MC38 Syngeneic Model

MC38 Syngeneic Model Overview

The MC38 syngeneic model is one of the most extensively characterized murine models of colorectal carcinoma, derived from a chemically induced colon adenocarcinoma in C57BL/6 mice. It has become a cornerstone of preclinical immuno-oncology research due to its reproducible growth, moderate immunogenicity, and responsiveness to checkpoint blockade. Unlike its BALB/c counterpart CT26.WT, the MC38 model grows in a C57BL/6 genetic background, allowing for studies that utilize the broad range of genetically engineered and immune-deficient derivatives of this strain.

When implanted subcutaneously or orthotopically, MC38 tumors exhibit consistent growth kinetics, robust vascularization, and active immune infiltration. The model is highly relevant for studying mechanisms of immune regulation, tumor escape, and therapeutic synergy among checkpoint inhibitors, cytokine modulators, and cellular therapies. Because of its well-defined mutational profile and sensitivity to PD-1 and CTLA-4 inhibition, MC38 remains one of the most widely used systems for evaluating novel immunotherapies targeting colorectal carcinoma in an immunocompetent environment.

Request a Custom Quote for MC38 Syngeneic Model

Biological and Molecular Characteristics

The MC38 cell line originates from a C57BL/6 mouse treated with the carcinogen dimethylhydrazine (DMH), which induces mutations leading to spontaneous colon adenocarcinoma formation. The tumors display poorly differentiated epithelial morphology and a high mutational burden, producing a large number of immunogenic neoantigens that elicit strong T-cell responses. MC38 tumors lack hormone receptor expression and exhibit molecular characteristics consistent with microsatellite instability (MSI-high) and mismatch repair deficiency, features that make them analogous to a subset of human colorectal cancers responsive to immunotherapy.

The cytokine profile of MC38 tumors includes elevated IL-6, IFN-γ, and TNF-α, reflecting an active inflammatory environment. The tumors also express VEGF and CXCL10, promoting angiogenesis and immune cell infiltration. The immune microenvironment is characterized by abundant CD8⁺ T cells, macrophages, and dendritic cells, as well as variable populations of regulatory T cells and myeloid-derived suppressor cells (MDSCs). This immune complexity enables precise evaluation of both immune activation and suppression under therapeutic modulation.

ParameterDescription
Host strainC57BL/6 (female, 6–8 weeks)
Tumor originChemically induced colon adenocarcinoma (mouse)
Histological typePoorly differentiated adenocarcinoma
Inoculation routeSubcutaneous or orthotopic
Tumor take rate>95%
Doubling timeApproximately 3–4 days in vivo
Metastatic potentialLow; liver or lung metastases under specific conditions
ImmunophenotypeImmunogenic; CD8⁺ T-cell and macrophage-rich environment
Common applicationsCheckpoint blockade, combination immunotherapy, cytokine research

In Vivo Model Development and Tumorigenicity

The MC38 syngeneic model is established through subcutaneous or orthotopic implantation of tumor cells into immunocompetent C57BL/6 mice. Tumor nodules typically become palpable within one week after inoculation, showing reproducible growth kinetics and predictable morphology. Orthotopic implantation into the colon or cecum produces localized tumor formation and occasional metastasis to regional lymph nodes or the liver, providing a physiologically relevant model of colorectal tumor progression.

MC38 tumors grow at a moderate rate, allowing for longitudinal evaluation of immune infiltration, therapeutic response, and cytokine modulation. The model’s responsiveness to immune checkpoint inhibitors, particularly anti–PD-1 and anti–CTLA-4 antibodies, enables quantifiable assessment of immune activation and tumor regression. Its use in the C57BL/6 background further allows integration with a wide range of genetically modified mouse strains, making it ideal for mechanistic studies that explore gene-specific contributions to immune regulation, antigen presentation, and therapeutic resistance.

Request a Custom Quote for MC38 Syngeneic Model

Histopathology and Immunohistochemical Profile

Histologically, MC38 tumors consist of poorly differentiated epithelial cells with high nuclear-to-cytoplasmic ratios, prominent nucleoli, and frequent mitotic figures. The tumor parenchyma is supported by fibrous stroma and infiltrated by dense populations of immune cells. Angiogenesis is pronounced, with irregular vascular structures and focal areas of necrosis typical of rapidly expanding carcinomas.

Immunohistochemical characterization demonstrates high Ki-67 expression, reflecting strong proliferative activity. CD3 and CD8 staining reveal extensive T-cell infiltration throughout the tumor and perivascular spaces, while F4/80 and CD11b staining confirm macrophage and myeloid cell presence. PD-L1 is frequently expressed on tumor cells and infiltrating immune populations, with expression levels increasing following exposure to interferon signaling. The overall immunohistochemical profile supports the classification of MC38 as an immunogenic colorectal tumor model, suitable for studying immune-mediated tumor regression and checkpoint inhibitor responsiveness.

Preclinical Applications and Drug Response

The MC38 syngeneic model is one of the most widely utilized systems for evaluating the efficacy of immune checkpoint inhibitors and combination immunotherapies. It has demonstrated reproducible sensitivity to PD-1 and CTLA-4 blockade, producing significant tumor regression and durable immune memory in responsive animals. This has made MC38 the reference model for mechanistic studies of checkpoint inhibitor function, T-cell exhaustion, and adaptive resistance.

The model has also been applied to assess cytokine-based therapies, cancer vaccines, oncolytic viral treatments, and adoptive cell therapies, each showing measurable immune activation and modulation of tumor microenvironmental composition. Combination regimens, such as checkpoint blockade with chemotherapeutic agents or radiation, further enhance tumor control and T-cell recruitment. Because of its immunogenic nature and compatibility with genetically modified hosts, MC38 serves as a key platform for the discovery and optimization of immunotherapeutic agents targeting colorectal and gastrointestinal malignancies.

Request This Model

To request the MC38 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 MC38 Syngeneic Model