Sensitive monitoring of xenograft cancer models using cell-free DNA

Tumor-derived xenograft mouse models are widely used tools in cancer studies. We reported that in xenograft models without recognizable tumors, however, circulating tumor-derived cell-free DNA (cfDNA) was persistently detectable in peripheral blood long after engraftment, suggesting that measurement of tumor-derived cfDNA could be more sensitive for tumor assessment in xenograft models as well as serve as valuable supplementary parameters in outcome interpretations, especially for those without visible tumors. We inoculated immunodeficiency mice with luciferase-eGFP expressing human HCC1937, A427, or A2058 cells, and performed whole genome sequencing of the cfDNA from mice plasma to detect the human original DNA in xenograft mice, with cfDNA from wild-type mice without engraftment as control.