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Hoyt K. Super-Resolution Ultrasound Imaging for Monitoring the Therapeutic Efficacy of a Vascular Disrupting Agent in an Animal Model of Breast Cancer. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2024; 43:1099-1107. [PMID: 38411352 DOI: 10.1002/jum.16438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/01/2024] [Accepted: 02/10/2024] [Indexed: 02/28/2024]
Abstract
OBJECTIVE Evaluate the use of super-resolution ultrasound (SRUS) imaging for the early detection of tumor response to treatment using a vascular-disrupting agent (VDA). METHODS A population of 28 female nude athymic mice (Charles River Laboratories) were implanted with human breast cancer cells (MDA-MB-231, ATCC) in the mammary fat pad and allowed to grow. Ultrasound imaging was performed using a Vevo 3100 scanner (FUJIFILM VisualSonics Inc) equipped with the MX250 linear array transducer immediately before and after receiving bolus injections of a microbubble (MB) contrast agent (Definity, Lantheus Medical Imaging) via the tail vein. Following baseline ultrasound imaging, VDA drug (combretastatin A4 phosphate, CA4P, Sigma Aldrich) or control saline was injected via the placed catheter. After 4 or 24 hours, repeat ultrasound imaging along the same tumor cross-section occurred. Direct intratumoral pressure measurements were obtained using a calibrated sensor. All raw ultrasound data were saved for offline processing and SRUS image reconstruction using custom MATLAB software (MathWorks Inc). From a region encompassing the tumor space and the entire postprocessed ultrasound image sequence, time MB count (TMC) curves were generated in addition to traditional SRUS maps reflecting MB enumeration at each pixel location. Peak enhancement (PE) and wash-in rate (WIR) were extracted from these TMC curves. At termination, intratumoral microvessel density (MVD) was quantified using tomato lectin labeling of patent blood vessels. RESULTS SRUS images exhibited a clear difference between control and treated tumors. While there was no difference in any group parameters at baseline (0 hour, P > .09), both SRUS-derived PE and WIR measurements in tumors treated with VDA exhibited significant decreases by 4 (P = .03 and P = .05, respectively) and 24 hours (P = .02 and P = .01, respectively), but not in control group tumors (P > .22). Similarly, SRUS derived microvascular maps were not different at baseline (P = .81), but measures of vessel density were lower in treated tumors at both 4 and 24 hours (P < .04). An inverse relationship between intratumoral pressure and both PE and WIR parameters were found in control tumors (R2 > .09, P < .03). CONCLUSION SRUS imaging is a new modality for assessing tumor response to treatment using a VDA.
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Affiliation(s)
- Kenneth Hoyt
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA
- Department of Small Animal Clinical Sciences, Texas A&M University, College Station, Texas, USA
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2
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Salavati H, Pullens P, Debbaut C, Ceelen W. Hydraulic conductivity of human cancer tissue: A hybrid study. Bioeng Transl Med 2024; 9:e10617. [PMID: 38435818 PMCID: PMC10905546 DOI: 10.1002/btm2.10617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/22/2023] [Accepted: 10/15/2023] [Indexed: 03/05/2024] Open
Abstract
Background Elevated tumor tissue interstitial fluid pressure (IFP) is an adverse biomechanical biomarker that predicts poor therapy response and an aggressive phenotype. Advances in functional imaging have opened the prospect of measuring IFP non-invasively. Image-based estimation of the IFP requires knowledge of the tissue hydraulic conductivity (K), a measure for the ease of bulk flow through the interstitium. However, data on the magnitude of K in human cancer tissue are not available. Methods We measured the hydraulic conductivity of tumor tissue using modified Ussing chambers in surgical resection specimens. The effect of the tumor microenvironment (TME) on K was investigated by quantifying the collagen content, cell density, and fibroblast density of the tested samples using quantitative immune histochemistry. Also, we developed a computational fluid dynamics (CFD) model to evaluate the role of K on interstitial fluid flow and drug transport in solid tumors. Results The results show that the hydraulic conductivity of human tumor tissues is very limited, ranging from approximately 10-15 to 10-14 m2/Pa∙s. Moreover, K values varied significantly between tumor types and between different samples from the same tumor. A significant inverse correlation was found between collagen fiber density and hydraulic conductivity values. However, no correlation was detected between K and cancer cell or fibroblast densities. The computational model demonstrated the impact of K on the interstitial fluid flow and the drug concentration profile: higher K values led to a lower IFP and deeper drug penetration. Conclusions Human tumor tissue is characterized by a very limited hydraulic conductivity, representing a barrier to effective drug transport. The results of this study can inform the development of realistic computational models, facilitate non-invasive IFP estimation, and contribute to stromal targeting anticancer therapies.
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Affiliation(s)
- Hooman Salavati
- Department of Human Structure and RepairGhent UniversityGhentBelgium
- IBiTech–BioMMedA, Ghent UniversityGhentBelgium
- Cancer Research Institute Ghent (CRIG)GhentBelgium
| | - Pim Pullens
- Department of RadiologyUniversity Hospital GhentGhentBelgium
- Ghent Institute of Functional and Metabolic Imaging (GIFMI)Ghent UniversityGhentBelgium
- IBiTech–Medisip, Ghent UniversityGhentBelgium
| | - Charlotte Debbaut
- IBiTech–BioMMedA, Ghent UniversityGhentBelgium
- Cancer Research Institute Ghent (CRIG)GhentBelgium
| | - Wim Ceelen
- Department of Human Structure and RepairGhent UniversityGhentBelgium
- Cancer Research Institute Ghent (CRIG)GhentBelgium
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3
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Salavati H, Pullens P, Ceelen W, Debbaut C. Drug transport modeling in solid tumors: A computational exploration of spatial heterogeneity of biophysical properties. Comput Biol Med 2023; 163:107190. [PMID: 37392620 DOI: 10.1016/j.compbiomed.2023.107190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/09/2023] [Accepted: 06/19/2023] [Indexed: 07/03/2023]
Abstract
Inadequate uptake of therapeutic agents by tumor cells is still a major barrier in clinical cancer therapy. Mathematical modeling is a powerful tool to describe and investigate the transport phenomena involved. However, current models for interstitial flow and drug delivery in solid tumors have not yet embedded the existing heterogeneity of tumor biomechanical properties. The purpose of this study is to introduce a novel and more realistic methodology for computational models of solid tumor perfusion and drug delivery accounting for these regional heterogeneities as well as lymphatic drainage effects. Several tumor geometries were studied using an advanced computational fluid dynamics (CFD) modeling approach of intratumor interstitial fluid flow and drug transport. Hereby, the following novelties were implemented: (i) the heterogeneity of tumor-specific hydraulic conductivity and capillary permeability; (ii) the effect of lymphatic drainage on interstitial fluid flow and drug penetration. Tumor size and shape both have a crucial role on the interstitial fluid flow regime as well as drug transport illustrating a direct correlation with interstitial fluid pressure (IFP) and an inverse correlation with drug penetration, except for large tumors having a diameter larger than 50 mm. The results also suggest that the interstitial fluid flow and drug penetration in small tumors depend on tumor shape. A parameter study on the necrotic core size illustrated that the core effect (i.e. fluid flow and drug penetration alteration) was only profound in small tumors. Interestingly, the impact of a necrotic core on drug penetration differs depending on the tumor shape from having no effect in ideally spherical tumors to a clear effect in elliptical tumors with a necrotic core. A realistic presence of lymphatic vessels only slightly affected tumor perfusion, having no substantial effect on drug delivery. In conclusion, our findings illustrated that our novel parametric CFD modeling strategy in combination with accurate profiling of heterogeneous tumor biophysical properties can provide a powerful tool for better insights into tumor perfusion and drug transport, enabling effective therapy planning.
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Affiliation(s)
- Hooman Salavati
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium; IBiTech-BioMMedA, Ghent University, Ghent, Belgium; Cancer Research Institute Ghent (CRIG), Ghent, Belgium.
| | - Pim Pullens
- Department of Radiology, University Hospital Ghent, Ghent, Belgium; Ghent Institute of Functional and Metabolic Imaging (GIFMI), Ghent University, Ghent, Belgium; IBitech-Medisip, Ghent University, Ghent, Belgium
| | - Wim Ceelen
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium; Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Charlotte Debbaut
- IBiTech-BioMMedA, Ghent University, Ghent, Belgium; Cancer Research Institute Ghent (CRIG), Ghent, Belgium
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4
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The influence of hypoxia and energy depletion on the response of endothelial cells to the vascular disrupting agent combretastatin A-4-phosphate. Sci Rep 2020; 10:9926. [PMID: 32555222 PMCID: PMC7303175 DOI: 10.1038/s41598-020-66568-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 05/15/2020] [Indexed: 12/25/2022] Open
Abstract
Combretastatin A-4 phosphate (CA4P) is a microtubule-disrupting tumour-selective vascular disrupting agent (VDA). CA4P activates the actin-regulating RhoA-GTPase/ ROCK pathway, which is required for full vascular disruption. While hypoxia renders tumours resistant to many conventional therapies, little is known about its influence on VDA activity. Here, we found that active RhoA and ROCK effector phospho-myosin light chain (pMLC) were downregulated in endothelial cells by severe hypoxia. CA4P failed to activate RhoA/ROCK/pMLC but its activity was restored upon reoxygenation. Hypoxia also inhibited CA4P-mediated actinomyosin contractility, VE-cadherin junction disruption and permeability rise. Glucose withdrawal downregulated pMLC, and coupled with hypoxia, reduced pMLC faster and more profoundly than hypoxia alone. Concurrent inhibition of glycolysis (2-deoxy-D-glucose, 2DG) and mitochondrial respiration (rotenone) caused profound actin filament loss, blocked RhoA/ROCK signalling and rendered microtubules CA4P-resistant. Withdrawal of the metabolism inhibitors restored the cytoskeleton and CA4P activity. The AMP-activated kinase AMPK was investigated as a potential mediator of pMLC downregulation. Pharmacological AMPK activators that generate AMP, unlike allosteric activators, downregulated pMLC but only when combined with 2DG and/or rotenone. Altogether, our results suggest that Rho/ROCK and actinomyosin contractility are regulated by AMP/ATP levels independently of AMPK, and point to hypoxia/energy depletion as potential modifiers of CA4P response.
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Predicting Clinical Efficacy of Vascular Disrupting Agents in Rodent Models of Primary and Secondary Liver Cancers: An Overview with Imaging-Histopathology Correlation. Diagnostics (Basel) 2020; 10:diagnostics10020078. [PMID: 32024029 PMCID: PMC7168934 DOI: 10.3390/diagnostics10020078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 01/24/2020] [Accepted: 01/28/2020] [Indexed: 12/16/2022] Open
Abstract
Vascular disrupting agents (VDAs) have entered clinical trials for over 15 years. As the leading VDA, combretastatin A4 phosphate (CA4P) has been evaluated in combination with chemotherapy and molecular targeting agents among patients with ovarian cancer, lung cancer and thyroid cancer, but still remains rarely explored in human liver cancers. To overcome tumor residues and regrowth after CA4P monotherapy, a novel dual targeting pan-anticancer theragnostic strategy, i.e., OncoCiDia, has been developed and shown promise previously in secondary liver tumor models. Animal model of primary liver cancer is time consuming to induce, but of value for more closely mimicking human liver cancers in terms of tumor angiogenesis, histopathological heterogeneity, cellular differentiation, tumor components, cancer progression and therapeutic response. Being increasingly adopted in VDA researches, multiparametric magnetic resonance imaging (MRI) provides imaging biomarkers to reflect in vivo tumor responses to drugs. In this article as a chapter of a doctoral thesis, we overview the construction and clinical relevance of primary and secondary liver cancer models in rodents. Target selection for CA4P therapy assisted by enhanced MRI using hepatobiliary contrast agents (CAs), and therapeutic efficacy evaluated by using MRI with a non-specific contrast agent, dynamic contrast enhanced (DCE) imaging, diffusion weighted imaging (DWI) are also described. We then summarize diverse responses among primary hepatocellular carcinomas (HCCs), secondary liver and pancreatic tumors to CA4P, which appeared to be related to tumor size, vascularity, and cellular differentiation. In general, imaging-histopathology correlation studies allow to conclude that CA4P tends to be more effective in secondary liver tumors and in more differentiated HCCs, but less effective in less differentiated HCCs and implanted pancreatic tumor. Notably, cirrhotic liver may be responsive to CA4P as well. All these could be instructive for future clinical trials of VDAs.
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6
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Gao M, Zhang D, Jin Q, Jiang C, Wang C, Li J, Peng F, Huang D, Zhang J, Song S. Combretastatin-A4 phosphate improves the distribution and antitumor efficacy of albumin-bound paclitaxel in W256 breast carcinoma model. Oncotarget 2018; 7:58133-58141. [PMID: 27531898 PMCID: PMC5295418 DOI: 10.18632/oncotarget.11249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 07/27/2016] [Indexed: 11/25/2022] Open
Abstract
Nanomedicine holds great promise for fighting against malignant tumors. However, tumor elevated interstitial fluid pressure (IFP) seriously hinders convective transvascular and interstitial transport of nanomedicines and thus damages its antitumor efficacy. In this study, combretastatin-A4 phosphate (CA4P) was utilized to reduce tumor IFP, and thereby to improve the intratumoral distribution and antitumor efficacy of nanoparticle albumin-bound paclitaxel (nab-paclitaxel). IFP was measured using the wick-in-needle method in tumors growing subcutaneously pretreatment and posttreatment with a single intravenous injection of CA4P. The tracing method of iodine 131 isotope was used for biodistribution analysis of nab-paclitaxel. Liquid chromatography coupled with tandem mass spectrometry was used to detect the intratumoral concentration of paclitaxel. Magnetic resonance imaging was applied to monitor tumor volume and ratios of necrosis. The tumor IFP continued to decline gradually over time following CA4P treatment, reaching approximately 31% of the pretreatment value by 1 h posttreatment. Biodistribution data indicated that both 131I-nab-paclitaxel and paclitaxel exhibited higher tumor uptake in CA4P + 131I-nab-paclitaxel group compared with I131-nab-paclitaxel group. Nab-paclitaxel combined with CA4Pshowed significant tumor growth inhibition and higher tumor necrosis ratio relative to PBS, CA4P and nab-paclitaxel group, respectively. In conclusion, CA4P improved the intratumoral distribution and antitumor efficacy of nab-paclitaxel in W256 tumor-bearing rats.
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Affiliation(s)
- Meng Gao
- Laboratory of Translational Medicine, Jiangsu Province Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China.,Laboratory of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China
| | - Dongjian Zhang
- Laboratory of Translational Medicine, Jiangsu Province Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China.,Laboratory of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China
| | - Qiaomei Jin
- Laboratory of Translational Medicine, Jiangsu Province Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China.,Laboratory of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China
| | - Cuihua Jiang
- Laboratory of Translational Medicine, Jiangsu Province Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China.,Laboratory of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China
| | - Cong Wang
- Department of Natural Medicinal Chemistry and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, Jiangsu Province, P.R. China
| | - Jindian Li
- Department of Natural Medicinal Chemistry and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, Jiangsu Province, P.R. China
| | - Fei Peng
- Laboratory of Translational Medicine, Jiangsu Province Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China.,Laboratory of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China
| | - Dejian Huang
- Laboratory of Translational Medicine, Jiangsu Province Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China.,Laboratory of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China
| | - Jian Zhang
- Laboratory of Translational Medicine, Jiangsu Province Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China.,Laboratory of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, Jiangsu Province, P.R.China
| | - Shaoli Song
- Department of Nuclear Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200127, P.R. China
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7
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Siemann DW, Chaplin DJ, Horsman MR. Realizing the Potential of Vascular Targeted Therapy: The Rationale for Combining Vascular Disrupting Agents and Anti-Angiogenic Agents to Treat Cancer. Cancer Invest 2017; 35:519-534. [DOI: 10.1080/07357907.2017.1364745] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- D. W. Siemann
- Department of Radiation Oncology, University of Florida, Gainesville, FL, USA
| | | | - M. R. Horsman
- Department of Experimental Clinical Oncology, Aarhus University, Denmark
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8
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Liu Y, Yin T, Keyzer FD, Feng Y, Chen F, Liu J, Song S, Yu J, Vandecaveye V, Swinnen J, Bormans G, Himmelreich U, Oyen R, Zhang J, Huang G, Ni Y. Micro-HCCs in rats with liver cirrhosis: paradoxical targeting effects with vascular disrupting agent CA4P. Oncotarget 2017; 8:55204-55215. [PMID: 28903414 PMCID: PMC5589653 DOI: 10.18632/oncotarget.19339] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/27/2017] [Indexed: 12/11/2022] Open
Abstract
We sought to investigate anticancer efficacy of a vascular disrupting agent (VDA) combretastatin A-4 phosphate (CA4P) in relation to tumor size among hepatocellular carcinomas (HCCs) in rats using magnetic resonance imaging (MRI) and postmortem techniques. Nineteen rats with 43 chemically-induced HCCs of 2.8–20.9 mm in size on liver cirrhosis received CA4P intravenously at 10 mg/kg. Tumor-diameter was measured by T2-weighted imaging (T2WI) to define microcancers (< 5 mm) versus larger HCCs. Vascular responses and tissue necrosis were detected by diffusion-weighted imaging (DWI), contrast-enhanced T1-weighted imaging (CE-T1WI) and dynamic contrast enhanced (DCE-) MRI, which were validated by microangiography and histopathology. MRI revealed nearly complete necrosis in 5 out of 7 micro-HCCs, but diverse therapeutic necrosis in larger HCCs with a positive correlation with tumor size. Necrosis in micro-HCCs was 36.9% more than that in larger HCCs. While increased diffusion coefficient (ADCdiff) suggested tumor necrosis, perfusion coefficient (ADCperf) indicated sharply decreased blood perfusion in cirrhotic liver together with a reduction in micro-HCCs. DCE revealed lowered tumor blood flow from intravascular into extravascular extracellular space (EES). Microangiography and histopathology revealed hypo- and hypervascularity in 4 and 3 micro-HCCs, massive, partial and minor degrees of tumoral necrosis in 5, 1 and 1 micro-HCCs respectively, and patchy necrotic foci in cirrhotic liver. CD34-PAS staining implicated that poorly vascularized micro-HCCs growing on liver cirrhosis tended to respond better to CA4P treatment. In this study, more complete CA4P-response occurred unexpectedly in micro-HCCs in rats, along with CA4P-induced necrotic foci in cirrhotic liver. These may help to plan clinical applications of VDAs in patients with HCCs and liver cirrhosis.
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Affiliation(s)
- Yewei Liu
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium.,Institute of Clinical Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China.,Shanghai University of Medicine and Health Sciences, Shanghai 201318, China.,Institute of Health Sciences, Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS), Shanghai 200025, China
| | - Ting Yin
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium
| | | | - Yuanbo Feng
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium
| | - Feng Chen
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium
| | - Jianjun Liu
- Institute of Clinical Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Shaoli Song
- Institute of Clinical Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Jie Yu
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium
| | | | - Johan Swinnen
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium
| | - Guy Bormans
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium
| | - Uwe Himmelreich
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium
| | - Raymond Oyen
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium
| | - Jian Zhang
- Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, China
| | - Gang Huang
- Institute of Clinical Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China.,Shanghai University of Medicine and Health Sciences, Shanghai 201318, China.,Institute of Health Sciences, Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS), Shanghai 200025, China
| | - Yicheng Ni
- Biomedical Group, Campus Gasthuisberg, KU Leuven, Leuven 3000, Belgium.,Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, China
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Fruytier AC, Le Duff CS, Po C, Magat J, Bouzin C, Neveu MA, Feron O, Jordan BF, Gallez B. The Blood Flow Shutdown Induced by Combretastatin A4 Impairs Gemcitabine Delivery in a Mouse Hepatocarcinoma. Front Pharmacol 2016; 7:506. [PMID: 28066252 PMCID: PMC5179558 DOI: 10.3389/fphar.2016.00506] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 12/07/2016] [Indexed: 01/31/2023] Open
Abstract
In recent clinical studies, vascular disrupting agents (VDAs) are mainly used in combination with chemotherapy. However, an often overlooked concern in treatment combination is the VDA-induced impairment of chemotherapy distribution in the tumor. The work presented here investigated the impact of blood flow shutdown induced by Combretastatin A4 (CA4) on gemcitabine uptake into mouse hepatocarcinoma. At 2 h after CA4 treatment, using DCE-MRI, a significant decrease in the perfusion-relevant parameters Ktrans and Vp were observed in treated group compared with the control group. The blood flow shutdown was indeed confirmed by a histology study. In a third experiment, the total gemcitabine uptake was found to be significantly lower in treated tumors, as assessed in a separate experiment using ex vivo fluorine nuclear magnetic resonance spectroscopy. The amount of active metabolite gemcitabine triphosphate was also lower in treated tumors. In conclusion, the blood flow shutdown induced by VDAs can impact negatively on the delivery of small cytotoxic agents in tumors. The present study outlines the importance of monitoring the tumor vascular function when designing drug combinations.
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Affiliation(s)
- Anne-Catherine Fruytier
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain Brussels, Belgium
| | - Cecile S Le Duff
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain Louvain-la-Neuve, Belgium
| | - Chrystelle Po
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain Brussels, Belgium
| | - Julie Magat
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain Brussels, Belgium
| | - Caroline Bouzin
- Institut de Recherche Expérimentale et Clinique, Pole of Pharmacology, Angiogenesis and Cancer Research Laboratory, Université Catholique de Louvain Brussels, Belgium
| | - Marie-Aline Neveu
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain Brussels, Belgium
| | - Olivier Feron
- Institut de Recherche Expérimentale et Clinique, Pole of Pharmacology, Angiogenesis and Cancer Research Laboratory, Université Catholique de Louvain Brussels, Belgium
| | - Benedicte F Jordan
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain Brussels, Belgium
| | - Bernard Gallez
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain Brussels, Belgium
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10
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Siemann DW, Horsman MR. Modulation of the tumor vasculature and oxygenation to improve therapy. Pharmacol Ther 2015; 153:107-24. [PMID: 26073310 DOI: 10.1016/j.pharmthera.2015.06.006] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/03/2015] [Indexed: 12/12/2022]
Abstract
The tumor microenvironment is increasingly recognized as a major factor influencing the success of therapeutic treatments and has become a key focus for cancer research. The progressive growth of a tumor results in an inability of normal tissue blood vessels to oxygenate and provide sufficient nutritional support to tumor cells. As a consequence the expanding neoplastic cell population initiates its own vascular network which is both structurally and functionally abnormal. This aberrant vasculature impacts all aspects of the tumor microenvironment including the cells, extracellular matrix, and extracellular molecules which together are essential for the initiation, progression and spread of tumor cells. The physical conditions that arise are imposing and manifold, and include elevated interstitial pressure, localized extracellular acidity, and regions of oxygen and nutrient deprivation. No less important are the functional consequences experienced by the tumor cells residing in such environments: adaptation to hypoxia, cell quiescence, modulation of transporters and critical signaling molecules, immune escape, and enhanced metastatic potential. Together these factors lead to therapeutic barriers that create a significant hindrance to the control of cancers by conventional anticancer therapies. However, the aberrant nature of the tumor microenvironments also offers unique therapeutic opportunities. Particularly interventions that seek to improve tumor physiology and alleviate tumor hypoxia will selectively impair the neoplastic cell populations residing in these environments. Ultimately, by combining such therapeutic strategies with conventional anticancer treatments it may be possible to bring cancer growth, invasion, and metastasis to a halt.
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Affiliation(s)
- Dietmar W Siemann
- Department of Radiation Oncology, University of Florida Health Cancer Center, Gainesville, FL, USA.
| | - Michael R Horsman
- Department of Experimental Clinical Oncology, Aarhus University Hospital-NBG, Aarhus, Denmark
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11
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Colliez F, Fruytier AC, Magat J, Neveu MA, Cani PD, Gallez B, Jordan BF. Monitoring Combretastatin A4-induced tumor hypoxia and hemodynamic changes using endogenous MR contrast and DCE-MRI. Magn Reson Med 2015; 75:866-72. [PMID: 25765253 DOI: 10.1002/mrm.25642] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 12/15/2014] [Accepted: 01/07/2015] [Indexed: 01/01/2023]
Abstract
PURPOSE To benchmark MOBILE (Mapping of Oxygen By Imaging Lipid relaxation Enhancement), a recent noninvasive MR method of mapping changes in tumor hypoxia, electron paramagnetic resonance (EPR) oximetry, and dynamic contrast-enhanced MRI (DCE-MRI) as biomarkers of changes in tumor hemodynamics induced by the antivascular agent combretastatin A4 (CA4). METHODS NT2 and MDA-MB-231 mammary tumors were implanted subcutaneously in FVB/N and nude NMRI mice. Mice received 100 mg/kg of CA4 intraperitoneally 3 hr before imaging. The MOBILE sequence (assessing R1 of lipids) and the DCE sequence (assessing K(trans) hemodynamic parameter), were assessed on different cohorts. pO2 changes were confirmed on matching tumors using EPR oximetry consecutive to the MOBILE sequence. Changes in tumor vasculature were assessed using immunohistology consecutive to DCE-MRI studies. RESULTS Administration of CA4 induced a significant decrease in lipids R1 (P = 0.0273) on pooled tumor models and a reduction in tumor pO2 measured by EPR oximetry. DCE-MRI also exhibited a significant drop of K(trans) (P < 0.01) that was confirmed by immunohistology. CONCLUSION MOBILE was identified as a marker to follow a decrease in oxygenation induced by CA4. However, DCE-MRI showed a higher dynamic range to follow changes in tumor hemodynamics induced by CA4.
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Affiliation(s)
- Florence Colliez
- Université Catholique de Louvain, Louvain Drug Research Institute, Biomedical Magnetic Resonance Group, Avenue Mounier 73, B1.73.08, Brussels, Belgium
| | - Anne-Catherine Fruytier
- Université Catholique de Louvain, Louvain Drug Research Institute, Biomedical Magnetic Resonance Group, Avenue Mounier 73, B1.73.08, Brussels, Belgium
| | - Julie Magat
- Université Catholique de Louvain, Louvain Drug Research Institute, Biomedical Magnetic Resonance Group, Avenue Mounier 73, B1.73.08, Brussels, Belgium
| | - Marie-Aline Neveu
- Université Catholique de Louvain, Louvain Drug Research Institute, Biomedical Magnetic Resonance Group, Avenue Mounier 73, B1.73.08, Brussels, Belgium
| | - Patrice D Cani
- Université Catholique de Louvain, Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Avenue Mounier 73, B1.73.08, Brussels, Belgium
| | - Bernard Gallez
- Université Catholique de Louvain, Louvain Drug Research Institute, Biomedical Magnetic Resonance Group, Avenue Mounier 73, B1.73.08, Brussels, Belgium
| | - Bénédicte F Jordan
- Université Catholique de Louvain, Louvain Drug Research Institute, Biomedical Magnetic Resonance Group, Avenue Mounier 73, B1.73.08, Brussels, Belgium
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Fruytier AC, Magat J, Neveu MA, Karroum O, Bouzin C, Feron O, Jordan B, Cron GO, Gallez B. Dynamic contrast-enhanced MRI in mouse tumors at 11.7 T: comparison of three contrast agents with different molecular weights to assess the early effects of combretastatin A4. NMR IN BIOMEDICINE 2014; 27:1403-1412. [PMID: 25323069 DOI: 10.1002/nbm.3220] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 08/29/2014] [Accepted: 08/29/2014] [Indexed: 06/04/2023]
Abstract
Dynamic contrast-enhanced (DCE)-MRI is useful to assess the early effects of drugs acting on tumor vasculature, namely anti-angiogenic and vascular disrupting agents. Ultra-high-field MRI allows higher-resolution scanning for DCE-MRI while maintaining an adequate signal-to-noise ratio. However, increases in susceptibility effects, combined with decreases in longitudinal relaxivity of gadolinium-based contrast agents (GdCAs), make DCE-MRI more challenging at high field. The aim of this work was to explore the feasibility of using DCE-MRI at 11.7 T to assess the tumor hemodynamics of mice. Three GdCAs possessing different molecular weights (gadoterate: 560 Da, 0.29 mmol Gd/kg; p846: 3.5 kDa, 0.10 mmol Gd/kg; and p792: 6.47 kDa, 0.15 mmol Gd/kg) were compared to see the influence of the molecular weight in the highlight of the biologic effects induced by combretastatin A4 (CA4). Mice bearing transplantable liver tumor (TLT) hepatocarcinoma were divided into two groups (n = 5-6 per group and per GdCA): a treated group receiving 100 mg/kg CA4, and a control group receiving vehicle. The mice were imaged at 11.7 T with a T1 -weighted FLASH sequence 2 h after the treatment. Individual arterial input functions (AIFs) were computed using phase imaging. These AIFs were used in the Extended Tofts Model to determine K(trans) and vp values. A separate immunohistochemistry study was performed to assess the vascular perfusion and the vascular density. Phase imaging was used successfully to measure the AIF for the three GdCAs. In control groups, an inverse relationship between the molecular weight of the GdCA and K(trans) and vp values was observed. K(trans) was significantly decreased in the treated group compared with the control group for each GdCA. DCE-MRI at 11.7 T is feasible to assess tumor hemodynamics in mice. With K(trans) , the three GdCAs were able to track the early vascular effects induced by CA4 treatment.
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Affiliation(s)
- A-C Fruytier
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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Effect of tumor shape, size, and tissue transport properties on drug delivery to solid tumors. J Biol Eng 2014; 8:12. [PMID: 24987457 PMCID: PMC4076317 DOI: 10.1186/1754-1611-8-12] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 05/30/2014] [Indexed: 12/21/2022] Open
Abstract
Background The computational methods provide condition for investigation related to the process of drug delivery, such as convection and diffusion of drug in extracellular matrices, drug extravasation from microvessels or to lymphatic vessels. The information of this process clarifies the mechanisms of drug delivery from the injection site to absorption by a solid tumor. In this study, an advanced numerical method is used to solve fluid flow and solute transport equations simultaneously to investigate the effect of tumor shape and size on drug delivery to solid tumor. Methods The advanced mathematical model used in our previous work is further developed by adding solute transport equation to the governing equations. After applying appropriate boundary and initial conditions on tumor and surrounding tissue geometry, the element-based finite volume method is used for solving governing equations of drug delivery in solid tumor. Also, the effects of size and shape of tumor and some of tissue transport parameters such as effective pressure and hydraulic conductivity on interstitial fluid flow and drug delivery are investigated. Results Sensitivity analysis shows that drug delivery in prolate shape is significantly better than other tumor shapes. Considering size effect, increasing tumor size decreases drug concentration in interstitial fluid. This study shows that dependency of drug concentration in interstitial fluid to osmotic and intravascular pressure is negligible. Conclusions This study shows that among diffusion and convection mechanisms of drug transport, diffusion is dominant in most different tumor shapes and sizes. In tumors in which the convection has considerable effect, the drug concentration is larger than that of other tumors at the same time post injection.
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Yang RM, Zou Y, Huang DP, Lai SS, Xu XD, Wei XH, Chang HZ, Huang TK, Wang L, Tang WJ, Jiang XQ. In vivo assessment of the vascular disrupting effect of M410 by DCE-MRI biomarker in a rabbit model of liver tumor. Oncol Rep 2014; 32:709-15. [PMID: 24898785 DOI: 10.3892/or.2014.3230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 04/07/2014] [Indexed: 11/05/2022] Open
Abstract
The present study aimed to prospectively monitor the vascular disrupting effect of M410 by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rabbits with VX2 liver tumors. Twenty-eight rabbits bearing VX2 tumors in the left lobe of the liver were established and randomly divided into treatment and control groups, intravenously injected with 25 mg/kg M410 or sterile saline, respectively. Conventional and DCE-MRI data were acquired on a 3.0-T MR unit at pretreatment, 4 h, 1, 4, 7 and 14 days post-treatment. Histopathological examinations [hematoxylin and eosin (H&E) and CD34 immunohistochemisty staining] were performed at each time point. The dynamic changes in tumor volume, kinetic DCE-MRI parameter [volume transfer constant (Ktrans)] and histological data were evaluated. Tumors grew slower in the M410 group 4-14 days following treatment, compared with rapidly growing tumors in the control group (P<0.05). At 4 h, 1 and 4 days, Ktrans significantly decreased in the M410 group compared with that in the control group (P<0.05). However, Ktrans values were similar in the two groups for the other time points studied. The changes in DCE-MRI parameters were consistent with the results obtained from H&E and CD34 staining of the tumor tissues. DCE-MRI parameter Ktrans may be used as a non-invasive imaging biomarker to monitor the dynamic histological changes in tumors following treatment with the vascular targeting agent M410.
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Affiliation(s)
- Rui-Meng Yang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Yong Zou
- Guangzhou Institute of Chemistry, Chinese Academy of Science, Guangzhou 510650, P.R. China
| | - Dan-Ping Huang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Sheng-Sheng Lai
- Department of Medical Equipment, Guangdong Food and Drug Vocational College, Guangzhou 510520, P.R. China
| | - Xiang-Dong Xu
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Xin-Hua Wei
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Han-Zheng Chang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Tong-Kun Huang
- Guangzhou Institute of Chemistry, Chinese Academy of Science, Guangzhou 510650, P.R. China
| | - Li Wang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Wen-Jie Tang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
| | - Xin-Qing Jiang
- Department of Radiology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, P.R. China
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Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) in Preclinical Studies of Antivascular Treatments. Pharmaceutics 2012; 4:563-89. [PMID: 24300371 PMCID: PMC3834929 DOI: 10.3390/pharmaceutics4040563] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 10/29/2012] [Accepted: 10/30/2012] [Indexed: 12/18/2022] Open
Abstract
Antivascular treatments can either be antiangiogenic or targeting established tumour vasculature. These treatments affect the tumour microvasculature and microenvironment but may not change clinical measures like tumour volume and growth. In research on antivascular treatments, information on the tumour vasculature is therefore essential. Preclinical research is often used for optimization of antivascular drugs alone or in combined treatments. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is an in vivo imaging method providing vascular information, which has become an important tool in both preclinical and clinical research. This review discusses common DCE-MRI imaging protocols and analysis methods and provides an overview of preclinical research on antivascular treatments utilizing DCE-MRI.
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Role of convection and diffusion on DCE-MRI parameters in low leakiness KHT sarcomas. Microvasc Res 2012; 84:306-13. [DOI: 10.1016/j.mvr.2012.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 08/17/2012] [Accepted: 09/06/2012] [Indexed: 11/19/2022]
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Wei Y, Chen Q, Wu B, Zhou A, Xing D. High-sensitivity in vivo imaging for tumors using a spectral up-conversion nanoparticle NaYF4: Yb3+, Er3+ in cooperation with a microtubulin inhibitor. NANOSCALE 2012; 4:3901-3909. [PMID: 22652931 DOI: 10.1039/c2nr30804e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Fluorescein has been used for in vivo imaging to identify tumors. However, this technique presents several limitations, mainly due to its limited targeting efficiency, tissue autofluorescence and poor light penetration in tissue. In the present study, an alternative fluorescence imaging technique to localize tumors has been developed by using up-conversion nanoparticles (UCNs) and enhanced targeting approaches. A folic acid molecule is conjoined with UCNs (NaYF(4): Yb(3+), Er(3+)) to improve the tumor-specificity; the UCN is also loaded with the microtubule inhibitor CA4P, to further improve the local delivery of particles in the tumor. The proposed imaging technique combines several well-established individual concepts into one novel integrated procedure and significantly improves its tumor-imaging capability: the near-infrared excitation for UCNs minimizes tissue autofluorescence and allows imaging into deeper tissue; the improvement in the signal to noise ratio (SNR) is at least a magnitude better than that of a conventional fluorescence imaging technique, and the modification of UCNs with folic acid significantly improves the tumor targeting efficiency by utilizing its affinity for the folic acid receptor that is often over expressed in tumors. The loading of CA4P further helps UCNs to cross blood vessel walls to reach tumor cells by depolymerizing the microtubules of endothelial cells. The integrated nanoparticle possesses the near-infrared-identical optical properties of UCNs alone, thus achieving a highly effective fluorescence imaging probe. The results demonstrated that the proposed method provides an excellent alternative for tumor localization and a potential traceable vehicle for highly efficient drug delivery.
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Affiliation(s)
- Yanchun Wei
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
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Bertelsen LB, Shen YY, Nielsen T, Stødkilde-Jørgensen H, Lloyd GK, Siemann DW, Horsman MR. Vascular effects of plinabulin (NPI-2358) and the influence on tumour response when given alone or combined with radiation. Int J Radiat Biol 2011; 87:1126-34. [PMID: 21815749 DOI: 10.3109/09553002.2011.605418] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE This study investigated the anti-tumour effects of the novel vascular disrupting agent plinabulin (NPI-2358) when given alone or combined with radiation. MATERIALS AND METHODS Foot implanted C3H mammary carcinomas or leg implanted KHT sarcomas were used, with plinabulin injected intraperitoneally. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measurements were made with gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) on a 7-tesla magnet. Treatment response was assessed using regrowth delay (C3H tumours), clonogenic survival (KHT sarcomas) or histological estimates of necrosis for both models. RESULTS Plinabulin (7.5 mg/kg) significantly reduced the initial area under curve (IAUC) and the transfer constant (K(trans)) within 1 hour after injection, reaching a nadir at 3 h, but returning to normal within 24 h. A dose-dependent decrease in IAUC and K(trans), was seen at 3 h. No significant anti-tumour effects were observed in the C3H tumours until doses of 12.5 mg/kg were achieved, but started at 1.5 mg/kg in the KHT sarcoma. Irradiating tumours 1 h after injecting plinabulin enhanced response in both models. CONCLUSIONS Plinabulin induced a time- and dose-dependent decrease in tumour perfusion. The KHT sarcoma was more sensitive than the C3H tumour to the anti-tumour effects of plinabulin, while radiation response was enhanced in both models.
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Affiliation(s)
- Lotte B Bertelsen
- Department of Experimental Clinical Oncology, Aarhus University Hospital-NBG, Aarhus, Denmark
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Larsson E, Ljungberg M, Strand SE, Jönsson BA. Monte Carlo calculations of absorbed doses in tumours using a modified MOBY mouse phantom for pre-clinical dosimetry studies. Acta Oncol 2011; 50:973-80. [PMID: 21767199 DOI: 10.3109/0284186x.2011.582517] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Clinical treatment with radionuclides is usually preceded by biokinetic and dosimetry studies in small animals. Evaluation of the therapeutic efficacy is essential and must rely on accurate dosimetry, which in turn must be based on a realistic geometrical model that properly describes the transport of radiation. It is also important to include the source distribution in the dosimetry calculations. Tumours are often implanted subcutaneously in animals, constituting an important additional source of radiation that often is not considered in the dosimetry models. The aims of this study were to calculate S values of the mouse, and determine the absorbed dose contribution to and from subcutaneous tumours inoculated at four different locations. METHODS The Moby computer program generates a three dimensional (3D) voxel-based phantom. Tumours were modelled as half-spheres on the body surface, and the radius was varied to study different tumour masses. The phantoms were used as input for Monte Carlo simulations of absorbed fractions and S factors with the radiation transport code MCNPX 2.6f. Calculations were performed for monoenergetic photons and electrons, and the radionuclides (125)I, (131)I, (111)In, (177)Lu and (90)Y. RESULTS Electron energy and tumour size are important for both self- and cross-doses. If the activity is non-uniformly distributed within the body, the position of the tumour must be considered in order to calculate the tumour absorbed dose accurately. If the uptake in the tumour is high compared with that in adjacent organs the absorbed dose contribution to organs from the tumour cannot be neglected. CONCLUSIONS In order to perform accurate tumour dosimetry in mouse models it is necessary to take the additional contribution from the activity distribution within the body of the mouse into account. This may be of significance in the interpretation of radiobiological tumour response in pre-clinical studies.
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Affiliation(s)
- Erik Larsson
- Department of Medical Radiation Physics, Clinical Sciences-Lund, Lund University, Sweden.
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Grau C, Olsen DR, Overgaard J, Høyer M, Lindegaard JC, Muren LP. Biology-guided adaptive radiation therapy - presence or future? Acta Oncol 2010; 49:884-7. [PMID: 20831476 DOI: 10.3109/0284186x.2010.516010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
MESH Headings
- Adaptation, Biological/physiology
- Adaptation, Biological/radiation effects
- Biology/methods
- Biology/trends
- Dose Fractionation, Radiation
- Fluorodeoxyglucose F18
- Humans
- Radiation Oncology/methods
- Radiation Oncology/trends
- Radiosurgery/methods
- Radiosurgery/trends
- Radiotherapy Dosage
- Radiotherapy, Computer-Assisted/methods
- Radiotherapy, Computer-Assisted/trends
- Radiotherapy, Conformal/adverse effects
- Radiotherapy, Conformal/methods
- Radiotherapy, Conformal/trends
- Surgery, Computer-Assisted/methods
- Surgery, Computer-Assisted/trends
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