GSE171336
Defining Cellular Population Dynamics in Advanced Prostate Cancer using Single-cell RNA Sequencing
Advanced prostate cancer is a leading cause of cancer-related deaths in men, in large part due to our poor understanding of advanced castration-resistant prostate cancer (CRPC). This form of prostate cancer is uniformly lethal. Currently, the main treatments against this disease are anti-androgenic therapies; however, CRPC always develops resistance to these therapeutic modalities. Of particular interest is CRPC lacking androgen receptor (AR) activity, or AR-low CRPC. This subtype has dramatically increased in incidence in the past decade. While many studies have identified a complex architecture in the prostate, we still lack a unified view of the cellular interactions and phenotypes that facilitate advanced prostate cancer maintenance and survival, particularly without AR signaling.To better understand the cellular changes that drive CRPC, we harvested prostates from a mouse model of prostate cancer under multiple conditions and performed single-cell RNA sequencing (scRNASeq). Our findings reveal a subset of the epithelial compartment that is primed for AR-low survival during tumorigenesis, as well as a complex basal-driven mechanism to facilitate expansion of this subtype. Androgen deprivation via castration of the mouse modulates this process by increasing proliferation rates in epithelia. In addition, we observe a dramatic increase in immune cell population upon tumorigenesis. We identify this immune influx as pro-tumor and pinpoint unique signaling phenotypes from individual epithelial subtypes, demonstrating a multifaceted process of recruitment and remodeling by the tumor to build a favorable environment. Androgen signaling is also crucial for maintaining these immune populations, and castration dramatically remodels the tumor environment. Finally, we uncover the importance of protein synthesis regulation in maintaining these complex dynamics; inhibiting the eIF4F translation initiation complex leads to decreased epithelial proliferation and immune recruitment. These findings shed new light on the cellular dynamics of advanced prostate cancer and highlight the importance of employing high-throughput technologies to provide a complete picture of the tumor and its microenvironment. Better understanding of the epithelial subtypes involved in tumor growth, as well as their influence on immune populations in the prostate, can lead to new avenues of treatment. Overall design: We harvested prostates from a mouse model of prostate cancer under multiple conditions and performed single-cell RNA sequencing for 13 samples ( 3 wt castrate, 3 WT intact, 2 PTEN intact, 3 PTEN castrate, 2 PTEN castrate 4EBP1) using 10x genomics v2 kit.