Expression of Po66-CBP, a type-8 galectin, in different healthy, tumoral and peritumoral tissues

Abstract

A monoclonal antibody, Po66, recognized an antigen named Po66 carbohydrate binding protein (PO66-CBP), which was homologous to the galectin-8 protein. Two additional isoforms previously not described were characterized. The aim of this study was to compare the expression of Po66-CBP and its isoforms in different healthy, tumoral and peritumoral tissues and at last to determine the localization of the protein in tumors and distant tissues.

Materials and methods: Reverse transcriptase PCR of Po66-CBP was performed on total RNA extract from eleven healthy and eleven tumoral and peritumoral tissue specimens. Antibody Po66 was used to localize the protein in the tumors and distant tissues by an immunohistochemistry method.

Results: Po66-CBP was expressed by half of the healthy tissues. One of the isoforms, the last often present in healthy tissues, was found in all tumoral and peritumoral tissues studied. Immunohistochemistry evidenced a gradient of protein expression in normal cells depending on the vicinity of tumoral tissue. Po66-CBP expression was modified in cancerous tissue, suggesting the implication of galectins in carcinogenesis.