JAK/STAT signaling maintains an intermediate cell population during prostate basal cell fate determination

Unipotent basal and luminal stem cells maintain prostate homeostasis, with an intermediate cell population emerging during prostate inflammation or cancer. However, the identities of basal stem cell and intermediate cell population remain unclear. Here we identified a rare intermediate cell population expressing luminal markers (termed Basal-B) with enhanced organoid formation capacity, and a larger basal population (termed Basal-A). Genetic lineage tracing revealed Basal-B cells represented a transient basal stem cell state during prostate homeostasis and androgen-mediated regeneration. Activated JAK/STAT signaling was identified in Basal-B cells, and its inhibition significantly reduced Basal-B markers expression. Inflammation increased Basal-B-to-luminal cell transdifferentiation, but JAK/STAT inhibition notably attenuated this effect. Pten gene deletion increased Nkx3.1-expressing Basal-B-like cell population and led to neoplasia. In humans, h-Basal-B cells were more prevalent in benign prostate hyperplasia. This study reveals the identities of intermediate Basal-B cells and underscores the role of JAK/STAT signaling in prostate cell fate determination.