DDR1 plays a distinctive role in mammary tumour growth

Purpose: The goals of this study are to compare mammary tumor transcriptome profiling with or without DDR1 in immunocompetent mice in an unbiased way. Methods: In vitro samples: DDR1 WT or KO in vitro cultured E0771 cells were sequenced. Rag1-/- samples: DDR1 WT or KO E0771 cells were injected in Rag1-/- mice, and tumors were harvested and sequenced. C57BL/6 samples: DDR1 WT or KO E0771 cells were firstly inoculated into Rag1-/- mice. When tumor volume reached approximately 200~300 mm3 (usually 20 days after inoculation), 60 mg of tumor organoid were transplanted to WT C57BL/6 mice. Tumor samples were collected on day 4 after transplantation for RNA-seq. Antibody treatment samples: DDR1 KO E0771 cells were reconstituted with human DDR1, then injected into C57BL/6 mice. Isotype control IgG or anti-hDDR1 ECD antibody treatment (10mg/kg intrutumural) started when tumor volume reached approximately 100 mm3. Tumor samples were collected on day 6 after treatment for RNA-seq. Results: Approximately 50 million sequence reads were obtained per sample and identified more than 20,000 transcript isoforms. Conclusions: The RNA-seq results represents the detailed analysis of DDR1 WT/KO mammary tumor transcriptomes in immunocompetent mice C57BL/6. Overall design: RNA-seq of DDR1 WT or KO E0771 cells in vitro, in Rag1-/- hosts, and transplanted from Rag1-/- to C57BL/6 hosts. RNA-seq of E0771 tumors treated with DDR1 antibody.