Preclinical Tumor Analysis and Imaging (PTAI) Shared Resource
Preclinical Studies Services:
- Project Management – assist with project design, prepare cost estimates for, and gain animal welfare committee (IACUC) and biosafety committee (BSL) approval for preclinical studies.
- Subcutaneous Xenograft Services – placement of cells or tumor pieces just beneath the skin (sub cutaneous) on the flank or hind leg. This is the common xenograft model for patient tumor propagation, simple growth analysis, chemotherapeutic dose response analysis, some metastasis studies, as well as some radiation studies.
- Orthotopic Xenografts – deposition of cells or tumor pieces in the anatomical location of cancer origin including renal capsule, splenic capsule, ovarian bursa, intra-tracheal, pancreas, intraperitoneal, intravesicular/bladder, mammary fat pad, prostate, tibia and femur. This approach aims to mimic the tissue environment of a primary tumor more accurately than subcutaneous implantation.
- Metastatic Xenografts – occurrence of transplantable metastases from orthotopic xenograft models or by tail vein, intra-cardiac, and intra-carotid injections of cancer cells (New).
- Drug preparation and delivery – calculation, preparation, and delivery of chemotherapeutics for all xenograft models. Drug delivery methods include gavage, ip injections, sc injections, iv injections, and Alzet pump filling and installation. PTAI offers once a day, twice a day, four times a day, and multiple therapies multiple times a day for multiple preclinical studies.
- Maximum Tolerated Dose (MTD) Studies – test novel therapeutics including small molecules, biologics (viruses, antibodies), radiosensitizers, nanobodies, nanoparticles, and novel drug combinations in mice. MTD studies require daily monitoring of mice throughout the treatment period.
- Cancer Cell Services – PTAI has over 100 cancer cell lines stored on site, including many proprietary lines derived from patient tumors, and grows the cells for in vitro or xenograft studies.
- Surgical model adjustments – orchiectomies, catheterizations, oophrectomies, thyroidectomies, etc. as needed to develop the correct animal model for specific studies.
- Data collection – monitor mice and record data for health, weight changes, and tumor development. Sample blood by submandibular puncture for CBC and serum analysis (New). PTAI staff will perform necropsy and harvest tumors, organs, and tissues for molecular analysis as required. Photography of mice and organs (New).
- Coordinate services – facilitate research by coordinating PTAI client projects with other Cancer Center Shared Resources to fulfill project needs.
Imaging Services provide noninvasive rodent imaging for preclinical studies including:
- Magnetic Resonance Imaging (MRI) for noninvasive tumor imaging and sizing. MRI is particularly useful for following tumor growth over time in orthotopic and metastaic xenograft models. PTAI will also administer contrast agents when needed to distinguish the tumor from surrounding soft tissue (e.g., Gd-DTPA to enhance brain tumors).
- Dual Modality X-Ray CT and single gamma (SPECT) Imaging. CT provides anatomical images to help to localize signal from the SPECT scanner. It is also useful for detection and measurement of bone lesions. SPECT is used for imaging radiolabeled biomarkers that have a long biological half life (e.g. 111-Indium labeled targeting pancreatic cancer). The CT is also used to provide anatomical images for PET.
- Positron Emission Tomography (PET) is currently used largely for imaging upregulated glucose metabolism using 18F-fluorodeoxyglucose (FDG) for detecting tumors and assessing their viability post-therapy. It is also used to image 64-copper labeled biomarkers. The use of the PET scanner will greatly increase once the new cyclotron is installed. Access to the new isotopes produced by the cyclotron and generated by the radiochemists will allow in vivo biodistribution studies of novel small molecule therapeutics.
- Bioluminescence/Fluorescence Imaging is used largely to serially follow the growth of subcutaneous xenografts where cancer cells have been stably transfected with the Firefly Luciferase gene or with a gene expressing a red-shifted protein (e.g., Katushka).
Molecular Assessment Services:
- Cell Growth Assays – convenient drug response assays using the Biomek® NXP Laboratory Automation Workstation (New), a robotic high throughput screening (HTS) liquid handler for studying induction and inhibition of cell proliferation. Toward these ends, PTAI offers target assessment, assay development, and validation.
- Western Blotting – lysate samples are prepared from frozen tumor tissue and cultured cells to analyze the level of expression of proteins involved in various types of signaling pathways using custom or commercial antibodies. This service has been especially helpful for clinicians who otherwise do not have direct access to laboratory facilities.
- Normal mouse tissue arrays – standardized extracts of various mouse tissues that can be used for characterizing tissue specific expression of signaling molecules and characterization of the specificity of novel antibodies.
- ELISA assays – routine and novel assays. For example, an ELISA assay was created and optimized to screen a chemical library for novel inhibitors of Rho-family GTPases.
Additional Key Services:
- Consultation in the design of animal experiments, from start to finish, including consideration of: regulatory and logistical issues; biostatistics; specimen collection, storage and analysis; imaging, and molecular assessments, to ensure the highest probability that a planned experiment will be fully informative.
- Training in basic animal handling through therapy delivery options, surgical procedures, specimen collection and storage, animal monitoring, and tumor analysis.