Backgrounds: Recently, research at genetic and molecular levels has extensively accelerated due to advances in new technologies. Since the mid-90s, a relatively new discipline--clinical proteomics, has evolved, which focuses on studying gene products--proteins. The evaluation of protein profiles may contribute to the more accurate stratification of patients in the future, in terms of both prediction of treatment results and prognosis. In pursuing this objective, proteomic approaches are currently used for the identification of new biomarkers. This is also the case with malignant melanoma, a disease without typical serum marker possessing high sensitivity and high specificity.
Methods: We analyzed human blood serum samples from 25 patients with metastatic malignant melanoma treated with palliative chemotherapy at the Masaryk Memorial Cancer Institute, Brno, in 2004-2006. The analysis was performed by Surface Enhanced Laser Desorption/lonisation Time of Flight Mass Spectrometry (SELDI-TOF-MS). Our patients were divided into two subgroups: a group relatively resistant to chemotherapy--14 patients--and a group with certain clinical benefit from the treatment (complete and partial remission, stabilized disease)--11 patients. We were searching for a new biomarker or typical protein profile in the selected two subgroups. Then, we recategorized our patients into three groups according to the similarity of their protein profiles regardless of sensitivity to chemotherapy. Finally, we evaluated differences in laboratory and clinical parameters, between both the groups of chemo-resistant and chemo-sensitive patients, and newly defined subgroups with similar protein profiles.
Conclusion: We did not identify any significant differences in protein profiles or laboratory parameters in the predefined chemo-sensitive or chemo-resistant groups of patients. However, with regard to the new groups with similar protein profiles, we identified a subgroup of patients with different laboratory and clinical parameters. The results are very interesting and merit further research.