RNA sequencing data from MCF7 luminal breast cancer cells expressing STAT5a phospho-point mutants

Purpose: The goal of this study was to generate mRNA profiles for MCF7 breast cancer cells expressing phospho-deficient STAT5a point mutants with treatment of prolactin (PRL) to determine differential global genomic effects in breast cancer. This data was compared to in vitro studies using the same cells to determine phenotypic outcomes of the STAT5a point mutations. Methods: mRNA profiles of prolactin (PRL) treated or untreated MCF7 cells expressing wild type (WT)-STAT5a, or phospho-deficient point mutants Y694F-, S726A-, or S780A-STAT5a were generated in triplicate by sequencing on the S4 flow cell platform of the Illumina NovaSEQ 6000 System (Illumina, Inc), generating ≥50 million 150 bp paired-end (PE) reads per sample. All libraries were prepared and sequenced in a single batch/flow cell lane. Results: RNA-sequencing and subsequent Ingenuity Pathway Analysis predicted that loss of each phospho-site differentially affected both prolactin-induced gene expression as well as functional pathways of breast cancer (e.g. cell survival, proliferation, and colony formation). Gene set analysis for transcription factor activity (using ENCODE project ChIP-sequencing and the web platform Enrichr), illustrated multiple transcription factors at work in MCF7 cells expressing each phospho-deficient STAT5a point mutant, indicating that these point mutants have roles regulating STAT5a activity at various enhancer/promoters in a enhancer/promoter specific context. Conclusion: mRNA profiling of MCF7 cells containing either WT-STAT5a, or point mutants Y694F-, S726A-, or S780A-STAT5a treated or untreated for 2 hours with prolactin (PRL).