Alex Hiroto^1,4, Won Kyung Kim^1,4, Ariana Pineda¹, Yongfeng He¹, Dong-Hoon Lee¹, Vien Le¹, Adam W. Olson¹, Joseph Aldahl¹, Christian H. Nenninger¹, Alyssa J. Buckley¹, Guang-Qian Xiao², Joseph Geradts3 & Zijie Sun ¹

¹Department of Cancer Biology, Cancer Center and Beckman Research Institute, City of Hope, Duarte, CA, USA. 
²Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA. 
³Department of Pathology and Laboratory Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA. 
⁴These authors contributed equally: Alex Hiroto, Won Kyung Kim

Corresponding author: Correspondence to Zijie Sun.

The androgen receptor (AR)-signaling pathways are essential for prostate tumorigenesis. Although significant effort has been devoted to directly targeting AR-expressing tumor cells, these therapies failed in most prostate cancer patients. Here, we demonstrate that loss of AR in stromal sonic-hedgehog Gli1-lineage cells diminishes prostate epithelial oncogenesis and tumor development using in vivo assays and mouse models. Single-cell RNA sequencing and other analyses identified a robust increase of insulin-like growth factor (IGF) binding protein 3 expression in AR-deficient stroma through attenuation of AR suppression on Sp1-regulated transcription, which further inhibits IGF1-induced Wnt/β-catenin activation in adjacent basal epithelial cells and represses their oncogenic growth and tumor development. Epithelial organoids from stromal AR-deficient mice can regain IGF1-induced oncogenic growth. Loss of human prostate tumor basal cell signatures reveals in basal cells of stromal AR-deficient mice. These data demonstrate a distinct mechanism for prostate tumorigenesis and implicate co-targeting stromal and epithelial AR-signaling for prostate cancer.