Yanghui Sheng, Wubin Qian, Sheng Guo
Patient-derived xenografts (PDXs) have become the leading model system in oncology drug discovery. Depending on their site of implantation, PDX models from solid tumors can be divided into two categories: subcutaneous (s.c.) and orthotopic (ortho). The advantage of s.c. implantation is that tumor size can be easily monitored, allowing fast validation of drug efficacy.
However, since the s.c. microenvironment is likely different from the tissue of origin for most tumor types, there is concern that s.c. PDXs may not fully recapitulate the complexities of human cancer. Understanding how the site of implantation impacts the PDX transcriptome is essential for selecting suitable models for an oncology study. In this study, the transcriptome of 49 ortho/s.c. pairs from five different cancer types were analyzed.