Mouse embryonic fibroblasts - transcriptional analysis following uracil treatment

To characterise the metabolic landscape of metastatic breast cancer we investigated differences in metabolites between the serum of MMTV-PyMT mice (n=29) and their wild-type counterparts (n=9) (https://doi.org/10.1101/2024.07.02.601676). Uracil was identified as a metabolite that had a positive correlation with metastatic burden in tumor-bearing animals (p=0.030). Serum uracil was quantified as 10µM in tumor-bearing mice with no lung metastases, compared to 30µM in mice with >10 lung metastases. To understand the physiological effects of these uracil concentrations, mouse embryonic fibroblasts (MEFs) were cultured in the presence of 10µM and 30µM uracil and the cellular derived matrices (CDMs) deposited characterised. CDMs generated in the presence of 30uM uracil had increased fibronectin deposition and were able to support increased invasive capacity of PyMT tumor cells. We performed RNA-Seq on MEFs treated with 0uM v 10uM v 30uM to understand the transcriptional effects of these concentrations of uracil on fibroblasts. Overall design: MEFs were plated to confluence, treated with 0µM, 10µM or 30µM uracil for 24 hours (37°C/5%CO2). Six samples per biological condition.