Hyaluronic acid facilitates glioma cell invasion in vitro

We investigated the effects of hyaluronic acid (HA) on the invasiveness of three human glioma cell lines (A172, T98G and U251) and their secretion of matrix metalloproteinases (MMPs), plasminogen activators (PAs), and hyaluronidase. The invasion of all three glioma cell lines was enhanced by the impregnation of Matrigel with HA in an in vitro invasion assay using 12 microns porosity polycarbonate filter transwells. The secretion of MMPs and PAs was not influenced by the presence of HA. Hyaluronidase activity was not detected in the culture media of any glioma cell line. HA also enhanced the motility of A172 and U251 glioma cells, but did not influence the motility of T98G glioma cells. The adhesion and spreading of all glioma cell lines were inhibited on HA-coated plates. HA, however, did not influence the proliferation of any of the glioma cell line. These results suggest that the presence of HA contributes to glioma cell invasion, which involves the stimulation of detachment and motility of glioma cells and the maintenance of proteinase secretion by glioma cells.