Association between cancer and "acid mucopolysaccharides": an old concept comes of age, finally.

"Acid mucopolysaccharides" is an old name for the glycosaminoglycans. These carbohydrate polymers of the extracellular matrix provide tissue organization, cell-cell communication and a platform for signaling. They also support tumor cell proliferation, progression and invasion. Among the most prevalent is hyaluronan. Its support of cancer is an old concept, but only now is it recognized as an integral component of the cancerous state. Hyaluronan occurs not only in malignant cells, but also in peritumor stroma. Finally, it is now realized that the association between tumor and stroma must be investigated to fully understand the process of cancer growth and metastasis. Most recently, hyaluronan has been identified as essential to malignant stem cells, and a component of the cancer stem cell niche. While hyaluronan does not give up its secrets easily, recent progress justifies a review of its role in malignancy.