MOSEC Syngeneic Model Overview
The MOSEC syngeneic model is a murine ovarian carcinoma system derived from C57BL/6 mice and is one of the earliest and most frequently utilized immunocompetent models for epithelial ovarian cancer research. Originating from spontaneously transformed mouse ovarian surface epithelial cells, MOSEC tumors closely resemble high-grade serous ovarian carcinoma in morphology, immunogenicity, and disease progression.
When implanted intraperitoneally or subcutaneously, MOSEC cells produce solid and disseminated ovarian tumors with consistent kinetics and reproducible ascites formation. The model accurately reproduces key pathological features of human ovarian carcinoma, including peritoneal dissemination, omental colonization, and immune suppression, making it an indispensable system for studying tumor biology, metastasis, and therapeutic response.
Request a Custom Quote for MOSEC Syngeneic ModelBiological and Molecular Characteristics
The MOSEC cell line was established from untransformed ovarian surface epithelial cells isolated from C57BL/6 mice, which underwent spontaneous neoplastic transformation during extended in vitro culture. The resulting tumor cells exhibit epithelial morphology and express ovarian carcinoma markers, including cytokeratin, E-cadherin, and Wilms’ tumor protein (WT1).
Molecular analyses reveal constitutive activation of oncogenic signaling pathways such as PI3K-AKT, STAT3, and MAPK, supporting tumor proliferation and survival. The tumor microenvironment is immunosuppressive, characterized by abundant macrophages, myeloid-derived suppressor cells (MDSCs), and regulatory T cells (Tregs), along with elevated levels of IL-10 and TGF-beta. These immune-modulatory features mirror those observed in advanced human ovarian carcinoma and make MOSEC a valuable platform for immunotherapy, cytokine modulation, and combination therapy research.
| Parameter | Description |
|---|---|
| Host strain | C57BL/6 (female, 6–8 weeks) |
| Tumor origin | Spontaneously transformed ovarian surface epithelial cells (mouse) |
| Histological type | Epithelial ovarian carcinoma |
| Inoculation route | Intraperitoneal or subcutaneous |
| Tumor take rate | >90% |
| Doubling time | Approximately 5–7 days in vivo |
| Metastatic potential | High; peritoneal dissemination and ascites formation |
| Immunophenotype | Cytokeratin⁺, E-cadherin⁺, WT1⁺, PD-L1⁺ |
| Common applications | Immunotherapy, ovarian cancer biology, cytokine studies, peritoneal metastasis modeling |
In Vivo Model Development and Tumorigenicity
MOSEC tumors are most commonly established by intraperitoneal injection of viable tumor cells into immunocompetent C57BL/6 mice, leading to peritoneal carcinomatosis and ascites accumulation over a period of several weeks. Subcutaneous implantation produces solid, measurable tumors that facilitate real-time evaluation of drug efficacy. Intraperitoneal models, however, better replicate the clinical behavior of human ovarian cancer, including widespread peritoneal dissemination and organ infiltration.
Tumors progress gradually, typically accompanied by ascitic fluid containing tumor cells, macrophages, and lymphocytes. Because of its immunocompetent background, the MOSEC model is suitable for testing immune checkpoint blockade, cytokine therapy, oncolytic virotherapy, and adoptive T-cell therapies. It is also used in studies evaluating combination regimens that target both tumor growth and the immunosuppressive tumor microenvironment.
Request a Custom Quote for MOSEC Syngeneic ModelHistopathology and Immunohistochemical Profile
Histopathological examination of MOSEC tumors reveals glandular and papillary structures composed of epithelial tumor cells with pleomorphic nuclei, prominent nucleoli, and high mitotic indices. In intraperitoneal models, tumor nodules spread across the mesentery, diaphragm, and omentum, accompanied by significant inflammatory infiltration and fibrosis. The presence of malignant ascites containing tumor aggregates and immune cells closely parallels human ovarian cancer pathology.
Immunohistochemical staining confirms strong cytokeratin and E-cadherin expression, consistent with epithelial differentiation, and positive WT1 staining, validating ovarian origin. Ki-67 staining demonstrates high proliferative activity, while CD31 highlights extensive neovascularization. PD-L1 is moderately expressed and upregulated in response to interferon signaling or immunotherapy. Immune profiling reveals abundant macrophages (F4/80-positive), MDSCs (Gr-1-positive), and scattered T cells (CD3- and CD8-positive), reflecting an immunosuppressive yet therapeutically targetable microenvironment.
Preclinical Applications and Drug Response
The MOSEC syngeneic model is a cornerstone in preclinical ovarian cancer research. It has been widely used to evaluate immune checkpoint inhibitors, cytokine therapies, and adoptive cell transfer, as well as to study the effects of chemotherapy and radiotherapy in immunocompetent hosts. The model demonstrates measurable responsiveness to PD-1 and CTLA-4 blockade, particularly when combined with immune adjuvants or oncolytic viral therapy.
Due to its capacity to form peritoneal metastases and ascites, MOSEC is frequently employed in studies assessing the interaction between tumor cells and immune effector mechanisms in the peritoneal cavity. It has also been used to test nanoparticle-based drug delivery systems and gene therapies targeting ovarian carcinoma. The model’s immunological relevance, biological consistency, and close resemblance to human disease make it a leading preclinical system for translational ovarian cancer research.
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To request the MOSEC syngeneic model for your preclinical studies, please use the form below. A customized quote and additional model specifications will be provided upon inquiry.
Request a Custom Quote for MOSEC Syngeneic Model