Mt. Goodarzi et Ga. Turner, DECREASED BRANCHING, INCREASED FUCOSYLATION AND CHANGED SIALYLATION OF ALPHA-1-PROTEINASE INHIBITOR IN BREAST AND OVARIAN-CANCER, Clinica chimica acta, 236(2), 1995, pp. 161-171
Proteolytic enzymes could be very important in spread of cancer, but t
he role of the body's natural inhibitors of these enzymes in this proc
ess is unknown. One such inhibitor is the serum glycoprotein, alpha-1-
proteinase inhibitor (API). In previous studies we showed that the fuc
ose-specific lectin, lotus tetragonolobus, extracted high amounts of A
PI in cancer when patients were unresponsive to treatment. The aim of
this study was to determine whether the carbohydrate structure of API
is altered in cancer. API was isolated from the sera of healthy women
and women with breast or ovarian cancer. By means of high-performance
anion-exchange chromatography, cancer API was shown to contain more fu
cose and less N-acetylglucosamine than healthy API. Further investigat
ion of the purified specimens using a lectin-binding assay suggested t
hat the cancer API was less branched and contained more alpha 2-6 and
less alpha 2-3 sialic acid. Observations from both methods were consis
tent with an increase in bi-antennary chains terminating in alpha 2-6
sialic acid and possibly more alpha 1-6 fucose in the core of the unit
. These distinctive changes could have important consequences for the
function of API in cancer and may help to develop more precise markers
for monitoring pathological progression in this disease.