Rat Fibrosarcoma Research Articles

Acoustic Molecular Imaging Beyond the Diffraction Limit In Vivo.

Ultrasound molecular imaging (USMI) is a technique used to noninvasively estimate the distribution of molecular markers in vivo by imaging microbubble contrast agents (MCAs) that have been modified to target receptors of interest on the vascular endothelium. USMI is especially relevant for preclinical and clinical cancer research and has been used to predict tumor malignancy and response to treatment. In the last decade, methods that improve the resolution of contrast-enhanced ultrasound by an order of magnitude and allow researchers to noninvasively image individual capillaries have emerged. However, these approaches do not translate directly to molecular imaging. In this work, we demonstrate super-resolution visualization of biomarker expression in vivo using superharmonic ultrasound imaging (SpHI) with dual-frequency transducers, targeted contrast agents, and localization microscopy processing. We validate and optimize the proposed method in vitro using concurrent optical and ultrasound microscopy and a microvessel phantom. With the same technique, we perform a proof-of-concept experiment in vivo in a rat fibrosarcoma model and create maps of biomarker expression co-registered with images of microvasculature. From these images, we measure a resolution of 23 μm, a nearly fivefold improvement in resolution compared to previous diffraction-limited molecular imaging studies.

Decoding the Role of CD271 in Melanoma.

The evolution of melanoma, the most aggressive type of skin cancer, is triggered by driver mutations that are acquired in the coding regions of particularly BRAF (rat fibrosarcoma serine/threonine kinase, isoform B) or NRAS (neuroblastoma-type ras sarcoma virus) in melanocytes. Although driver mutations strongly determine tumor progression, additional factors are likely required and prerequisite for melanoma formation. Melanocytes are formed during vertebrate development in a well-controlled differentiation process of multipotent neural crest stem cells (NCSCs). However, mechanisms determining the properties of melanocytes and melanoma cells are still not well understood. The nerve growth factor receptor CD271 is likewise expressed in melanocytes, melanoma cells and NCSCs and programs the maintenance of a stem-like and migratory phenotype via a comprehensive network of associated genes. Moreover, CD271 regulates phenotype switching, a process that enables the rapid and reversible conversion of proliferative into invasive or non-stem-like states into stem-like states by yet largely unknown mechanisms. Here, we summarize current findings about CD271-associated mechanisms in melanoma cells and illustrate the role of CD271 for melanoma cell migration and metastasis, phenotype-switching, resistance to therapeutic interventions, and the maintenance of an NCSC-like state.

Oxygen microbubbles improve radiotherapy tumor control in a rat fibrosarcoma model - A preliminary study.

Cancer affects 39.6% of Americans at some point during their lifetime. Solid tumor microenvironments are characterized by a disorganized, leaky vasculature that promotes regions of low oxygenation (hypoxia). Tumor hypoxia is a key predictor of poor treatment outcome for all radiotherapy (RT), chemotherapy and surgery procedures, and is a hallmark of metastatic potential. In particular, the radiation therapy dose needed to achieve the same tumor control probability in hypoxic tissue as in normoxic tissue can be up to 3 times higher. Even very small tumors (<2–3 mm3) comprise 10–30% of hypoxic regions in the form of chronic and/or transient hypoxia fluctuating over the course of seconds to days. We investigate the potential of recently developed lipid-stabilized oxygen microbubbles (OMBs) to improve the therapeutic ratio of RT. OMBs, but not nitrogen microbubbles (NMBs), are shown to significantly increase dissolved oxygen content when added to water in vitro and increase tumor oxygen levels in vivo in a rat fibrosarcoma model. Tumor control is significantly improved with OMB but not NMB intra-tumoral injections immediately prior to RT treatment and effect size is shown to depend on initial tumor volume on RT treatment day, as expected.

Early Assessment of Tumor Response to Radiation Therapy using High-Resolution Quantitative Microvascular Ultrasound Imaging.

Measuring changes in tumor volume using anatomical imaging weeks to months post radiation therapy (RT) is currently the clinical standard for indicating treatment response to RT. For patients whose tumors do not respond successfully to treatment, this approach is suboptimal as timely modification of the treatment approach may lead to better clinical outcomes. We propose to use tumor microvasculature as a biomarker for early assessment of tumor response to RT. Acoustic angiography is a novel contrast ultrasound imaging technique that enables high-resolution microvascular imaging and has been shown to detect changes in microvascular structure due to cancer growth. Data suggest that acoustic angiography can detect longitudinal changes in the tumor microvascular environment that correlate with RT response.Methods: Three cohorts of Fisher 344 rats were implanted with rat fibrosarcoma tumors and were treated with a single fraction of RT at three dose levels (15 Gy, 20 Gy, and 25 Gy) at a dose rate of 300 MU/min. A simple treatment condition was chosen for testing the feasibility of our imaging technique. All tumors were longitudinally imaged immediately prior to and after treatment and then every 3 days after treatment for a total of 30 days. Both acoustic angiography (using in-house produced microbubble contrast agents) and standard b-mode imaging was performed at each imaging time point using a pre-clinical Vevo770 scanner and a custom modified dual-frequency transducer.Results: Results show that all treated tumors in each dose group initially responded to treatment between days 3-15 as indicated by decreased tumor growth accompanied with decreased vascular density. Untreated tumors continued to increase in both volume and vascular density until they reached the maximum allowable size of 2 cm in diameter. Tumors that displayed complete control (no tumor recurrence) continued to decrease in size and vascular density, while tumors that progressed after the initial response presented an increase in tumor volume and volumetric vascular density. The increase in tumor volumetric vascular density in recurring tumors can be detected 10.25 ± 1.5 days, 6 ± 0 days, and 4 ± 1.4 days earlier than the measurable increase in tumor volume in the 15, 20, and 25 Gy dose groups, respectively. A dose-dependent growth rate for tumor recurrence was also observed.Conclusions: In this feasibility study we have demonstrated the ability of acoustic angiography to detect longitudinal changes in vascular density, which was shown to be a potential biomarker for tumor response to RT.

Early Assessment of Tumor Response to Radiation Therapy Using High-Resolution Quantitative Microvascular Ultrasound Imaging

Tumor volume imaging several months after radiation therapy is currently used as an indicator for treatment response. For patients who did not respond well to the treatment, precious time may have been wasted as timely modification of the treatment approach may lead to better clinical outcomes. We propose to use tumor microvasculature as a biomarker for early assessment of long-term tumor response to radiation therapy. Acoustic Angiography is a novel contrast ultrasound imaging technique that enables high-resolution microvascular imaging. We aim to demonstrate that AA is capable of early prediction of long-term radiation therapy response by monitoring longitudinal changes in tumor microvasculature. Three cohorts of rats implanted with rat fibrosarcoma tumors were treated with a single dose at three dose levels. The rats were split into four different dose cohorts and received either 0 Gy (treatment control, n = 9), 15 Gy (n = 8), 20 Gy (n = 5), or 25 Gy (n = 8) radiation dose. A non-toxic FDA approved microbubble contrast agent is administrated before each ultrasound imaging by tail vein injection. Contrast enhanced ultrasound (CEUS) is a low-cost and safe imaging modality that can visualize and measure vascularity and perfusion in tissue with high contrast sensitivity compared to CT and MRI. A high-resolution microvascular imaging is performed using Acoustic Angiography, a super-harmonic CEUS imaging technique. A special ultrasound probe capable of both b-mode and Acoustic Angiography mode imaging is used and the longitudinal study lasts until 30 days post radiation. Tumor microvascular density is measured within the tumor volume defined by 3D b-mode ultrasound imaging. All tumors in each dose group responded initially (days 3-15) to treatment as indicated by decreased tumor growth accompanied with decreased vascular density. Tumors that displayed long-term control (complete response) continued to decrease in size and in vascular density. Tumors that regrew after the initial response (partial response) exhibited an increase in tumor volumetric vascular density before an increase in tumor volume. The change in tumor volumetric vascular density can be used to distinguish which animals eventually have complete control or partial control 10.25 ± 1.5 days, 9 ± 4.2 days, and 4 ± 1.4 days earlier than from the observable tumor volume change in the 15, 20, and 25 Gy dose groups, respectively. We have demonstrated the ability of a novel ultrasound tumor vascular imaging for early detection of treatment response in a preclinical study. In clinical practice, tumors often do not significantly change in size until months after treatment. Our study indicates that for some tumors we may detect non-responsive tumors 50% earlier than using the conventional RECIST method alone. By decreasing the wait time to determine treatment response doctors can make more timely modifications to treatment strategy to improve treatment outcome for individual patients.

Oncolytic peptide LTX-315 induces an immune-mediated abscopal effect in a rat sarcoma model

ABSTRACTLTX 315 is an oncolytic peptide with potent immunological properties. In the present study, we demonstrate that intratumoral treatment with LTX-315 resulted in a complete regression and systemic immune response in a rat fibrosarcoma model. The treatment was T-cell dependent, and also resulted in an abscopal effect as demonstrated by the regression of distal non-treated lesions. Significant infiltration of CD8+ T cells was observed in both treated and non-treated lesions, as shown by immunohistochemical and flow cytometric analysis. LTX-315 rapidly killed the cells in vitro with a lytic mode of action followed by the subsequent release of Danger-Associated Molecular Pattern (DAMP) molecules such as HMGB1, ATP and Cytochrome c. Together, our data demonstrate that LTX-315 represents a new approach to cancer immunotherapy, which has the potential as a novel immunotherapeutic agent.

A novel rat fibrosarcoma cell line from transformed bone marrow-derived mesenchymal stem cells with maintained in vitro and in vivo stemness properties

Increasing evidence suggests a possible relationship between mesenchymal stem cells (MSCs) and sarcoma. MSCs are hypothesized to be the cells initiating sarcomagenesis, and cancer stem cells (CSCs) sharing features of MSCs have been identified in sarcomas. Here, we report on the characteristics of a bone marrow-derived rat mesenchymal stem cell line that spontaneously transformed in long-term culture. The rat transformed mesenchymal stem cells (rTMSCs) produced soft-tissue fibrosarcomas in immunocompromised mice and immunocompetent rats. In vitro, the rTMSCs displayed increased proliferation capacity compared to the untransformed cell line. The transformed MSCs maintained the mesenchymal phenotype by expression of the stem cell marker CD 90 and the lack of hematopoietic and endothelial markers. Cytogenetic analysis detected trisomy 6 in the rTMSCs. Side population (SP) isolation and tumorsphere cultivation of the transformed cells confirmed the presence of CSCs among the rTMSCs. Importantly, the rTMSCs retained their differentiation capacity towards osteogenic and adipogenic lineages. This transformed MSC-based cell line may be valuable in examining the balance in a mixed cell population between cancer stem cell properties and the ability to differentiate to specific non-transformed cell populations. Moreover, it may also be a useful tool to evaluate the efficacy of novel targeted immunotherapies in vivo.

Effect of the autonomic nervous system on cancer progression depends on the type of tumor: solid are more affected then ascitic tumors.

A number of recently published studies have shown that the sympathetic nervous system may influence cancer progression. There are, however, some ambiguities about the role of the parasympathetic nerves in the modulation of growth of different tumor types. Moreover, tumor models used for investigation of the autonomic neurotransmission role in the processes related to the cancer growth and progression are mainly of the solid nature. The knowledge about the nervous system involvement in the modulation of the development and progression of malignant ascites is only fragmental. Therefore, the aim of the present article was to summarize the results of our experimental studies focused on the elucidation of the role of the autonomic nervous system in the modulation of tumor growth in animals. We are summarizing data from studies, in which not only different experimental approaches in order to influence the autonomic neurotransmission, but also different tumor models have been used. Three different types of tumor models, namely solid rat intra-abdominal fibrosarcoma, solid murine subcutaneous melanoma, and rat ascites hepatoma, and three types of interventions have been used in order to modulate the autonomic neurotransmission, specifically chemical sympathectomy, subdiaphragmatic vagotomy, or the electric stimulation of the vagus nerve. We have proved a strong stimulatory effect of the sympathetic nerves on the development and growth in both solid tumors, rat fibrosarcoma as well as murine melanoma, and significant inhibitory impact on the survival time of tumor-bearing animals. The progression of ascites hepatoma in rats was not influenced by chemical sympathectomy. Modulation of parasympathetic signalization by vagotomy or vagal nerve stimulation does not affect fibrosarcoma and ascites hepatoma growth and survival of the tumor-bearing rats. Based on the obtained data, it seems that the solid types of tumors are suitable substrate for the direct action of neurotransmitters released especially from the sympathetic nerves. In contrast, it appears that the malignant ascites are not under the direct autonomic nerves control; however, an indirect action via the immune functions modulation cannot be excluded.

Molecular Acoustic Angiography: A New Technique for High-resolution Superharmonic Ultrasound Molecular Imaging

Ultrasound molecular imaging utilizes targeted microbubbles to bind to vascular targets such as integrins, selectins and other extracellular binding domains. After binding, these microbubbles are typically imaged using low pressures and multi-pulse imaging sequences. In this article, we present an alternative approach for molecular imaging using ultrasound that relies on superharmonic signals produced by microbubble contrast agents. Bound bubbles were insonified near resonance using a low frequency (4 MHz) element and superharmonic echoes were received at high frequencies (25–30 MHz). Although this approach was observed to produce declining image intensity during repeated imaging in both in vitro and in vivo experiments because of bubble destruction, the feasibility of superharmonic molecular imaging was demonstrated for transmit pressures, which are sufficiently high to induce shell disruption in bound microbubbles. This approach was validated using microbubbles targeted to the αvβ3 integrin in a rat fibrosarcoma model (n = 5) and combined with superharmonic images of free microbubbles to produce high-contrast, high-resolution 3-D volumes of both microvascular anatomy and molecular targeting. Image intensity over repeated scans and the effect of microbubble diameter were also assessed in vivo, indicating that larger microbubbles yield increased persistence in image intensity. Using ultrasound-based acoustic angiography images rather than conventional B-mode ultrasound to provide the underlying anatomic information facilitates anatomic localization of molecular markers. Quantitative analysis of relationships between microvasculature and targeting information indicated that most targeting occurred within 50 μm of a resolvable vessel (>100 μm diameter). The combined information provided by these scans may present new opportunities for analyzing relationships between microvascular anatomy and vascular targets, subject only to limitations of the current mechanically scanned system and microbubble persistence to repeated imaging at moderate mechanical indices.

Sequential processing of quantitative phase images for the study of cell behaviour in real-time digital holographic microscopy.

Transmitted light holographic microscopy is particularly used for quantitative phase imaging of transparent microscopic objects such as living cells. The study of the cell is based on extraction of the dynamic data on cell behaviour from the time-lapse sequence of the phase images. However, the phase images are affected by the phase aberrations that make the analysis particularly difficult. This is because the phase deformation is prone to change during long-term experiments. Here, we present a novel algorithm for sequential processing of living cells phase images in a time-lapse sequence. The algorithm compensates for the deformation of a phase image using weighted least-squares surface fitting. Moreover, it identifies and segments the individual cells in the phase image. All these procedures are performed automatically and applied immediately after obtaining every single phase image. This property of the algorithm is important for real-time cell quantitative phase imaging and instantaneous control of the course of the experiment by playback of the recorded sequence up to actual time. Such operator's intervention is a forerunner of process automation derived from image analysis. The efficiency of the propounded algorithm is demonstrated on images of rat fibrosarcoma cells using an off-axis holographic microscope.

WE‐E‐134‐02: High Resolution Acoustic Angiography for Early Assessment of Tumor Response to Radiation Treatment in Rat Tumor Model

Purpose: To test the hypothesis that acoustic angiography would enable early assessment of tumor response to radiation therapy at multiple timepoints after a single‐fraction radiotherapy treatment. Methods: 15 fibrosarcoma tumor‐bearing rats were irradiated (field‐size:1.8×1.8cm) by 6MV photon beam from a clinical linac. Tumors were implanted subcutaneously in the lower flank area and treated 14 days later (Mean‐diameter: 7.03+/−1.62mm). Animals were randomized into three groups (doses of 0, 5 or 20 Gy). Tumors were imaged prior to treatment (Day 0) using both acoustic angiography (microbubble contrast‐based microvessel imaging) and standard high frequency b‐mode, and then again at Days 3, 6, 9, 12, and 18. Tumor volume, and perfused volume ratio (PVR ‐ the ratio of tumor volume with perfused voxels, to total tumor volume) were quantified at each timepoint. Results: The tumors in the 0 or 5 Gy groups continued to grow exponentially after treatment. All animals in the 20 Gy group experienced an inflection point in their growth curve at Day 3, and tumor volume reduced exponentially until Day 12. Three of these tumors are non‐responders(20Gy‐NRs) and had second inflection point at Day 12, and proceeded to increase in volume, on average to their original Day 0 tumor size by Day 18. The other two tumors in the 20 Gy group are responders(20Gy‐R' s) and reduced to undetectable tumor volumes by Day 18. The PVR metric for vascularization revealed differences in the 20Gy‐NR and 20Gy‐R groups at Day 12, which correlated with tumor volumetric differences. Conclusion: Our preliminary data indicate that the acoustic angiography‐derived PVR metric can detect rat fibrosarcoma tumors responded (N=2) and those which did not (N=3) to 20 Gy radiation six days before there is a detectable difference in tumor volumes.

Antiproliferative role of Indigofera aspalathoides on 20 methylcholanthrene induced fibrosarcoma in rats

ObjectiveTo find out the anticancer effect of Indigofera aspalathoides (I. aspalathoides) on 20-methylcholanthrene induced fibrosarcoma in rats. MethodsFibrosarcoma was induced in Wistar strain male albino rats by 20-methylcholanthrene. Intraperitoneous (i.p.) administration of 250 mg/kg body weight/day of aqueous extract of I. aspalathoides for 30 d effectively suppressed chemically induced tumors. Parameters such as body weight, liver and kidney weight, tumor weight, mean survival time, behavioral changes, blood glucose, blood glycogen and marker enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), acid phosphatase (ACP) and 5′-nucleiotidase (5′-NT) in serum, liver and kidney and lipid profiles such as total cholesterol, phospholipids, free fatty acids in liver and kidney of control and experimental animals were studied. ResultsFibrosarcoma bearing animals were ferocious and anxious. The mean survival time was found to increase after the treatment. The body weights were significantly decreased (P < 0.001) in group II fibrosarcoma animals which steadily increased after the treatment with I. aspalathoides. The liver and kidney weights were significantly increased whereas the tumor weights decreased as compared to the weights in untreated fibrosarcoma bearing rats. The blood glucose and the liver and kidney glycogen levels were found to decrease significantly (P < 0.001) in group II animals. Elevated activities of marker enzymes were observed in serum, liver and kidney of fibrosarcoma bearing Group II animals which were normalize after I. aspalathoides treatment. In the liver and kidney of Group II animals the total cholesterol increased whereas the phospholipids and free fatty acid levels decreased (P < 0.001) which were normalized after treatment. ConclusionsThe treatment by I. aspalathoides on fibrosarcoma bearing rats has improved the levels of various parameters indicating its antiproliferative and anticancer activity.

Side effects of systemic oncological therapies in dermatology

The discovery of specific gene mutations, termed "driver mutations", in different tumors has brought personalized medicine into the focus of cancer treatment. Targeted treatment agents generally are administered orally and have a tolerable adverse event profile; they have become widely used in both inpatient and outpatient settings. The approval of the selective BRAF inhibitor vemurafenib (Zelboraf®) as first-line therapy of metastatic melanoma in Europe in February 2012 as well as the increasing use of MEK inhibitors within clinical trials confronts dermatologists and oncologists with a new spectrum of side effects. Knowledge of these possible adverse events and their management will be crucial for optimized patient care. This article offers an overview of the most important adverse events of currently employed dermato-oncologic therapeutic agents.

Chemotherapeutic Efficacy of Indigofera aspalathoides on 20-Methylcholanthrene-Induced Fibrosarcoma in Rats.

The present study was undertaken to test the chemopreventive effects of one herbal medicinal plant, Indigofera aspalathoides, on chemically induced carcinogenesis in rats. A well-known polyaromatic hydrocarbon, namely, 20-methylcholanthrene, which is a known carcinogenic substance, was used to induce fibrosarcoma in Wistar strain of male albino rats. Fibrosarcoma rats were treated with aqueous extracts of Indigofera aspalathoides. The rats were divided into four groups, each consisting of six animals. Group I served as normal control, Group II served as fibrosarcoma-induced animals, Group III were fibrosarcoma-bearing animals treated with aqueous extracts of Indigofera aspalathoides, and Group IV animals, which were normal healthy animals treated with Indigofera aspalathoides aqueous extract, served as drug control set. Group III and Group IV animals were treated with aqueous extract of Indigofera aspalathoides intraperitoneally at a dose of 250 mg/kg. b.w. for 30 days. The fibrosarcoma was proved by pathological examinations. The activity levels of nucleic acids such as total DNA and RNA and hexose, hexosamine, and sialic acid in liver and kidney of treated rats were used to monitor the chemopreventive role of the plant extract. The observed increase in the levels of DNA, RNA, hexose, hexosamine, and sialic acid in liver and kidney tissues of fibrosarcoma-bearing animals reached near normal state after the treatment with aqueous extracts of Indigofera aspalathoides, suggesting that Indigofera aspalathoides does have a chemotherapeutic role.

An In Vivo Validation of the Application of Acoustic Radiation Force to Enhance the Diagnostic Utility of Molecular Imaging Using 3-D Ultrasound

For more than a decade, the application of acoustic radiation force (ARF) has been proposed as a mechanism to increase ultrasonic molecular imaging (MI) sensitivity in vivo. Presented herein is the first noninvasive in vivo validation of ARF-enhanced MI with an unmodified clinical system. First, an in vitro optical-acoustical setup was used to optimize system parameters and ensure sufficient microbubble translation when exposed to ARF. 3-D ARF-enhanced MI was then performed on 7 rat fibrosarcoma tumors using microbubbles targeted to αvβ3 and nontargeted microbubbles. Low-amplitude (<25 kPa) 3-D ARF pulse sequences were tested and compared with passive targeting studies in the same animal. Our results demonstrate that a 78% increase in image intensity from targeted microbubbles can be achieved when using ARF relative to the passive targeting studies. Furthermore, ARF did not significantly increase image contrast when applied to nontargeted agents, suggesting that ARF did not increase nonspecific adhesion.

Improving interstitial transport of macromolecules through reduction in cell volume fraction in tumor tissues

Interstitial transport of large molecules and nanoparticles is an important concern in nanomedicine-mediated cancer treatment. To that end, the current study was proposed to improve the transport through enlargement of extracellular space by treating tumors with hypertonic solution of mannitol and cytotoxic agents (e.g., ethacrynic acid [ECA]), which could effectively shrink and kill cells, respectively. In the study, the improvement in interstitial penetration of dextran was investigated ex vivo using rat fibrosarcoma tissues sectioned into 600 μm slices. Experimental data showed that the hypertonic solution was more effective than ECA for improving interstitial penetration of dextran with molecular weights ranging from 4000 to 2,000,000. The extent of improvement depended on the size of dextran molecules and the time when the treatment was applied. Results from the study suggested that increases in both size and connectedness of interstitial pathways were important for improvement of interstitial transport of large molecules and nanoparticles. From the Clinical EditorThis study reports on the optimization of interstitial transport both for large molecules and nanoparticles in nanomedicine-mediated cancer treatment. The study demonstrates that hypertonic solutions could efficiently lead to cancer cell shrinkage and more so than the applied cytotoxic agent thereby improving transport of chemotherapeutic entities.

Effect of Terminalia catappa on lipid profile in transplanted fibrosarcoma in rats

To evaluate the effect of an antitumor activity of Terminalia catappa on lipid lowering activity in transplanted fibrosarcoma in Wistar albino rats. Methylcholantherene–induced fibrosarcoma was transplanted in rats. After 30th day when tumor became palpable, started the treatment of ethanolic extract of Terminalia catappa by orally (250 and 500 mg/kg) for a period of 20 days. The blood sample was collected on 21st day, and the liver and the kidney were also removed for studying the lipid profile in serum and the tissues. The levels of total cholesterol, triglycerides and very low density lipoprotein (VLDL) were markedly elevated and high density lipoprotein (HDL) was markedly decreased in the serum of tumor bearing rats. Significant alterations were also observed in the lipid profile of liver and kidney. These changes were significantly reversed in Terminalia catappa (500 mg/kg) treated animals. The reversal of altered lipid levels to normal values in rats with experimentally induced tumor was showed antitumor activity by Terminalia catappa.

Assessment of Molecular Imaging of Angiogenesis with Three-Dimensional Ultrasonography

Molecular imaging (MI) with ultrasonography relies on microbubble contrast agents (MCAs) adhering to a ligand-specific target for applications such as characterizing tumor angiogenesis. It is projected that ultrasonic (US) MI can provide information about tumor therapeutic response before the detection of phenotypic changes. One of the limitations of preclinical US MI is that it lacks a comprehensive field of view. We attempted to improve targeted MCA visualization and quantification by performing three-dimensional (3D) MI of tumors expressing αvβ3 integrin. Volumetric acquisitions were obtained with a Siemens Sequoia system in cadence pulse sequencing mode by mechanically stepping the transducer elevationally across the tumor in 800-micron increments. MI was performed on rat fibrosarcoma tumors (n = 8) of similar sizes using MCAs conjugated with a cyclic RGD peptide targeted to αvβ3 integrin. US MI and immunohistochemical analyses show high microbubble targeting variability, suggesting that individual two-dimensional (2D) acquisitions risk misrepresenting more complex heterogeneous tissues. In 2D serial studies, where it may be challenging to image the same plane repeatedly, misalignments as small as 800 microns can introduce substantial error. 3D MI, including volumetric analysis of inter- and intra-animal targeting, provides a thorough way of characterizing angiogenesis and will be a more robust assessment technique for the future of MI.

Anticarcinogenic Effects of Indigofera Aspalathoides on 20-Methylcholanthrene Induced Fibrosarcoma in Rats

Anticarcinogenic Effects of Indigofera Aspalathoides on 20-Methylcholanthrene Induced Fibrosarcoma in Rats

Chemopreventive Effects of Indigofera aspalathoides on 20-Methylcholanthrene Induced Fibrosarcoma in Rats

Chemopreventive Effects of Indigofera aspalathoides on 20-Methylcholanthrene Induced Fibrosarcoma in Rats