Protein tyrosine kinase 7 (PTK7) as a predictor of lymph node metastases and a novel prognostic biomarker in patients with prostate cancer.

Protein tyrosine kinase 7 (PTK7) has been studied in various tumors, but its role in prostate cancer remains unknown. This study is aimed to investigate the prognostic and predictive significance of PTK7 in patients with prostate cancer. PTK7 expression was evaluated by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis in 20 pairs of benign prostatic hyperplasia specimens and prostate cancer specimens. Then, we examined the immunohistochemical expression of PTK7 in 180 prostate cancer specimens and evaluated its clinical significances. Elevated PTK7 expression was significantly associated with lymph node metastases, seminal vesicle invasion, prostate cancer stage, the higher preoperative prostate-specific antigen, the higher Gleason score, angiolymphatic invasion, and biochemical recurrence. The results revealed that the overexpression of PTK7 in prostate cancer was an independent prognostic factor for poor overall survival and biochemical recurrence-free survival. The present data provide evidence that PTK7 predicts lymph node metastasis and poor overall survival and biochemical recurrence-free survival, highlighting its potential function as a therapeutic target for prostate cancer.