Among well-known circulating melanoma markers 5-S-cysteinyldopa (5-SCD), a precursor of pheomelanin biosynthesis and S-100 beta (S-100B) are extensively investigated. Our earlier observations confirmed that serum concentration of 5-SCD and S-100B correlates well with the stages and progression of the disease. Interleukin-6 (IL-6) is a multifunctional inflammatory cytokine implicated in advanced stage of various diseases and tumour recurrence. Malignant melanoma cells are known to secrete IL-6. According to the recent reports skin could produce DHEA and DHEA-S due to the presence of key enzymes. This study was aimed to establish the significance and the possible relationship among different serum parameters. In 124 melanoma patients with (n=63) or without (n=61) metastasis, concentrations of IL-6, DHEA, DHEA-S were simultaneously measured in comparison with the metastatic markers of 5-SCD and S-100B. The presence of metastasis was verified by conventional imaging techniques. Serum 5-SCD concentration was determined by high pressure liquid chromatography with electrochemical detection. Serum levels of IL-6, DHEA, DHEA-S and S-100B were measured by RIA/IRMA and ILMA methods. For statistical analysis MedCalc Software was used. In patients with metastases compared to the metastasis-free cases significant increase in 5-SCD, S-100B and IL-6 serum levels were observed. On the contrary, significant decrease in DHEAS and DHEA concentrations was found. Correlations between serum concentrations of 5-SCD and IL-6 (P<0.0001), as well as DHEA and DHEA-S (P<0.0001) were significant and Spearmans coefficient of rank correlation (rho) was 0.69 and 0.71, respectively. Using multiple regression analysis a negative correlation between IL-6 and DHEA or DHEAS levels was found. These results suggest that simultaneous determination of IL-6, DHEA and DHEA-S together with 5-SCD and S-100B measured in melanoma patients could be predictive factors of the disease.
This research was supported by the Hungarian Research Fund (OTKA No. T 049814).