Using Novel Genetically Engineered Mouse Models of Soft Tissue Sarcoma to Interrogate the Contribution of Cell of Origin and Tissue Injury to Sarcoma Development

Soft tissue sarcomas (STSs) are a heterogeneous group of mesenchymal tumors comprised of >70 subtypes. An important question is how the cell of origin and the pathways to tumor development shape the broad array of STS subtypes. By forcing identical tumor-promoting mutations to different cell types in Genetically Engineered Mouse Models (GEMMs) of STS, I have a unique model system to investigate this question. In the process of performing these experiments I observed that genetic mutations are necessary, but not sufficient for rapid sarcoma formation. However, tissue injury dramatically accelerates sarcoma formation in our GEMM of STS. For my thesis, I have worked to understand how cell of origin affects sarcoma subtype and how the microenvironment in our models promotes transformation. I have observed that cell of origin plays an important, but not the only, role in defining STS subtype. Additionally, I have concluded that the microenvironment, and specifically the HGF/c-MET signaling pathway play a crucial role in promoting sarcoma development after acute tissue injury.