SB1 Syngeneic Model Service for Cholangiocarcinoma

The SB1 syngeneic model service for cholangiocarcinoma is an immune-competent murine platform in which YAP/Akt-driven SB1 intrahepatic cholangiocarcinoma cells are implanted into the liver of syngeneic C57BL/6 mice, recreating desmoplastic, stroma-rich intrahepatic tumors with a species-matched immune microenvironment. Alfa Cytology delivers this model as a complete preclinical capability — spanning authenticated SB1 expansion and cell banking, liver-parenchymal orthotopic implantation or flank engraftment, scheduled tumor monitoring with ultrasound or imaging confirmation, and comprehensive histopathology with immune-microenvironment profiling — all configured around each sponsor’s therapeutic hypothesis and endpoint plan.

Overview of SB1 Syngeneic Model for Cholangiocarcinoma

SB1 is one of the best-characterized murine intrahepatic cholangiocarcinoma (iCCA) lines — and one of the most deliberately engineered. It was generated at the Mayo Clinic by Ilyas and colleagues and published in 2018 as the flagship of seven sibling lines (SB1–SB7) derived from distinct tumor nodules harvested from C57BL/6 mice ten weeks after Sleeping Beauty transposon-mediated delivery of constitutively active Akt and YAP (YAP S127A, FLAG-tagged) to the biliary epithelium, combined with lobar bile-duct ligation and systemic interleukin-33 administration. The genotype is experimentally inscribed rather than incidental: both YAP1 and Akt1 integrations are verifiable in the Cellosaurus record. SB1 cells express the cholangiocyte lineage markers cytokeratin-7, cytokeratin-19, and SOX9 while lacking hepatocellular (HNF4α, HepPar1) and fibroblast (α-SMA) markers, form colonies in soft agar, and — critically for model selection — genetically resemble iCCAs found in a defined subset of patients, matching distinct mutational signatures seen in Western and Japanese CCA cohorts.

Fig 1. Comparative summary of syngeneic iCCA models: SB1 (YAPS127A/myr-Akt, TMB 6.64) shows an immunosuppressive TIME with decreased CTLs and increased G-MDSCs, and no response to ICI monotherapy, versus T-cell-infiltrated FAC and high-TMB KPPC. (Tomlinson, Jennifer L., et al., 2024)

Implanted into the liver parenchyma of immunocompetent C57BL/6 mice, SB1 cells establish orthotopic intrahepatic tumors within about four weeks that reproduce human CCA’s defining histology: malignant glandular elements embedded in a desmoplastic, stroma-rich reaction with immune infiltration. Because host and tumor are fully syngeneic, the model has become a workhorse for tumor-immune microenvironment research: comprehensive multi-omic comparisons show SB1 tumors carry a preponderance of suppressive myeloid cells and match specific immune signatures in human iCCA, making them a rational substrate for immunotherapy, combination, and microenvironment-targeting studies — from ferroptosis-induction regimens to immune-checkpoint combinations. The lineage has also been productively extended: SB1-JP4, a faster-growing derivative isolated from an in vivo immunoedited SB1 tumor, serves groups needing accelerated growth, and flank engraftment or PDX-parallel designs broaden the model’s deployment options. Practical experience with the line is instructive: the original culture was contaminated with mycoplasma and had to be cured — a caution that underscores the value of rigorous incoming quality control before any in vivo study begins.

Cell Line Information: SB1

The table below consolidates the key biological, cultural, and modeling characteristics of the SB1 line and its ecosystem of derivative and sibling lines.

Our Services

Few syngeneic platforms pack this much translational logic into one line, and Alfa Cytology runs the SB1 program accordingly: authenticated, mycoplasma-verified cell banks, standardized liver-parenchymal implantation with consistent take and desmoplastic histology, scheduled monitoring with ultrasound confirmation, and endpoint pathology paired with immune-microenvironment profiling — all under one accountable preclinical operation.

Workflow of SB1 Syngeneic Model Construction

Construction follows the published orthotopic methodology: SB1 cells are expanded under authenticated conditions, formulated in a Matrigel-supported suspension, injected into the left lateral liver lobe of anesthetized C57BL/6 mice, confirmed by ultrasound, and followed through treatment and endpoint analysis. The workflow comprises the following stages.

1. Cell authentication and banking: SB1 cells are STR/identity-verified, confirmed mycoplasma-negative (with documented cure history checked), and expanded into low-passage working banks under standardized DMEM culture conditions.
2. Cell harvest and formulation: Healthy cultures are trypsinized, washed, counted and viability-checked, then resuspended at approximately 7.5 × 10⁵ cells (or 1 × 10⁶ per standard protocol) in 30 μL of 50% DMEM/50% Matrigel kept on ice until implantation.
3. Anesthesia and liver exposure: C57BL/6 mice are anesthetized with 1.5–3% isoflurane; a 1 cm abdominal incision below the xiphoid process opens the cavity, and a sterile cotton-tipped applicator gently exposes the superomedial aspect of the left lateral liver lobe.
4. Orthotopic implantation: Using a 27-gauge needle, the cell suspension is injected into the left lateral lobe parenchyma; the applicator is held over the injection site to prevent leakage and encourage hemostasis.
5. Closure and perioperative care: The abdominal wall and skin are closed in separate layers with absorbable suture, and animals receive analgesia with close post-operative monitoring until fully recovered.
6. Tumor confirmation and randomization: Tumor presence is confirmed by small-animal ultrasound before treatment start; animals are randomly and equally assigned to vehicle or treatment arms, with dosing typically initiated 14 days after SB1 implantation (a later start than faster CCA lines such as KPPC).
7. Intervention and endpoint analysis: Experimental arms — immune checkpoint inhibitors, multikinase/VEGFR-pathway agents, ferroptosis modulators, YAP/Akt-pathway inhibitors, and combinations — proceed per study design; endpoints integrate tumor burden and size with body and liver weight, serum chemistry (ALP, ALT, albumin, BUN), ex vivo liver assessment, and histopathology (H&E with CK19, α-SMA, CD45, and Ki67 immunohistochemistry for tumor, stromal, and immune components).

Fig 2. SB1 Syngeneic Model construction workflow.

Case Study-SB1 Syngeneic Model Development

Alfa Cytology has conducted preclinical programs on the SB1 platform spanning immunotherapy combination evaluation, ferroptosis-pathway intervention, and targeted-agent testing against YAP/Akt signaling. In these studies, orthotopically implanted SB1 tumors were confirmed by ultrasound, treated per randomized arms, and characterized at endpoint by tumor-burden measurement, serum chemistry, and histopathology with immune-context immunohistochemistry. Study-level datasets are available upon request.

Why Choose Alfa Cytology?

Alfa Cytology combines syngeneic-CCA expertise with disciplined quality control and immune-aware endpoint profiling, so every SB1 study is executed with take-rate control and reporting that sponsors can act on.

• Focused experience with genetically defined, immune-competent CCA models including SB1 and derivative SB1-JP4 workflows.
• Documented mycoplasma-screening discipline reflecting the line’s published contamination-and-cure history.
• Standardized left-lobe orthotopic implantation with ultrasound confirmation and consistent desmoplastic histology.
• Endpoint panels pairing H&E and Ki67 with CK19, α-SMA, and CD45 immunohistochemistry for tumor-stroma-immune context.
• Transparent milestone reporting and rapid scientific feedback throughout the engagement.

Contact Us

If your cholangiocarcinoma program needs an immune-competent, genetically defined orthotopic platform, Alfa Cytology is ready to build the study around your mechanism. Reach out to us with your compound profile and endpoint requirements, or contact us today for a customized proposal and quotation for the SB1 syngeneic model service.

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