EXPRESSION OF CD44 AND THE PATTERN OF CD44 ALTERNATIVE SPLICING IN UVEAL MELANOMA

In cutaneous melanoma, the standard CD44 molecule is abundantly expres sed, whereas the expression of certain splice variants is related to t umour progression and to the metastatic potential of the cell line. In the present study we have investigated the expression of CD44 and the pattern of CD44 alternative splicing in uveal melanoma in relation to the cell type, diameter and invasiveness of the tumour. All uveal mel anomas strongly stained with antibodies to the standard portion of CD4 4. No expression of the CD44 variant (v) exon CD44v7 was found, wherea s v5, v6 and v10 were expressed (in 2/12, 5/12 and 8/12 cases, respect ively). No correlation was observed between expression of particular s plice variants and cell type, tumour diameter or invasion of the scler a or Bruch's membrane, All three uveal melanoma cell lines tested were strongly CD44 positive and expressed low levels of v6-containing isof orms at the cell surface, but v5, v7 and v10 were absent, Our results show that CD44 is strongly expressed in uveal melanoma and that the pa ttern of CD44 alternative splicing is similar to that observed in cuta neous melanoma. However, in uveal melanoma this alternative splicing d oes not appear to be related to prognostic parameters.