, 716 Jerome L. Greene Building, New York, New York 10025, U.S.A
| | - L Lei
- Department of Statistics, Stanford University, Sequoia Hall, Palo Alto, California 94305, U.S.A
| | - W Fithian
- Department of Statistics, University of California, Berkeley, 367 Evans Hall, Berkeley, California 94720, U.S.A
| | - W Tansey
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, 321 E 61st St., New York, New York 10065, U.S.A
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8
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Affiliation(s)
- Jaan Altosaar
- Department of Biomedical Informatics Columbia University New York New York USA
| | - Rajesh Ranganath
- Courant Institute of Mathematical Sciences New York University New York New York USA
| | - Wesley Tansey
- Department of Epidemiology and Biostatistics Memorial Sloan Kettering Cancer Center New York New York USA
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Tansey W, Li K, Zhang H, Linderman SW, Rabadan R, Blei DM, Wiggins CH. Dose-response modeling in high-throughput cancer drug screenings: an end-to-end approach. Biostatistics 2021; 23:643-665. [PMID: 33417699 DOI: 10.1093/biostatistics/kxaa047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 12/18/2022] Open
Abstract
Personalized cancer treatments based on the molecular profile of a patient's tumor are an emerging and exciting class of treatments in oncology. As genomic tumor profiling is becoming more common, targeted treatments for specific molecular alterations are gaining traction. To discover new potential therapeutics that may apply to broad classes of tumors matching some molecular pattern, experimentalists and pharmacologists rely on high-throughput, in vitro screens of many compounds against many different cell lines. We propose a hierarchical Bayesian model of how cancer cell lines respond to drugs in these experiments and develop a method for fitting the model to real-world high-throughput screening data. Through a case study, the model is shown to capture nontrivial associations between molecular features and drug response, such as requiring both wild type TP53 and overexpression of MDM2 to be sensitive to Nutlin-3(a). In quantitative benchmarks, the model outperforms a standard approach in biology, with $\approx20\%$ lower predictive error on held out data. When combined with a conditional randomization testing procedure, the model discovers markers of therapeutic response that recapitulate known biology and suggest new avenues for investigation. All code for the article is publicly available at https://github.com/tansey/deep-dose-response.
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Affiliation(s)
- Wesley Tansey
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, NewYork, NY, USA
| | - Kathy Li
- Data Science Institute, Columbia University and Columbia University Medical Center, New York, NY, USA and Applied Physics and Applied Mathematics, Columbia University and Columbia University Medical Center, New York, NY, USA
| | - Haoran Zhang
- Applied Physics and Applied Mathematics, Columbia University and Columbia University Medical Center, New York, NY, USA
| | - Scott W Linderman
- Data Science Institute, Columbia University and Columbia University Medical Center, New York, NY, USA and Department of Statistics, Columbia University and Columbia University Medical Center, New York, NY, USA
| | - Raul Rabadan
- Department of Systems Biology, Columbia University and Columbia University Medical Center, New York, NY, USA
| | - David M Blei
- Data Science Institute, Columbia University and Columbia University Medical Center, New York, NY, USA, Department of Statistics, Columbia University and Columbia University Medical Center, New York, NY, USA and Department of Statistics, Columbia University and Columbia University Medical Center, New York, NY, USA
| | - Chris H Wiggins
- Data Science Institute, Columbia University and Columbia University Medical Center, New York, NY, USA, Department of Applied Physics and Applied Mathematics, Columbia University and Columbia University Medical Center, New York, NY, USA and Department of Systems Biology, Columbia University and Columbia University Medical Center, New York, NY, USA
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10
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Sudarshan M, Tansey W, Ranganath R. Deep direct likelihood knockoffs. Adv Neural Inf Process Syst 2020; 33:5036-5046. [PMID: 33953523 PMCID: PMC8096517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Predictive modeling often uses black box machine learning methods, such as deep neural networks, to achieve state-of-the-art performance. In scientific domains, the scientist often wishes to discover which features are actually important for making the predictions. These discoveries may lead to costly follow-up experiments and as such it is important that the error rate on discoveries is not too high. Model-X knockoffs [2] enable important features to be discovered with control of the false discovery rate (fdr). However, knockoffs require rich generative models capable of accurately modeling the knockoff features while ensuring they obey the so-called "swap" property. We develop Deep Direct Likelihood Knockoffs (ddlk), which directly minimizes the KL divergence implied by the knockoff swap property. ddlk consists of two stages: it first maximizes the explicit likelihood of the features, then minimizes the KL divergence between the joint distribution of features and knockoffs and any swap between them. To ensure that the generated knockoffs are valid under any possible swap, ddlk uses the Gumbel-Softmax trick to optimize the knockoff generator under the worst-case swap. We find ddlk has higher power than baselines while controlling the false discovery rate on a variety of synthetic and real benchmarks including a task involving a large dataset from one of the epicenters of COVID-19.
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Affiliation(s)
| | - Wesley Tansey
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center
| | - Rajesh Ranganath
- Courant Institute of Mathematical Sciences, Center for Data Science, New York University
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Affiliation(s)
- Wesley Tansey
- Department of Epidemiology and Biostatistics Memorial Sloan Kettering Cancer Center New York New York USA
| | - Yixin Wang
- Department of Statistics Columbia University New York New York USA
| | - Raul Rabadan
- Department of Systems Biology Columbia University Medical Center New York New York USA
| | - David Blei
- Department of Statistics Columbia University New York New York USA
- Department of Computer Science Columbia University New York New York USA
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12
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Diallo AB, Nguifo EM, Dhifli W, Azizi E, Prabhakaran S, Tansey W. Selected Papers from the Workshop on Computational Biology: Joint with the International Joint Conference on Artificial Intelligence and the International Conference on Machine Learning, 2018. J Comput Biol 2019; 26:507-508. [DOI: 10.1089/cmb.2019.29020.abd] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | - Engelbert Mephu Nguifo
- Laboratoire d'Information de Modélisation et Optimisation des Systèmes (LIMOS), Université Clermont Auvergne, Clermont-Ferrand, Aubière Cedex, France
| | - Wajdi Dhifli
- Faculty of Pharmaceutical and Biological Sciences, University of Lille, Lille Cedex, France
| | - Elham Azizi
- Computational and Systems Biology Program, Memorial Sloan Kettering Cancer Centre, New York, New York
| | - Sandhya Prabhakaran
- Computational and Systems Biology Program, Memorial Sloan Kettering Cancer Centre, New York, New York
| | - Wesley Tansey
- Data Science Institute, Columbia University, New York, New York
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13
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Affiliation(s)
- Wesley Tansey
- Department of Computer Science, University of Texas at Austin, Austin, TX
| | - Oluwasanmi Koyejo
- Department of Computer Science, University of Illinois at Urbana-Champaign, Champaign, IL
| | | | - James G. Scott
- Department of Information, Risk, and Operations Management; Department of Statistics and Data Sciences; University of Texas at Austin, Austin, TX
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14
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Tansey W, Athey A, Reinhart A, Scott JG. Multiscale Spatial Density Smoothing: An Application to Large-Scale Radiological Survey and Anomaly Detection. J Am Stat Assoc 2017. [DOI: 10.1080/01621459.2016.1276461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Wesley Tansey
- Department of Computer Science, University of Texas at Austin, TX
| | - Alex Athey
- Applied Research Laboratories, University of Texas at Austin, TX
| | - Alex Reinhart
- Department of Statistics, Carnegie Mellon University, Pittsburgh, PA
| | - James G. Scott
- Department of Information, Risk, and Operations Management
- Department of Statistics and Data Sciences, University of Texas at Austin, TX
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15
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Abstract
Polymeric drug delivery systems are used not only to improve aqueous solubility of drug molecules but also to achieve desirable pharmacokinetics and an enhanced therapeutic index. New biodegradable polymers are needed to improve the biodistribution and targeting-ability of polymeric carriers. In this study, the synthesis and characterization of branched poly(L-glutamic acid) (PG) containing multiple PG chains centered on a poly(amidoamine) (PAMAM) dendrimer or polyethyleneimine (PEI) cores were described. The branched PG polymers were obtained by ring-opening polymerization of benzyl ester of L-glutamic acid N-carboxyanhydride using PAMAM or PEI as the initiator. These polymers were degradable in the presence of the lysosomal enzyme cathepsin B, albeit more slowly than linear PG. Unlike conventional linear PG, each branched PG possessed multiple terminal amino groups. This made it possible to attach multiple targeting moieties selectively to the termini of branched PG. Conjugation of monofunctional or heterodifunctional polyethylene glycol to the chain ends of branched PG was demonstrated in the presence of side chain carboxyl groups. Furthermore, folic acid, a model targeting moiety, and the near-infrared dye indocyanine green, a model diagnostic agent, were successfully conjugated to the terminal amino groups and the side chain carboxyl groups of branched PG, respectively. The resulting conjugate had reduced nonspecific interaction and bound selectively to tumor cells expressing folate receptors. Thus, branched PG may be useful as a polymeric carrier for targeted drug delivery.
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Affiliation(s)
- W Tansey
- Department of Experimental Diagnostic Imaging, Unit 59, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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16
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Yang DJ, Azhdarinia A, Wu P, Yu DF, Tansey W, Kalimi SK, Kim EE, Podoloff DA. In vivo and in vitro measurement of apoptosis in breast cancer cells using 99mTc-EC-annexin V. Cancer Biother Radiopharm 2001; 16:73-83. [PMID: 11279800 DOI: 10.1089/108497801750096087] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [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] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE The purpose of this study was to develop an imaging technique to measure and monitor tumor cells undergoing programmed death caused by radiation and chemotherapy using 99mTc-EC-annexin V. Annexin V has been used to measure programmed cell death both in vitro and in vivo. Assessment of apoptosis would be useful to evaluate the efficacy and mechanisms of therapy and disease progression or regression. METHODS Ethylenedicysteine (EC) was conjugated to annexin V using sulfo-N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-HCl as coupling agents. The yield of EC-annexin V was 100%. In vitro cellular uptake, pre- and post-radiation (10-30 Gy) and paclitaxel treatment, was quantified using 99mTc-EC-annexin V. Tissue distribution and planar imaging of 99mTc-EC-annexin V were determined in breast tumor-bearing rats at 0.5, 2, and 4 hrs. To demonstrate in vivo cell apoptosis that occurred during chemotherapy, a group of rats was treated with paclitaxel and planar imaging studies were conducted at 0.5-4 hrs. Computer outlined region of interest (ROI) was used to quantify tumor uptake on day 3 and day 5 post-treatment. RESULTS In vitro cellular uptake showed that there was significantly increased uptake of 99mTc-EC-annexin V after irradiation (10-30 Gy) and paclitaxel treatment. In vivo biodistribution of 99mTc-EC-annexin in breast tumor-bearing rats showed increased tumor-to-blood, tumor-to-lung and tumor-to-muscle count density ratios as a function of time. Conversely, tumor-to-blood count density ratios showed a time-dependent decrease with 99mTc-EC in the same time period. Planar images confirmed that the tumors could be visualized clearly with 99mTc-EC-annexin. There was a significant difference of ROI ratios between pre- and post-paclitaxel treatment groups at 2 and 4 hrs post injection. CONCLUSION The results indicate that apoptosis can be quantified using 99mTc-EC-annexin and that it is feasible to use 99mTc-EC-annexin to image tumor apoptosis.
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Affiliation(s)
- D J Yang
- Univ. of Texas M. D. Anderson Cancer Center, Dept. of Nuclear Medicine, Box 59, 1515 Holcombe Boulevard, Houston, Texas 77030, USA.
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Zou Y, Wu QP, Tansey W, Chow D, Hung MC, Charnsangavej C, Wallace S, Li C. Effectiveness of water soluble poly(L-glutamic acid)-camptothecin conjugate against resistant human lung cancer xenografted in nude mice. Int J Oncol 2001; 18:331-6. [PMID: 11172600 DOI: 10.3892/ijo.18.2.331] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [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] [Indexed: 11/06/2022] Open
Abstract
A camptothecin (CPT) formulation that can be easily administered, is less toxic, and has greater antitumor effect is needed. In this study, a water-soluble CPT derivative was obtained by direct coupling of CPT to poly(L-glutamic acid) (PG) through the C20(S)-hydroxyl group. CPT was released from the resulting conjugate, PG-CPT, in phosphate-buffered saline with a zero-order kinetics in the initial 50 days. The release rates were 0.623% per day, 1.081% per day, and 1.396% per day at pH 5.3, 7.4, and 9.0, respectively. In vitro, PG-CPT was less potent in inhibiting cell growth than was free CPT in all human tumor cell lines tested. However, PG-CPT showed better antitumor activity and tolerability than did CPT in vivo. When H322 human lung tumor cells were inoculated subcutaneously in nude mice, PG-CPT delayed the growth of these well-established tumors with an absolute growth delay of 32 days when given as 4 doses with 4-day intervals between injections at an equivalent CPT dose of 40 mg/kg. When H322 cells were inoculated intratracheally in nude mice, 5 doses of intravenous injection of PG-CPT at an equivalent CPT dose of 10 mg/kg on days 4, 8, 12, 16, and 20 after inoculation significantly prolonged the median survival of treated mice, averaging 1.8-fold that of untreated mice (p=0.01). Increasing the dose of PG-CPT to an equivalent CPT dose of 40 mg/kg per injection administered in 4 doses on days 4, 8, 12, and 16 prolonged the median survival of treated mice by 4-fold (p=0.0008). Significantly, mice with intratracheally inoculated H322 tumors were resistant to both CPT and cisplatin treatments. These studies demonstrated that PG may be used as an effective solubilizing carrier for CPT and that PG-CPT may have potential application in the treatment of lung cancer.
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Affiliation(s)
- Y Zou
- Department of Molecular and Cellular Oncology, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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Li C, Ke S, Wu QP, Tansey W, Hunter N, Buchmiller LM, Milas L, Charnsangavej C, Wallace S. Potentiation of ovarian OCa-1 tumor radioresponse by poly (L-glutamic acid)-paclitaxel conjugate. Int J Radiat Oncol Biol Phys 2000; 48:1119-26. [PMID: 11072171 DOI: 10.1016/s0360-3016(00)00757-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [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] [Indexed: 11/29/2022]
Abstract
PURPOSE It has been shown that paclitaxel (TXL) can strongly enhance tumor cells' sensitivity to radiation. We examined whether the radiosensitizing effect of paclitaxel can be further enhanced when it is delivered systemically as a polymer-drug conjugate that provides enhanced tumor uptake and prolonged release of TXL in the tumor. METHODS AND MATERIALS C3Hf/Kam mice bearing 8-mm murine ovarian OCa-1 tumors were treated with i.v.-injected Poly(L-glutamic acid)-paclitaxel (PG-TXL) at an equivalent TXL dose of 80 mg/kg, followed 24 h later by single doses of local radiation ranging from 5 to 15 Gy. To determine how long the radiopotentiation persisted at extended times after PG-TXL administration, mice with OCa-1 tumors were given i.v. PG-TXL and 4, 24, 48, 72, 120, or 168 h later their tumors were irradiated at a dose of 10 Gy. Antitumor activity was determined by delay in tumor growth. Cell cycle distribution was assayed using flow cytometry. Tumor vascular volume was estimated using Tc-99 m-labeled red blood cells. RESULTS PG-TXL strongly potentiated the radioresponse of the OCa-1 tumor. The enhancement factors ranged from 2.79 to 4.28, depending on radiation dose, when PG-TXL preceded radiation by 24 h. The enhancement factor derived from radiation dose-response curves was as high as 5.13. The radiosensitizing effect of PG-TXL was also dependent on the interval between PG-TXL administration and radiation delivery, with greater enhancement been observed when the interval was decreased. The percentage of G2/M cells was significantly increased to 21.4% 48 h after PG-TXL but declined to a preinjection level of 14.8% 72 h after PG-TXL. PG-TXL only moderately increased the tumor vascular volume by 37% 24 h after PG-TXL administration. CONCLUSION PG-TXL markedly potentiated response of OCa-1 tumor to radiation. When compared to literature data obtained from the same tumor model used here, PG-TXL exhibited stronger radiosensitization effect than TXL. Although its action is possibly mediated by arrest of cells in G2/M phases of cell cycle and by increased tumor blood supply, PG-TXL may exert its radiopotentiation activity through increased tumor uptake of PG-TXL and sustained release of TXL in the tumor. Our results show that conjugation of TXL to a polymer has the potential to further enhance its radiosensitizing activity and that clinical trials of PG-TXL in combination with radiation is warranted.
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Affiliation(s)
- C Li
- Department of Diagnostic Imaging, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
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19
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Li C, Ke S, Wu QP, Tansey W, Hunter N, Buchmiller LM, Milas L, Charnsangavej C, Wallace S. Tumor irradiation enhances the tumor-specific distribution of poly(L-glutamic acid)-conjugated paclitaxel and its antitumor efficacy. Clin Cancer Res 2000; 6:2829-34. [PMID: 10914731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The poly(L-glutamic acid)-paclitaxel (PG-TXL) conjugate has been shown to exhibit significantly greater antitumor activity than conventionally formulated paclitaxel (TXL) against solid tumors (Li et al., Cancer Res., 58: 2404-2409, 1998). Here we report that local tumor irradiation enhanced the distribution of PG-TXL given 24 h later to ovarian OCa-1 carcinoma implanted i.m. in C3Hf/Kam mice. Radiation significantly increased tumor uptake of PG-TXL and tumor vascular permeability, caused elevation of the serum concentration of vascular endothelial growth factor, and arrested OCa-1 cells in the G1 phase of cell cycle. The enhancement factors, as measured by incremental tumor growth delay compared with PG-TXL alone, ranged from 1.36-4.44. Complete tumor regression was also observed at a higher radiation dose (>10 Gy) and a higher PG-TXL dose (>80 mg equivalentTXL/kg). Furthermore, combined radiation and PG-TXL produced a significantly greater tumor growth delay than treatment with radiation and TXL when both drugs were given at the same equivalent TXL dose of 60 mg/kg 24 h after tumor irradiation (enhancement factors, 4.44 versus 1.50). These data suggest that conjugation of TXL to poly(L-glutamic acid) is necessary for improved response and that the supra-additive effect of combined radiation and PG-TXL therapy is due in part to modulation of the enhanced permeability and retention effect of macromolecules by radiation. We propose a treatment strategy combining radiation and macromolecular chemotherapy that may have important clinical implications in terms of scheduling and optimization of the therapeutic ratio.
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Affiliation(s)
- C Li
- Division of Diagnostic Imaging, The University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
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20
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Zareneyrizi F, Yang DJ, Oh CS, Ilgan S, Yu DF, Tansey W, Liu CW, Kim EE, Podoloff DA. Synthesis of [99mTc]ethylenedicysteine-colchicine for evaluation of antiangiogenic effect. Anticancer Drugs 1999; 10:685-92. [PMID: 10507319 DOI: 10.1097/00001813-199908000-00009] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Angiogenesis is in part responsible for tumor growth and the development of metastasis. Radiolabeled angiongenesis inhibitors would be useful to assess tumor microvasculature density. Colchicine (COL), a potent antiangiogenic agent, is known to inhibit microtubule polymerization and cell arrest at metaphase. This study aimed to develop 99mTc-labeled COL (EC-COL) using ethylenedicysteine (EC) as a chelator to assess tumor microvascular density. EC was conjugated to trimethylcolchicinic acid using N-hydroxysuccinimide and 1-ethyl-3-dimethylaminopropyl carbodiimide as coupling agents with a yield of 50-60%. In vivo stability was analyzed in rabbit serum at 0.5-4 h. Tissue distribution and planar imaging studies of [99mTc]EC-COL were evaluated in breast tumor-bearing rats at 0.5, 2 and 4 h. The data was compared to that using [99mTc]EC (control). The radiochemical yield of [99mTc]EC-COL was greater than 95%. [99mTc]EC-COL was stable in rabbit serum. In vivo biodistribution of [99mTc]EC-COL in breast tumor-bearing rats showed increased tumor-to-blood (0.52+/-0.12 to 0.72+/-0.07) and tumor-to-muscle (3.47+/-0.40 to 7.97+/-0.93) ratios as a function of time. Conversely, tumor-to-blood values showed a time-dependent decrease with [99mTc]EC over the same time period. Planar images confirmed that the tumors could be visualized clearly with [99mTc]EC-COL from 0.5 to 4 h. [99mTc]EC-COL may be useful to assess antiangiogenic and therapeutic effects during chemotherapy.
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Affiliation(s)
- F Zareneyrizi
- Division of Diagnostic Imaging, University of Texas MD Anderson Cancer Center, Houston 77030, USA
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Currie LM, Lichtiger B, Livesey SA, Tansey W, Yang DJ, Connor J. Enhanced circulatory parameters of human platelets cryopreserved with second-messenger effectors: an in vivo study of 16 volunteer platelet donors. Br J Haematol 1999; 105:826-31. [PMID: 10354154 DOI: 10.1046/j.1365-2141.1999.01411.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Platelet transfusion represents an important component of the therapy for thrombocytopenic patients. Prolonged storage capabilities for platelets would alleviate many problems associated with blood banking. Unfortunately, current cryopreservation methods are complex to implement and result in loss of cell number and functional activity. Previous in vitro studies have shown that the use of ThromboSolTM, a platelet-stabilizing formulation, in the cryopreservation of platelets results in significant retention of cell number and in vitro functional activities in addition to reducing the DMSO requirement to only 2%. We evaluated the in vivo circulatory parameters of platelets cryopreserved with ThromboSol. Single donor platelet units were obtained from healthy volunteers (n = 16); the units were then split and cryopreserved with either ThromboSol and 2% DMSO or 6% DMSO alone. Following storage at -80 degrees C for 7-10 d the samples were thawed, washed and radiolabelled with either 51Cr or 111In. The paired samples were then mixed and reinfused into the autologous volunteer. At various time intervals following transfusion a blood sample was drawn and the quantity of circulating labelled platelets was determined. The percent recovery and survival time was determined by multiple-hit analysis. The ThromboSol-treated platelets, as compared to the 6% DMSO-treated platelets, displayed statistically higher percent recovery (40.2% v 28.8%) and survival time (166.3 h v 152.1 h). These results demonstrated that platelets cryopreserved with ThromboSol displayed superior in vitro and in vivo characteristics as compared to the standard 6% DMSO method. The use of ThromboSol allowed for a 3-fold reduction in the DMSO concentration in conjunction with a 40% increase in circulating cell number and normal survival times.
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Affiliation(s)
- L M Currie
- LifeCell Corporation, The Woodlands, Texas, USA
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Li C, Yu DF, Inoue T, Yang DJ, Tansey W, Liu CW, Milas L, Hunter NR, Kim EE, Wallace S. Synthesis, biodistribution and imaging properties of indium-111-DTPA-paclitaxel in mice bearing mammary tumors. J Nucl Med 1997; 38:1042-7. [PMID: 9225788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
UNLABELLED Paclitaxel, an antineoplastic agent that stabilizes microtubules and arrests cells in the G2/M cell cycle phase, has shown activity against many common cancers, including ovarian and breast tumors. In order to evaluate the potential value of radiolabeled paclitaxel as an imaging tool in tumors, we synthesized 111In-DEPA-paclitaxel and investigated its biodistribution and gamma scintigraphic imaging properties. METHODS Mice bearing a paclitaxel-responsive mammary tumor (MCA-4) were used. DTPA-paclitaxel was labeled with 111In with a radiochemical yield of 84% and radiochemical purity of 90%. Each mouse received 5 microCi of radiotracers intravenously for biodistribution studies and 100 microCi for gamma scintigraphic studies. Indium-111-DTPA was used as a control. RESULTS In tumor-bearing mice, 111In-DTPA was characterized by rapid clearance from the plasma with negligible retention in the tumor, the liver and other body parts. In contrast, 111In-DTPA-paclitaxel exhibited a pharmacological profile resembling that of paclitaxel. Furthermore, a significant uptake of 111In-DTPA-paclitaxel was observed in the tumor. The tumor-to-muscle ratios were 2.64, 3.16 and 6.94 at 30 min, 2 hr and 24 hr, respectively, although absolute uptake in the tumor decreased from 1.95% (injected dose/g) at 30 min to 0.21% at 24 hr after injection. The tumor-to-blood ratio reached 50 at 24 hr after injection. Gamma scintigraphy and autoradiographic studies clearly showed the retention of radiolabeled paclitaxel in the tumor 24 hr after injection. CONCLUSION These studies suggest that 111In-DTPA-paclitaxel may be clinically useful in studying the uptake of paclitaxel in solid tumors.
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Affiliation(s)
- C Li
- Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston, USA
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Inoue T, Yang DJ, Wallace S, Cherif A, Tansey W, Kim EE, Hunter N, Milross CG, Milas L, Podoloff DA. Evaluation of [131I]iodoerythronitroimidazole as a predictor for the radiosensitizing effect. Anticancer Drugs 1996; 7:858-65. [PMID: 8991190 DOI: 10.1097/00001813-199611000-00007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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] [Indexed: 02/03/2023]
Abstract
The aim of this study was to evaluate whether radiolabeled iodoerythronitroimidazole (IETNIM) could predict the radiosensitization effect on tumors. Tumor-bearing mice were irradiated at a dose of 25, 31 and 37 Gy after the injection of IETNIM. They were also exposed to 37 Gy radiation at 35, 70, 140 and 240 min after the i.p. injection of IETNIM. After the irradiation, tumor growth assays were conducted and the effect of IETNIM as a radiosensitizer was estimated as enhancement factor (EF). Tumor uptake was measured at 35, 70, 140 and 240 min after i.p. injection of [131I]IETNIM, which were the same intervals used in the radiosensitization study. EF of IETNIM in mice treated with 25, 30 and 37 Gy irradiation was 0.72, 0.98 and 1.28, respectively. EF of IETNIM in mice irradiated at 35, 70, 140 and 240 min after the injection was 1.50, 1.69, 1.46 and 1.08, which corresponded to the tumor uptake and blood clearance of [131I]IETNIM. [131I]IETNIM may be a suitable radiopharmaceutical to predict the radiosensitization effect of misonidazole analogs on tumors.
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Affiliation(s)
- T Inoue
- Department of Nuclear Medicine, University of Texas MD Anderson Cancer Center, Houston 77030, USA
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Inoue T, Kim EE, Wong FC, Yang DJ, Bassa P, Wong WH, Korkmaz M, Tansey W, Hicks K, Podoloff DA. Comparison of fluorine-18-fluorodeoxyglucose and carbon-11-methionine PET in detection of malignant tumors. J Nucl Med 1996; 37:1472-6. [PMID: 8790196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
UNLABELLED Two commonly used tumor-seeking agents for PET are 2-deoxy-2-18F-fluoro-D-glucose (FDG) and L-methyl-11C-methionine (Met). This study compared FDG and Met in detecting residual or recurrent malignant tumors in the same patients. METHODS Thirty-four lesions in 24 patients with clinically suspected recurrent or residual tumors were studied with PET using Met as well as FDG. FDG scans were conducted 1 hr after the completion of PET with Met. The color-coded superimposed images of standardized uptake values (SUVs) and transmission data were produced, and the peak SUVs in the lesions were then evaluated. Lesions above 2.5 SUV were interpreted as positive results for active tumor. RESULTS The sensitivity of FDG-PET and Met-PET were 64.5% (20/31 lesions) and 61.3% (19/31 lesions), respectively. The mean SUV of FDG in residual or recurrent malignant tumors (n = 31) was significantly higher than that of Met but there was a significant correlation (r = 0.788, p < 0.01) between FDG and Met SUVs in all lesions (n = 34). CONCLUSION PET using FDG and Met appear equally effective in detecting residual or recurrent malignant tumors although FDG uptakes were slightly higher than Met uptakes. Both showed a limited diagnostic sensitivity for small (< 1.5 cm) tumors.
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Affiliation(s)
- T Inoue
- Department of Nuclear Medicine, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA
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Li C, Yu D, Kan Z, Yang DJ, Tansey W, Kuang LR, Wallace S. Biodistribution of cyclic carbonate of ioxilan: a radiopaque particulate macrophage imaging agent. Acad Radiol 1996; 3:500-6. [PMID: 8796708 DOI: 10.1016/s1076-6332(96)80010-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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] [Indexed: 02/02/2023]
Abstract
RATIONALE AND OBJECTIVES A biodegradable radiopaque particulate contrast agent formulated from cyclic carbonate of ioxilan (IXC), which is a prodrug of nonionic water-solubel contrast ioxilan, recently has been developed. This contrast agent enhances liver attenuation and is cleared from the body as ioxilan. In the current study, we tested whether the biodistribution of IXC particles would be affected by the characteristics of particles. METHODS IXC nanoparticles (average diameter = 290 nm) and IXC microparticles (average diameter = 1.7 mm) were prepared, characterized, and injected intravenously (i.v.; 50 mg I/kg body weight) into rats. Two sensitive, reproducible analytic methods--inductively coupled plasma-mass spectrometry (ICP-MS) and high-performance liquid chromatography (HPLC)- were used to quantify tissue iodine and ioxilan concentrations. RESULTS Both IXC nanoparticles and microparticles were taken up in the liver and spleen. The IXC nanoparticles remained in the liver at high concentrations for 6 hr and were slowly cleared. They also gave a high blood iodine concentration in the first 5 min after i.v. injection, suggesting their potential use as a blood-pool imaging agent. Unlike the nanoparticles, the microparticles had a significantly lower uptake by the kidney. CONCLUSION Because of reduced renal uptake, microparticles are a preferred macrophage imaging agent. Biodegradable radiopaque particles may be used either as blood-pool imaging agents or as macrophage imaging agents depending on their size and distribution characteristics. The ICP-MS and HPLC methods are useful for biodistribution studies of iodinated contrast agents.
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Affiliation(s)
- C Li
- Department of Diagnostic Radiology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA
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26
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Kim CG, Yang DJ, Kim EE, Cherif A, Kuang LR, Li C, Tansey W, Liu CW, Li SC, Wallace S, Podoloff DA. Assessment of tumor cell proliferation using [18F]fluorodeoxyadenosine and[18F]fluoroethyluracil. J Pharm Sci 1996; 85:339-44. [PMID: 8699341 DOI: 10.1021/js950402i] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [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] [Indexed: 02/01/2023]
Abstract
This study was to develop radiofluorinated ethyluracil (FEU) and deoxyadenosine analogues (FAD) for noninvasive assessment of tumor proliferative potential by positron emission tomography (PET). 5-(2-Fluoroethyl)uracil ([18F]FEU) was prepared by treating 2,4-dimethoxy-5-(2-hydroxyethyl)pyrimidine with K18F, followed by hydrolysis with HBr. Fluorodeoxyadenosine ([18F]FAD) was prepared by treating a triacetylated analogue of adenosine with K18F. In vitro cell proliferation assay of [18F]-FEU was performed using human peripheral blood mononucleus cells. Tissue distributions were studied in breast tumor-bearing rats at 0.5, 1, 2 and 4 h along with autoradiography at 45 min postinjection. PET imaging studies were conducted in VX-2 tumor-bearing rabbits. In vitro assay indicated that [18F]FEU incorporated into DNA/RNA during cell proliferation. Tumor-to-tissue count density ratios of [18F]FAD and [18F]-FEU increased as a function of time. [18F]FAD had higher tumor-to-nontumor tissue count density ratios than [18F]FEU. Autoradiograms of [18F]FEU and [18F]FAD, and PET images of [18F]FEU, showed that the tumors could be well visualized. The results suggest that [18F]FEU and [18F]FAD have potential use in evaluating tumor cell proliferation by PET.
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Affiliation(s)
- C G Kim
- Department of Nuclear Medicine, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA
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Li C, Yang DJ, Nikiforow S, Tansey W, Kuang LR, Wright KC, Wallace S. Formation and characterization of cisplatin-loaded poly(benzyl l-glutamate) microspheres for chemoembolization. Pharm Res 1994; 11:1792-9. [PMID: 7534920 DOI: 10.1023/a:1018979703726] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [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] [Indexed: 01/25/2023]
Abstract
Chemoembolization using microspheres of 100- to 200-microns is a useful way to treat primary and secondary hepatic tumors. In a search for a better embolic material, we described in detail the preparation and characterization of a poly(benzyl l-glutamate) (PBLG) microspheres containing cisplatin (CDDP). We determined the optimal experimental conditions to produce spherical free-flowing microspheres that were able to release drug content (44% [w/w] CDDP) in a sustained manner. We found that solvent viscosity played a key role in determining the resulting microsphere characteristics. Microscopic studies showed that increasing the polymer concentration (to 10% [w/v]) and the viscosity of the organic phase produced microspheres with uniform drug distribution. Increasing polymer concentration also markedly improved drug incorporation efficiency. In vitro release studies revealed that the release of CDDP was a function of drug loading; microspheres with a higher amount of entrapped CDDP had a slower release rate. This observation and the fact that CDDP/PBLG microspheres did not show "burst effect" at higher loading is ascribed to the formation of uniformly distributed drug crystal networks within the polymer matrix. The favorable properties of the CDDP/PBLG system warrants its further evaluation on experimental animal models for the treatment of hepatic tumors.
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Affiliation(s)
- C Li
- Division of Diagnostic Imaging, University of Texas M. D. Anderson Cancer Center, Houston 77030
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Cherif A, Yang DJ, Tansey W, Kim EE, Wallace S. Rapid synthesis of 3-[18F]fluoro-1-(2'-nitro-1'-imidazolyl)-2-propanol ([18F]fluoromisonidazole). Pharm Res 1994; 11:466-9. [PMID: 8008718 DOI: 10.1023/a:1018937709835] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- A Cherif
- Division of Diagnostic Imaging, University of Texas M. D. Anderson Cancer Center, Houston 77030
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Yang DJ, Li C, Kuang LR, Price JE, Buzdar AU, Tansey W, Cherif A, Gretzer M, Kim EE, Wallace S. Imaging, biodistribution and therapy potential of halogenated tamoxifen analogues. Life Sci 1994; 55:53-67. [PMID: 8015349 DOI: 10.1016/0024-3205(94)90081-7] [Citation(s) in RCA: 52] [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] [Indexed: 01/28/2023]
Abstract
Tamoxifen binds to estrogen receptors (ERs) and prevents breast cancer cell proliferation. This study is aimed at developing a ligand for imaging ER (+) breast tumors by positron emission tomography (PET) or single photon emission computed tomography (SPECT). [18F]-Labeled tamoxifen analogue ([18F]FTX) was prepared in 30-40% yield and [131I]-labeled tamoxifen analogue ([131I]ITX) was prepared in 20-25% yield. In mammary tumor-bearing rats, the biodistribution of [18F]FTX at 2 h showed a tumor uptake value (% injected dose/gram tissue) of 0.41 +/- 0.07; when rats were pretreated with diethylstilbestrol (DES), the value changed to 0.24 +/- 0.017. [131I]ITX at 6 h showed a tumor uptake value of 0.26 +/- 0.166; when rats were pretreated with DES, the value changed to 0.22 +/- 0.044. Priming tumor-bearing rats with estradiol, a tumor uptake value for [131I]ITX was increased to 0.48 +/- 0.107 at 6 h. In the [3H]estradiol receptor assay, tumors had a mean estrogen receptor density of 7.5 fmol/mg of protein. In gamma scintigraphic imaging studies with [131I]ITX, the rabbit uterus uptake can be blocked by pretreatment with DES. Both iodo-tamoxifen and tamoxifen reduced ER(+) breast tumor growth at the dose of 50 micrograms in tumor-bearing mice. The findings indicate that tamoxifen analogue uptake in tumors occurs via an ER-mediated process. Both analogues should have potential for diagnosing functioning ER(+) breast cancer.
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Affiliation(s)
- D J Yang
- Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston 77030
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Yang D, Kuang LR, Cherif A, Tansey W, Li C, Lin WJ, Liu CW, Kim EE, Wallace S. Synthesis of [18F]fluoroalanine and [18F]fluorotamoxifen for imaging breast tumors. J Drug Target 1993; 1:259-67. [PMID: 8069568 DOI: 10.3109/10611869308996084] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To develop ligands for imaging breast tumors, [18F]fluoro analogue of tamoxifen and [18F]fluoroalanine were radiosynthesized. In vivo biodistribution studies were performed in mammary tumor-bearing rats. In studies on the biodistribution of an [18F]fluoro analogue of tamoxifen, tumor uptake decreased when rats were pretreated with diethylstilbestrol (DES), suggesting that tracer uptake in tumors was receptor-mediated. An estrogen receptor assay indicated that tumors have a receptor density of 7.5 fmol/mg protein. Studies of the distribution of [18F]fluoroalanine in tissue showed that the tumor-to-tissue ratio increases as a function of time. Positron emission tomography (PET) images of tumor-bearing rats demonstrated that tumors can be visualized 1 h after rats are injected with an [18F]fluoro analogue of tamoxifen. PET imaging of pigs after injection of 10 mCi of [18F]fluoro analogue of tamoxifen showed uterine uptake that could be blocked by DES (50 mg). The findings suggest that both radiotracers are useful for imaging breast tumors.
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Affiliation(s)
- D Yang
- Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston 77030
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Yang DJ, Cherif A, Tansey W, Kuang LR, Li C, Wright KC, Kim EE, Wallace S. N,N-Diethylfluoromethyltamoxifen: Synthesis, assignment of 1H and 13C spectra and receptor assay. Eur J Med Chem 1992. [DOI: 10.1016/0223-5234(92)90023-t] [Citation(s) in RCA: 3] [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: 10/26/2022]
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Yang DJ, Tewson T, Tansey W, Kuang LR, Reger G, Cherif A, Wright KC, Moult RG, Tilbury RS, Chu K. Halogenated analogues of tamoxifen: synthesis, receptor assay, and inhibition of MCF7 cells. J Pharm Sci 1992; 81:622-5. [PMID: 1403692 DOI: 10.1002/jps.2600810706] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This study was conducted to develop a ligand for imaging estrogen-receptor-positive breast tumors by positron emission tomography or single photon emission computed tomography. We synthesized fluoro and iodo analogues of tamoxifen, and these halogenated analogues produced greater affinity for binding to the receptor than tamoxifen. Values of the inhibition affinity constants were as follows: tamoxifen, 15,000 nM; fluoromethyl-N,N-diethyltamoxifen, 2500 nM for the cis isomer and 500 nM for the trans isomer; and iodomethyl-N,N-diethyltamoxifen, 1500 nM for the cis isomer and 1000 nM for the trans isomer. In studies of human MCF7 breast tumor cell growth, concentrations that inhibited tumor growth in 50% of the cases were as follows: tamoxifen, 11 microM; fluoromethyl-N,N-diethyltamoxifen, 4.5 and 11.8 microM for the cis and trans isomers, respectively; and iodomethyl-N,N-diethyltamoxifen, 2.4 and 6.3 microM for the cis and trans isomers, respectively. These studies suggest that both fluoro and iodo analogues of tamoxifen may be useful diagnostic compounds for predicting the response of estrogen-receptor-positive breast tumors to tamoxifen analogues used in chemotherapy.
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Affiliation(s)
- D J Yang
- Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston 77030
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Yang DJ, Wallace S, Tansey W, Wright KC, Kuang LR, Tilbury RS, Diego I, Lim JL, Emran AM, Kim EE. Synthesis and in vitro receptor binding studies of fluorotamoxifen analogues. Pharm Res 1991; 8:174-7. [PMID: 2023864 DOI: 10.1023/a:1015879717742] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We describe the synthesis of new fluorotamoxifen analogues with the fluorine atom positioned on the end of the aliphatic chain of tamoxifen. The binding of fluorotamoxifens to cytosol estrogen receptors of rat uteri was determined with [3H]estradiol (5 nM). The fluorotamoxifens had similar or superior binding affinities compared with tamoxifen. The IC50 value was as follows: tamoxifen, 5 x 10(-7) M; fluorotamoxifen (VII), 5 x 10(-7) M; N,N-diethylfluorotamoxifen (IV)-cis, 1 x 10(-6) M, and trans, 2 x 10(-7) M; and (cis) fluoromethyl-N,N-diethyltamoxifen (VI) 1 x 10(-7) M. Therefore, the fluorinated tamoxifens have potential use in imaging estrogen receptors by PET.
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Affiliation(s)
- D J Yang
- Division of Diagnostic Imaging, University of Texas, M. D. Anderson Cancer Center, Houston 77030
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Taylor DL, Tansey W, Cook JM, Ho BT. Evaluation of two distinctive beta-carbolines on serotonin binding in human platelets. Res Commun Chem Pathol Pharmacol 1985; 47:133-6. [PMID: 3983465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
6-MeOTHBC binds to both high and low affinity receptors in human platelets. The beta-carboline is less active than chlorimipramine at the low affinity site, and it is weaker than methysergide, a known 5-HT antagonist, at the high affinity site. The other beta-carboline, B-CCE, is not active at either receptor in platelets. The data supports the view that platelets could be used as a limited model for studying 5-HT-ergic neurons.
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