Biochemical, histochemical and immunohistochemical study of glycosaminoglycans in human meningiomas

The localization and quantitation of glycosaminoglycans classes (GAGs) were studied in human meningiomas. Meningiomas presented high amounts of these compounds and electrophoretic separation revealed that they were 90% sulphated. The Alcian method and a polyclonal antiserum against chondroitin sulphate were used to localize the different GAGs in tissue sections. Quantitative and qualitative differences and different tissue distributions of GAGs were observed among transitional, syncytial and fibroblastic meningiomas. Syncytial meningiomas presented the lowest amount of GAGs and the immuno- and histochemical studies showed that they were located only in vessels and connectival trabeculae. Transitional meningiomas contained the highest concentration of GAGs; the percentage of the different GAG classes was similar to that observed in the syncytial oncotype indicating a quantitative but not qualitative difference between the two oncotypes. The high amount of GAGs in transitional meningiomas was attribute to the whorls, the structures stained by the histochemical and immunohistochemical techniques. The tumoral parenchyma of these two oncotypes was negative. On the contrary, fibroblastic meningiomas showed a fine meshwork among tumoral cells containing chondroitin sulphate and heparan sulphate. Biochemical data were consistent with the histochemical and immunohistochemical findings revealing a high percentage of chondroitin sulphate and heparan sulphate in fibroblastic meningiomas. This study suggests that the three meningioma types have different abilities to produce extracellular matrix components.