Breast cancer is a heterogeneous disease involving complex cellular interactions between the developing tumor and immune system, eventually resulting in exponential tumor growth and metastasis to distal tissues and the collapse of anti-tumor immunity. Many useful animal models exist to study breast cancer, but none completely recapitulate the disease progression that occurs in humans. In order to gain a better understanding of the cellular interactions that result in the formation of latent metastasis and decreased survival, we have generated an inducible transgenic mouse model of YFP-expressing ductal carcinoma that develops after sexual maturity in immune-competent mice and is driven by consistent, endocrine-independent oncogene expression. Activation of YFP, ablation of p53, and expression of an oncogenic form of K-ras was achieved by the delivery of an adenovirus expressing Cre-recombinase into the mammary duct of sexually mature, virgin female mice. Tumors begin to appear 6 weeks after the initiation of oncogenic events. After tumors become apparent, they progress slowly for approximately two weeks before they begin to grow exponentially. After 7-8 weeks post-adenovirus injection, vasculature is observed connecting the tumor mass to distal lymph nodes, with eventual lymphovascular invasion of YFP+ tumor cells to the distal axillary lymph nodes. Infiltrating leukocyte populations are similar to those found in human breast carcinomas, including the presence of αβ and γδ T cells, macrophages and MDSCs. This unique model will facilitate the study of cellular and immunological mechanisms involved in latent metastasis and dormancy in addition to being useful for designing novel immunotherapeutic interventions to treat invasive breast cancer.
24 Related JoVE Articles!
Adaptation of Semiautomated Circulating Tumor Cell (CTC) Assays for Clinical and Preclinical Research Applications
Institutions: London Health Sciences Centre, Western University, London Health Sciences Centre, Lawson Health Research Institute, Western University.
The majority of cancer-related deaths occur subsequent to the development of metastatic disease. This highly lethal disease stage is associated with the presence of circulating tumor cells (CTCs). These rare cells have been demonstrated to be of clinical significance in metastatic breast, prostate, and colorectal cancers. The current gold standard in clinical CTC detection and enumeration is the FDA-cleared CellSearch system (CSS). This manuscript outlines the standard protocol utilized by this platform as well as two additional adapted protocols that describe the detailed process of user-defined marker optimization for protein characterization of patient CTCs and a comparable protocol for CTC capture in very low volumes of blood, using standard CSS reagents, for studying in vivo
preclinical mouse models of metastasis. In addition, differences in CTC quality between healthy donor blood spiked with cells from tissue culture versus patient blood samples are highlighted. Finally, several commonly discrepant items that can lead to CTC misclassification errors are outlined. Taken together, these protocols will provide a useful resource for users of this platform interested in preclinical and clinical research pertaining to metastasis and CTCs.
Medicine, Issue 84, Metastasis, circulating tumor cells (CTCs), CellSearch system, user defined marker characterization, in vivo, preclinical mouse model, clinical research
Coordinate Mapping of Hyolaryngeal Mechanics in Swallowing
Institutions: Georgia Regents University, New York University, Georgia Regents University, Georgia Regents University.
Characterizing hyolaryngeal movement is important to dysphagia research. Prior methods require multiple measurements to obtain one kinematic measurement whereas coordinate mapping of hyolaryngeal mechanics using Modified Barium Swallow (MBS) uses one set of coordinates to calculate multiple variables of interest. For demonstration purposes, ten kinematic measurements were generated from one set of coordinates to determine differences in swallowing two different bolus types. Calculations of hyoid excursion against the vertebrae and mandible are correlated to determine the importance of axes of reference.
To demonstrate coordinate mapping methodology, 40 MBS studies were randomly selected from a dataset of healthy normal subjects with no known swallowing impairment. A 5 ml thin-liquid bolus and a 5 ml pudding swallows were measured from each subject. Nine coordinates, mapping the cranial base, mandible, vertebrae and elements of the hyolaryngeal complex, were recorded at the frames of minimum and maximum hyolaryngeal excursion. Coordinates were mathematically converted into ten variables of hyolaryngeal mechanics.
Inter-rater reliability was evaluated by Intraclass correlation coefficients (ICC). Two-tailed t-tests were used to evaluate differences in kinematics by bolus viscosity. Hyoid excursion measurements against different axes of reference were correlated. Inter-rater reliability among six raters for the 18 coordinates ranged from ICC = 0.90 - 0.97. A slate of ten kinematic measurements was compared by subject between the six raters. One outlier was rejected, and the mean of the remaining reliability scores was ICC = 0.91, 0.84 - 0.96, 95% CI. Two-tailed t-tests with Bonferroni corrections comparing ten kinematic variables (5 ml thin-liquid vs. 5 ml pudding swallows) showed statistically significant differences in hyoid excursion, superior laryngeal movement, and pharyngeal shortening (p
< 0.005). Pearson correlations of hyoid excursion measurements from two different axes of reference were: r = 0.62, r2
= 0.38, (thin-liquid); r = 0.52, r2
= 0.27, (pudding).
Obtaining landmark coordinates is a reliable method to generate multiple kinematic variables from video fluoroscopic images useful in dysphagia research.
Medicine, Issue 87, videofluoroscopy, modified barium swallow studies, hyolaryngeal kinematics, deglutition, dysphagia, dysphagia research, hyolaryngeal complex
Isolation of Neonatal Extrahepatic Cholangiocytes
Institutions: The Children's Hospital of Philadelphia, The Perelman School of Medicine at the University of Pennsylvania.
The intra and extrahepatic bile ducts of the liver are developmentally distinct, and may be differentially affected by certain diseases. However, differences between intra and extrahepatic cholangiocytes, and between neonatal and adult cells, are not well understood.
Methods for the isolation of cholangiocytes from intrahepatic bile ducts are well established1-4
. Isolation of extrahepatic ductal cells, especially from the neonate, has not yet been described, although this would be of great benefit in understanding the differences between distinct cholangiocyte populations and in studying diseases such as biliary atresia that appear to target the extrahepatic ducts. Described here is an optimized technique to isolate both neonatal and adult mouse extrahepatic bile duct cells. This technique yields a pure cell population with minimal contamination from mesenchymal cells like fibroblasts.
This method is based on the removal of the extrahepatic ducts and gallbladder, followed by meticulous dissection and scraping to remove fat and fibroblast layers. Structures are embedded in thick layers of collagen and cultured for approximately 3 weeks to allow outgrowth of cholangiocytes in monolayers, which can then be trypsinized and re plated for experimental use.
Medicine, Issue 88, Bile Ducts, Bile Ducts, Extrahepatic, Common Bile Duct, Bile Duct Diseases, Cell culture, bile duct, biliary atresia, Liver, gallbladder, fibrosis
Tumor Treating Field Therapy in Combination with Bevacizumab for the Treatment of Recurrent Glioblastoma
Institutions: Southern Illinois University School of Medicine.
A novel device that employs TTF therapy has recently been developed and is currently in use for the treatment of recurrent glioblastoma (rGBM). It was FDA approved in April 2011 for the treatment of patients 22 years or older with rGBM. The device delivers alternating electric fields and is programmed to ensure maximal tumor cell kill1
Glioblastoma is the most common type of glioma and has an estimated incidence of approximately 10,000 new cases per year in the United States alone2
. This tumor is particularly resistant to treatment and is uniformly fatal especially in the recurrent setting3-5
. Prior to the approval of the TTF System, the only FDA approved treatment for rGBM was bevacizumab6
. Bevacizumab is a humanized monoclonal antibody targeted against the vascular endothelial growth factor (VEGF) protein that drives tumor angiogenesis7
. By blocking the VEGF pathway, bevacizumab can result in a significant radiographic response (pseudoresponse), improve progression free survival and reduce corticosteroid requirements in rGBM patients8,9
. Bevacizumab however failed to prolong overall survival in a recent phase III trial26
. A pivotal phase III trial (EF-11) demonstrated comparable overall survival between physicians’ choice chemotherapy and TTF Therapy but better quality of life were observed in the TTF arm10
There is currently an unmet need to develop novel approaches designed to prolong overall survival and/or improve quality of life in this unfortunate patient population. One appealing approach would be to combine the two currently approved treatment modalities namely bevacizumab and TTF Therapy. These two treatments are currently approved as monotherapy11,12
, but their combination has never been evaluated in a clinical trial. We have developed an approach for combining those two treatment modalities and treated 2 rGBM patients. Here we describe a detailed methodology outlining this novel treatment protocol and present representative data from one of the treated patients.
Medicine, Issue 92, Tumor Treating Fields, TTF System, TTF Therapy, Recurrent Glioblastoma, Bevacizumab, Brain Tumor
Modeling Astrocytoma Pathogenesis In Vitro and In Vivo Using Cortical Astrocytes or Neural Stem Cells from Conditional, Genetically Engineered Mice
Institutions: University of North Carolina School of Medicine, University of North Carolina School of Medicine, University of North Carolina School of Medicine, University of North Carolina School of Medicine, University of North Carolina School of Medicine, Emory University School of Medicine, University of North Carolina School of Medicine.
Current astrocytoma models are limited in their ability to define the roles of oncogenic mutations in specific brain cell types during disease pathogenesis and their utility for preclinical drug development. In order to design a better model system for these applications, phenotypically wild-type cortical astrocytes and neural stem cells (NSC) from conditional, genetically engineered mice (GEM) that harbor various combinations of floxed oncogenic alleles were harvested and grown in culture. Genetic recombination was induced in vitro
using adenoviral Cre-mediated recombination, resulting in expression of mutated oncogenes and deletion of tumor suppressor genes. The phenotypic consequences of these mutations were defined by measuring proliferation, transformation, and drug response in vitro
. Orthotopic allograft models, whereby transformed cells are stereotactically injected into the brains of immune-competent, syngeneic littermates, were developed to define the role of oncogenic mutations and cell type on tumorigenesis in vivo
. Unlike most established human glioblastoma cell line xenografts, injection of transformed GEM-derived cortical astrocytes into the brains of immune-competent littermates produced astrocytomas, including the most aggressive subtype, glioblastoma, that recapitulated the histopathological hallmarks of human astrocytomas, including diffuse invasion of normal brain parenchyma. Bioluminescence imaging of orthotopic allografts from transformed astrocytes engineered to express luciferase was utilized to monitor in vivo
tumor growth over time. Thus, astrocytoma models using astrocytes and NSC harvested from GEM with conditional oncogenic alleles provide an integrated system to study the genetics and cell biology of astrocytoma pathogenesis in vitro
and in vivo
and may be useful in preclinical drug development for these devastating diseases.
Neuroscience, Issue 90, astrocytoma, cortical astrocytes, genetically engineered mice, glioblastoma, neural stem cells, orthotopic allograft
Isolation of Murine Lymph Node Stromal Cells
Institutions: University of Basel and University Hospital Basel.
Secondary lymphoid organs including lymph nodes are composed of stromal cells that provide a structural environment for homeostasis, activation and differentiation of lymphocytes. Various stromal cell subsets have been identified by the expression of the adhesion molecule CD31 and glycoprotein podoplanin (gp38), T zone reticular cells or fibroblastic reticular cells, lymphatic endothelial cells, blood endothelial cells and FRC-like pericytes within the double negative cell population. For all populations different functions are described including, separation and lining of different compartments, attraction of and interaction with different cell types, filtration of the draining fluidics and contraction of the lymphatic vessels. In the last years, different groups have described an additional role of stromal cells in orchestrating and regulating cytotoxic T cell responses potentially dangerous for the host.
Lymph nodes are complex structures with many different cell types and therefore require a appropriate procedure for isolation of the desired cell populations. Currently, protocols for the isolation of lymph node stromal cells rely on enzymatic digestion with varying incubation times; however, stromal cells and their surface molecules are sensitive to these enzymes, which results in loss of surface marker expression and cell death. Here a short enzymatic digestion protocol combined with automated mechanical disruption to obtain viable single cells suspension of lymph node stromal cells maintaining their surface molecule expression is proposed.
Immunology, Issue 90, lymph node, lymph node stromal cells, digestion, isolation, enzymes, fibroblastic reticular cell, lymphatic endothelial cell, blood endothelial cell
Substernal Thyroid Biopsy Using Endobronchial Ultrasound-guided Transbronchial Needle Aspiration
Institutions: State University of New York, Buffalo, Roswell Park Cancer Institute, State University of New York, Buffalo.
Substernal thyroid goiter (STG) represents about 5.8% of all mediastinal lesions1
. There is a wide variation in the published incidence rates due to the lack of a standardized definition for STG. Biopsy is often required to differentiate benign from malignant lesions. Unlike cervical thyroid, the overlying sternum precludes ultrasound-guided percutaneous fine needle aspiration of STG. Consequently, surgical mediastinoscopy is performed in the majority of cases, causing significant procedure related morbidity and cost to healthcare. Endobronchial Ultrasound-guided Transbronchial Needle Aspiration (EBUS-TBNA) is a frequently used procedure for diagnosis and staging of non-small cell lung cancer (NSCLC). Minimally invasive needle biopsy for lesions adjacent to the airways can be performed under real-time ultrasound guidance using EBUS. Its safety and efficacy is well established with over 90% sensitivity and specificity. The ability to perform EBUS as an outpatient procedure with same-day discharges offers distinct morbidity and financial advantages over surgery. As physicians performing EBUS gained procedural expertise, they have attempted to diversify its role in the diagnosis of non-lymph node thoracic pathologies. We propose here a role for EBUS-TBNA in the diagnosis of substernal thyroid lesions, along with a step-by-step protocol for the procedure.
Medicine, Issue 93, substernal thyroid, retrosternal thyroid, intra-thoracic thyroid, goiter, endobronchial ultrasound, EBUS, transbronchial needle aspiration, TBNA, biopsy, needle biopsy
A Next-generation Tissue Microarray (ngTMA) Protocol for Biomarker Studies
Institutions: University of Bern.
Biomarker research relies on tissue microarrays (TMA). TMAs are produced by repeated transfer of small tissue cores from a ‘donor’ block into a ‘recipient’ block and then used for a variety of biomarker applications. The construction of conventional TMAs is labor intensive, imprecise, and time-consuming. Here, a protocol using next-generation Tissue Microarrays (ngTMA) is outlined. ngTMA is based on TMA planning and design, digital pathology, and automated tissue microarraying. The protocol is illustrated using an example of 134 metastatic colorectal cancer patients. Histological, statistical and logistical aspects are considered, such as the tissue type, specific histological regions, and cell types for inclusion in the TMA, the number of tissue spots, sample size, statistical analysis, and number of TMA copies. Histological slides for each patient are scanned and uploaded onto a web-based digital platform. There, they are viewed and annotated (marked) using a 0.6-2.0 mm diameter tool, multiple times using various colors to distinguish tissue areas. Donor blocks and 12 ‘recipient’ blocks are loaded into the instrument. Digital slides are retrieved and matched to donor block images. Repeated arraying of annotated regions is automatically performed resulting in an ngTMA. In this example, six ngTMAs are planned containing six different tissue types/histological zones. Two copies of the ngTMAs are desired. Three to four slides for each patient are scanned; 3 scan runs are necessary and performed overnight. All slides are annotated; different colors are used to represent the different tissues/zones, namely tumor center, invasion front, tumor/stroma, lymph node metastases, liver metastases, and normal tissue. 17 annotations/case are made; time for annotation is 2-3 min/case. 12 ngTMAs are produced containing 4,556 spots. Arraying time is 15-20 hr. Due to its precision, flexibility and speed, ngTMA is a powerful tool to further improve the quality of TMAs used in clinical and translational research.
Medicine, Issue 91, tissue microarray, biomarkers, prognostic, predictive, digital pathology, slide scanning
Non-enzymatic, Serum-free Tissue Culture of Pre-invasive Breast Lesions for Spontaneous Generation of Mammospheres
Institutions: George Mason University, Virginia Surgery Associates.
Breast ductal carcinoma in situ
(DCIS), by definition, is proliferation of neoplastic epithelial cells within the confines of the breast duct, without breaching the collagenous basement membrane. While DCIS is a non-obligate precursor to invasive breast cancers, the molecular mechanisms and cell populations that permit progression to invasive cancer are not fully known. To determine if progenitor cells capable of invasion existed within the DCIS cell population, we developed a methodology for collecting and culturing sterile human breast tissue at the time of surgery, without enzymatic disruption of tissue.
Sterile breast tissue containing ductal segments is harvested from surgically excised breast tissue following routine pathological examination. Tissue containing DCIS is placed in nutrient rich, antibiotic-containing, serum free medium, and transported to the tissue culture laboratory. The breast tissue is further dissected to isolate the calcified areas. Multiple breast tissue pieces (organoids) are placed in a minimal volume of serum free medium in a flask with a removable lid and cultured in a humidified CO2
incubator. Epithelial and fibroblast cell populations emerge from the organoid after 10 - 14 days. Mammospheres spontaneously form on and around the epithelial cell monolayer. Specific cell populations can be harvested directly from the flask without disrupting neighboring cells. Our non-enzymatic tissue culture system reliably reveals cytogenetically abnormal, invasive progenitor cells from fresh human DCIS lesions.
Cancer Biology, Issue 93, Breast, ductal carcinoma in situ, epidermal growth factor, mammosphere, organoid, pre-invasive, primary cell culture, serum-free, spheroid
Analysis of Cell Migration within a Three-dimensional Collagen Matrix
Institutions: Witten/Herdecke University.
The ability to migrate is a hallmark of various cell types and plays a crucial role in several physiological processes, including embryonic development, wound healing, and immune responses. However, cell migration is also a key mechanism in cancer enabling these cancer cells to detach from the primary tumor to start metastatic spreading. Within the past years various cell migration assays have been developed to analyze the migratory behavior of different cell types. Because the locomotory behavior of cells markedly differs between a two-dimensional (2D) and three-dimensional (3D) environment it can be assumed that the analysis of the migration of cells that are embedded within a 3D environment would yield in more significant cell migration data. The advantage of the described 3D collagen matrix migration assay is that cells are embedded within a physiological 3D network of collagen fibers representing the major component of the extracellular matrix. Due to time-lapse video microscopy real cell migration is measured allowing the determination of several migration parameters as well as their alterations in response to pro-migratory factors or inhibitors. Various cell types could be analyzed using this technique, including lymphocytes/leukocytes, stem cells, and tumor cells. Likewise, also cell clusters or spheroids could be embedded within the collagen matrix concomitant with analysis of the emigration of single cells from the cell cluster/ spheroid into the collagen lattice. We conclude that the 3D collagen matrix migration assay is a versatile method to analyze the migration of cells within a physiological-like 3D environment.
Bioengineering, Issue 92, cell migration, 3D collagen matrix, cell tracking
Generation of Induced Pluripotent Stem Cells by Reprogramming Mouse Embryonic Fibroblasts with a Four Transcription Factor, Doxycycline Inducible Lentiviral Transduction System
Institutions: Stemgent, MIT - Massachusetts Institute of Technology.
Using a defined set of transcription factors and cell culture conditions, Yamanaka and colleagues demonstrated that retrovirus-mediated delivery and expression of Oct4, Sox2, c-Myc, and Klf4 is capable of inducing pluripotency in mouse fibroblasts.1
Subsequent reports have demonstrated the utility of the doxycycline (DOX) inducible lentiviral delivery system for the generation of both primary and secondary iPS cells from a variety of other adult mouse somatic cell types.2,3
Induced pluripotent stem (iPS) cells are similar to embryonic stem (ES) cells in morphology, proliferation and ability to induce teratoma formation. Both types of cell can be used as the pluripotent starting material for the generation of differentiated cells or tissues in regenerative medicine.4-6
iPS cells also have a distinct advantage over ES cells as they exhibit key properties of ES cells without the ethical dilemma of embryo destruction.
Here we demonstrate the protocol for reprogramming mouse embryonic fibroblast (MEF) cells with the Stemgent DOX Inducible Mouse TF Lentivirus Set. We also demonstrate that the Stemgent DOX Inducible Mouse TF Lentivirus Set is capable of expressing each of the four transcription factors upon transduction into MEFs thereby inducing a pluripotent stem cell state that displays the pluripotency markers characteristic of ES cells.
Developmental Biology, Issue 33, reprogramming, Doxycycline, DOX, iPS, induced pluripotent stem cells, lentivirus, pluripotency, transduction, stem cells
Intralymphatic Immunotherapy and Vaccination in Mice
Institutions: University Hospital Zurich.
Vaccines are typically injected subcutaneously or intramuscularly for stimulation of immune responses. The success of this requires efficient drainage of vaccine to lymph nodes where antigen presenting cells can interact with lymphocytes for generation of the wanted immune responses. The strength and the type of immune responses induced also depend on the density or frequency of interactions as well as the microenvironment, especially the content of cytokines. As only a minute fraction of peripherally injected vaccines reaches the lymph nodes, vaccinations of mice and humans were performed by direct injection of vaccine into inguinal lymph nodes, i.e.
intralymphatic injection. In man, the procedure is guided by ultrasound. In mice, a small (5-10 mm) incision is made in the inguinal region of anesthetized animals, the lymph node is localized and immobilized with forceps, and a volume of 10-20 μl of the vaccine is injected under visual control. The incision is closed with a single stitch using surgical sutures. Mice were vaccinated with plasmid DNA, RNA, peptide, protein, particles, and bacteria as well as adjuvants, and strong improvement of immune responses against all type of vaccines was observed. The intralymphatic method of vaccination is especially appropriate in situations where conventional vaccination produces insufficient immunity or where the amount of available vaccine is limited.
Immunology, Issue 84, Vaccination, Immunization, intralymphatic immunotherapy, Lymph node injection, vaccines, adjuvants, surgery, anesthesia
Oscillation and Reaction Board Techniques for Estimating Inertial Properties of a Below-knee Prosthesis
Institutions: University of Northern Colorado, Arizona State University, Iowa State University.
The purpose of this study was two-fold: 1) demonstrate a technique that can be used to directly estimate the inertial properties of a below-knee prosthesis, and 2) contrast the effects of the proposed technique and that of using intact limb inertial properties on joint kinetic estimates during walking in unilateral, transtibial amputees. An oscillation and reaction board system was validated and shown to be reliable when measuring inertial properties of known geometrical solids. When direct measurements of inertial properties of the prosthesis were used in inverse dynamics modeling of the lower extremity compared with inertial estimates based on an intact shank and foot, joint kinetics at the hip and knee were significantly lower during the swing phase of walking. Differences in joint kinetics during stance, however, were smaller than those observed during swing. Therefore, researchers focusing on the swing phase of walking should consider the impact of prosthesis inertia property estimates on study outcomes. For stance, either one of the two inertial models investigated in our study would likely lead to similar outcomes with an inverse dynamics assessment.
Bioengineering, Issue 87, prosthesis inertia, amputee locomotion, below-knee prosthesis, transtibial amputee
Multispectral Real-time Fluorescence Imaging for Intraoperative Detection of the Sentinel Lymph Node in Gynecologic Oncology
Institutions: University Medical Center Groningen, Technical University Munich, University Medical Center Groningen.
The prognosis in virtually all solid tumors depends on the presence or absence of lymph node metastases.1-3
Surgical treatment most often combines radical excision of the tumor with a full lymphadenectomy in the drainage area of the tumor. However, removal of lymph nodes is associated with increased morbidity due to infection, wound breakdown and lymphedema.4,5
As an alternative, the sentinel lymph node procedure (SLN) was developed several decades ago to detect the first draining lymph node from the tumor.6
In case of lymphogenic dissemination, the SLN is the first lymph node that is affected (Figure 1). Hence, if the SLN does not contain metastases, downstream lymph nodes will also be free from tumor metastases and need not to be removed. The SLN procedure is part of the treatment for many tumor types, like breast cancer and melanoma, but also for cancer of the vulva and cervix.7
The current standard methodology for SLN-detection is by peritumoral injection of radiocolloid one day prior to surgery, and a colored dye intraoperatively. Disadvantages of the procedure in cervical and vulvar cancer are multiple injections in the genital area, leading to increased psychological distress for the patient, and the use of radioactive colloid.
Multispectral fluorescence imaging is an emerging imaging modality that can be applied intraoperatively without the need for injection of radiocolloid. For intraoperative fluorescence imaging, two components are needed: a fluorescent agent and a quantitative optical system for intraoperative imaging. As a fluorophore we have used indocyanine green (ICG). ICG has been used for many decades to assess cardiac function, cerebral perfusion and liver perfusion.8
It is an inert drug with a safe pharmaco-biological profile. When excited at around 750 nm, it emits light in the near-infrared spectrum around 800 nm. A custom-made multispectral fluorescence imaging camera system was used.9
The aim of this video article is to demonstrate the detection of the SLN using intraoperative fluorescence imaging in patients with cervical and vulvar cancer. Fluorescence imaging is used in conjunction with the standard procedure, consisting of radiocolloid and a blue dye. In the future, intraoperative fluorescence imaging might replace the current method and is also easily transferable to other indications like breast cancer and melanoma.
Medicine, Issue 44, Image-guided surgery, multispectral fluorescence, sentinel lymph node, gynecologic oncology
Visualization of the Interstitial Cells of Cajal (ICC) Network in Mice
Institutions: Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Cancer Center, Medical Institute, The Rockefeller University.
The interstitial cells of Cajal (ICC) are mesenchymal derived "pacemaker cells" of the gastrointestinal (GI) tract that generate spontaneous slow waves required for peristalsis and mediate neuronal input from the enteric nervous system1. Different subtypes of ICC form distinct networks in the muscularis of the GI tract 2,3
. Loss or injury to these networks is associated with a number of motility disorders4
. ICC cells express the KIT receptor tyrosine kinase on the plasma membrane and KIT immunostaining has been used for the past 15 years to label the ICC network5,6
. Importantly, normal KIT activity is required for ICC development5,6
. Neoplastic transformation of ICC cells results in gastrointestinal stromal tumor (GIST), that frequently harbor gain-of-function KIT mutations7,8
. We recently showed that ETV1 is a lineage-specific survival factor expressed in the ICC/GIST lineage and is a master transcriptional regulator required for both normal ICC network formation and for of GIST tumorigenesis9
. We further demonstrate that it cooperates with activating KIT mutations in tumorigenesis. Here, we describe methods for visualization of ICC networks in mice, largely based on previously published protocols10,11
. More recently, the chloride channel anoctamin 1 (ANO1) has also been characterized as a specific membrane marker of ICC11,12
. Because of their plasma membrane localization, immunofluorescence of both proteins can be used to visualize the ICC networks. Here, we describe visualization of the ICC networks by fixed-frozen cyrosections and whole mount preparations.
Developmental Biology, Issue 53, mice, fluorescence microscopy, gastrointestinal track, motility, interstital cells of cajal, kit, ano1, pgp9.5
Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
Institutions: UMDNJ-Robert Wood Johnson Medical School, University of Missouri-Kansas City, Ohio State University .
Described here is a method to measure contractility of isolated skeletal muscles. Parameters such as muscle force, muscle power, contractile kinetics, fatigability, and recovery after fatigue can be obtained to assess specific aspects of the excitation-contraction coupling (ECC) process such as excitability, contractile machinery and Ca2+
handling ability. This method removes the nerve and blood supply and focuses on the isolated skeletal muscle itself. We routinely use this method to identify genetic components that alter the contractile property of skeletal muscle though modulating Ca2+
signaling pathways. Here, we describe a newly identified skeletal muscle phenotype, i.e.
, mechanic alternans, as an example of the various and rich information that can be obtained using the in vitro
muscle contractility assay. Combination of this assay with single cell assays, genetic approaches and biochemistry assays can provide important insights into the mechanisms of ECC in skeletal muscle.
Physiology, Issue 69, extensor digitorum longus, soleus, in vitro contractility, calcium signaling, muscle-tendon complex, mechanic alternans
3-Dimensional Resin Casting and Imaging of Mouse Portal Vein or Intrahepatic Bile Duct System
Institutions: Vanderbilt University, Cincinnati Children's Hospital, Duke University .
In organs, the correct architecture of vascular and ductal structures is indispensable for proper physiological function, and the formation and maintenance of these structures is a highly regulated process. The analysis of these complex, 3-dimensional structures has greatly depended on either 2-dimensional examination in section or on dye injection studies. These techniques, however, are not able to provide a complete and quantifiable representation of the ductal or vascular structures they are intended to elucidate. Alternatively, the nature of 3-dimensional plastic resin casts generates a permanent snapshot of the system and is a novel and widely useful technique for visualizing and quantifying 3-dimensional structures and networks.
A crucial advantage of the resin casting system is the ability to determine the intact and connected, or communicating, structure of a blood vessel or duct. The structure of vascular and ductal networks are crucial for organ function, and this technique has the potential to aid study of vascular and ductal networks in several ways. Resin casting may be used to analyze normal morphology and functional architecture of a luminal structure, identify developmental morphogenetic changes, and uncover morphological differences in tissue architecture between normal and disease states. Previous work has utilized resin casting to study, for example, architectural and functional defects within the mouse intrahepatic bile duct system that were not reflected in 2-dimensional analysis of the structure1,2
, alterations in brain vasculature of a Alzheimer's disease mouse model3
, portal vein abnormalities in portal hypertensive and cirrhotic mice4
, developmental steps in rat lymphatic maturation between immature and adult lungs5
, immediate microvascular changes in the rat liver, pancreas, and kidney in response in to chemical injury6
Here we present a method of generating a 3-dimensional resin cast of a mouse vascular or ductal network, focusing specifically on the portal vein and intrahepatic bile duct. These casts can be visualized by clearing or macerating the tissue and can then be analyzed. This technique can be applied to virtually any vascular or ductal system and would be directly applicable to any study inquiring into the development, function, maintenance, or injury of a 3-dimensional ductal or vascular structure.
Medicine, Issue 68, Resin cast, 3-dimensional, portal vein, intrahepatic bile duct, vascular, ductal
Right Ventricular Systolic Pressure Measurements in Combination with Harvest of Lung and Immune Tissue Samples in Mice
Institutions: New York University School of Medicine, Tuxedo, Vanderbilt University Medical Center, New York University School of Medicine.
The function of the right heart is to pump blood through the lungs, thus linking right heart physiology and pulmonary vascular physiology. Inflammation is a common modifier of heart and lung function, by elaborating cellular infiltration, production of cytokines and growth factors, and by initiating remodeling processes 1
Compared to the left ventricle, the right ventricle is a low-pressure pump that operates in a relatively narrow zone of pressure changes. Increased pulmonary artery pressures are associated with increased pressure in the lung vascular bed and pulmonary hypertension 2
. Pulmonary hypertension is often associated with inflammatory lung diseases, for example chronic obstructive pulmonary disease, or autoimmune diseases 3
. Because pulmonary hypertension confers a bad prognosis for quality of life and life expectancy, much research is directed towards understanding the mechanisms that might be targets for pharmaceutical intervention 4
. The main challenge for the development of effective management tools for pulmonary hypertension remains the complexity of the simultaneous understanding of molecular and cellular changes in the right heart, the lungs and the immune system.
Here, we present a procedural workflow for the rapid and precise measurement of pressure changes in the right heart of mice and the simultaneous harvest of samples from heart, lungs and immune tissues. The method is based on the direct catheterization of the right ventricle via the jugular vein in close-chested mice, first developed in the late 1990s as surrogate measure of pressures in the pulmonary artery5-13
. The organized team-approach facilitates a very rapid right heart catheterization technique. This makes it possible to perform the measurements in mice that spontaneously breathe room air. The organization of the work-flow in distinct work-areas reduces time delay and opens the possibility to simultaneously perform physiology experiments and harvest immune, heart and lung tissues.
The procedural workflow outlined here can be adapted for a wide variety of laboratory settings and study designs, from small, targeted experiments, to large drug screening assays. The simultaneous acquisition of cardiac physiology data that can be expanded to include echocardiography5,14-17
and harvest of heart, lung and immune tissues reduces the number of animals needed to obtain data that move the scientific knowledge basis forward. The procedural workflow presented here also provides an ideal basis for gaining knowledge of the networks that link immune, lung and heart function. The same principles outlined here can be adapted to study other or additional organs as needed.
Immunology, Issue 71, Medicine, Anatomy, Physiology, Cardiology, Surgery, Cardiovascular Abnormalities, Inflammation, Respiration Disorders, Immune System Diseases, Cardiac physiology, mouse, pulmonary hypertension, right heart function, lung immune response, lung inflammation, lung remodeling, catheterization, mice, tissue, animal model
Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy
Institutions: University of California, Davis , University of California, Davis , University of Tromsø, University of California, Davis , University of California, Davis , University of California, Davis .
Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, traditional chemotherapeutic approaches have been largely unsuccessful. Hormone therapy is effective at early stage, but often fails with the eventual development of hormone-refractory tumors. We have been interested in developing therapeutics targeting specific metabolic deficiency of tumor cells. We recently showed that prostate tumor cells specifically lack an enzyme (argininosuccinate synthase, or ASS) involved in the synthesis of the amino acid arginine1
. This condition causes the tumor cells to become dependent on exogenous arginine, and they undergo metabolic stress when free arginine is depleted by arginine deiminase (ADI)1,10
. Indeed, we have shown that human prostate cancer cells CWR22Rv1
are effectively killed by ADI with caspase-independent apoptosis and aggressive autophagy
. Autophagy is an evolutionarily-conserved process that allows cells to metabolize unwanted proteins by lysosomal breakdown during nutritional starvation4,5
. Although the essential components of this pathway are well-characterized6,7,8,9
, many aspects of the molecular mechanism are still unclear - in particular, what is the role of autophagy in the death-response of prostate cancer cells after ADI treatment? In order to address this question, we required an experimental method to measure the level and extent of autophagic response in cells - and since there are no known molecular markers that can accurately track this process, we chose to develop an imaging-based approach, using quantitative 3D fluorescence microscopy11,12
Using CWR22Rv1 cells specifically-labeled with fluorescent probes for autophagosomes and lysosomes, we show that 3D image stacks acquired with either widefield deconvolution microscopy (and later, with super-resolution, structured-illumination microscopy) can clearly capture the early stages of autophagy induction. With commercially available digital image analysis applications, we can readily obtain statistical information about autophagosome and lysosome number, size, distribution, and degree of colocalization from any imaged cell. This information allows us to precisely track the progress of autophagy in living cells and enables our continued investigation into the role of autophagy in cancer chemotherapy.
Cellular Biology, Issue 75, Biochemistry, Molecular Biology, Medicine, Cancer Biology, Biophysics, Chemical Biology, Proteins, Microscopy, Fluorescence, autophagy, arginine deiminase, prostate cancer, deconvolution microscopy, super-resolution structured-illumination microscopy, live cell imaging, tumors, autophagosomes, lysosomes, cells, cell culture, microscopy, imaging, visualization
Bioluminescent Orthotopic Model of Pancreatic Cancer Progression
Institutions: Monash University, University of Bern, University of California Los Angeles .
Pancreatic cancer has an extremely poor five-year survival rate of 4-6%. New therapeutic options are critically needed and depend on improved understanding of pancreatic cancer biology. To better understand the interaction of cancer cells with the pancreatic microenvironment, we demonstrate an orthotopic model of pancreatic cancer that permits non-invasive monitoring of cancer progression. Luciferase-tagged pancreatic cancer cells are resuspended in Matrigel and delivered into the pancreatic tail during laparotomy. Matrigel solidifies at body temperature to prevent leakage of cancer cells during injection. Primary tumor growth and metastasis to distant organs are monitored following injection of the luciferase substrate luciferin, using in vivo
imaging of bioluminescence emission from the cancer cells. In vivo
imaging also may be used to track primary tumor recurrence after resection. This orthotopic model is suited to both syngeneic and xenograft models and may be used in pre-clinical trials to investigate the impact of novel anti-cancer therapeutics on the growth of the primary pancreatic tumor and metastasis.
Cancer Biology, Issue 76, Medicine, Molecular Biology, Cellular Biology, Genetics, Biomedical Engineering, Surgery, Neoplasms, Pancreatic Cancer, Cancer, Orthotopic Model, Bioluminescence, In Vivo Imaging, Matrigel, Metastasis, pancreas, tumor, cancer, cell culture, laparotomy, animal model, imaging
Isolation and Th17 Differentiation of Naïve CD4 T Lymphocytes
Institutions: The University of Florida.
Th17 cells are a distinct subset of T cells that have been found to produce interleukin 17 (IL-17), and differ in function from the other T cell subsets including Th1, Th2, and regulatory T cells. Th17 cells have emerged as a central culprit in overzealous inflammatory immune responses associated with many autoimmune disorders. In this method we purify T lymphocytes from the spleen and lymph nodes of C57BL/6 mice, and stimulate purified CD4+ T cells under control and Th17-inducing environments. The Th17-inducing environment includes stimulation in the presence of anti-CD3 and anti-CD28 antibodies, IL-6, and TGF-β. After incubation for at least 72 hours and for up to five days at 37 °C, cells are subsequently analyzed for the capability to produce IL-17 through flow cytometry, qPCR, and ELISAs. Th17 differentiated CD4+CD25- T cells can be utilized to further elucidate the role that Th17 cells play in the onset and progression of autoimmunity and host defense. Moreover, Th17 differentiation of CD4+CD25- lymphocytes from distinct murine knockout/disease models can contribute to our understanding of cell fate plasticity.
Immunology, Issue 79, Cellular Biology, Molecular Biology, Medicine, Infection, Th17 cells, IL-17, Th17 differentiation, T cells, autoimmunity, cell, isolation, culture
Ex Vivo Treatment Response of Primary Tumors and/or Associated Metastases for Preclinical and Clinical Development of Therapeutics
Institutions: Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Cancer Center.
The molecular analysis of established cancer cell lines has been the mainstay of cancer research for the past several decades. Cell culture provides both direct and rapid analysis of therapeutic sensitivity and resistance. However, recent evidence suggests that therapeutic response is not exclusive to the inherent molecular composition of cancer cells but rather is greatly influenced by the tumor cell microenvironment, a feature that cannot be recapitulated by traditional culturing methods. Even implementation of tumor xenografts, though providing a wealth of information on drug delivery/efficacy, cannot capture the tumor cell/microenvironment crosstalk (i.e.
, soluble factors) that occurs within human tumors and greatly impacts tumor response. To this extent, we have developed an ex vivo
(fresh tissue sectioning) technique which allows for the direct assessment of treatment response for preclinical and clinical therapeutics development. This technique maintains tissue integrity and cellular architecture within the tumor cell/microenvironment context throughout treatment response providing a more precise means to assess drug efficacy.
Cancer Biology, Issue 92, Ex vivo sectioning, Treatment response, Sensitivity/Resistance, Drug development, Patient tumors, Preclinical and Clinical
Monitoring Tumor Metastases and Osteolytic Lesions with Bioluminescence and Micro CT Imaging
Institutions: Caliper Life Sciences.
Following intracardiac delivery of MDA-MB-231-luc-D3H2LN cells to Nu/Nu mice, systemic metastases developed in the injected animals. Bioluminescence imaging using IVIS Spectrum was employed to monitor the distribution and development of the tumor cells following the delivery procedure including DLIT reconstruction to measure the tumor signal and its location.
Development of metastatic lesions to the bone tissues triggers osteolytic activity and lesions to tibia and femur were evaluated longitudinally using micro CT. Imaging was performed using a Quantum FX micro CT system with fast imaging and low X-ray dose. The low radiation dose allows multiple imaging sessions to be performed with a cumulative X-ray dosage far below LD50. A mouse imaging shuttle device was used to sequentially image the mice with both IVIS Spectrum and Quantum FX achieving accurate animal positioning in both the bioluminescence and CT images. The optical and CT data sets were co-registered in 3-dimentions using the Living Image 4.1 software. This multi-mode approach allows close monitoring of tumor growth and development simultaneously with osteolytic activity.
Medicine, Issue 50, osteolytic lesions, micro CT, tumor, bioluminescence, in vivo, imaging, IVIS, luciferase, low dose, co-registration, 3D reconstruction
Right Hemihepatectomy by Suprahilar Intrahepatic Transection of the Right Hemipedicle using a Vascular Stapler
Institutions: Tübingen University Hospital.
Successful hepatic resection requires profound anatomical knowledge and delicate surgical technique. Hemihepatectomies are mostly performed after preparing the extrahepatic hilar structures within the hepatoduodenal ligament, even in benign tumours or liver metastasis.1-5
. Regional extrahepatic lymphadenectomy is an oncological standard in hilar cholangiocarcinoma, intrahepatic cholangio-cellular carcinoma and hepatocellular carcinoma, whereas lymph node metastases in the hepatic hilus in patients with liver metastasis are rarely occult. Major disadvantages of these procedures are the complex preparation of the hilus with the risk of injuring contralateral structures and the possibility of bleeding from portal vein side-branches or impaired perfusion of bile ducts. We developed a technique of right hemihepatectomy or resection of the left lateral segments with intrahepatic transection of the pedicle that leaves the hepatoduodenal ligament completely untouched. 6
However, if intraoperative visualization or palpation of the ligament is suspicious for tumor infiltration or lymph node metastasis, the hilus should be explored and a lymphadenectomy performed.
Medicine, Issue 35, Liver resection, liver tumour, intrahepatic hilus stapling, right hemipedicle