Distribution and changes of glycosaminoglycans in neoplasias of rectum

The content, composition and physicochemical characteristics of glycosaminoglycans in human rectum and rectum carcinoma were investigated by chemical analyses, enzymic treatments, chromatographic and electrophoretic techniques. The overall glycosaminoglycan content was increased about 2 fold in neoplastic tissues compared to nonneoplastic tissues. The absolute amounts of chondroitin sulfate, hyaluronic acid and dermatan sulfate significantly increased but the amounts of heparan sulfate decreased in neoplastic tissues compared with nonneoplastic tissues. In addition an increased fraction of keratan sulfate and undersulfated chondroitin was identified in neoplastic tissues. HPLC analysis of chondroitinase AC and ABC digests showed a marked increase in delta di-6S and delta di-OS disaccharides in tumor chondroitin sulfate, revealing significant alterations on the sulfation pattern. The results indicate that specific glycosaminoglycan alterations occur in human rectum carcinoma and suggest that proteoglycan metabolism is also altered in this carcinoma.