Epithelioid inflammatory myofibroblastic sarcoma (eIMS) is characterised by perinuclear ALK localisation, CD30 expression and early relapse despite crizotinib treatment. We aimed to identify ...therapies to prevent and/or treat ALK inhibitor resistance.
Malignant ascites, from an eIMS patient at diagnosis and following multiple relapses, were used to generate matched diagnosis and relapse xenografts.
Xenografts were validated by confirmation of RANBP2-ALK rearrangement, perinuclear ALK localisation and CD30 expression. Although brentuximab-vedotin (BV) demonstrated single-agent activity, tumours regrew during BV therapy. BV resistance was associated with reduced CD30 expression and induction of ABCB1. BV resistance was reversed in vitro by tariquidar, but combination BV and tariquidar treatment only briefly slowed xenograft growth compared with BV alone. Combining BV with either crizotinib or ceritinib resulted in marked tumour shrinkage in both xenograft models, and resulted in prolonged tumour-free survival in the diagnosis compared with the relapse xenograft.
CD30 is a therapeutic target in eIMS. BV efficacy is limited by the rapid emergence of resistance. Prolonged survival with combination ALK and CD30-targeted-therapy in the diagnosis model provides the rationale to trial this combination in eIMS patients at diagnosis. This combination could also be considered for other CD30-positive, ALK-rearranged malignancies.
Metastasis (the spread of cancer from a primary tumor to secondary organs) is responsible for most cancer deaths. The ability to follow the fate of a population of tumor cells over time in an ...experimental animal would provide a powerful new way to monitor the metastatic process. Here we describe a magnetic resonance imaging (MRI) technique that permits the tracking of breast cancer cells in a mouse model of brain metastasis at the single‐cell level. Cancer cells that were injected into the left ventricle of the mouse heart and then delivered to the brain were detectable on MR images. This allowed the visualization of the initial delivery and distribution of cells, as well as the growth of tumors from a subset of these cells within the whole intact brain volume. The ability to follow the metastatic process from the single‐cell stage through metastatic growth, and to quantify and monitor the presence of solitary undivided cells will facilitate progress in understanding the mechanisms of brain metastasis and tumor dormancy, and the development of therapeutics to treat this disease. Magn Reson Med, 2006. Published 2006 Wiley‐Liss, Inc.
Biomarkers which better match anticancer drugs with cancer driver genes hold the promise of improved clinical responses and cure rates. We developed a precision medicine platform of rapid ...high‐throughput drug screening (HTS) and patient‐derived xenografting (PDX) of primary tumor tissue, and evaluated its potential for treatment identification among 56 consecutively enrolled high‐risk pediatric cancer patients, compared with conventional molecular genomics and transcriptomics. Drug hits were seen in the majority of HTS and PDX screens, which identified therapeutic options for 10 patients for whom no targetable molecular lesions could be found. Screens also provided orthogonal proof of drug efficacy suggested by molecular analyses and negative results for some molecular findings. We identified treatment options across the whole testing platform for 70% of patients. Only molecular therapeutic recommendations were provided to treating oncologists and led to a change in therapy in 53% of patients, of whom 29% had clinical benefit. These data indicate that in vitro and in vivo drug screening of tumor cells could increase therapeutic options and improve clinical outcomes for high‐risk pediatric cancer patients.
Synopsis
A precision diagnostic platform integrating genomics and transcriptomics with drug testing of patient's primary tumor cells in high throughput drug screening (HTS) and patient‐derived xenograft (PDX) was established to improve identification of therapies in high‐risk pediatric cancer patients.
Treatment options could be identified for 70% of patients across the four‐part platform.
HTS provided orthogonal proof of drug efficacy suggested by molecular analyses and identified many new drug responses without prior molecular hallmarks.
Effective treatments were observed in more than half of PDX models.
There was a strong correlation between HTS and PDX results, and the clinical responses in patients.
A precision diagnostic platform integrating genomics and transcriptomics with drug testing of patient's primary tumor cells in high throughput drug screening (HTS) and patient‐derived xenograft (PDX) was established to improve identification of therapies in high‐risk pediatric cancer patients.
Liver metastasis is a clinically significant contributor to the mortality associated with melanoma, colon, and breast cancer. Preclinical mouse models are essential to the study of liver metastasis, ...yet their utility has been limited by the inability to study this dynamic process in a noninvasive and longitudinal manner. This study shows that three-dimensional high-frequency ultrasound can be used to noninvasively track the growth of liver metastases and evaluate potential chemotherapeutics in experimental liver metastasis models. Liver metastases produced by mesenteric vein injection of B16F1 (murine melanoma), PAP2 (murine H-ras-transformed fibroblast), HT-29 (human colon carcinoma), and MDA-MB-435/HAL (human breast carcinoma) cells were identified and tracked longitudinally. Tumor size and location were verified by histologic evaluation. Tumor volumes were calculated from the three-dimensional volumetric data, with individual liver metastases showing exponential growth. The importance of volumetric imaging to reduce uncertainty in tumor volume measurement was shown by comparing three-dimensional segmented volumes with volumes estimated from diameter measurements and the assumption of an ellipsoid shape. The utility of high-frequency ultrasound imaging in the evaluation of therapeutic interventions was established with a doxorubicin treatment trial. These results show that three-dimensional high-frequency ultrasound imaging may be particularly well suited for the quantitative assessment of metastatic progression and the evaluation of chemotherapeutics in preclinical liver metastasis models.
OBJECTIVES:To determine if intraperitoneally (IP) administered contrast (iohexol), used in conjunction with a liver-specific agent (Fenestra), can improve measurement precision and accuracy when ...quantifying tumor volume from micro-CT images of a liver metastasis model.
MATERIALS AND METHODS:We compared images acquired with Fenestra alone to images acquired with the combination of Fenestra and IP iohexol. The variability in tumor volume and tumor-burden measurement was evaluated for both techniques. The tumor-burden measurement accuracy of both in vivo techniques was determined by comparison with tumor-burden quantified from ex vivo images.
RESULTS:The addition of IP iohexol decreased measurement variability for individual tumors and overall tumor-burden by 4–8 fold and 2–3 fold, respectively. IP iohexol significantly improved the accuracy of tumor-burden measurement for both low and high tumor-burdened animals.
CONCLUSIONS:The combination of IP iohexol with Fenestra provides superior delineation of liver tumors, in comparison to Fenestra alone. The complete tumor delineation provided by this imaging strategy allows for noninvasive quantification of liver tumor-burden.
OBJECTIVES:To determine a timepoint after contrast injection that yields equal liver parenchymal and vascular enhancement in micro-computed tomography images. To evaluate the utility of images ...acquired during this time period for the noninvasive measurement of liver-tumor volume.
MATERIALS AND METHODS:The imaging timepoint was determined by quantifying the enhancement kinetics of Fenestra VC (0.015 mL/g) in NIH III mice. In respiratory-gated images of tumor bearing mice, the ability to measure tumor volume was evaluated with a measurement variability study, and by comparing in vivo and histologically measured tumor volume.
RESULTS:Eight hours after contrast injection the liver parenchyma and vasculature were equally enhanced allowing for clear delineation of the unenhanced tumors. The smallest tumor detected in this study was 1.1 mm in diameter. The coefficient of variation for tumor-volume measurement ranged from 3.6% to 12.9% and from 6.3% to 25.8% for intra and interobserver variability, respectively. In vivo and histologic tumor-volume measurements were closely correlated (r = 0.98, P < 0.0001).
CONCLUSIONS:Imaging at a time period of equal liver parenchyma and vascular enhancement after contrast injection allows for clear delineation of liver-tumor borders, thereby enabling quantitative tumor-volume monitoring.
Introduction
The use of MRI with iron-based magnetic nanoparticles for imaging cells is a rapidly growing field of research. We have recently reported that single iron-labeled cells could be ...detected, as signal voids, in vivo in mouse brains using a balanced steady-state free precession imaging sequence (b-SSFP) and a customized microimaging system at 1.5 T.
Methods
In the current study we assess the benefits, and challenges, of using a higher magnetic field strength for imaging iron-labeled cells with b-SSFP, using ex vivo mouse brain specimens imaged with near identical systems at 1.5 and 3.0 T.
Results
The substantial banding artifact that appears in 3 T b-SSFP images was readily minimized with RF phase cycling, allowing for banding-free b-SSFP images to be compared between the two field strengths. This study revealed that with an optimal 3 T b-SSFP imaging protocol, more than twice as many signal voids were detected as with 1.5 T.
Conclusion
There are several factors that contributed to this important result. First, a greater-than-linear SNR gain was achieved in mouse brain images at 3 T. Second, a reduction in the bandwidth, and the associated increase in repetition time and SNR, produced a dramatic increase in the contrast generated by iron-labeled cells.
Departments of 1 Medical Biophysics and 2 Oncology, University of Western Ontario, and 3 London Regional Cancer Centre, London, Ontario, Canada
Submitted 30 October 2003
; accepted in final form 16 ...September 2004
A functional microcirculation is vital to the survival of mammalian tissues. In vivo video microscopy is often used in animal models to assess microvascular function, providing real-time observation of blood flow in normal and diseased tissues. To extend the capabilities of in vivo video microscopy, we have developed a contrast-enhanced system with postprocessing video analysis tools that permit quantitative assessment of microvascular geometry and function in vital organs and tissues. FITC-labeled dextran (250 kDa) was injected intravenously into anesthetized mice to provide intravascular fluorescence contrast with darker red blood cell (RBC) motion. Digitized video images of microcirculation in a variety of internal organs (e.g., lung, liver, ovary, and kidney) were processed using computer-based motion correction to remove background respiratory and cardiac movement. Stabilized videos were analyzed to generate a series of functional images revealing microhemodynamic parameters, such as plasma perfusion, RBC perfusion, and RBC supply rate. Fluorescence contrast revealed characteristic microvascular arrangements within different organs, and images generated from video sequences of liver metastases showed a marked reduction in the proportion of tumor vessels that were functional. Analysis of processed video sequences showed large reductions in vessel volume, length, and branch-point density, with a near doubling in vessel segment length. This study demonstrates that postprocessing of fluorescence contrast video sequences of the microcirculation can provide quantitative images useful for studies in a wide range of model systems.
microhemodynamics; fluorescence microscopy; video analysis
Address for reprint requests and other correspondence: I. C. MacDonald, Dept. of Medical Biophysics, Univ. of Western Ontario, London, Ontario, Canada N6A 5C1 (E-mail: imacd{at}uwo.ca )
Abstract
Rationale: Inflammatory myofibroblastic tumors (IMTs) are a particularly rare type of soft tissue sarcoma comprised of myofibroblastic spindle cells and an accompanying inflammatory ...infiltrate. There is an unmet clinical need for effective treatment regimens for patients diagnosed with IMT with anaplastic lymphoma kinase (ALK) rearrangement, who relapse following ALK inhibitor (ALKi) therapy or who present with aggressive disease. Fusion of RAN Binding Protein 2 (RANBP2) with ALK in IMT is associated with aggressive disease and has been correlated with tumor cell expression of CD30. This study investigated CD30 as a potential therapeutic target in IMT and the efficacy of the CD30-targeted antibody-monomethyl auristatin E conjugate, Brentuximab Vedotin (BV).
Methods and Results: In a cohort of five recent IMT patients at the Sydney Children’s Hospital, RANBP2-ALK fusion was identified in three patients (IMT1, IMT2 and IMT3) by RNA capture sequencing, while patients IMT4 and IMT5 (who did not relapse) harbored CLTC-ALK or SEC31A-ALK fusions respectively. Expression of CD30 was confirmed two of three RANBP2-ALK fusion positive tumors by immunohistochemistry. We established cell cultures and xenografts from malignant ascites of IMT1, at diagnosis (IMT1A) and at relapse (IMT1D) after treatment with ALKi’s and low dose chemotherapy. CD30 expression was retained in the cell cultures and xenograft tumors, as demonstrated by flow cytometry and tumor histology. BV was investigated as a potential treatment for IMT with RANBP2-ALK fusion. BV reduced IMT1A and IMT1D cell viability in vitro in resazurin cell viability assays. IMT1A and IMT1D xenograft mice had a partial response to BV which significantly (p<0.0001) prolonged survival compared to untreated controls. However, tumors eventually recurred. Resistance to BV correlated with upregulation of P-glycoprotein and reduced CD30 antigen expression in cells from treated IMT xenograft tumors. The combination of the ALK inhibitor crizotinib with BV has also been investigated. In vivo, the combination of crizotinib and BV resulted in complete resolution of tumor and significantly (p<0.0001) improved survival compared to the individual agents.
Conclusion: CD30 is a promising therapeutic target in RANBP2-ALK-rearranged IMT. BV successfully reduced IMT cell viability in vitro and prolonged survival in IMT xenografted mice, both as a single agent and when given in combination with crizotinib. Since BV is current clinical use for the treatment of Hodgkin lymphoma it may be possible to rapidly translate these findings into clinical practice for the treatment of IMT.
Citation Format: Ashleigh M. Fordham, James Blackburn, Erin E. Heyer, Jinhan Xie, Emily V. Mould, Andrew J. Gifford, Lisa T. Morgan, Carol Wadham, Mitali Fadia, Jamie I. Fletcher, Karen L. MacKenzie, Toby N. Trahair. Targeting CD30 as a novel treatment strategy in RANBP2-ALK-rearranged inflammatory myofibroblastic tumor abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4824.
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