ID2 Promotes Lineage Transition of Prostate Cancer through FGFR and JAK-STAT Signaling

The use of ARPIs has led to an increase in the proportion of AR-null prostate cancer, including NEPC and DNPC, but the mechanism underlying this lineage transition has not been elucidated. We found that ID2 expression was increased in AR-null prostate cancer. In vitro and in vivo studies confirmed that ID2 promotes PCa malignancy and can confer resistance to enzalutamide in PCa cells. We generated a ID2 UP50 signature, which is capable to determine resistance to enzalutamide and also valuable for predicting patient prognosis. Functional experiments showed that ID2 could activate the stemness-associated JAK/STAT and FGFR signaling while inhibiting the AR signaling pathway. Our study indicates that ID2 promotes the acquisition of a stem-like phenotype in adenocarcinoma cells, leading to resistance to ADT and next-generation ARPIs in prostate cancer.