WGS and RNASeq analyses of ER-positive breast cancer PDX model BCX1 and two tamoxifen-resistant sublines grown in prolactin-humanized mice (NSG-Pro; NSG.hPRL)

The therapy-naive, estrogen receptor(ER)-positive BCX1 patient-derived xenograft (PDX) breast cancer model was established and propagated in prolactin-humanized mice (NSG-Pro; NSG.hPRL). BCX1 is tamoxifen-sensitive while two tamoxifen-resistant sub-lines BCX1TamR1 and BCX1TamR2 were established that grow in NSG-Pro mice in the continuous presence of tamoxifen. This study generated WGS data for these three related PDX lines and patient germline DNA from blood to identify potential genomic aberrations that facilitate tamoxifen resistance. In parallel, three tumors from each treatment group were collected, species-specific RNASeq analysis was performed and human mRNA data are provided.