Biochemical and morphological differences between CA125 isolated from healthy women and patients with epithelial ovarian cancer from Tunisian population.

Analysis of the structure of CA125 is essential for determining the physiological role of this significant tumor antigen. The objectives of this study were: (1) to identify the characteristics of the CA125 isolated from healthy and patient women with epithelial ovarian cancer; and (2) to determine the ferning structure of this antigen. The cancer-derived CA125 antigen (cCA125) purified by gel filtration and affinity chromatography (Concanavalin A) was run on SDS-PAGE and examined using light microscopy and compared with healthy-derived CA125 antigen (hCA125). Both purified antigen cCA125 and hCA125 showed a high molecular mass (> 2,000 kDa) with high mannose glycans. The ferning patterns related to cCA125 and hCA125 revealed distinct differences in the patterns of arborescence. The ferning morphology of cCA125 antigen was denser than that of hCA125 antigen making an obvious difference between cCA125 and hCA125, with respect to length, branching and distribution of crystals. The current study provides the first evidence for a potential functional link between CA125 and its structure which, in the light of a comparison between cCA125 and hCA125, might proof to be of significant biomedical importance in the future.