MAT-B-III Xenograft Rat Model Service for Breast Cancer

The MAT-B-III xenograft rat model represents a syngeneic, highly aggressive mammary adenocarcinoma platform that preserves intact host immunity while delivering rapid, reproducible tumor growth kinetics ideal for preclinical breast cancer drug development. Alfa Cytology leverages authenticated 13762-MAT-B-III cell stocks and standardized Fischer 344 implantation protocols to construct robust preclinical cohorts, supporting everything from cytotoxic screening and antibody-drug conjugate evaluation to anti-angiogenic and immune-oncology studies with rigorous histopathological and biomarker endpoints.

Overview of MAT-B-III Xenograft Rat Model for Breast Cancer

The 13762-MAT-B-III cell line was originally derived from a mammary adenocarcinoma induced in Fischer 344 rats by oral administration of 7,12-dimethylbenz[a]anthracene (DMBA), a polycyclic aromatic hydrocarbon carcinogen widely used in experimental mammary tumorigenesis. Unlike human CDX models that require immunodeficient hosts, MAT-B-III operates within a fully syngeneic, immunocompetent framework, allowing researchers to interrogate tumor–immune interactions, stromal remodeling, and angiogenic responses in a physiologically intact microenvironment. Histologically, the model produces poorly differentiated adenocarcinomas with high mitotic index and prominent neovascularization, closely mirroring the aggressive biology of triple-negative or basal-like breast cancer subtypes in humans.

Fig 1. Comparison of human, rat and mouse in regards to their biology, mammary gland architecture and tumor features in the context of HR⁺ BC (Nicotra, Raquel, et al., 2024)

A defining feature of the MAT-B-III model is its exceptional tumor induction reliability—approaching 100% take rates in Fischer 344 recipients—combined with rapid volume expansion that permits compressed study timelines without sacrificing statistical power. The model is further distinguished by its hypervascular phenotype, as confirmed by CD34 immunostaining and angiographic imaging, making it particularly suited for evaluating anti-angiogenic agents, transarterial embolization strategies, and vascular-disrupting therapies. Beyond the orthotopic mammary fat pad, MAT-B-III cells can be inoculated into the mammary duct to generate ductal carcinoma in situ (DCIS)-like lesions within 48 hours, or into the liver to model metastatic hepatoma, offering versatile anatomical contexts for diverse mechanistic and therapeutic questions.

Cell Line Information: MAT-B-III

The table below summarizes the authenticated characteristics of the 13762-MAT-B-III rat mammary adenocarcinoma cell line, compiled from established cell repositories and peer-reviewed literature.

Our Services

Alfa Cytology operationalizes the MAT-B-III platform through a fully documented preclinical pipeline: authenticated cell banking, surgical implantation by experienced veterinary surgeons, longitudinal tumor monitoring via caliper and imaging modalities, and terminal histopathology with quantitative biomarker readouts. Every study is designed to align with your compound's mechanism of action, whether you are profiling a vascular-targeting biologic, a next-generation ADC payload, or a small-molecule cytotoxic, with all work conducted under accredited IACUC oversight and GLP-aligned documentation standards.

Workflow of MAT-B-III Xenograft Rat Model Construction

Construction of the MAT-B-III syngeneic breast cancer model follows a reproducible surgical and cell-biology workflow optimized for high tumor take rates, consistent growth kinetics, and minimal perioperative morbidity. The protocol can be adapted for orthotopic mammary fat pad, subcutaneous flank, intraductal, or hepatic metastatic implantation depending on the scientific objective.

1. Cell Line Resuscitation & Quality Control: Cryopreserved 13762-MAT-B-III stocks are thawed and expanded in antibiotic-free complete medium under low-passage conditions. Cell identity is confirmed by morphology and STR profiling (RRID: CVCL_3475). Viability is assessed by trypan blue exclusion, and only suspensions exceeding 95% viability are advanced to implantation. Cells are harvested at 70–80% confluence, washed in PBS, and resuspended in serum-free medium at a concentration of 1–2 × 10⁶ cells per 100 µL for mammary fat pad injection.
2. Recipient Preparation & Anesthesia: Female Fischer 344 rats (typically 8–12 weeks old, 150–200 g) are acclimated for one week prior to surgery. On the day of implantation, animals are anesthetized with isoflurane inhalation (2–3% in oxygen) or ketamine/xylazine cocktail, with continuous monitoring of respiratory rate and pedal reflex. Ophthalmic ointment is applied to prevent corneal desiccation, and the surgical field is shaved and disinfected with alternating betadine and ethanol scrubs.
3. Orthotopic Mammary Fat Pad Implantation: A small skin incision is made adjacent to the fourth or fifth inguinal mammary gland. The mammary fat pad is gently exteriorized with sterile forceps, and 50–100 µL of the MAT-B-III single-cell suspension is injected directly into the fat pad using a 27-gauge needle. Successful delivery is confirmed by visible blanching of the tissue. The fat pad is returned to its anatomical position, and the incision is closed with absorbable suture or surgical clips. Analgesia (buprenorphine, 0.05–0.1 mg/kg) is administered subcutaneously immediately post-surgery.
4. Post-Operative Monitoring & Tumor Tracking: Animals are housed individually or in small groups on warming pads until fully conscious. Body weight, food intake, and incision integrity are monitored daily for the first 72 hours, then twice weekly. Tumor palpation begins on day 7; once tumors become measurable, caliper dimensions (length × width) are recorded two to three times weekly, with volume calculated as V = (L × W²) / 2. Optional non-invasive imaging (bioluminescence, ultrasound, or MRI) is employed for luciferase-tagged variants or vascular phenotyping.
5. Therapeutic Intervention & Endpoint Harvest: Upon reaching the target tumor volume (typically 100–200 mm³), animals are randomized into treatment and control cohorts. Test articles are administered according to the sponsor-defined regimen—intravenous, intraperitoneal, oral, or intratumoral. Tumor measurements continue on schedule until the study endpoint, at which time animals are euthanized humanely. Tumors, draining lymph nodes, lungs, liver, and blood are harvested for downstream analysis, including H&E histopathology, CD34 microvessel density quantification, Ki-67 proliferation index, TUNEL apoptosis scoring, and plasma pharmacokinetic profiling.

Fig 2. MAT-B-III Xenograft Rat Model construction workflow.

Case Study-MAT-B-III Xenograft Rat Model Development

In a recent preclinical program, Alfa Cytology utilized the MAT-B-III orthotopic model to assess the efficacy of a novel antibody-drug conjugate (ADC) candidate targeting a tumor-associated antigen expressed in aggressive breast cancer subtypes. Following authenticated cell expansion and orthotopic implantation into Fischer 344 rats, tumors were permitted to establish for 10 days prior to randomization into vehicle, benchmark, and escalating dose cohorts. The ADC was administered intravenously on a q4d × 4 schedule, with longitudinal tumor volume monitoring and interim body-weight assessments. Terminal analyses included H&E grading, CD34 microvessel density quantification to assess anti-angiogenic effects, and Ki-67/TUNEL dual staining to parse proliferation versus apoptosis dynamics. The dataset revealed a clear dose-dependent tumor growth delay and vascular normalization signature, furnishing the sponsor with pharmacodynamic evidence to support downstream candidate selection and IND-enabling toxicology planning.

Why Choose Alfa Cytology?

Partnering with Alfa Cytology for your MAT-B-III breast cancer program means gaining access to a specialized preclinical infrastructure built around reproducible syngeneic modeling, multimodal analytics, and regulatory-grade documentation.

• Authenticated 13762-MAT-B-III master and working cell banks are maintained under documented low-passage protocols with periodic STR verification to ensure genetic stability and consistent tumorigenicity.
• Our surgical team has extensive experience in rat mammary fat pad orthotopic implantation, achieving high tumor take rates with minimal perioperative mortality through refined anesthesia and post-operative pain management.
• Integrated vascular biology capabilities—including CD34 immunohistochemistry, microvessel density quantification, and contrast-enhanced small-animal imaging—directly support anti-angiogenic and interventional oncology study designs.
• Flexible endpoint packages span standard caliper-based tumor tracking through to advanced histopathology, multiplex cytokine profiling, flow cytometric immune phenotyping, and plasma drug-concentration analysis.
• Study protocols are customized to your therapeutic modality, whether the focus is cytotoxic chemotherapy, targeted biologics, ADCs, immune checkpoint inhibitors, or vascular-disrupting agents.
• All in vivo work is conducted under fully accredited IACUC oversight with real-time veterinary monitoring, ensuring ethical integrity and generating audit-ready data packages for regulatory submissions.

Contact Us

If your breast cancer therapeutic pipeline requires a preclinical model that couples aggressive tumor biology with intact immune surveillance and translational vascular phenotyping, reach out to us to discuss how Alfa Cytology can architect a MAT-B-III study tailored to your development milestones. Our scientific team will review your target profile, propose a customized study design with clear go/no-go decision criteria, and deliver a comprehensive proposal within 48 hours. Contact us today and accelerate your preclinical proof-of-concept with a CRO that understands the nuances of syngeneic breast cancer modeling.

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