A Syngeneic ErbB2 Mammary Cancer Model for Preclinical Immunotherapy Trials [RNA-seq]

A cell line was derived from a mammary carcinoma in the transgenic FVB/N-Tg(MMTV-ErbB2)NDL2-5Mul mouse. The line, referred to as “NDL(UCD)” is adapted to standard cell culture and can be transplanted into syngeneic FVB/N mice. The line maintains a stable phenotype over multiple in vitro passages and rounds of in vivo transplantation. The cell line exhibits high expression of ErbB2 and ErbB3 and signaling molecules downstream from ErbB2. The line was previously shown to be reactive to anti-immune checkpoint therapy with responses conducive to immunotherapy studies. Here, using both histology/immunophenotyping and gene expression/microarray analysis, we show that the syngeneic transplant tumors elicit an immune reaction in the adjacent stroma, with additional tumor infiltrating lymphocytes. We also show that this immune activating effect is greater in the syngeneic transplants than in the primary tumors arising in the native transgenic mouse. We further analyzed the PD-1 and PD-L-1 expression in the model and found PD-L1 expression in the tumors and in vitro. In conclusion these data document the validity and utility of this cell line for in vivo preclinical immunotherapy trials. Overall design: Flash frozen NDL(UCD) cell line tumor transplants were sampled and whole-transcriptome analysis was performed by next-generation sequencing (NGS)-based RNA-Sequencing. This series includes three biological replicates of the same cell line grown in three different (but same strain) mouse.

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Pénzváltó Z, Chen JQ, Tepper CG, Davis RR, Silvestrini MT, Umeh-Garcia M, Sweeney C, Borowsky AD