Sialylation and fucosylation of cancer-associated prostate specific antigen

To examine sialylation and fucosylation of prostate cancer-associated prostate-specific antigen (PCa PSA) from localized prostate cancer and from metastatic prostate cancer, as relevant indicators of tumour stage-dependent microheterogeneity of its oligosaccharide chain.

Sera and urine were collected from a group of consenting patients and used as source of the examined PSA. Lectin-affinity chromatography was performed on the columns with immobilized sialic acid-specific lectins Sambucus nigra agglutinin (SNA) and Maackia amurensis lectin (MAA), and fucose-specific lectins Aleuria aurantia agglutinin (AAA) and Ulex europaeus agglutinin (UEA). PSA elution from the corresponding columns was monitored by measuring immunoreactivity to free (f) PSA form.

The results of lectin affinity chromatographies of PCa PSA indicated distinct and high microheterogeneity of its oligosaccharide chain in respect to the presence of glycoforms differing in the position and the type of linkage of sialic acid or fucose, as well as alterations related to the examined PSA source (localized or metastatic prostate cancer).

The observed decrease in SNA reactivity to metastatic PCa PSA in comparison with PCa PSA from localized prostate cancer may be of interest in the monitoring of response to therapy and scoring of its metastatic potential.