Serum DJ-1/PARK 7 is a potential biomarker of choroidal nevi transformation

There is substantial evidence that intraocular melanomas arise from benign nevi in the uveal tract. Previous studies performed by the authors revealed that uveal melanoma cells secrete the oncoprotein DJ-1/PARK7 into the extracellular environment and circulation. The aim of this study was to determine whether circulating DJ-1 serum levels correlate with known clinical risk factors of nevi growth.

Standardized ultrasonography, optical coherence tomography, and eye fundus examinations were used to evaluate the clinical risk factors of nevi growth. These clinical risk factors (including nevi size, distance of margins to the optic disc, detection of acoustic hollowness, presence of ocular symptoms, orange pigment, subretinal fluid, and absence of drusen) were examined in 53 consecutive patients from January 2009 to February 2011. Serum levels of DJ-1/PARK7 in these patients and in healthy age- and sex-matched controls (n = 32) were analyzed using ELISA.

Within the choroidal nevi group, DJ-1 serum levels were higher in those with symptoms (P < 0.033), with a nevus thickness greater than 1.5 mm (P < 0.001), a large basal diameter greater than 8 mm (P < 0.001), and the presence of acoustic hollowness (P < 0.001), compared to those patients without these risk factors. Similar significant differences were found when these at risk nevi subgroups were compared to healthy persons.

Elevated serum levels of DJ-1 are associated with choroidal nevi transformation risk factors. Therefore, DJ-1 appears to be a promising factor for predicting the growth of choroidal nevi and may be a potential biomarker of malignancy.