Up-regulation of POM121 is linked to prostate cancer aggressiveness and serves as a prognostic biomarker

Nucleoporins as components of the nuclear pore complex (NCP) are known for regulating nuclear-cytoplasmatic transport. Recently, the nucleoporin POM121 was found to have an important impact on intranuclear translocation of prostate cancer (PCa)-specific tumor drivers including the androgen receptor (AR). The aim of our study was to assess the potential of POM121 as a prognostic biomarker.

Therefore, we performed immunohistochemistry (IHC) for POM121 on a large clinically, well characterized PCa tissue cohort comprising benign prostatic samples, radical prostatectomy (RPE) samples, lymph node metastases, local recurrent tumors and distant metastases of 289 patients. Using a semi automated tissue image analysis software we evaluated POM121 protein expression level based on IHC.

We could show that POM121 expression increases during tumor progression. Expression levels were significantly higher in primary tumors compared to benign samples (P = 0.001), and substantially higher in advanced tumors (P < 0.001) and in distant metastases (P = 0.006) compared to primary tumors. Furthermore, POM121 expression predicts biochemical recurrence free survival (BFS) after surgery independent of the WHO group and other clinicopathological markers. 5-years BFS with primary tumors lacking POM121 and expressing POM121 was 88.8% and 68.9%, respectively.

Our study reveals the potential of POM121 as a potential biomarker for PCa, predicting BFS independent of other common clinicopathological parameters. Furthermore, POM121 might be a new targetable structure for patients suffering from advanced PCa.