PROFILING THE REPERTOIRE OF GALECTIN EXPRESSION DURING PROSTATE CANCER PROGRESSION

LADERACH D; GIRIBALDI L; GAUDIN C; SACCA P; CASAS G; VAZQUEZ E; MAZZA O; CHAUCHEREAU A; RABINOVICH G; COMPAGNO D

Buenos Aires

Congreso; First French-Argentine Immunology Congress; 2010

INTRODUCTION and AIMS: As cancer cells grow in a complex microenvironment surrounded by multiple intra- and extra-cellular signals and prostate tumours inevitably progress towards an aggressive phenotype, it is essential to understand how these tumours manage to coordinate the signals which promote dissemination and thwart antigen-specific immune responses. The critical functions of galectins (Gals), evolutionarily conserved beta-galactoside binding lectin, during inflammation, angiogenesis and tumor immune escape prompted us to analyze associations between the expression levels of each member of the galectin family and the progression of prostate cancer. RESULTS: We analyzed the transcriptional pattern of galectin expression in several prostate cancer cell lines characterized by differential biological properties. We found that Gal-8 mRNA was ubiquitously detected in all cell lines whereas Gals-1, -3, -4, -9 and -12 mRNA show differential expression profiles suggesting a fine transcriptional control of galectin members in prostate cancer cell lines. These results induced us to analyze protein levels in patient biopsies by IHC. Gal-1 was the most highly expressed member of this family and was significantly up-regulated during disease progression (p<0.05 BHP vs. T1, T2, T3 and T4). On the contrary, Gals-3, -4, -9 and -12 were down-regulated during disease progression (p<0.05 by comparing BHP and progressive stages of the disease, respectively). Gal-8, while being expressed by prostate tumours did not experience any statistically significant modulation during the progression of the disease. CONCLUSIONS: Prostate cancer progression is associated with a particular galectin signature prompting further investigation of these glycan-binding proteins as selective prognostic biomarkers that could delineate non-progressive from progressive clinical outcomes.