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Updated: May 10, 2026
Intratibial Osteosarcoma Cell Injection to Generate Orthotopic Osteosarcoma and Lung Metastasis Mouse Models
Published on: October 28, 2021
Gene delivery in a mouse xenograft of a retargeted retrovirus to a solid 143B osteosarcoma
Xia Zhang1, Anindita Sarangi, Dai-Tze Wu
1Department of Biochemistry, University of Medicine and Dentistry of New Jersey–Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA
Background:
Osteosarcomas are the most common primary bone malignancies found in children and adolescents. An optimized system was developed for efficient retroviral gene delivery into solid 143B osteosarcoma tumors in mice using a retargeted Env. In these studies, the viral Env CP was isolated from an in vitro screen of a library of feline leukemia virus Env randomized in the receptor-binding domain and maintained high titer on human 143B osteosarcoma cell line.
Findings:
The vector developed to express the random Env libraries encoded the drug selectable marker neo. To adapt this for studies in live animals, the murine based vector was modified to express the luciferase gene. The bicistronic vector developed expressed both the CP Env and luciferase in the presence of either the MPMV CTE or a WPRE element. Virus bearing the CP FeLV Env variant maintained high titers after concentration allowing for direct visualization of delivery of the luciferase gene in subcutaneous 143B osteosarcoma tumors.
Conclusion:
This system serves as a proof-of-concept for the use of novel FeLV Env pseudotyped MLV particles for in vivo gene delivery. Gene delivery and expression of lucerifase from viral particles bearing the CP Env was readily detected in live mice after a single round of intratumor injection.
Insights
This study demonstrates a novel feline leukemia virus (FeLV) Env-pseudotyped Moloney murine leukemia virus (MLV) system for efficient in vivo gene delivery. The optimized system successfully delivered the luciferase gene into osteosarcoma tumors in mice.
Area of Science:
- Oncology
- Gene Therapy
- Virology
Background:
- Osteosarcomas are the most common primary bone cancers in children and adolescents.
- Developing effective gene delivery systems for solid tumors is crucial for therapeutic advancements.
- Previous methods required optimization for efficient retroviral gene delivery into specific tumor types.
Purpose of the Study:
- To develop an optimized retroviral gene delivery system for osteosarcoma tumors.
- To utilize a retargeted feline leukemia virus (FeLV) Env for enhanced viral tropism.
- To establish a proof-of-concept for in vivo gene delivery using novel pseudotyped MLV particles.
Main Methods:
- In vitro screening of a feline leukemia virus Env library to isolate a CP Env variant with high titer on 143B osteosarcoma cells.
- Modification of a murine-based vector to express the luciferase reporter gene for in vivo tracking.
- Construction of a bicistronic vector encoding both the CP FeLV Env and luciferase, incorporating MPMV CTE or WPRE elements.
Main Results:
- The engineered FeLV Env variant maintained high viral titers after concentration.
- Direct visualization of luciferase gene delivery was achieved in subcutaneous 143B osteosarcoma tumors in mice.
- Efficient gene delivery and expression were detected after a single intratumor injection.
Conclusions:
- The developed system is a proof-of-concept for using novel FeLV Env-pseudotyped MLV particles for in vivo gene delivery.
- This approach enables efficient gene delivery and expression in osteosarcoma tumors.
- The findings support the potential of this system for future gene therapy applications in oncology.
