Model Introduction
This model is constructed by inoculating human-derived multiple myeloma cell lines (e.g., RPMI8226) subcutaneously into immunodeficient mice (e.g., nude mice), creating a Cell line-Derived Xenograft (CDX) model. Its core principle leverages the low rejection of heterologous cells by immunodeficient animals, allowing human tumor cells to proliferate and form tumors in vivo, thereby simulating the pathological process of human multiple myeloma. This model is a vital biological tool for studying the pathogenesis of plasma cell malignant proliferative diseases and evaluating related therapies.
Research Applications
This model is primarily used to simulate the subcutaneous tumorigenesis process of human Multiple Myeloma (MM), observing the growth characteristics of tumor tissues, the evolution of pathological morphology, and the impact on host organs.
Key Points of Experimental Design
- Experimental Animals: 5–6 week old female nude mice, weighing 17–20g.
- Cell Line and Culture:
- Use of the human multiple myeloma RPMI8226 cell line.
- Culture Medium: RPMI 1640 (containing 10% FBS, 80 U/L penicillin, 0.08 mg/mL streptomycin).
- Culture Conditions: $37^\circ\text{C}$, 5% $CO_2$, passaged approximately every 2–3 days; cells in the logarithmic growth phase are used to prepare the single-cell suspension.
- Pre-modeling Treatment: 24 hours prior to inoculation, nude mice receive 3 Gy dose of X-ray whole-body irradiation (WBI) to enhance the tumorigenicity rate.
- Inoculation Parameters:
- Inoculation Site: Subcutaneous injection.
- Inoculation Quantity: $2 \times 10^7$ tumor cells per mouse.
- Expected Tumorigenicity Rate: 50%–70%.
- Observation Period: Typically observed for 6–7 weeks, or the endpoint is determined based on tumor growth and the moribund state of the animal.
Key Monitoring Indicators
- General Physical Signs: Daily observation of mental and activity status; recording body weight, tumor volume, tumor ulceration, and mortality every 2–3 days.
- Pathological Detection:
- HE Staining: Histopathological detection of subcutaneous nodules to confirm whether they consist of plasmacytoma tissue.
- Organ Involvement Examination: Fixation, sectioning, and HE staining of organs such as the liver, spleen, lungs, and kidneys to evaluate tumor metastasis or injury.
- Biochemical Indicators:
- Serum Immunofixation Electrophoresis: Collection of nude mouse serum for electrophoresis to observe the presence of monoclonal immunoglobulin bands (M-spikes), serving as a key criterion for successful modeling.
- Tumor Growth Kinetics: Periodic measurement and calculation of tumor volume.
