High serum galectin-3 in advanced melanoma: preliminary results

Background. Galectin-3 (Gal-3) is a member of the family of beta-galactoside-binding mammalian lectins, and has been implicated in tumour invasion and metastatic process in vitro and in vivo. Aim. To determine whether an increase in serum Gal-3 production could be found in patients with advanced metastatic melanoma. Methods. We collected 18 sera from patients with AJCC stage IV metastatic melanomas and 20 sera from healthy volunteers. Determination of Gal-3 was performed by ELISA, and in the group of patients with melanoma, these results were compared with the serum lactate dehydrogenase (LDH) and the C-reactive protein (CRP) concentrations. Results. Gal-3 concentration was shown to be significantly higher in the group of patients with melanoma compared with healthy volunteers, and Gal-3 concentration was significantly correlated with both LDH and CRP in the melanoma group. We also selected four patients in the melanoma group for Gal-3 retrospective immunostaining analysis on cutaneous metastases. Two of these patients, who had a higher Gal-3 serum level, showed more intense staining and the other two patients, with a lower serum level of Gal-3, had moderate immunostaining, suggesting that at least part of serum Gal-3 might be produced by metastatic melanoma tissue. Conclusions. Gal-3 might play a role in melanoma progression and/or inflammation, and warrants further study.