Generation and characterization of Myc knockin mouse model of osteosarcoma

To understand the mechanisms that underlie the ability of Myc to alter both the tumor and its surrounding tumor microenvironment (TME) of osteosarcoma, we generated and molecularly characterized an osteoblast-specific Cre-Lox-Stop-Lox;(LSL)-c-MycT58A;p53fl/+ knockin genetically engineered mouse model (GEMM). Phenotypically, the Myc knockin-GEMM had rapid tumor development with a high incidence of metastasis. Overall design: Myc knockin genetically engineered mouse model (GEMM) were generated by crossing Col2.3-Cre/Trp53fl/+and Lox-Stop-Lox (LSL)-MycT58A mice. Col2.3-Cre/Trp53fl/+ mouse model was generated by crossing mice expressing Cre recombinase under the transcriptional regulation of the osteoblast-specific promoter Col2.3 with Trp53-floxed mice. After development of the spontaneous tumor, tumors were resected, mRNA was isolated using Qiagen RNAeasy Plus Mini kit, and RNA sequencing was performed.