CT-2A-luc Orthotopic Mouse Model Service for Brain Cancer

The CT-2A-luc orthotopic mouse model recapitulates the aggressive growth, hemorrhagic infiltration, and mesenchymal molecular signature of PTEN-deficient high-grade glioma within the immunocompetent brain microenvironment of C57BL/6 mice. Alfa Cytology designs, validates, and manages this syngeneic luciferase-reporter glioma system under rigorous preclinical standards, equipping researchers with quantitative imaging endpoints and histopathological readouts to advance their neuro-oncology discovery programs.

Overview of CT-2A-luc Orthotopic Mouse Model for Brain Cancer

The CT-2A-luc orthotopic model is established by stereotactically implanting luciferase-transduced CT-2A murine glioma cells into the striatum of syngeneic C57BL/6 mice, generating an intracranial tumor that closely mirrors the hemorrhagic, infiltrative, and highly angiogenic phenotype of human mesenchymal glioblastoma. Because CT-2A was originally derived from a 20-methylcholanthrene-induced malignant astrocytoma in an immunocompetent host, the model preserves full tumor–immune interactions, including myeloid cell infiltration, microglial activation, and T-cell engagement—features that are largely absent in immunodeficient xenograft platforms. The stable expression of firefly luciferase enables non-invasive, longitudinal bioluminescence imaging of tumor engraftment and expansion deep within the brain parenchyma, providing a sensitive surrogate for intracranial tumor burden without the need for serial magnetic resonance imaging or repeated terminal sampling.

Fig 1. Schematic diagram of traditional vs. optimized orthotopic mouse models (internal carotid artery injection, brain microenvironment, BBB disruption, tumor cell colonization). (Liu, Zihao, et al., 2025)

Histologically, CT-2A-luc tumors exhibit high-grade astrocytoma morphology characterized by elevated mitotic indices, dense cellularity, nuclear polymorphism, pseudopalisading necrosis, and florid microvascular proliferation with tortuous, enlarged vessels. The cell line is distinguished by PTEN and TSC2 protein deficiency, wild-type p53 status, an N-ras activating mutation, and heterozygous deletion of Cdkn2a/b—genomic alterations that converge to drive PI3K-AKT-mTOR hyperactivation and aggressive angiogenesis. Additionally, CT-2A cells display a unique ganglioside profile marked by high levels of complex gangliosides and markedly reduced anti-angiogenic GM3, further accentuating their pro-vascular phenotype. These attributes render the CT-2A-luc model particularly valuable for interrogating radiation response, temozolomide resistance mechanisms, immune checkpoint inhibitor efficacy, and anti-angiogenic strategies in a fully immunocompetent preclinical setting.

Cell Line Information: CT-2A-luc

CT-2A-luc is a luciferase-reporter derivative of the CT-2A murine glioma cell line, generated through lentiviral transduction to stably express firefly luciferase for in vivo bioluminescent tracking. The parental CT-2A line was established from a malignant astrocytoma induced by 20-methylcholanthrene in the cerebrum of a C57BL/6J mouse and has been extensively characterized as a representative model of PTEN-deficient, mesenchymal-subtype high-grade glioma. Key attributes are summarized below:

Our Services

Our ServicesOur ServicesAlfa Cytology delivers comprehensive CT-2A-luc orthotopic glioma model services spanning stereotactic surgical implantation, longitudinal bioluminescence imaging, magnetic resonance imaging integration, and detailed neuropathological endpoint analysis. Every study is conducted within fully accredited vivarium facilities under IACUC oversight, ensuring scientific precision, ethical compliance, and complete data traceability from model construction through final report delivery.

Workflow of CT-2A-luc Orthotopic Mouse Model Construction

Construction of the CT-2A-luc orthotopic glioma model employs stereotactic intracranial injection to achieve precise cell delivery into the murine striatum, ensuring reproducible tumor engraftment, minimal surgical morbidity, and consistent growth kinetics. The protocol integrates pre-operative analgesia, aseptic stereotactic surgery, controlled cell infusion, and longitudinal bioluminescence monitoring, as outlined below:

1. Cell Preparation and Batch Validation: CT-2A-luc cells are expanded under low-passage conditions (passage 3–8) in complete medium to preserve tumorigenicity and mesenchymal phenotype. Viability is confirmed by trypan blue exclusion (>95% required), and luciferase expression is validated via in vitro bioluminescence assay to ensure uniform reporter signal intensity across the batch.
2. Animal Selection and Acclimation: Female C57BL/6J mice (8–10 weeks old) are selected to maintain syngeneic compatibility and preserve intact tumor–immune interactions. A one-week acclimation period is observed under specific-pathogen-free housing, with daily health monitoring and body weight recording to establish individual baseline parameters.
3. Pre-Operative Analgesia and Anesthesia: Mice receive pre-operative analgesia comprising buprenorphine (0.1 mg/kg) and carprofen (5 mg/kg) subcutaneously. General anesthesia is induced and maintained with isoflurane (3% induction, 1.5–2% maintenance) delivered via nose cone, with continuous respiration and body temperature monitoring throughout the procedure.
4. Surgical Site Preparation: The scalp is shaved and depilatory cream is applied to remove fur, followed by sterilization with iodine solution. The mouse is secured in a stereotaxic frame with ear bars and a bite bar, and a single midline incision is made to expose the skull surface and identify the bregma landmark.
5. Craniotomy and Dural Exposure: A small burr hole is drilled at the predetermined stereotactic coordinates (anteroposterior +1 mm, mediolateral +2 mm relative to bregma) using a high-speed microdrill under constant saline cooling. The dura mater is carefully pierced to expose the underlying parenchyma without causing cortical trauma or hemorrhage.
6. Tumor Cell Injection: A 10 µL Hamilton syringe fitted with a glass micropipette is lowered through the burr hole to a depth of −3 mm relative to bregma, targeting the right striatum. CT-2A-luc cells (5 × 10⁴) in 2 µL PBS are delivered using a micropump injector over 2 minutes at a constant infusion rate. A single-cell suspension is essential to prevent clumping and ensure uniform tumor seeding within the striatal parenchyma.
7. Needle Retraction and Wound Closure: The needle is left in place for an additional 2 minutes to prevent retrograde flow along the injection tract, then withdrawn slowly over 1 minute to minimize cell tracking. The scalp incision is closed with surgical sutures or tissue adhesive, and the mouse is transferred to a heated recovery chamber.
8. Post-Operative Care and Monitoring: Mice receive carprofen-supplemented drinking water (33 µg/mL) for 72 hours post-surgery and are monitored twice daily for neurological deficits, body weight, and wound integrity. Animals are allowed to recover for a minimum of 3 days before initiation of any imaging or treatment protocol.
9. Bioluminescence Imaging and Tumor Monitoring: Starting at day 3–7 post-implantation, tumor establishment and growth are monitored via IVIS Spectrum or equivalent bioluminescence imaging system following intraperitoneal D-luciferin administration (150 mg/kg). Regions of interest are drawn over the cranial vault, and photon flux (photons/sec/cm²/sr) is quantified to generate longitudinal growth curves for each animal.
10. Endpoint Analysis and Neuropathology: At study termination, mice are humanely euthanized and brains are excised, weighed, and processed for formalin-fixed paraffin embedding. Coronal serial sections are stained with H&E for morphological assessment, and immunohistochemistry is performed for Ki67, CD31, GFAP, Iba1, and human/mouse-specific markers to confirm tumor origin, proliferative index, vascular density, and immune cell infiltration.

Fig 2. CT-2A-luc Orthotopic Mouse Model construction workflow.

Case Study-CT-2A-luc Orthotopic Mouse Model Development

In a representative preclinical engagement, the CT-2A-luc orthotopic model was utilized to evaluate the efficacy of a novel therapeutic regimen targeting the mesenchymal tumor microenvironment in PTEN-deficient glioblastoma. Following stereotactic implantation and confirmation of engraftment by bioluminescence imaging within the first week, cohorts were randomized to receive either the investigational agent or vehicle control. Longitudinal BLI revealed distinct growth trajectories between treatment arms, with the active compound cohort demonstrating attenuated photon flux accumulation relative to controls. Terminal neuropathological analysis showed reduced intracranial tumor burden, diminished microvascular proliferation, and lower Ki67 proliferation indices in treated animals, alongside preserved peritumoral brain architecture in responders. These preclinical findings informed the compound's mechanism-of-action hypothesis and supported advancement toward subsequent pharmacology and toxicology studies.

Why Choose Alfa Cytology?

Selecting Alfa Cytology for your CT-2A-luc orthotopic glioma program provides access to a neuroscience-focused, quality-driven preclinical infrastructure optimized for intracranial tumor research. Our distinguishing capabilities include:

• Deep expertise in neuro-oncology model development, with optimized stereotactic surgical protocols that achieve consistent striatal engraftment and physiologically relevant tumor progression in immunocompetent hosts.
• Integrated bioluminescence and small-animal MRI imaging platforms enabling non-invasive, quantitative longitudinal tracking of intracranial tumor dynamics without introducing serial sacrifice artifacts.
• Rigorous cell banking and authentication procedures, encompassing mycoplasma screening, luciferase expression validation, and short tandem repeat profiling to ensure model fidelity and batch-to-batch reproducibility.
• Flexible study architectures supporting single-agent efficacy, combination radiochemotherapy regimens, immune checkpoint inhibitor evaluation, and anti-angiogenic drug profiling tailored to your therapeutic modality.
• Comprehensive neuropathological endpoint capabilities including digital histopathology, immunohistochemistry for vascular and immune markers, multiplex immunofluorescence, and flow cytometry of tumor-infiltrating leukocytes.
• A dedicated scientific project management team providing transparent milestone reporting, timeline accountability, and direct consultation from protocol design through final data package delivery.

Contact Us

Whether your program targets PTEN-deficient glioblastoma with a novel kinase inhibitor, an immune-modulating biologic, or a blood-brain barrier-penetrant small molecule, Alfa Cytology is positioned to accelerate your preclinical development with our CT-2A-luc orthotopic glioma expertise. Contact us today to discuss your study design, review our imaging and surgical capabilities, and receive a customized proposal aligned with your scientific objectives and timeline. Our neuro-oncology team looks forward to partnering with you to generate the robust, translationally relevant data your pipeline demands.

For research use only. Not intended for any clinical use.