SW620-luc Orthotopic Mouse Model Service for Colon Cancer

The SW620-luc orthotopic mouse model pairs the KRAS^G12V-driven, metastatic lymph node-derived molecular profile of human colorectal adenocarcinoma with constitutive firefly luciferase expression, enabling sensitive, longitudinal optical tracking of tumor engraftment, local invasion, and therapeutic response within the physiologic cecal wall architecture. Alfa Cytology engineers this advanced bioluminescent xenograft system with authenticated isogenic cell bank stewardship, precision cecal wall surgical implantation, and calibrated IVIS imaging protocols, delivering quantitative tumor kinetics data and comprehensive metastatic endpoint analysis to accelerate your KRAS-directed and EMT-focused colon cancer drug discovery program.

Overview of SW620-luc Orthotopic Mouse Model for Colon Cancer

The SW620-luc cell line is a genetically engineered derivative of the parental SW620 human colorectal adenocarcinoma line, stably transduced with a constitutive firefly luciferase reporter construct to enable quantitative, substrate-dependent bioluminescent signal detection. The parental SW620 line was originally established in 1973 by Albert Leibovitz from a lymph node metastasis in a 51-year-old male patient who had previously provided the SW480 primary tumor line (Dukes type B, age 50), making SW620 and SW480 one of the most extensively characterized isogenic pairs in cancer biology. Genetically, SW620 is defined by a homozygous KRAS^G12V activating mutation that drives constitutive MAPK signaling, a homozygous TP53^R273H DNA contact domain mutation that abolishes p53 tumor suppressor function, a homozygous APC^Q1338X nonsense mutation that unleashes canonical Wnt/β-catenin pathway hyperactivity, and a heterozygous PIK3CA^E542K activating mutation that converges with KRAS to hyperactivate the PI3K/AKT axis. The line is microsatellite stable (MSS), classified within the consensus molecular subtype 4 (CMS4), and exhibits a mesenchymal, EMT-prone phenotype with enhanced resistance to TNF-α- and Fas-mediated apoptosis—molecular and phenotypic traits that faithfully mirror advanced metastatic colorectal cancer.

Fig 1. SW620-Luc orthotopic colorectal cancer xenografts established by cecal implantation, demonstrating the influence of stromal fibroblasts on metastatic dissemination and lung tumor burden. (Cattin, Sarah, et al., 2018)

When established as an orthotopic xenograft within the cecal wall of immunodeficient mice, SW620-luc recapitulates the serosal invasion and mesenteric lymphatic spread patterns characteristic of lymph node-metastasized human colorectal carcinoma. The bioluminescence reporter enables detection of tumor signal as early as 3–5 days post-implantation, with exponential growth typically observed over 2–3 weeks. Unlike subcutaneous models that grow in an ectopic stromal context, the orthotopic SW620-luc system preserves physiologic drug distribution, tumor-stromal crosstalk, and portal venous metastatic tropism. The optical tracking capability distinguishes true tumor regression from pseudoresponse, identifies occult metastatic seeding to the liver, and enables cohort randomization based on objective photon flux thresholds. Combined with the isogenic SW480 pairing potential, EMT-prone phenotype, and KRAS/Wnt/PI3K pathway dysregulation, this model offers a robust preclinical framework for evaluating KRAS^G12V-directed therapeutics, Wnt pathway modulators, EMT inhibitors, oncolytic virotherapies, and combination regimens in a metastatic disease context.

Cell Line Information: SW620-luc

SW620-luc is a luciferase-reporter derivative of the human colorectal adenocarcinoma SW620 cell line, engineered for constitutive firefly luciferase expression and validated for quantitative bioluminescence imaging applications. The following table summarizes its biological origin, genetic architecture, reporter characteristics, and culture specifications:

Our Services

Alfa Cytology delivers comprehensive SW620-luc orthotopic model services spanning authenticated luciferase-stable cell bank maintenance, cecal wall surgical implantation with validated direct injection or tumor fragment grafting techniques, serial bioluminescence imaging on calibrated IVIS platforms, and terminal multimodal endpoint analysis. Our capabilities include KRAS^G12V allele-specific validation, Wnt/β-catenin pathway biomarker assessment, EMT phenotype characterization via E-cadherin and vimentin immunohistochemistry, and isogenic SW480 comparative study design. We support single-agent efficacy studies, combination matrices targeting the KRAS/MAPK and Wnt axes, oncolytic virotherapy evaluations, and pharmacokinetic bridging investigations, all executed under AAALAC-accredited animal care standards with rigorous data documentation and GLP-compliant reporting upon request.

Workflow of SW620-luc Orthotopic Mouse Model Construction

Construction of the SW620-luc orthotopic model integrates reporter cell line quality assurance, sterile surgical technique, and standardized bioluminescence imaging calibration to ensure reproducible engraftment and quantitative tumor tracking. Our protocol is optimized for consistent optical signal fidelity, minimal perioperative mortality, and robust metastatic readouts suitable for KRAS-directed, Wnt-targeted, and EMT-focused therapeutic assessment. The workflow proceeds as follows:

1. Master Cell Bank Revival and Reporter Validation: SW620-luc master stocks are revived and expanded in antibiotic-free Leibovitz L-15 or DMEM/F-12 medium. Each production lot undergoes STR profiling against the ATCC reference database, mycoplasma PCR screening, KRAS^G12V allele-specific qPCR validation, and in vitro luciferase functional assay (Bright-Glo or equivalent) to confirm reporter expression levels, signal linearity across 10^2–10^6 cells, and signal-to-noise ratio >= 1,000 prior to surgical use.
2. Pre-Implantation Cell or Tumor Fragment Preparation: Two validated engraftment routes are prepared. Route A (direct cell injection): logarithmic-phase SW620-luc cells are harvested with 0.25% trypsin-EDTA, washed twice in sterile PBS, and resuspended at 1 x 10⁷ cells/mL in ice-cold PBS for a 50 μL cecal wall inoculum (5 x 10⁵ cells total). Route B (tumor fragment grafting): subcutaneous donor tumors are grown in nude mice, excised at ~100–150 mm³, necrotic tissue is trimmed, and fragments are sectioned to 1 mm³ pieces using a sterile scalpel with quality verified under a dissecting microscope.
3. Recipient Mouse Preparation and Anesthesia: Female athymic nude mice (BALB/c nu/nu or NOG, 6–8 weeks, 18–22 g) are acclimated for 7 days under SPF barrier conditions. On the procedure day, general anesthesia is induced with 1–2% isoflurane in medical oxygen via nose cone. The ventral abdomen is shaved, cleansed sequentially with povidone-iodine and 70% ethanol, and draped sterilely.
4. Cecal Wall Orthotopic Implantation: A 3–5 mm lower midline laparotomy exposes the cecum. For Route A, a 30-gauge Hamilton micro-syringe delivers 5 x 10⁵ cells in 50 μL PBS into the subserosal muscularis of the cecal wall. For Route B, a 1 mm³ tumor fragment is positioned onto the cecal serosa and secured with 8-0 absorbable sutures or a biocompatible tissue adhesive (~10 μL, drying 10–15 s). The cecum is returned to the peritoneal cavity, and the abdominal wall and skin are closed with 5-0 absorbable sutures or surgical staples.
5. Post-Operative Recovery and Clinical Surveillance: Mice recover on a heated pad until fully ambulatory. Post-operative analgesia (buprenorphine 0.05–0.1 mg/kg, s.c.) is administered per IACUC guidelines. Daily monitoring for 7–10 days assesses wound integrity, body weight, food intake, and abdominal distension. Humane endpoints include >20% body weight loss, wound dehiscence, or signs of severe distress.
6. Baseline Bioluminescence Imaging and Cohort Enrollment: Starting 3–5 days post-implantation, mice receive intraperitoneal D-luciferin (150 mg/kg) and are imaged under isoflurane anesthesia using an IVIS Spectrum system. Baseline total flux (photons/sec) is recorded for each animal. Mice with confirmed bioluminescent signal are enrolled; those without detectable engraftment are excluded. Cohorts are randomized once mean tumor burden reaches a predefined threshold (e.g., 1–5 x 10⁶ photons/sec).
7. Therapeutic Intervention and Longitudinal Bioluminescence Monitoring: Test articles are administered per protocol via oral gavage, intravenous, intraperitoneal, or subcutaneous routes. Tumor burden is monitored via bioluminescence imaging twice weekly; body weights and clinical observations are recorded three times weekly. Blood samples may be collected for pharmacokinetic analysis or CEA biomarker quantification. The optical readout enables early detection of treatment response, typically within 24–72 hours for cytotoxic or targeted agents, and distinguishes true regression from pseudoresponse.
8. Necropsy, Tumor Harvest, and Multimodal Endpoint Analysis: At study termination, mice are humanely euthanized. The primary cecal tumor is excised, weighed, photographed, and dimensions recorded. Ex vivo bioluminescence of excised tumors and organs is captured to corroborate in-life imaging data and identify occult metastatic deposits. The abdominal cavity is inspected for peritoneal carcinomatosis. Metastatic target organs (liver, lung, spleen, mesenteric lymph nodes, diaphragm) are harvested. Tissues are fixed in 10% neutral buffered formalin for H&E histology, or snap-frozen for molecular analysis. Immunohistochemistry for Ki-67, cleaved caspase-3, CD31, KRASG12V, phospho-ERK1/2, β-catenin (nuclear vs. cytoplasmic), E-cadherin, vimentin, and MMP-7 (matrilysin) provides mechanistic insight into proliferation, apoptosis, angiogenesis, MAPK/Wnt pathway suppression, EMT status, and matrix remodeling.

Fig 2. SW620-luc orthotopic mouse model construction workflow.

Case Study-SW620-luc Orthotopic Mouse Model Development

In a recent preclinical program, the SW620-luc orthotopic model was utilized to evaluate the therapeutic efficacy of a replication-competent oncolytic vaccinia virus engineered for selective tumor cell lysis and immune modulation in metastatic KRAS-mutant colorectal cancer. SW620-luc cells were implanted into the cecal wall of immunodeficient mice via subserosal injection, with tumor engraftment confirmed by bioluminescence imaging within 3–5 days. Mice were randomized at a standardized photon flux threshold and treated with intratumoral or intravenous oncolytic virus administration twice weekly for 3 weeks. The oncolytic virus arm demonstrated progressive bioluminescent signal attenuation beginning at day 7 of treatment, with several animals showing near-complete photon flux elimination by study endpoint, whereas vehicle controls exhibited continued exponential signal increase. At necropsy, the oncolytic virus cohort exhibited significantly reduced primary cecal tumor weight and diminished ex vivo bioluminescence of excised tumors compared to controls. Notably, immunohistochemical analysis revealed increased tumor infiltration of F4/80+ macrophages and CD31+ angiogenic vessels in the virus-treated group, alongside elevated cleaved caspase-3 positivity indicative of enhanced apoptotic cell death. These findings illustrate how the SW620-luc orthotopic platform integrates real-time optical tracking with mechanistic immune and vascular endpoint analysis to rigorously benchmark oncolytic virotherapy candidates in a metastatic, KRAS-driven colorectal cancer context.

Why Choose Alfa Cytology?

Preclinical programs targeting metastatic KRAS-mutant colorectal cancer demand a model that preserves molecular driver fidelity, EMT-prone phenotype, anatomical relevance, and quantitative longitudinal readouts. Alfa Cytology structures its SW620-luc orthotopic service around these imperatives, delivering capabilities that distinguish our offering in the preclinical CRO landscape:

• We maintain authenticated, low-passage SW620-luc master and working cell banks with documented STR profiles, routine mycoplasma surveillance, KRAS^G12V allele-specific qPCR validation, and serial luciferase activity QC—ensuring reporter fidelity and genetic stability across every study batch.
• Our surgical team achieves consistent engraftment via both direct cecal wall injection and tumor fragment grafting techniques, with bioluminescence signal detectable within 3–5 days and minimal perioperative mortality under AAALAC-accredited animal care standards.
• Bioluminescence imaging is conducted on calibrated IVIS Spectrum platforms with standardized D-luciferin dosing, exposure parameters, and automated ROI analysis protocols, yielding photon flux data with inter-study reproducibility suitable for cross-study meta-analysis.
• The isogenic SW480/SW620 pairing capability enables direct comparative studies between primary tumor and lymph node metastasis biology within the same patient genetic background, offering unique insights into tumor progression, EMT dynamics, and therapeutic resistance evolution.
• We offer integrated multimodal endpoint analysis as standard, including ex vivo bioluminescence corroboration, digital whole-slide H&E pathology, IHC for MAPK and Wnt pathway biomarkers (phospho-ERK1/2, nuclear β-catenin), EMT markers (E-cadherin, vimentin), and matrix remodeling enzymes (MMP-7/matrilysin).
• Study designs are fully modular—we accommodate oncolytic virotherapy assessments, KRAS^G12V inhibitor programs, Wnt pathway modulation studies, EMT-targeting agent evaluations, and complex combination matrices, with GLP-compliant documentation available to support IND-enabling packages and regulatory submissions.

Contact Us

If your colorectal cancer research program targets the metastatic KRAS-mutant population and requires an orthotopic model with real-time bioluminescent tracking, isogenic primary-metastasis pairing potential, and deep molecular endpoint characterization, we invite you to reach out to us for a confidential project consultation. The scientific team at Alfa Cytology is prepared to design a customized SW620-luc orthotopic study aligned with your therapeutic hypothesis, compound mechanism, and regulatory milestones. Contact us today to receive a detailed proposal, feasibility assessment, and projected timeline—let us advance your metastatic CRC pipeline with rigorous, publication-quality preclinical data.

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