A highly sensitive screening system to evaluate the reversibility of neuroendocrine prostate cancer to prostate adenocarcinoma

Lineage plasticity in prostate cancer primarily induces transdifferentiation of adenocarcinoma into neuroendocrine prostate cancer (NEPC). Lineage alteration is largely driven by epigenome and is potentially reversible. Nonetheless, evidence supporting NEPC reversibility is lacking in materials derived from clinical specimens. Hence, we established KUCaP13, a novel NEPC cell line derived from the tissue of a patient initially diagnosed with adenocarcinoma, which later recurred as NEPC. We aimed to prove the reversibility of cellular lineage by high‐throughput chemical screening using KUCaP13 cells.

We developed a highly sensitive screening system to evaluate the reversibility of plasticity in NEPC using a novel cell line. However, no compound demonstrated the ability to re‐express AR in this cell line. Nevertheless, in future studies, this screening system could prove valuable for elucidating the mechanism of lineage plasticity in NEPC and for developing novel therapies focused on reversing plasticity.

Compounds responsible for androgen receptor (AR) re‐expression in KUCaP13 cells were screened. A reporter gene, androgen response element luciferase (AREluc), was transduced into KUCaP13 cells to detect AR activity using luciferase assay.

Positive control cells (KUCaP13_AREluc_AR) overexpressing AR showed enhanced luminescence upon administration of synthetic androgen. An initial screen of 1552 compounds revealed 30 candidate molecules potentially enhancing luciferase luminescence. In the second screening, we eliminated false positives and validated the findings using luciferase assay and quantitative real‐time polymerase chain reaction. However, all hit compounds were confirmed as false positives, probably due to their inhibitory activity on luciferase. Conclusions: We developed a highly sensitive screening system to evaluate the reversibility of plasticity in NEPC using a novel cell line. However, no compound demonstrated the ability to re‐express AR in this cell line. Nevertheless, in future studies, this screening system could prove valuable for elucidating the mechanism of lineage plasticity in NEPC and for developing novel therapies focused on reversing plasticity.