Molecular characterization of prostate carcinoma tumor antigen-1, PCTA-1, a human Galectin-8 related gene

The galectin family of proteins has been associated with several diverse ce llular processes. More than 30 years since the discovery of the first membe r, precise biological functions for the family as a whole, or for individua l members has pro, cn elusive. The isolation of Prostate Carcinoma Tumor An tigen-1 (PCTA-1), a cDNA closely related to rat and human Galectin-8, as a surface marker associated with prostate cancer was achieved using a previou sly described immunological subtraction approach, Surface Epitope Masking ( SEM) approach, in combination,with expression screening. It appears that PC TA-1 expression is almost ubiquitous in normal human tissues and could alte r in specific contests such as transformation or metastasis. Multiple expre ssion isoforms of PCTA-1 at the mRNA level are observed. PCTA-1 maps to 1q4 2-43, a locus associated with predisposition to prostate cancer. We have de termined the genomic structure of PCTA-1 to account for the several observe d isoforms, performed expression analysis to determine distribution in norm al and transformed contests at the RNA and protein level and conducted over -expression studies to determine effects on cellular phenotype.