More importantly, we showed using a patient-derived xenograft tumor model where LGR5<sup>+</sup> CSCs coexisted with LGR5<sup>-</sup> cells, the RSPO1-liposomes were able to access more CSC cells and deliver the drug specifically and efficiently.
Altogether, our study provides direct evidence that endogenous Rspo2 and Rspo3 chromosome rearrangements can initiate and maintain tumour development, and indicate a viable therapeutic window for LGK974 treatment of RSPO-fusion cancers.
Human breast cancer tumors with high levels of MYC transcript have significantly more PVT1 transcript and RSPO1 transcript than tumors with low levels of MYC showing that the murine results are relevant to a subset of human tumors.
Within these loci members of the Wnt, Fgf and Rspo gene families plus two linked genes (Npm3 and Ddn) were frequently activated in tumors induced by MMTV.