GANGLIOSIDES AND SEX HORMONES IN HUMAN MELANOMA

Background. Malignant melanoma is the most aggressive form of skin cancer with a rapidly increasing incidence rate. In contrast to other tumors, the role of sex steroid hormones in the initiation and progression of melanoma remains unclear. Objective. To assess the interaction between the content and composition of gangliosides and sex steroid hormones 17 beta-estradiol (E2) and testosterone (T) in malignant melanoma. Patients and methods. The analysis included 45 melanoma patients (age 28-86; 14 men, 15 non -pregnant women in mid follicular phase and 16 postmenopausal women) and 46 healthy controls. Serum levels of gangliosides (GM1-3, GD1(a,b),2,3, GT1b, GQ1b), estradiol, testosterone measured in scrum by chromatographic and immunochemiluminescence methods were correlated with sex and age. Results. Steroid hormones levels showed no differences between groups (p>0.05), while total gangliosides in normal scrum were significantly lower than total ganglioside concentrations determined in melanoma samples (18.63 +/- 3.17 mg/dL versus 74.82 +/- 34.56 mg/dL) (p<0.05). There were no differences related to sex or age within groups regarding total gangliosides levels. Gangliosides pattern in melanoma patients compared to control showed lower GM3, higher GD3, lower GM3/GD3 ratio, increased GD2 levels, and no significant variation of GM1, GM2, GD1a, GT1b gangliosides. There is a positive correlation between estradiol levels and total gangliosides concentration both in non-pregnant premenopausal and postmenopausal melanoma patients. GM3 is negatively correlated with estradiol levels in melanoma group. GT1b and O-Acetyl GD3 concentrations are positively correlated with estradiol levels in women with melanoma. Testosterone levels showed no significant correlation with the content and pattern of gangliosides in melanoma patients. Conclusions. The correlations between content and composition of gangliosides and estradiol in melanoma suggest a possible role of these molecules in melanoma behavior.