ELF1 expression in prostate cells reduces oncogenic ETS functions and promotes senescence and sensitivity to chemotherapy through distinct gene expression programs [ChIP-seq]

Aberrant overexpression of oncogenic ETS factors through chromosomal rearrangments is the most common genomic event in primary prostate tumor and these factors have been well studied. Loss of ELF1, another ETS transcription factor family member, is a common event in prostate cancer, but the function of ELF1 has not been described within the prostate. Studies of ELF1 in different tissue types has determined that it can be important for oncogeneis or tumor suppression. Here, we show that ELF1 is a novel prostate tumor suppressor by hindering oncogenic ETS function at cell migration related genes, but also that ELF1 has the ability to regulate senescence and chemotherapy resistance. Next generation sequencing was used to determine gene expression changes in RWPE-1 cells upon addition of an oncogenic ETS factor and then with the loss of ELF1 through an shRNA knockdown. Genomic binding locations were also determined for ELF1 and ERG, through ChIP-seq to identify any cobound or unique regions. The combination of this data indicates that ELF1 repressed migration related genes which ERG activates, but ELF1 also uniquely binds genes related to cell senescence and activates their transcription. There, these data indicate a novel tumor suppressive mechanism for ELF1 within the prostate and better characterizes its function within this cell type.