Expression of nectin-4 in prostate cancer

OBJECTIVE: Nectin-4 is a transmembrane protein belonging to the nectin family of immunoglobulin-like molecules which is found in the placenta and trachea under physiological conditions and its expression has been shown in many cancer types. We aimed to investigate for the 1(st) time nectin-4 expression in human prostate cancer tissues. METHODS: We retrospectively analyzed the prostate pathology specimens of 82 patients who underwent initial transrectal ultrasound-guided prostate biopsy or transurethral prostate resection and were found to have atypical small acinar proliferation (ASAP) and incidentally prostate cancer. Tissue samples with prostatic cancer were used as a control for alpha-methylacyl-CoA racemase (AMACR), and benign prostatic glands in the same tissue provided the negative control. The intensity and extent of nectin-4 expression were determined microscopically using the histochemical scoring system which was defined as the product of the staining intensity (score: 0–3) and percentage of stained cells (0–100) at a given intensity. RESULTS: We conducted immunohistochemical analysis of nectin-4 and AMACR expression in all 82 samples. While AMACR expression was positive in prostate cancer tissues with a GS of <7 (n=24, 100%), 7 (n=18, 100%), and ≥8 (n=15, 100%), it was negative in all ASAP samples (n=25, 100%) (p<0.001). Nectin-4 expression was not detected in any of the GS <7, GS 7, or GS ≥8 samples but was found in benign prostatic gland tissues and all 25 (100%) ASAP samples (p<0.001). CONCLUSION: We found that nectin-4 was not expressed in prostate cancer tissues but was expressed in ASAP-and benign prostate gland containing tissues. We believe that prospective studies with more patients and samples including radical prostatectomy materials will reveal the relationship between nectin-4 and prostate cancer more clearly.