CD44 variant isoform CD44v10 expression of human melanoma cell lines is upregulated by hyaluronate and correlates with migration

CD44, a multifunctional adhesion receptor involved in cell-cell and cell-ma trix interactions, plays an important role in the local progression and met astasis of malignant tumours. We investigated relative CD44 variant isoform mRNA expression in six human melanoma cell lines and determined cell migra tion on hyaluronic acid (HA) coated substrates. Haematopoietic form (CD44H) mRNA expression increased in all melanoma cell lines after plating on HA, whereas the relative CD44 variant exon 10 (CD44v10) mRNA expression increas ed in only three of the cell lines. Cell migration rates increased on subst rates coated with HA in the three CD44v10-positive cell lines, whereas the three CD44v10-negative cell lines showed no modification in migration rates . Immunofluorescent labelling of CD44v10 revealed increased expression with plaques localized to the periphery of cells. Cell lines with increased rel ative CD44v10 expression exhibited significantly higher mean migration rate s on HA. These results indicate that CD44v10 expression functionally relate s to melanoma cell migration and suggest that interaction between CD44v10 a nd HA plays a role in the variable tissue invasion and aggressiveness of di fferent melanoma clones. (C) 1999 Lippincott Williams & Wilkins.