Expression of metallothionein in seminal vesicles: An immunohistochemical study

Objective: The seminal vesicles and prostate share the same blood supply and exposure to carcinogens. Despite these similarities, fewer than 60 adenocarcinomas of the seminal vesicles have been described, whereas prostate cancer is the most common cancer in men today. Metallothionein plays a significant role in the detoxification of heavy metals. Thus, this study investigated the expression of metallothionein in seminal vesicle tissue. Material and Methods: Twenty individual tissue specimens each of normal seminal vesicle tissue and benign prostatic tissue underwent immunohistochemical staining with a monoclonal mouse anti-metallothionein antibody. Results: Positive immunostaining for metallothionein was found in 8 of 20 (40%) of the seminal vesicle tissues, but in 14 of 20 (70%) of the prostate specimens. Seminal vesicle tissue stained only with weak intensity. Conclusion: Metallothionein expression is lower in seminal vesicles than in the prostate. The low cell turnover in seminal vesicle tissue may explain the lower staining activity of this tissue. These findings suggest that metallothionein expression cannot be regarded as the main reason for the vastly different cancer incidence in seminal vesicles and the prostate.