Abstract 2697: Single cell RNA sequencing and tumor cell heterogeneity in metastatic triple-negative breast cancer

Abstract

Abstract Tumor cell heterogeneity has been strongly implicated in metastatic progression of solid tumors such as breast cancer, leading to resistance and recurrence. We hypothesize that inhibiting metastasis will reduce tumor cell heterogeneity and thereby increase therapeutic sensitivity. To test this hypothesis, we expressed the metastasis suppressor Raf Kinase Inhibitory Protein (RKIP or PEBP1) in triple-negative breast cancer (TNBC) cells as a means of comparing the variation in gene expression between individual cells in metastatic versus non-metastatic tumors. Xenograft tumors with or without exogenous RKIP expression were dissociated into single cell suspensions. We removed mouse as well as dead cells, and the remaining cells were loaded onto a microfluidic device (Fluidigm C1) for separation and library preparation. For each condition we performed three independent experiments yielding a total of 1569 cells. Initially, we performed controls to ensure that differences were not due to batch effects, cell cycle stage or sample quality. Clustering of single cells across all samples indicated that gene expression profiles are similar, confirming reproducibility. Gene ontology analysis of differentially expressed genes between cells with and without RKIP overexpression reveals gene sets that are important in tumor cell transitions from metastatic to non-metastatic states. These data will allow us to specifically test whether metastatic tumors are more heterogeneous than non-metastatic tumors in TNBC. Citation Format: Dongbo Yang, Christopher Dann, Sebastian Pott, Marsha Rosner. Single cell RNA sequencing and tumor cell heterogeneity in metastatic triple-negative breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2697.