E0771 Orthotopic Mouse Model Service for Breast Cancer

The E0771 orthotopic mouse model delivers a fully immunocompetent, syngeneic platform for studying mammary tumor progression, metastatic dissemination, and therapeutic response within the native breast microenvironment. Alfa Cytology provides end-to-end preclinical services spanning model establishment, longitudinal monitoring, and efficacy evaluation to advance your breast cancer drug discovery pipeline.

Overview of E0771 Orthotopic Mouse Model for Breast Cancer

E0771 (also referenced as EO771 or EO 771) is a murine mammary adenocarcinoma cell line originally isolated from a spontaneous tumor arising in a female C57BL/6 mouse. When implanted orthotopically into the mammary fat pad of syngeneic C57BL/6 recipients, this model preserves intact host immunity while recapitulating the anatomical stromal context of human breast cancer, permitting investigation of primary tumor growth, angiogenesis, and spontaneous metastasis to organs such as the lung, bone, and brain.

Fig 1. Gross photographs (A), tumor volume (B), and tumor weight (C) of E0771 subcutaneous transplanted WT vs Cβ2 KO mice. (Guo, Shuai, et al., 2024)

Phenotypically, E0771 cells exhibit a luminal B molecular profile characterized by ER_α negativity, ER_β positivity, progesterone receptor positivity, and ErbB2/HER2 overexpression. This classification aligns the model with an aggressive breast cancer subtype frequently encountered in the clinic, making it particularly suitable for preclinical evaluation of anti-estrogen agents, targeted therapies, immune checkpoint inhibitors, and combination regimens.

Cell Line Information: E0771

E0771 was first established by Sugiura and Stock in 1952 from a spontaneously arising mammary tumor in a C57BL/6 mouse. The line has since become one of the most widely employed syngeneic breast cancer models in preclinical oncology research, offering the distinct advantage of an intact immune microenvironment absent from conventional xenograft platforms.

Our Services

Alfa Cytology specializes in constructing and validating E0771 orthotopic models under stringent preclinical standards, offering tailored study designs that encompass tumor implantation, in-life monitoring, biomarker analysis, and histopathological endpoint evaluation to support your investigative compound from initial proof-of-concept through late-stage pharmacological characterization.

Workflow of E0771 Orthotopic Mouse Model Construction

The construction of an E0771 orthotopic model follows a rigorously standardized surgical and husbandry protocol to ensure high tumor take rates, reproducible growth kinetics, and minimal inter-animal variability. Each phase is executed under controlled conditions with continuous quality oversight.

1. Cell Preparation and Quality Verification: Low-passage E0771 cells are expanded in vitro, authenticated by STR profiling, and confirmed for luminal B marker expression; viability is assessed by trypan blue exclusion prior to harvest.
2. Recipient Mouse Screening: Female C57BL/6 mice aged 6–8 weeks are acclimatized, health-screened, and randomized by body weight to reduce baseline bias.
3. Surgical Site Preparation: Mice are anesthetized with isoflurane, the fourth mammary gland area is shaved and sterilized with alternating iodine and ethanol scrubs, and ophthalmic ointment is applied.
4. Orthotopic Cell Inoculation: A small skin incision is made lateral to the nipple, the mammary fat pad is gently exteriorized, and a calibrated single-cell suspension (typically 5 × 10⁴ cells in 20–50 µL PBS/Matrigel) is injected directly into the fat pad under direct visualization.
5. Wound Closure and Postoperative Care: The incision is closed with sterile sutures or wound clips, analgesia is administered, and mice are monitored on a warming pad until fully recovered.
6. Longitudinal Tumor Monitoring: Tumor dimensions are measured twice weekly with digital calipers using the formula V = 0.5 × L × W²; body weight and clinical signs are recorded concurrently.
7. Endpoint Analysis and Tissue Collection: Upon reaching predetermined tumor volume or study duration, animals are euthanized, primary tumors are excised and weighed, and metastasis-bearing organs (lungs, bones, liver) are harvested for histology, IHC, flow cytometry, or molecular analysis.

Fig 2. E0771 Orthotopic Mouse Model construction workflow.

Case Study-E0771 Orthotopic Mouse Model Development

In a preclinical efficacy study, the E0771 orthotopic model was leveraged to assess the antitumor activity of a novel therapeutic modality administered as monotherapy or in combination with an immune checkpoint inhibitor. The study tracked primary tumor burden, systemic immune profiles, and spontaneous pulmonary metastatic load, yielding quantitative data on tumor growth inhibition, survival benefit, and biomarker modulation relevant to luminal B breast cancer biology.

Why Choose Alfa Cytology?

Selecting the right CRO partner can determine the translational value of your preclinical data. Alfa Cytology combines technical surgical expertise with deep oncological insight to deliver robust, publication-ready results.

• Syngeneic Orthotopic Specialization: Proven track record in immunocompetent mammary fat pad models with consistent tumor take and predictable growth curves.
• Immuno-Oncology Integration: Capability to evaluate checkpoint inhibitors, adoptive cell therapies, and combination regimens in a fully functional immune environment.
• Comprehensive Endpoint Portfolio: From digital tumor volumetrics and bioluminescence imaging to multiplex IHC, flow cytometry, and metastasis quantification.
• Flexible Study Architectures: Customizable treatment schedules, dose-ranging designs, and genetically modified host backgrounds to match your mechanistic hypotheses.
• Regulatory-Aligned Operations: All procedures conducted under IACUC-approved protocols with full documentation, traceability, and veterinary oversight.

Contact Us

Ready to advance your breast cancer program with a physiologically relevant, immunocompetent preclinical model? reach out to Alfa Cytology today to discuss your study requirements, and our scientific team will design an E0771 orthotopic program tailored to your discovery objectives.

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