Dataset Information

Linking prostate cancer cell AR heterogeneity to distinct castration and Enzalutamide responses

ABSTRACT: Molecular mechanisms underlying resistance to androgen deprivation therapy (ADT) and, in particular, to antiandrogen Enzalutamide, in treating castration-resistant prostate cancer (CRPC), remain incompletely understood. Through screening >120 CRPC patient samples, we observed 3 expression patterns of androgen receptor (AR) protein: primarily nuclear (nuc-AR), mixed nuclear/cytoplasmic expression (nuc/cyto-AR), and low/no expression (AR-/lo). Xenograft CRPC modeling in 4 models (i.e., LNCaP, VCaP, LAPC4, and LAPC9) recapitulated the 3 AR expression patterns in castration-resistant tumors developed from parental androgen-dependent tumors. Strikingly, although the 3 CRPC models that retained AR expression (LNCaP, VCaP, and LAPC4) responded, to different levels and in different kinetics, to Enzalutamide, the AR-/lo LAPC9 CRPC was completely refractory to Enzalutamide. By combining whole-genome RNA-Seq and biochemical analyses together with experimental combinatorial therapy in the LNCaP and LAPC9 models, we identified BCL-2 as a critical therapeutic target in both AR+/hi and AR-/lo, Enzalutamide-resistant CRPC models.

ORGANISM(S): Homo sapiens

PROVIDER: GSE88752 | GEO | 2018/08/01

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Continued androgen receptor (AR) signaling is an established mechanism underlying castration-resistant prostate cancer (CRPC), and suppression of AR signaling remains a therapeutic goal of CRPC therapy. Constitutively active androgen receptor splicing variants (AR-Vs) lack the AR ligand-binding domain (AR-LBD), the intended target of androgen deprivation therapies (ADT) including new CRPC therapies such as abiraterone and MDV3100. While the canonical full-length AR (AR-FL) and AR-Vs are both increased in CRPC, their expression regulation, associated transcriptional programs, functional relationships, and respective roles in mediating responses to endocrine therapies have not been dissected. In this study, we show that suppression of canonical AR-FL signaling by targeting AR-LBD leads to increased AR-V expression in two cell line models of CRPC. Importantly, treatment-induced AR-Vs activate a distinct expression signature enriched for cell cycle genes without requiring the presence of AR-FL. Conversely, activation of AR-FL signaling suppresses the AR-V signature but activates expression programs mainly associated with macromolecular synthesis, metabolism, and differentiation. In prostate cancer cells and CRPC xenografts treated with MDV3100 and abiraterone, increased expression of two constitutively active AR-Vs, AR-V7 and ARV567ES, but not AR-FL, parallels increased expression of the AR-driven cell cycle gene UBE2C. In addition, protein expression of AR-V7, but not AR-FL, is positively correlated with UBE2C in clinical CRPC specimens. The cumulative in vitro and in vivo evidence support an adaptive shift toward AR-V-mediated signaling in at least a subset of CRPC tumors as the AR-LBD is rendered inactive, suggesting an important mechanism contributing to drug resistance to CRPC therapies. LNCaP cells lacking AR-V were transfected with AR-V7 with or without androgen stimulation of AR-FL (4 conditions); LNCaP95 cells expressing AR-Vs were treated with control siRNA or siRNA trageting AR-LBD or AR-DBD, with or without androgen stimulation of AR-FL (6 conditions); VCaP cells expressing AR-Vs in the presence of androgen were treated with control siRNA, siRNA trageting AR-LBD, DMSO or MDV3100 to inhibit AR-FL (4 conditions). Total 14 arrays with no replicates.

Dataset Information

Linking prostate cancer cell AR heterogeneity to distinct castration and Enzalutamide responses

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure