Abstract
Purpose: :
There is a necessity to better characterize uveal melanoma (UM) according to their metastasis potential at an early stage. Therefore, efforts to find possible biomarkers are needed. We have recently identified the presence of GP-100 protein in secretome of melanoma cultures. Thus, the purpose of this study is to detect this protein in sera of patients affected of UM and small melanocytic choroidal tumors (SMCT), respectively.
Methods: :
20 SCMT patients, 7 untreated UM and 12 treated (I-125 brachytherapy with good local response) UM patients were clinically and ultrasonographycally studied following the criteria from the COMS. Serum levels of GP-100 protein were analyzed in the mentioned patients and in healthy age/sex matched volunteers (control group; n=15) by quantitative sandwich enzyme immunoassay (ELISA).
Results: :
A statistically significant difference (Mann-Whitney, p < .001) was found in GP-100 serum concentration between the SMCT (0.42 ng/ml) and the untreated UM (19.55 ng/ml) groups. In parallel, statistically significant differences were found comparing the control (0.32 ng/ml) and the untreated UM groups (Mann-Whitney, p < .001). Interestingly, within the group of untreated UM patients, GP-100 serum levels were more high more elevated were the tumor, estimated by ultrasonography, with a statistically significant exponential correlation (Pearson correlation r = 0.75, p < .01). Moreover, GP-100 serum levels were low in the treated UM (0.60 ng/ml) in relation to the untreated UM group (Mann-Whitney test, p < .001).
Conclusions: :
To our knowledge, this is the first time that GP-100 protein is detected in serum of patients with UM. Elevated GP-100 serum levels have an exponential correlation with height in UM patients.
Keywords: melanoma • tumors • choroid