Hepatocyte growth factor (HGF) is a pleiotrophic cytokine that stimulates motility and invasion of several cancer cell types and induces angiogenesis, which is known to be expressed in several malignancies including glioma. The effect of transforming growth factor-beta (TGF-β) isoforrns as well as gangliosides on HGF production was investigated in human glioma cell lines. TGF-β isoforms and gangliosides were found to differentially stimulate HGF production by these cells. The ganglioside GD3 enhanced this release to the greatest extent and the stimulation was more marked in a glioblastoma cell line than in the two other anaplastic astrocytoma cell lines. These results suggest that both TGF-βs and gangliosides may act as indirect angiogenic factors by stimulating HGF secretion.