Patient-Derived Xenograft (PDX)

  • Principle
  • Experimental Materials
  • Experimental Procedure
  • Troubleshooting

Materials Required

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Principle

Patient-derived xenograft (PDX) models are generated by engrafting primary human tumor tissue directly into immunodeficient mice, allowing in vivo propagation of patient tumor biology without initial in vitro adaptation. These models are used to preserve key histopathological and molecular characteristics of the original tumor and enable assessment of tumor growth dynamics and therapeutic response in a living organism. The biological readout is tumor engraftment and subsequent growth in the murine host, which reflects the ability of human tumor cells to survive, vascularize, and expand in an immunocompromised microenvironment.

MCE has not independently verified the accuracy of these methods. They are for reference only.

Experimental Materials

Reagents and chemicals

• Immunodeficient mice (e.g., severely immunodeficient strains used for human tissue engraftment) for tumor implantation and in vivo propagation;
• Sterile physiological solutions for tumor tissue transport and handling prior to implantation.

Antibodies, probes, dyes, or kits

• Not specifically required for the core PDX establishment procedure described in foundational methodology literature;
• Downstream characterization may use standard histological or molecular assays.

Equipment and instruments

• Surgical instruments for tumor tissue processing and implantation into mice;
• Animal housing systems compliant with immunocompromised mouse husbandry requirements for xenograft maintenance;
• Calipers or imaging systems for monitoring tumor growth over time.

Experimental Procedure

Preparation Steps

• Fresh tumor specimens are obtained from surgical resection or biopsy and maintained under conditions that preserve tissue viability prior to implantation into immunodeficient mice.

• Tumor fragments are typically processed into small viable pieces suitable for engraftment.

• Recipient mice are prepared under appropriate immunodeficient conditions to prevent graft rejection.

Operation Steps

• Tumor fragments are implanted directly into immunodeficient mice, commonly via subcutaneous or orthotopic implantation depending on tumor type and study design.

• Following implantation, mice are monitored longitudinally for tumor engraftment and growth.

• Successfully engrafted tumors can be serially passaged into additional mice to expand the PDX cohort while maintaining tumor propagation in vivo.

Data Acquisition and Analysis

• Tumor engraftment is assessed by measuring tumor growth over time using physical measurement or imaging-based approaches.

• Engraftment success rates, tumor growth kinetics, and response to therapeutic interventions are used as primary readouts.

• Comparative analyses are typically performed between PDX tumors and corresponding patient tumor characteristics to evaluate model fidelity.

Troubleshooting

Problem: Low or failed tumor engraftment

Possible Cause: Loss of tumor cell viability during processing or insufficient immunodeficiency of host mice
Literature-supported Solution: Use freshly obtained tumor tissue and highly immunodeficient mouse strains to improve engraftment success rates.

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