Human galectin-8 isoforms and cancer.

Galectins are animal lectins that can specifically bind beta-galactosides. Thirteen galectins have already been described. This review focuses on a specific member of this family: galectin-8. This galectin was discovered in prostate cancer cells eight years ago and has been studied extensively in the last few years. The galectin-8 gene ( LGALS8) encodes numerous mRNAs by alternate splicing and the presence of three unusual polyadenylation signals. These mRNAs encode six different isoforms of galectin-8: three belong to the tandem-repeat galectin group (with two CRDs linked by a hinge peptide) and three to the prototype group (with one CRD). Various studies showed that galectin-8 is widely expressed in tumor tissues as well as in normal tissues. The level of galectin-8 expression may correlate with the malignancy of human colon cancers and the degree of differentiation of lung squamous cell carcinomas and neuro-endocrine tumors. Recently, the differences in galectin-8 expression levels between normal and tumor tissues have been used as a guide for the selection of strategies for the prevention and treatment of lung squamous cell carcinoma. These experiments are still under investigation, but demonstrate the potential of galectin-8 research to enhance our understanding of, and possibly prevent, the process of neoplastic transformation.