MDA-MB-361-luc Orthotopic Mouse Model Service for Breast Cancer

The MDA-MB-361-luc orthotopic mouse model represents a well-characterized preclinical platform for studying hormone-receptor-positive, HER2-amplified breast cancer progression within the native mammary microenvironment, enabling longitudinal tumor monitoring via bioluminescence imaging. Alfa Cytology delivers this specialized orthotopic xenograft service with integrated luciferase-based whole-body imaging, supporting mechanistic exploration of endocrine resistance, HER2-targeted therapy response, and combination regimen optimization in an in vivo setting that faithfully recapitulates the pathophysiological context of luminal B breast cancer.

Overview of MDA-MB-361-luc Orthotopic Mouse Model for Breast Cancer

The MDA-MB-361 cell line was originally isolated from a brain metastatic lesion of a 40-year-old female patient diagnosed with breast adenocarcinoma. Molecularly, this line is classified within the luminal B intrinsic subtype, co-expressing estrogen receptor alpha (ER^α) and human epidermal growth factor receptor 2 (HER2/neu), while remaining progesterone receptor (PR) negative. Genetically, MDA-MB-361 harbors an activating PIK3CA mutation (E545K), a homozygous TP53 truncating mutation (E56Ter), and a heterozygous BRAF V600E alteration, alongside homozygous CDKN2A loss—collectively rendering it a representative model for studying PI3K/AKT/mTOR pathway activation, p53 dysfunction, and cyclin-dependent kinase deregulation in the context of receptor-driven breast malignancy. The luciferase-transduced derivative (MDA-MB-361-luc) enables non-invasive, quantitative tracking of tumor burden through bioluminescence imaging, facilitating real-time assessment of primary tumor growth, spontaneous dissemination, and therapeutic response kinetics without serial sacrifice.

Fig 1. Effects of actein on the expression of proteins in various signaling pathways in MDA-MB-361 cells. (Wu, Xiao-Xiao, et al., 2020)

Orthotopic implantation of MDA-MB-361-luc cells into the murine mammary fat pad reconstructs the tumor-stromal interactions, vascular architecture, and hormone-receptor signaling dynamics that are largely absent in subcutaneous counterparts. This configuration is particularly relevant for evaluating agents targeting the ER-HER2 crosstalk axis, as the model retains dependency on exogenous estrogen supplementation for robust engraftment and proliferation—mimicking the clinical scenario of aromatase inhibitor or selective estrogen receptor modulator intervention. The moderate growth kinetics (tumors typically palpable within 12–16 days, reaching 800–1,200 mm³ in 4–6 weeks) provide a practical therapeutic window for multi-cycle dosing schedules, pharmacodynamic endpoint collection, and longitudinal biomarker analysis, making it a cornerstone platform for preclinical breast cancer drug development.

Cell Line Information: MDA-MB-361-luc

The MDA-MB-361-luc cell line is a genetically engineered derivative of the parental MDA-MB-361 human breast adenocarcinoma line, stably transduced with firefly luciferase (Photinus pyralis) and puromycin resistance markers through lentiviral transduction. The following table summarizes the essential characteristics of this cell line:

Our Services

Alfa Cytology offers end-to-end construction and characterization of the MDA-MB-361-luc orthotopic model, encompassing cell line authentication, hormone-supplementation protocol design, surgical implantation, bioluminescence imaging scheduling, and comprehensive histopathological and molecular endpoint analysis. Our team tailors each study to your compound's mechanism of action, whether you are profiling a novel HER2-directed antibody, an ER degrader, or a dual-pathway inhibitor, ensuring robust data packages that advance your preclinical pipeline with scientific rigor and regulatory foresight.

Workflow of MDA-MB-361-luc Orthotopic Mouse Model Construction

Establishment of the MDA-MB-361-luc orthotopic model follows a standardized yet adaptable protocol designed to maximize engraftment efficiency, ensure reproducible tumor growth kinetics, and enable seamless integration of bioluminescence imaging and therapeutic intervention timelines. The workflow proceeds through the following sequential stages:

1. Cell Preparation and Quality Verification: MDA-MB-361-luc cells are expanded under antibiotic selection to maintain luciferase expression, then authenticated via STR profiling and confirmed mycoplasma-negative. Cells are harvested at logarithmic growth phase, counted, and resuspended in serum-free medium mixed with Matrigel (typically 1:1 ratio) to enhance extracellular matrix deposition upon implantation.
2. Recipient Mouse Preparation and Hormone Priming: Female immunodeficient mice (athymic nude or NOD-scid strains, 4–6 weeks old) are ovariectomized or supplemented with subcutaneous estrogen pellets (0.36 mg) 24–48 hours prior to cell injection. This hormonal priming is essential to support ER-dependent proliferation and mirror the endocrine environment of luminal B breast cancer.
3. Orthotopic Mammary Fat Pad Injection: A small incision is made over the inguinal mammary fat pad, and 5 × 10⁴ to 1 × 10⁶ MDA-MB-361-luc cells (in 25–50 µL total volume) are carefully injected into the fat pad using a Hamilton syringe. The incision is closed with surgical staples or sutures, and mice are monitored for postoperative recovery.
4. Baseline Bioluminescence Imaging and Cohort Randomization: At 7–10 days post-implantation, mice receive an intraperitoneal injection of D-luciferin substrate (150 mg/kg) and are imaged under isoflurane anesthesia using an IVIS spectrum system. Tumor-bearing mice are stratified by photon flux intensity into homogeneous treatment cohorts, ensuring balanced baseline tumor burdens across all experimental arms.
5. Therapeutic Dosing and Longitudinal Monitoring: Test compounds are administered according to the predefined regimen (route, frequency, and duration), while bioluminescence imaging is performed at regular intervals (typically weekly) to quantify tumor growth dynamics and early response patterns. Body weight and general health status are recorded concurrently to assess treatment tolerability.
6. Endpoint Collection and Ex Vivo Analysis: Upon reaching predetermined ethical endpoints (tumor volume ~1,000–1,500 mm³ or study completion), mice are euthanized. Primary tumors and relevant organs are excised, weighed, photographed, and processed for histopathology (H&E, IHC for ER, HER2, Ki-67, phospho-AKT), molecular profiling (Western blot, qPCR), and ex vivo bioluminescence confirmation of metastatic dissemination.
7. Data Compilation and Reporting: All imaging data, tumor growth curves, body weight trajectories, and histopathological scores are compiled into a comprehensive study report with statistical analysis. Pharmacodynamic biomarker data are correlated with antitumor efficacy to generate mechanism-of-action insights for your preclinical candidate.

Fig 2. MDA-MB-361-luc Orthotopic Mouse Model construction workflow.

Case Study-MDA-MB-361-luc Orthotopic Mouse Model Development

In a representative preclinical engagement, the MDA-MB-361-luc orthotopic model was employed to evaluate the efficacy of a dual-targeting strategy combining a HER2-directed monoclonal antibody with a selective PI3K_α inhibitor in ER+/HER2+ luminal B breast cancer. Following orthotopic engraftment and baseline imaging stratification, treatment cohorts received either vehicle, monotherapy, or combination regimens over a multi-cycle dosing period. Longitudinal bioluminescence imaging revealed distinct growth inhibition profiles across arms, with the combination group demonstrating substantially reduced photon flux accumulation compared to either single agent. At study endpoint, excised tumors from the combination cohort exhibited diminished Ki-67 proliferation indices, attenuated phospho-AKT staining, and preserved ER expression—suggesting pathway blockade without receptor phenotype switching. These findings illustrate the model's utility in dissecting drug synergy, identifying resistance biomarkers, and informing dose-schedule optimization prior to downstream development stages.

Why Choose Alfa Cytology?

Partnering with Alfa Cytology for your MDA-MB-361-luc orthotopic breast cancer study means accessing a scientifically driven CRO platform built around reproducibility, transparency, and mechanistic depth. Our distinguishing capabilities include:

• Integrated luciferase imaging infrastructure enabling quantitative, non-invasive tumor tracking throughout the entire study duration without compromising animal welfare.
• Customizable hormone-supplementation protocols (estrogen pellets, aromatase inhibitor co-administration) tailored to mimic specific endocrine treatment contexts relevant to your therapeutic hypothesis.
• In-house histopathology and immunohistochemistry services with validated antibody panels for ER, HER2, Ki-67, phospho-AKT, phospho-ERK, and downstream mTOR pathway markers.
• Flexible study designs accommodating single-agent, combination, and sequential treatment arms with appropriate statistical powering and randomization strategies.
• Rapid project initiation with established cell banking, authenticated MDA-MB-361-luc stocks, and streamlined IACUC-approved protocols to compress your timeline from contract to first dosing.
• Dedicated project scientists providing weekly progress updates, raw data access, and collaborative interpretation of pharmacodynamic and efficacy endpoints to inform your next-stage decisions.

Contact us

Whether you are initiating a first-in vivo efficacy screen or designing a complex combination therapy study, we invite you to reach out to us to discuss how Alfa Cytology's MDA-MB-361-luc orthotopic mouse model service can accelerate your preclinical breast cancer research program. Our scientific team is ready to review your protocol requirements, propose optimized study parameters, and provide a detailed quotation aligned with your discovery milestones. Contact us today to transform your compound hypothesis into actionable preclinical data.

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