TNFM-NM-1 Signaling Exposes Latent Estrogen Receptor Binding Sites in Breast Cancer Cells [GRO-seq]

ABSTRACT: The interplay between mitogenic and proinflammatory signaling pathways play key roles in determining the phenotypes and clinical outcomes of breast cancers. We have used global nuclear run-on coupled with deep sequencing to characterize the immediate transcriptional responses of MCF-7 breast cancer cells treated with estradiol, TNFM-NM-1, or both. In addition, we have integrated these data with chromatin immunoprecipitation coupled with deep sequencing for estrogen receptor alpha (ERM-NM-1), the pioneer factor FoxA1 and the p65 subunit of the NF-M-NM-:B transcription factor. Our results indicate extensive transcriptional interplay between these two signaling pathways, which is observed for a number of classical mitogenic and proinflammatory protein-coding genes. In addition, GRO-seq has allowed us to capture the transcriptional crosstalk at the genomic locations encoding for long non-coding RNAs, a poorly characterized class of RNAs which have been shown to play important roles in cancer outcomes. The synergistic and antagonistic interplay between estrogen and TNFM-NM-1 signaling at the gene level is also evident in the patterns of ERM-NM-1 and NF-M-NM-:B binding, which relocalize to new binding sites that are not occupied by either treatment alone. Interestingly, the chromatin accessibility of classical ERM-NM-1 binding sites is predetermined prior to estrogen treatment, whereas ERM-NM-1 binding sites gained upon co-treatment with TNFM-NM-1 require NF-M-NM-:B and FoxA1 to promote chromatin accessibility de novo. Our data suggest that TNFM-NM-1 signaling recruits FoxA1 and NF-M-NM-:B to latent ERM-NM-1 enhancer locations and directly impact ERM-NM-1 enhancer accessibility. Binding of ERM-NM-1 to latent enhancers upon co-treatment, results in increased enhancer transcription, target gene expression and altered cellular response. This provides a mechanistic framework for understanding the molecular basis for integration of mitogenic and proinflammatory signaling in breast cancer. Using GRO-seq and ChIP-seq (ER, FoxA1 and p65) to assay the molecular crosstalk of MCF-7 cells treated with E2, TNFM-NM-1 or both E2+TNFM-NM-1.

ORGANISM(S): Homo sapiens

SUBMITTER: W. Lee Kraus 

PROVIDER: E-GEOD-59531 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress