Abstract
Abstract: :
Purpose: The molecular mechanism of uveal melanoma development and progression is poorly understood. Promoter hypermethylation is an epigenetic process that is a hallmark of human cancer. The purpose of this study was to identify potential genes with promoter hypermethylation in human uveal melanoma cells. Methods: Three uveal melanoma cell lines, 92.1, Mel270, OCM1 were seeded at 5x105/T–25 flask for 24hr and treated with either the demethylating agent 5–aza–2–deoxycytidine (5–Aza) or PBS for 3 days. Total RNA was used to make biotin–labeled cRNA probe which was hybridized to a U133A Affymetrix microarray (18,400 transcripts). Genes upregulated by 5–Aza were identified using the manufacturer's algorithm. Genes that were upregulated 3–fold by 5–Aza in all three cell lines were identified for further analysis. Results: 538 genes were upregulated by 5–Aza at least 3–fold in all three cell lines, of which 16 genes showed significant upregulation in all three cell lines. Of the 16 genes, 5 have unknown function. Genes with function related to cancer development include, HAND1 (differentiation), MEOX1 (cell growth and differentiation), Corticotropin–releasing hormone, DYRK2 protein kinase (cell growth and development), KIF3C (microtubule translocator of membranous organelles), Caldesmon–1 (mitosis), spastic ataxia of Charlevoix–Saguenay (protein chaperone), Anaphase–promoting complex 10 (anaphase), Glypican–1 (cell division and growth), MMP1 (protease), IGFBP6 (negative cell cycle regulator). Conclusions: Pharmacologic reactivation by 5–Aza may represent an effective strategy to identify genes that are epigenetically silenced in uveal melanoma.
Keywords: melanoma • gene microarray • oncology