SL4 Metastatic Tumor Model Service for Colon Cancer

The SL4 metastatic tumor model tracks the spread of colon cancer to the liver — the most life-threatening route of dissemination in the disease — using a murine cell line engrafted in immunocompetent C57BL/6 hosts. From intrasplenic and intracecal inoculation to longitudinal bioluminescent monitoring and metastasis-scored endpoints, Alfa Cytology delivers this model as a complete preclinical package, with authenticated cells, standardized surgical technique, and IACUC-approved study execution throughout.

Overview of SL4 Metastatic Tumor Model for Colon Cancer

SL4 is a murine colon adenocarcinoma line with an unusually specific pedigree: it was selected in vivo from the parental Colon 38 (MC-38) line, which itself arose from a colon tumor chemically induced in a C57BL/6 mouse. Through four successive passages of tumor cells in the spleens of syngeneic C57BL/6J mice, Morimoto-Tomita and colleagues isolated SL4 as a variant that colonizes the liver with 100% efficiency after intrasplenic injection — compared with only 27% for the parental line — while also showing a markedly higher metastatic incidence after intracecal implantation. Because host and tumor are fully matched genetically, the model runs in immunocompetent animals: the metastatic process unfolds in the presence of an intact immune system, a property that human xenograft metastasis models simply cannot offer. The cells also display accelerated adherent growth (a doubling time of approximately 16 hours) and, unlike the parent, the ability to proliferate under anchorage-independent conditions — traits linked to their high metastatic competence.

Fig 1. NK cell infiltration and plasticity in the SL4 liver metastasis model: NKp46 immunofluorescence with quantified distance from CD31+ vessels, competitive adoptive transfer of labeled WT versus Cxcr3−/− NK cells into healthy and metastasis-bearing mice, demonstrating CXCR3-dependent NK recruitment to SL4 metastatic lesions. (Russo, Eleonora, et al., 2025)

In practice, the SL4 model supports two complementary experimental formats. The intrasplenic route delivers a defined number of cells (typically 1 × 10⁶) into the spleen, from which they drain via the splenic and portal veins to seed multiple foci throughout the liver within two to three weeks; splenectomy immediately after injection prevents confounding splenic outgrowth. The orthotopic cecal-serosa route instead implants tumor beneath the cecal wall, reproducing primary colonic growth with subsequent regional and hepatic spread, and is the design of choice when the full metastatic cascade — escape from the primary site through organ colonization — must be captured. Luciferase-tagged derivatives (SL4-Luc) allow metastatic burden to be quantified repeatedly by in vivo bioluminescence, and because the host is immunocompetent, the model readily accommodates immunotherapy arms such as checkpoint blockade, macrophage reprogramming strategies, and anti-angiogenic agents in a metastatic context.

Cell Line Information: SL4

SL4 (Cellosaurus CVCL_D7FA) was established in 2005 at the University of Tokyo by repeated in vivo selection of the Colon 38 murine colon carcinoma for hepatic metastasis. The parental Colon 38 lineage originates from a 1,2-dimethylhydrazine (DMH)-induced colon tumor in a C57BL/6 mouse and carries a KRAS mutation (G13D) together with a hypermutated, microsatellite-instability-high genome — a background that makes SL4-derived tumors inherently immunogenic and responsive to immune modulation. Under standard culture in DMEM/F-12 with 10% FBS, the cells grow as an adherent epithelial-like monolayer and can also be adapted to suspension/anchorage-independent growth, mirroring the property that underlies their metastatic advantage. Principal characteristics are summarized below.

Our Services

Few models combine reliable hepatic metastasis with an intact immune system, and that combination is precisely where SL4 stands apart. Alfa Cytology offers the SL4 model with both dissemination routes in active use — intrasplenic-portal for controlled, quantitative liver seeding and cecal orthotopic for a complete primary-to-metastatic course — plus luciferase-enabled tracking and immunologically rich endpoint analysis, all confined strictly to preclinical research.

Workflow of SL4 Metastatic Tumor Model Construction

An SL4 metastatic study is part surgical procedure, part imaging program: success depends on clean intrasplenic or cecal delivery, disciplined bioluminescent scheduling, and a necropsy that accounts for every lesion. The sequence below reflects the standard operating flow, adjusted in each project to the chosen route, readout, and treatment plan.

1. Cell banking and pre-study validation: SL4 cells are expanded from authenticated, mycoplasma-free stocks; for imaging studies, the luciferase-expressing derivative is confirmed for stable signal output in vitro so that photon flux measured later reflects true tumor burden.
2. Inoculum preparation: Logarithmic-phase cells are harvested by gentle detachment, passed through a strainer to remove clumps that could obstruct splenic vessels, counted, and adjusted — commonly to 1 × 10⁶ cells in 50–100 µL of serum-free medium.
3. C57BL/6 host preparation: Immunocompetent C57BL/6 mice (typically 6–10 weeks old) are acclimatized and randomized; analgesia is administered before any surgical procedure, and animals are monitored through anesthesia recovery per IACUC protocols.
4. Route-specific surgical inoculation: For the liver model, cells are injected slowly into the splenic pulp (visible pallor/distension confirms delivery), pressure is held on the puncture site, and the spleen is removed; for the orthotopic model, cells are injected beneath the cecal serosa and the bowel is returned to the abdomen before closure.
5. Metastatic outgrowth and bioluminescence monitoring: Tumor signal is acquired on a defined imaging schedule — for example days 3, 7, 10, and 14 — building individual metastatic growth curves; animals are randomized to treatment arms at matched burden to avoid baseline bias.
6. Treatment administration and tolerability monitoring: Test agents (chemotherapy, kinase inhibitors, anti-angiogenics, checkpoint antibodies, or combinations) are dosed on schedule while body weight and clinical status are recorded daily as indicators of treatment tolerability and disease progression.
7. Necropsy and metastasis quantification: At endpoint, the peritoneal cavity is inspected, and liver, spleen, mesenteric lymph nodes, and lungs are examined; liver weight, visible nodule counts, and metastatic incidence are scored systematically as the primary structural readouts.
8. Histopathology, immune analysis, and reporting: Livers are fixed and sectioned for H&E confirmation of metastatic foci, with optional IHC and immune-cell profiling (flow cytometry, macrophage markers) of metastatic tissue; imaging kinetics, lesion counts, and pathology are analyzed and compiled into the final study report.

Fig 2. SL4 Metastatic Tumor Model construction workflow.

Case Study-SL4 Metastatic Tumor Model Development

Alfa Cytology has developed and applied SL4 metastatic models in preclinical colon cancer research, spanning both the intrasplenic liver-seeding design and the cecal orthotopic format for sponsors studying hepatic dissemination. These programs have produced consistent metastatic take, imaging-derived burden kinetics suitable for arm-to-arm comparison, and histologically verified lesion data that supported candidate prioritization decisions. Further details on study configurations and representative outcomes can be made available through direct scientific discussion.

Why Choose Alfa Cytology?

The value of an SL4 study lies in the details: a technically clean splenic injection, a disciplined imaging calendar, and honest metastasis accounting. Alfa Cytology executes each of these elements under standardized SOPs, giving you a metastatic readout that is reproducible, quantitative, and — because the host is immunocompetent — directly relevant to immunotherapy questions.

• Immunocompetent C57BL/6 hosts preserve full immune-tumor interaction during metastatic colonization.
• 100% hepatic take rate after intrasplenic injection, documented from the line’s original derivation.
• Two route options — intrasplenic-portal and cecal orthotopic — matched to either quantitative seeding or full-cascade modeling.
• Luciferase-tagged SL4 derivatives with validated in vivo imaging for longitudinal, animal-sparing burden measurement.
• Standardized splenectomy and hemostasis technique that minimizes procedural loss and peritoneal spillover.
• Endpoint panels combining liver weight, nodule counts, H&E histology, and immune-cell profiling in metastatic tissue.
• IACUC-compliant, preclinical-only execution with full traceability from cell bank to final report.

Contact Us

If your colon cancer program needs a metastatic readout that retains the full complexity of the immune system, the SL4 model in Alfa Cytology’s hands is a strong place to start. Reach out to us to scope the route, imaging plan, and endpoint package that fit your compound and timeline. Contact us today to begin designing your preclinical metastasis study.

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