Lack of p53 protein immunoreactivity in bilateral diffuse uveal melanocytic proliferation

Background: Bilateral diffuse uveal melanocytic proliferation is a poorly understood disorder characterized by the progressive proliferation of uveal melanocytes associated with a systemic nonocular malignancy. Overexpression of p53 protein plays a role in the loss of regulatory control of normal cell proliferation, and p53 is the most commonly identified oncogenic protein in human malignancies. We tested the hypothesis that the aberrant cellular activity in bilateral diffuse uveal melanocytic proliferation involves the overexpression of p53 protein. Methods: Eight eyes from four patients with bilateral diffuse uveal melanocytic proliferation were tested for p53 protein using an immunoperoxidase technique with an anti-p53 protein monoclonal antibody sensitive for normal and mutant p53 protein. Results: The p53 protein could not be detected in any of the eight eyes. Conclusions: The proliferation of uveal melanocytes in bilateral diffuse uveal melanocytic proliferation does not depend on the overexpression of p53 protein. The loss of cellular regulatory control in bilateral diffuse uveal melanocytic proliferation is probably mediated through another mechanism.