CRISPR data for prostate cancer cell line(LNCaP) from Day0 , treated with either DMSO, Enzalutamide or synthetic androgen (R1881)

ABSTRACT: Prolonged use of androgen deprivation therapy (ADT) inevitably renders all hormone sensitive prostate cancer into castration-resistant prostate cancer (CRPC). Improved androgen receptor (AR) targeting therapies, such as enzalutamide, have led to advances for the treatment of CRPC, however, the disease undergoes remodeling of the phenotypic landscape leading to direct AR resistance and transdifferentiation. To identify novel regulators of enzalutamide resistance, we performed a genome-wide CRISPR-Cas9 knockout screen in a hormone sensitive prostate cancer cell line grown in enzalutamide. We discovered that loss of the AR cofactor SPEN (also known as SHARP) results in dramatic resistance to enzalutamide but no growth advantage in control conditions. This finding is supported by a large whole exome sequencing patient data set showing SPEN is one of the most commonly mutatedgenes in advanced prostate cancer with clonal variants enriched in metastases. SPEN is a large protein with numerous functions including steroid receptor binding, transcriptional repression through its interaction with NCOR/SMRT, and as an RNA binding protein (RBP). Interestingly, RNA-Seq in enzalutamide treated SPEN KO cells showed up-regulation of gastrointestinal (GI) lineage genes as well as steroid hormone metabolism genes. Given its function as an RBP, we tested if enzalutamide resistant SPEN knockout prostate cancer cells resulted in changes in translation. We observed a rapid increase in translation suggesting this process plays a role in therapy resistance. Polysome profiling also showed increased RNA abundance on polysomes. Moreover, polysome RNA-seq showed up-regulation of transcripts involved in GI-associated and steroid hormone metabolism pathways. To test for a functional role of the SPEN domain in driving castration-resistance by selectively targeting this repressor complex to a subset of pro-oncogenic genes, we have generated a DNA integrase landing pad at the AAVS safe harbor locus which permits doxycycline inducible rescue of each SPEN domain deleted construct. These studies will form the basis for further mechanistic studies and development of new therapeutics for CRPC patients.

ORGANISM(S): Homo sapiens

PROVIDER: GSE301584 | GEO | 2026/07/30

REPOSITORIES: GEO