Galectin-8: A complex sub-family of galectins (Review)

Galectins are animal lectins, that can specifically bind beta -galactosides . Twelve galectins have been described in vertebrates, belonging to three d ifferent groups: prototype, tandem-repeat and chimeric. These proteins seem to be involved in cellular interactions and neoplastic transformations. We present an overview of a particular galectin member: galectin-8. This gale ctin, which has been intensively studied over the last six years, presents a particular type of gene regulation. It is widely expressed in tumoral tis sues and seems to be involved in integrin-like cell interactions. Studies s how that the LGALS8 gene encodes for almost seven mRNAs by alternative spli cing pathways and various polyadenylation sites. These mRNAs could encode f or six isoforms of galectin-8, of which three belong to the tandem-repeat g alectin group (with two carbohydrate binding domains) and the three others to the prototype group (one carbohydrate binding domain). All these isoform s seem to be differentially expressed in various tumoral cells. This untypi cal galectin-8 subfamily seems to have a complex expression regulation, tha t could be involved in cancer phenomena.