Functional Implication of Netrin Expression in Malignant Melanoma

Abstract

Background: Malignant melanoma cells are known to have altered expression of genes supporting proliferation and invasion, however, the expression of molecules of the Netrin family of repellent factors has not been analyzed in melanomas until now.

Results: Here, we show that Netrin-1 expression is strongly induced in melanoma cells compared to melanocytes in vivo and in vitro controlled at the transcriptional level via ETS-1. In addition, the expression of the netrin receptor UNC5B was induced and that of UNC5C was reduced in the tumor cells. In order to determine the functional relevance of Netrin-1 expression in malignant melanoma, Netrin expression in melanoma cells was reduced by siRNA attempts and primary human melanocytes were treated with recombinant Netrin-1. The cells showed no changes in proliferation or apoptosis, however, a strong reduction of migratory properties was observed in the melanoma cells after reduction of Netrin expression whereas melanocyte migration was strongly induced by treatment with Netrin.

Conclusions: Our study suggests that Netrin-1 promotes melanoma cell invasion and migration and therefore has an important role in the progression of malignant melanoma.