Targeting pre-existing club-like cells in prostate cancer potentiates androgen deprivation therapy

A critical knowledge gap in prostate cancer research is understanding whether castration-tolerant progenitor-like cells that reside in treatment-naïve tumors play a direct role in therapy resistance and tumor progression. Herein, we reveal that the castration tolerance of LSC^med (Lin^-, Sca-1⁺, CD49f^med) progenitor cells, the mouse equivalent of human prostatic Club cells, arises not from intrinsic properties, but from significant transcriptional reprogramming. Utilizing single-cell RNA sequencing of LSC^med cells isolated from prostate-specific Pten-deficient (Pten^pc-/-) mice, we identify the emergence of castration-resistant LSC^med cells enriched in stem-like features, driven by the transcription factor FOSL1/AP-1. We demonstrate that cells exhibiting Pten^pc-/- LSC^med characteristics are prevalent in aggressive double-negative prostate cancer (DNPC) subtypes recently identified in human castration-resistant prostate cancer (CRPC). Furthermore, our findings show that the dual-targeting agents JQ-1 and CX-6258-focused on FOSL1/AP-1 and PIM kinases, respectively-effectively suppress both the progenitor properties and the growth of mouse and human DNPC surrogates in vitro and in vivo. Thus, early eradication of castration-tolerant Club-like cells presents a promising therapeutic strategy to mitigate prostate cancer progression toward CRPC.