Molecular Regulation of Uveal Melanoma Cell Vaculogenic Mimicry by Helix-Loop-Helix Id2 (Inhibitor of DNA Binding)

Abstract

Purpose: : _{^{To examine whether the helix-loop-helix Id2 (inhibitor of DNA binding) is involved in the process of human uveal melanoma vasculogenic mimicry.}}

Methods: : _{^{Paraffin-embedded tissue sections from primary uveal melanoma patients were underwent immunohistochemistry staining for testing Id-2 expression in human melanomas, and PAS staining was used to determine the presence of vasculogenic mimicry. The highly and poorly aggressive human uveal melanoma cells were treated with Id-2 RNA interference when cultured on a three dimensional matrix.}}

Results: : _{^{Id-2 expression was found decreased in human uveal melanoma tissues versus normal uvea tissues. In immunohistochemistry analysis, tumors with low Id-2 expression which was graded scores 2 and 3 significantly had more chances to form vasculogenic mimicry than tumors with high Id-2 expression which was graded scores 4 and 5 ( P< 0.01 ). In three-dimension cultures in vitro the highly aggressive cells can form tubular networks wherease the poorly aggressive cells can not form the tubular networks. And the observation demonstrated that highly aggressive melanoma cells were abrogated the capability of forming vasvulogenic mimicry whentransient knocked down of Id-2.}}

Conclusions: : _{^{These results suggest that Id-2 was involved in forming tubular networks in highly aggressive melanoma cells in vitro, which may represent a novel therapeutic target for further clinical investigation.}}

Keywords: melanoma • uvea • tumors