LAUSR

Purpose: To determine the expression of histone deacetylase enzymes in uveal melanoma tumour cells. Procedures: This is an observational immunohistochemical study of 16 formalin-fixed, paraffin-embedded eyes enucleated for uveal melanoma between January 2001 and March 2002. Haematoxylin and eosin paraffin sections were reviewed for histopathological parameters according to the American Joint Committee on Cancer 7th edition. Sections were then immunohistochemically stained for histone deacetylases 1, 2, 3, 4 and 6 and sirtuin 2 using an automated Leica Bond II platform and Fast Red chromogen, then digitally scanned using Aperio software before assessment of staining. Results: Nuclear expression of histone deacetylases 1, 2, 3, 4 and 6 and of sirtuin 2 was confirmed in uveal melanoma tumour cells. In addition, the tumour cells showed cytoplasmic expression of histone deacetylases 4 and 6 and sirtuin 2. Nuclear and cytoplasmic immunostaining was also seen in intraocular tissues uninvolved by the tumour. Conclusion: Uveal melanoma tumour cells express histone deacetylases 1, 2, 3, 4 and 6 and sirtuin 2, confirming potential tissue targets for histone deacetylase inhibitors.