Alterations in glycosaminoglycan composition of methylcholanthrene-induced sarcoma at various stages of the tumour growth.

The methylcholanthrene-induced sarcoma contains several types of glycosaminoglycans, hyaluronic acid being the major component. Furthermore it contains all sulphated glycosaminoglycans present in the skin: chondroitin-4-sulphate, chondroitin-6-sulphate, keratan sulphate, dermatan sulphate, heparan sulphate and heparin. It was found that the amount of all glycosaminoglycans distinctly increased during tumour growth. At the same time the amount of collagen significantly decreased. It is suggested that some of the GAGs participate in the creation of a storage depot for biologically active molecules (growth factors, enzymes) which are thereby stabilized and protected. Hydrolytic degradation of some GAGs may result in the release of some cytokines which may stimulate or inhibit the tumour growth. The changes in the quantities of various glycosaminoglycans during the tumour growth may be responsible for a dual-phase growth of this tumour.