Potent androgen receptor inhibition unleashes oncogenic action of the KLF5 stem cell transcription factor in castration-resistant prostate cancer [ChIP-seq]

ABSTRACT: Advanced prostate cancer (PC) can be treated with endocrine therapies that inhibit transcriptional activity of the androgen receptor (AR). However, PC will ultimately evolve under the selection pressure of these therapies and progress to a lethal phenotype termed castration-resistant PC (CRPC). Recent studies suggest that de-differentiation away from an AR-driven luminal cell identity may be a key, early step. However, early therapy-induced mechanisms of prostate cancer cell de-differentiation are poorly understood. Here we show that the stem cell transcription factor Kruppel-like factor 5 (KLF5) is transcriptionally repressed by AR, and de-repressed by enzalutamide. KLF5 expression is high in a subset of CRPC tissues, but low in primary adenocarcinoma. KLF5 functioned as oncogene in CPRC cells, promoting cellular migration, anchorage-independent growth, expression of basal cell markers, and transcriptional signatures of CRPC lineage plasticity, but had modest effects on cell proliferation. Chromatin immuno-precipitation (ChIP)-sequencing, RNA-sequencing, and co-immunoprecipitation experiments established a physical interaction between KLF5 and AR, and integrative analysis revealed that KLF5 and AR drive opposing transcriptional programs. We identified ERBB2 as a point of transcriptional convergence that was activated by KLF5 and repressed by AR. Accordingly, KLF5 expression levels in CRPC tissues correlated with predicted sensitivity to the dual EGFR inhibitor lapatanib, and the ERBB2-specific inhibitor mubritinib blocked KLF5-driven cell migration. Collectively, these findings implicate KLF5 as an AR-suppressed oncogene that drives early steps in CRPC de-differentiation and disease progression.

ORGANISM(S): Homo sapiens

PROVIDER: GSE148807 | GEO | 2021/09/21

REPOSITORIES: GEO