SW620 Orthotopic Mouse Model Service for Colon Cancer

The SW620 orthotopic mouse model provides a lymph node-derived, KRAS-mutant human colorectal adenocarcinoma platform that captures the metastatic phenotype and aggressive invasive behavior of advanced-stage disease within a physiologically faithful colonic microenvironment. Alfa Cytology constructs and manages this orthotopic xenograft system with authenticated SW620 cell stocks, standardized cecal wall or rectal submucosal implantation protocols, and comprehensive molecular and histopathological endpoint analysis, delivering translationally relevant datasets for metastatic colorectal malignancies under in vivo conditions.

Overview of SW620 Orthotopic Mouse Model for Colon Cancer

The SW620 cell line is a human colorectal adenocarcinoma originally established from a metastatic lymph node of the same tumor from which the SW480 cell line was derived, representing a paired primary-to-metastasis model system. The donor was a 51-year-old Caucasian male whose malignancy recurred with widespread metastasis from the colon to an abdominal mass. Genetically, SW620 harbors a homozygous KRAS activating mutation (G12V, p.Gly12Val) that drives constitutive MAPK/ERK signaling, alongside a homozygous truncating mutation in APC (p.Gln1338Ter, c.4012C>T) that abolishes canonical Wnt/^β-catenin regulation. The line also carries heterozygous TP53 missense mutations (R273H and P309S) that impair DNA damage responses and apoptotic signaling. Morphologically, SW620 consists predominantly of individual small spherical and bipolar cells lacking microvilli, synthesizing only small quantities of carcinoembryonic antigen (CEA), and testing negative for CSAp (colon-specific antigen-p) and colon antigen 3. The line is positive for keratin by immunoperoxidase staining and expresses multiple oncogenes including c-myc, K-ras, H-ras, N-ras, Myb, sis, and fos, while N-myc expression is not detected.

Fig 1. Longitudinal bioluminescence imaging of an SW620-Luc orthotopic colorectal cancer model established by intracecal implantation, enabling non-invasive monitoring of primary tumor growth and therapeutic response. (Blanco-Domínguez, Rafael, et al., 2025)

Orthotopic implantation of SW620 cells into the cecal wall or rectal submucosa of immunodeficient mice (athymic nude or NOD-scid strains) reconstructs the anatomical positioning, stromal architecture, and invasive behavior of clinical metastatic colorectal cancer. Tumors establish reliably with high take rates and typically become palpable within 10–14 days post-implantation, progressing to endpoint volumes over 4–6 weeks. The model supports progressive infiltration through the mucosal layers, dissemination to mesenteric lymph nodes, and eventual formation of distant metastases—mimicking the natural TNM staging trajectory of human disease. SW620 has been extensively employed to evaluate oncolytic virotherapy platforms, Rho GTPase signaling inhibitors, and multidrug resistance mechanisms, with well-characterized resistant sublines including SW620/L-OHP (oxaliplatin-resistant) and SW620-FX-R (FOLFOXIRI-resistant). The combination of metastatic origin, defined mutational landscape, documented invasive capacity, and resistance profiling renders this model indispensable for preclinical development in advanced and refractory colorectal malignancies.

Cell Line Information: SW620

SW620 is a lymph node-derived human colorectal adenocarcinoma cell line distinguished by its paired relationship with SW480 (primary tumor from the same patient), defined KRAS G12V mutational status, and well-documented drug resistance potential. The table below consolidates its essential biological, genetic, and culture parameters:

Our Services

Alfa Cytology delivers a comprehensive SW620 orthotopic model service encompassing authenticated cell line banking, surgical cecal wall or rectal submucosal implantation in immunodeficient hosts, longitudinal tumor monitoring, therapeutic intervention, resistance profiling, and multi-parameter endpoint analysis. Our platform is optimized for metastatic colorectal cancer studies, leveraging the line's lymph node-derived origin, defined KRAS G12V mutational landscape, and well-characterized resistant sublines to generate mechanistically rich datasets that inform your drug development strategy for advanced and refractory disease.

Workflow of SW620 Orthotopic Mouse Model Construction

Establishment of the SW620 orthotopic model requires meticulous surgical technique, authenticated human cell line stocks, and immunodeficient host management to achieve consistent engraftment and physiologically relevant invasive tumor growth. The protocol proceeds through the following sequential stages:

1. Cell Expansion and Authentication: SW620 cells are propagated in Leibovitz's L-15 medium with 10% FBS, harvested during logarithmic growth, and authenticated via STR profiling against the human reference. Mycoplasma negativity is confirmed by PCR. Cells are washed, counted by automated hemocytometer, and resuspended in ice-cold PBS at a concentration of 1 × 10⁷ cells/mL for in vitro preparation.
2. Recipient Mouse Preparation: Female athymic nude (BALB/c nu/nu) or NOD-scid mice (6–8 weeks old) are quarantined and acclimated for a minimum of 72 hours. Health status is assessed daily, and any mice displaying abnormal behavior or weight loss are excluded prior to cell implantation.
3. Matrigel Suspension Preparation: The cell suspension is mixed 1:1 by volume with ice-cold Matrigel Basement Membrane Matrix immediately prior to injection. Matrigel provides an extracellular scaffold that supports initial tumor colonization within the cecal wall, enhances engraftment consistency, and facilitates invasive growth through the mucosal layers.
4. Surgical Cecal Wall or Rectal Submucosal Implantation: Under general anesthesia, either a midline laparotomy is performed to expose the cecum for submucosal injection (5 × 10⁵ to 1 × 10⁶ cells in 50–100 µL Matrigel-PBS suspension via 27-gauge needle), or cells are delivered transanally into the rectal submucosa under endoscopic guidance. The cecum is repositioned and the abdominal wall closed in two layers, or the transanal procedure is completed without external incision.
5. Postoperative Care and Monitoring: Mice receive sustained-release buprenorphine for analgesia and are monitored closely during the 48-hour perioperative period for signs of pain, dehydration, or intestinal obstruction. Body weights are recorded daily for the first week and twice weekly thereafter.
6. Tumor Monitoring and Cohort Randomization: Tumor establishment is assessed by palpation of the abdominal cavity beginning on day 7–10 post-surgery. Once tumors reach 50–100 mm³, mice are randomized into treatment cohorts based on tumor volume to ensure balanced baseline distributions across all experimental arms.
7. Therapeutic Intervention and Longitudinal Assessment: Test compounds are administered according to the predefined regimen (dose, route, frequency, and duration). Tumor dimensions are measured twice weekly with digital calipers, and body weights are recorded concurrently to monitor treatment tolerability. Optional high-frequency ultrasound imaging can be incorporated for non-invasive volumetric assessment and invasive depth evaluation.
8. Endpoint Necropsy and Multi-Organ Analysis: Upon reaching study endpoints (tumor volume ~2,000 mm³, humane moribund criteria, or scheduled termination), mice are euthanized. The primary cecal or rectal tumor is excised, weighed, and photographed. Mesenteric lymph nodes, liver, lungs, and spleen are harvested for metastasis assessment. Tumor tissues are fixed for H&E and immunohistochemistry (CD31, Ki-67, cleaved caspase-3, phospho-ERK, E-cadherin, vimentin), or snap-frozen for Western blot, qPCR, and RNA-seq.

Fig 2. SW620 orthotopic mouse model construction workflow.

Case Study-SW620 Orthotopic Mouse Model Development

In a preclinical program investigating metastatic dissemination mechanisms in KRAS-mutant colorectal cancer, the SW620 orthotopic model was employed to evaluate the efficacy of a novel Rho GTPase inhibitor administered as monotherapy and in combination with standard-of-care oxaliplatin. Following surgical cecal wall implantation and postoperative recovery, tumor-bearing mice were randomized into treatment arms receiving the Rho inhibitor alone, oxaliplatin alone, the combination regimen, or vehicle control. Longitudinal tumor monitoring revealed that oxaliplatin monotherapy produced initial growth inhibition followed by progressive tumor rebound, consistent with the documented emergence of drug-tolerant persister cells in SW620 tumors. In contrast, the combination cohort exhibited sustained and significantly greater tumor growth suppression throughout the study duration, with reduced invasive depth into the muscularis propria as assessed by high-frequency ultrasound. Endpoint histopathological analysis demonstrated diminished E-cadherin downregulation and vimentin expression in the combination-treated tumors, indicating attenuated epithelial-to-mesenchymal transition (EMT), alongside reduced Ki-67 proliferation indices and enhanced cleaved caspase-3 staining. Mesenteric lymph node harvest revealed fewer metastatic nodules in the combination group compared to vehicle controls. These findings illustrate the model's capacity to capture both primary tumor response and metastatic dissemination patterns, providing actionable insights for optimizing combination strategies that target invasive signaling in advanced KRAS-mutant colorectal malignancies.

Why Choose Alfa Cytology?

Engaging Alfa Cytology for your SW620 orthotopic colon cancer study provides access to a specialized platform with deep expertise in metastatic human xenograft model construction and invasive behavior assessment. Our distinguishing capabilities include:

• Authenticated SW620 cell banking with documented STR profiling, mycoplasma clearance, and low-passage expansion to preserve KRAS G12V mutation fidelity, APC truncating status, and invasive phenotype across study cohorts.
• Skilled surgical team experienced in both cecal wall and rectal submucosal orthotopic implantation with high take rates and low perioperative mortality, ensuring robust statistical power for metastatic endpoint analysis.
• Integrated invasive behavior assessment capabilities encompassing EMT marker profiling (E-cadherin, vimentin, N-cadherin), invasive depth quantification by high-frequency ultrasound, and lymph node metastasis enumeration.
• Drug resistance profiling infrastructure featuring validated oxaliplatin-resistant (SW620/L-OHP) and FOLFOXIRI-resistant (SW620-FX-R) subline characterization, efflux functional assays, and comparative pharmacodynamic analysis.
• Flexible combination study designs supporting Rho GTPase inhibitors, oncolytic virotherapies, oxaliplatin, 5-FU, irinotecan, and targeted agents with customized dosing schedules, sequential treatment arms, and resistance monitoring endpoints.
• Dedicated project scientists providing weekly tumor monitoring updates, interim invasive depth assessments, and collaborative interpretation of metastatic and resistance trends to align preclinical findings with your clinical development roadmap for advanced colorectal cancer.

Contact Us

If your preclinical pipeline demands a lymph node-derived, metastatic colorectal cancer model that faithfully recapitulates the in vivo invasive behavior and drug resistance patterns of advanced KRAS-mutant disease, we invite you to reach out to us to discuss how Alfa Cytology can design and execute a tailored SW620 orthotopic study aligned with your therapeutic hypotheses. From surgical implantation and longitudinal monitoring through metastasis assessment and resistance mechanism profiling, our team is committed to delivering translationally relevant data that advance your colorectal cancer drug development program. Contact us today to initiate your project and leverage our specialized expertise in metastatic colorectal cancer preclinical research.

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