Determination of eumelanin and pheomelanin in melanomas using solid-phase extraction and high performance liquid chromatography-diode array detection (HPLC-DAD) analysis.
Determination of eumelanin and pheomelanin in melanomas that exhibit different pigmentation was carried using a solid-phase extraction (SPE) preparation method based on weak anion exchange chemistry. This extraction significantly enhanced the chromatographic profile obtained by reverse phase high performance liquid chromatography-diode array detection (RP-HPLC-DAD). The SPE method was developed using aqueous standards of melanin markers: thiazole-2,4,5-tricarboxylic acid (TTCA), thiazole-4,5-dicarboxylic acid (TDCA), pyrrole-2,3-dicarboxylic acid (PDCA) and pyrrole-2,3,5-tricarboxylic acid (PTCA) and non-pigmented cell lines spiked with those markers. An excellent average recovery, above 90%, was obtained for the four markers with a relative standard deviation below 7%. We have also optimized the stationary phase and the mobile phase (phosphate concentration and pH) to improve sensitivity and to reduce the analysis time. Elution of the four markers is achieved in 5 min and total analysis of biological samples is completed in 15 min. The quantification limits for TDCA, TTCA, PDCA and PTCA are 60, 50, 47 and 48 ng/mL respectively. Furthermore, DAD detection improves the marker identification in complex matrices through the analysis of UV spectra. We have successfully applied this method to melanoma tumors and cells. Murine B16BL6 tumor are highly pigmented with mostly eumelanin (98.1% of eumelanin) while human SK-MEL-3 tumor contain about 30% pheomelanin. B16BL6 and B16F10 are eumelanic cells lines and NHEM melanocytes contain about 24% of pheomelanin.
['Rioux|Benjamin|B|', 'Rouanet|Jacques|J|', 'Akil|Hussein|H|', 'Besse|Sophie|S|', 'Debiton|Eric|E|', 'Bouchon|Bernadette|B|', 'Degoul|Françoise|F|', 'Quintana|Mercedes|M|']
D000818:Animals D045744:Cell Line, Tumor D002851:Chromatography, High Pressure Liquid D006801:Humans D057230:Limit of Detection D016014:Linear Models D008297:Male D008543:Melanins D008545:Melanoma D051379:Mice D015203:Reproducibility of Results D052616:Solid Phase Extraction
Eumelanin Pheomelanin Solid-phase extraction (SPE) Melanoma tumors High performance liquid chromatography–diode array detection (HPLC-DAD)