establishment of pdx models by osteosarcoma tissue transplantation at the mouse flank region

Protocol for Osteosarcoma PDX Mouse Models: Studying Growth and Drug Resistance

Osteosarcoma is a primary bone malignancy derived from interosseous lobe cells and is most common in adolescents as well as children. It often occurs in the epiphysis of the long diaphysis and is characterized by high malignancy, early metastasis, and poor prognosis1,2. Lung metastasis is the main cause of death in osteosarcoma patients. The 5-year survival rate of patients with non-metastatic osteosarcoma is 65%-70%3. However, over the last 40 years, the 5-year survival rate (only 20%) of patients with metastatic osteosarcoma has not significantly improved, and 25% of osteosarcoma patients have metastases at the time of diagnosis4. Currently, the first-line drugs for osteosarcoma treatment have reached a consensus, but there are still significant differences in chemotherapy regimen and treatment time5. It is important to perform preclinical experiments based on appropriate animal models to obtain more effective chemotherapy regimens.
Currently, models commonly used for osteosarcoma preclinical experiments include cell line-based in vitro cell culture and in vivo cell-derived xenografts (CDX), as well as patient-derived xenografts (PDX)6,7.
The cell lines are convenient for culturing and for use in in vitro studies, or for transplantation into immunodeficient mice to establish CDX models8. However, cell lines cultured in vitro may not accurately reflect the heterogeneity of malignancies and the individual characteristics of patients due to potential mutations that occur to adapt to the in vitro culture environment during repeated passages. Additionally, they lack the microenvironment and immune system necessary for tumor growth and development in vivo. While CDX models offer some advantages over in vitro cell culture, they still may not fully reflect the individual characteristics of osteosarcoma patients, although tumor tissues obtained from CDX models have limited intratumoral heterogeneity and immune system representation compared to cell lines cultured in vitro9. Therefore, establishing a preclinical model with high fidelity is crucial.
PDX models involve the immediate transplantation of freshly resected human cancer tissues into immunodeficient mice. This method allows for the faithful preservation of genetic, epigenetic, and heterogeneous characteristics of human malignancies for each patient, even after successive passages in mice. Furthermore, PDX models are known to accurately predict later clinical outcomes10, making them valuable tools for creating individualized treatments and advancing precision medicine research11.
This work describes the procedure for establishing a PDX model in immunodeficient mice by transplanting human osteosarcoma tissue. Such models serve as platforms for conducting preclinical experiments for osteosarcoma.

Author Spotlight: Replicating Human Osteosarcoma Progression in Immunodeficient Mice for Cancer Study

Establishment of Patient-Derived Xenograft Mouse Model with Human Osteosarcoma Tissues

This study meticulously replicates the lateral progression of human osteosarcoma tissue growth in immunodeficient mice, providing a platform for studying the growth, the drug resistance, relapse, and metastasis of osteosarcoma. We realized the procedural steps involved in establishing a patient-derived xenograft model using human osteosarcoma tissue, thereby advising the preclinical research on osteosarcoma. This technical accuracy mimics the human cancer and maintains primary tumor similarity, facilitating the exploration of osteosarcoma biology and the treatment efficacy.

Establishment of PDX Models by Osteosarcoma Tissue Transplantation at the Mouse Flank Region

To begin, take the freshly resected osteosarcoma tissue, stored in the tissue protective solution. Rinse the osteosarcoma tissues twice with pre-cool sterile physiological saline in a sterile hood. Then remove the areas of osteosarcoma tissue with bleeding and necrosis.Using a scalpel, cut the clean osteosarcoma tissue in a tissue culture dish containing pre-cool sterile physiological saline. Keep the tissue on ice. Now, place the nude mice on sterile surgical drapes.Pinch the toes of the mice to ensure that they are completely anesthetized. Then secure the mouse in a lateral decubitus position. With a marker pen, mark the surgical incision site on the skin.Use the scalpel to make a five millimeter incision from the skin to the subcutaneous tissues. Now, hold ophthalmic tweezers in the left hand and lift the upper margin of the incision. Simultaneously, use a straight needle holder with the right hand to perform blunt dissection upward under the dermis of the mice.With ophthalmic tweezers, hold the upper side skin of the incision. Then transplant the osteosarcoma tissue under the skin five millimeters above the incision margin. Suture the incision using surgical lines, with two to three stitches for a five millimeter incision.Transplanting femoral osteosarcoma tissue from a 15-year-old patient to P0, P1, P2, and P3 mice resulted in the successful creation of a patient-derived xenograft.

establishment-pdx-models-osteosarcoma-tissue-transplantation-at-mouse

Research

JoVE Journal

Cancer Research

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. Despite the development of new treatment plans in recent years, the prognosis for osteosarcoma patients has not significantly improved. Therefore, it is crucial to establish a robust preclinical model with high fidelity. The patient-derived xenograft (PDX) model faithfully preserves the genetic, epigenetic, and heterogeneous characteristics of human malignancies for each patient. Consequently, PDX models are considered authentic in vivo models for studying various cancers in transformation studies. This article presents a comprehensive protocol for creating and maintaining a PDX mouse model that accurately mirrors the morphological features of human osteosarcoma. This involves the immediate transplantation of freshly resected human osteosarcoma tissue into immunocompromised mice, followed by successive passaging. The described model serves as a platform for studying the growth, drug resistance, relapse, and metastasis of osteosarcoma. Additionally, it aids in screening the target therapeutics and establishing personalized treatment schemes.

The present protocol describes the method for establishing a patient-derived xenograft (PDX) mouse model using human osteosarcoma tissue.

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. Despite the development of new treatment plans in recent years, ...