U-2 OS / U-2 OS-luc Orthotopic Mouse Model Service for Sarcoma

The U-2 OS / U-2 OS-luc orthotopic mouse model for sarcoma is a human osteosarcoma xenograft platform built on one of the oldest continuously used human cancer lines — wild-type p53, transfection-friendly, and imaging-ready — in which tibial grafting recreates bone-confined tumor growth for drug, imaging-agent, and DNA-damage-response studies. Alfa Cytology delivers this model as a complete preclinical capability — spanning authenticated U-2 OS / U-2 OS-luc expansion and luciferase-stable banking, precision intratibial implantation, scheduled in vivo bioluminescence tracking of bone lesions, micro-CT correlation, and full skeletal histopathology — all configured around each sponsor’s compound class, schedule, and endpoint plan.

Overview of U-2 OS / U-2 OS-luc Orthotopic Mouse Model for Sarcoma

U-2 OS is a genuine landmark of cancer cell culture: derived by Jan Pontén and Eero Saksela in 1964 — originally designated “2T” — from a moderately differentiated sarcoma of the tibia in a 15-year-old donor, it is regarded as one of the first human cell lines ever established from a mesenchymal tumor. The line has an epithelial-like, adherent morphology despite its mesenchymal origin, carries a hypertriploid and heavily rearranged karyotype with some twenty-two stable marker chromosomes, and — unlike most osteosarcoma lines — retains wild-type TP53, which has made it the standard cellular substrate for DNA damage response, cell-cycle checkpoint, and p53-pathway research for decades. Its growth is driven by a well-characterized autocrine circuit: U-2 OS cells express both IGF-I and IGF-II/mannose-6-phosphate receptors and secrete IGF-II, which stimulates DNA synthesis through the IGF-I receptor, while the line additionally secretes a PDGF-AA-like osteosarcoma-derived growth factor (ODGF) first structurally characterized from this very line.

Fig 1. WTAP is overexpressed in osteosarcoma tissues and cell lines: GEO data, TCGA validation, western blot (N/T pairs), survival analysis, nomogram, and expression across hFOB1.19/143B/U2OS/SJSA-1/MG63 (U2OS panel H). (Chen, Shijie, et al., 2020)

These properties translate into distinctive utility in vivo. U-2 OS cells proliferate briskly (doubling time roughly 25–30 hours), transfect with high efficiency, and tolerate fluorescent labeling — qualities that made U-2 OS the workhorse line behind advanced imaging methods such as Cell Painting, live-cell organelle studies, and dual GFP-luciferase reporter platforms (commercial U2OS-GFP-luc lines, stably co-expressing firefly luciferase and GFP, have remained stable for 30 passages and are validated for whole-animal imaging). Orthotopic grafting into the tibia of immunodeficient mice places this tractable biology in its skeletal context: intratibial U-2 OS-luc tumors are followed longitudinally by in vivo bioluminescence after luciferin administration, with radiography and micro-CT characterizing cortical involvement, while systemic inoculation routes extend the platform to lung-metastasis modeling. The result is a uniquely versatile platform in which imaging-agent development, IGF-pathway and DNA-damage-targeted therapy evaluation, radiation-oncology research, and combination regimens can all be run in the same bone-faithful setting.

Cell Line Information: U-2 OS / U-2 OS-luc

The table below consolidates the key biological, cultural, and modeling characteristics of the U-2 OS parental line and its luciferase-labeled derivative U-2 OS-luc. Both are human-derived and require immunodeficient hosts for in vivo work.

Our Services

Few lines reward methodological care the way this sixty-year-old workhorse does, and Alfa Cytology runs the U-2 OS / U-2 OS-luc orthotopic program accordingly: authenticated banks, standardized intratibial implantation, weekly in vivo bioluminescence with micro-CT correlation, and endpoint pathology matched to DNA-damage and imaging-study needs — all under one accountable preclinical operation.

Workflow of U-2 OS / U-2 OS-luc Orthotopic Mouse Model Construction

Construction follows established intratibial xenograft methodology: luciferase-labeled U-2 OS cells are expanded under authenticated conditions, concentrated into a small-volume suspension, injected into the proximal tibial medullary cavity of immunodeficient mice, and followed by serial imaging with bone-focused endpoint analysis. The workflow comprises the following stages.

1. Cell authentication and banking: U-2 OS or U-2 OS-luc cells are verified by STR profiling, confirmed mycoplasma-free, and expanded into low-passage working banks under standardized McCoy’s 5a culture conditions.
2. Cell harvest and formulation: Exponentially growing cultures are trypsinized, washed, counted and viability-checked, then resuspended at approximately 1 × 10⁶ cells in 10–20 μL of PBS or a Matrigel-supported suspension and kept on ice until implantation.
3. Anesthesia and tibial access: Male immunodeficient mice are anesthetized with isoflurane, the proximal tibia is exposed through a small incision, and a fine-gauge needle enters the medullary cavity at the tibial plateau.
4. Orthotopic implantation: The cell suspension is slowly injected into the proximal tibial cavity; the needle is held briefly after injection to limit reflux along the cortical tract and standardize take rates.
5. Closure and perioperative care: The puncture site is sealed, the skin is closed, and animals receive analgesia with close post-operative monitoring, including gait observation for lameness and limb swelling.
6. Engraftment confirmation and serial imaging: Luciferin is administered intraperitoneally and bioluminescence is acquired to confirm tibial tumor take and normalize group allocation; imaging repeats on a weekly cadence alongside radiographic or micro-CT assessment of cortical involvement.
7. Intervention and endpoint analysis: Experimental arms — DNA-damaging agents and checkpoint inhibitors, IGF-pathway inhibitors, radiopharmaceuticals and imaging agents, radiation fractions, and combination regimens — proceed per study design; endpoints integrate imaging with tumor-bearing limb dissection and weighing, bone architecture scoring, ex vivo organ bioluminescence for metastatic survey, and histopathology (H&E with Ki67, p53-pathway markers, and marker-specific immunohistochemistry).

Fig 2. U-2 OS / U-2 OS-luc orthotopic mouse model construction workflow.

Case Study-U-2 OS / U-2 OS-luc Orthotopic Mouse Model Development

Alfa Cytology has conducted preclinical programs on the U-2 OS / U-2 OS-luc orthotopic platform spanning imaging-agent evaluation, DNA-damage-response and IGF-pathway inhibitor testing, and radiation-combination studies. In these programs, intratibially implanted U-2 OS-luc tumors were quantified longitudinally by in vivo bioluminescence, with bone architecture and tumor histopathology characterized at endpoint. Study-level datasets are available upon request.

Why Choose Alfa Cytology?

Alfa Cytology combines long-lineage cell-handling expertise with integrated surgical, imaging, and pathology execution, so every U-2 OS / U-2 OS-luc orthotopic study is run with disciplined reproducibility and reporting sponsors can trust.

• Experienced handling of classical wild-type-p53 osteosarcoma lines and their imaging-ready derivatives, including dual GFP-luciferase formats.
• A single coordinated team managing cell banking, tibial implantation surgery, in vivo imaging, micro-CT, and endpoint pathology under one quality framework.
• Longitudinal bioluminescence readouts with radiographic and micro-CT correlation for precise bone-lesion quantification.
• Flexible arms spanning DNA-damaging agents, IGF-pathway inhibitors, radiopharmaceuticals, and radiation combinations.
• Transparent milestone reporting and rapid scientific feedback throughout the engagement.

Contact Us

If your sarcoma program calls for a wild-type-p53, imaging-friendly orthotopic platform with decades of characterization behind it, Alfa Cytology is ready to help. Reach out to us with your study design and endpoint needs, or contact us today for a customized proposal and quotation for the U-2 OS / U-2 OS-luc orthotopic mouse model service.

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