Glycosaminoglycans undergo significant structural alterations in
cancer, namely in terms of their sulfation pattern and hydrodynamic size. Numerous studies have focused on this issue, and have demonstrated that
glycosaminoglycans play a crucial role in
cancer growth and invasion. However, the majority of the
enzymes involved in
glycosaminoglycan alterations have yet to be examined in detail. The present study focused on the expression of
chondroitin-synthesizing
enzymes in
colorectal cancer. Specimens from healthy controls and
cancer patients were subjected to RT-PCR analysis after
RNA isolation, and to Western blotting after sequential extraction. The results indicated that
chondroitin polymerizing factor and
glucuronyltransferase gradually increased with
cancer stage, and were expressed at much higher levels in
adenomas compared to adjacent normal tissue. The opposite profile was obtained for
chondroitin synthase I.
Chondroitin synthase III was present at low levels in all the samples examined; however, its expression was higher in the samples from the
cancer patients than in those from the healthy controls. It can therefore be concluded that, among the various factors regulating the structure of
glycosaminoglycans in
cancer, the differential expression of
chondroitin-synthesizing
enzymes is of the most significance.