Immunohistochemical localization of proteoglycans in interstitial elements of human pancreas and biliary system

Age differences in immunohistochemical localizations of large proteoglycan, PG-M/versican, and small proteoglycan, decorin, in the dermis of rats

Proteoglycans were localized immunohistochemically in the dermis of Donryu rats, using monoclonal antibodies raised against large proteoglycan (PG-M/versican) and small proteoglycan (decorin). The localizations of these proteoglycans in the dermis were compared between young rats (22-day old) and old ones (24 or 30 months of age), and distinct age differences were observed. In the young dermis, PG-M/versican was observed to be abundant in almost all fibroblastic cells (both cytoplasm and cell processes) whose cellularity was very rich compared with the dermis of old rats. Decorin was only faintly visible in the interstitial fibrous elements of young dermis. In the old dermis, however, decorin was distinctly detected on the fibrous elements, which were diffusely distributed as a fibrous network, and likewise PG-M/versican was visible in only a few fibrous elements which seemed to be the fine processes of fibroblastic cells. In the border layer between epidermis and dermis as well as the basal layer surrounding hair follicles, both large and small proteoglycans could be observed in old dermis. Since decorin, which was abundant in old dermis, has been found to have a growth inhibitory effect, it is conceivable that decorin may be one of the Cell Growth Inhibitory Factors in aging as proposed by Tauchi et al. [17, 18].

Pancreatic carcinoma is characterized by elevated content of hyaluronan and chondroitin sulfate with altered disaccharide composition

The amount and the types of glycosaminoglycans (GAGs) present in human pancreatic carcinoma were examined and compared with those in normal pancreas. Human pancreatic carcinoma contained increased levels (4-fold) of total GAGs. Particularly, this carcinoma is characterized by a 12-fold increase of hyaluronan (HA) and a 22-fold increase in chondroitin sulfate (CS) content. CS in pancreatic carcinoma exhibited an altered disaccharide composition which is associated with marked increase of non-sulfated and 6-sulfated disaccharides. Dermatan sulfate (DS) was also increased (1.5-fold) in carcinoma, whereas heparan sulfate (HS), the major GAG of normal pancreas, becomes the minor GAG in pancreatic carcinoma without significant changes in the content and in molecular size. In all cases, the galactosaminoglycans (GalGAGs, i.e. CS and DS) derived from pancreatic carcinomas were of lower molecular size compared to those from normal pancreas. The results in this study indicate, for the first time, that human pancreatic carcinoma is characterized by highly increased amounts of HA and of a structurally altered CS.

Immunohistochemical localization of extracellular matrix components in human breast tumours with special reference to PG-M/versican

Immunohistochemical localization of the large proteoglycan, PG-M/versican, was studied in 36 breast tumours, including infiltrating ductal carcinomas, benign tumours and fibrocystic diseases. The relation between the proteoglycan and the other extracellular matrix components was also investigated. In the carcinoma tissues, the interstitial elements of the 'specific stroma', consisting of fibroblastic cells and fine fibrils, were reactive to antibody 2B1, which specifically recognizes the large proteoglycan, PG-M/versican. In the peripheral invasive areas of infiltrating ductal carcinoma, the most intense 2B1-positive reaction was visualized in mesenchymal tissues between carcinoma cells clumps and the surrounding tissues, where hyaluronic acid could be demonstrated histochemically. The 2B1-positive elements were not reactive to antibody 6B6, which specifically recognizes small proteoglycan. In the central sclerotic areas, where antibody 6B6 was reactive, a 2B1-positive reaction was detected only in elastosis masses, which also bound antibodies to type IV collagen and laminin, and to some extent antibody raised against chondroitin 6-sulphate proteoglycan. Elastic tissues of blood vessel walls and perivascular elements became reactive to antibody 2B1 when they were involved in carcinoma invasion. The present results have shown that PG-M/versican was localized in the proliferating interstitial tissues, in particular in hyaluronic acid-rich portions, in association with carcinoma cell growth, and also that PG-M/versican accumulated in vascular and perivascular elastic tissues involved in carcinoma invasion. The biological significance of PG-M/versican was briefly discussed.