AP-1 regulates heterogeneous cellular dormancy in TNBC II

Slow-cycling cells (SCCs) are a heterogeneous subpopulation of tumor cells. They pre-exist in tumor tissues and evade killing by chemotherapeutics that target mitosis due to their dormant nature. We here utilized PKH26 retaining method to label and isolate SCCs, and RNA-seq was performed to understand the gene expression characteristics of SCCs. Here we reported that up-regulations of AP-1 subunits regulate triple negative breast cancer (TNBC) dormancy by up-regulating the expression of CDKN1A and GADD45 family as transcription factors. Overall design: To investigate the gene expression characteristic of slow-cycling cells (SCCs), we first labeled MDA-MB-231 cells with PKH26 and chased in complete DMEM for 12 days. SCCs retain more PKH26 after multiple mitoses due to their slow-cycling nature. We then sorted cells with top 1% PE fluorescence intensity as SCCs by FACS. We also sorted cells with moderate fluorescence intensity as rapid cycling cells (RCCs) / proliferating cells control. Three biological replicates were collected from each group. We performed gene expression profiling assay using data obtained from RNA-seq of 6 samples (two groups with three biological replicates per group). Comparative gene expression profiling analysis of RNA-seq data for SCCs (dormant) and RCCs (proliferating).