Geranylgeranyltransferase I regulates HIF-1α promoting glioblastoma cell migration and invasion.

Glioblastoma multiforme is a highly migratory and invasive brain tumor in which hypoxia inducible factor-1α (HIF-1α) plays important roles. However, the underlying mechanisms regulating the action of HIF-1α in glioma cell migration and invasion ability remain unclear. We reported here that HIF-1α was regulated by geranylgeranyltransferase I (GGTI), a protein prenylation transferase, and then promoted glioma cell migration and invasion. The migratory and invasive ability of glioma cells were enhanced by hypoxia treatment but inhibited by down-regulation of HIF-1α. GGTI activity inhibition or GGTI specific β subunit (GGTI β) knocking-down decreased HIF-1α protein level. In addition, down-regulation of GGTI β inhibited migration and invasion of glioma cells under hypoxia, while GGTI β over-expression promoted it. Furthermore, the effect of GGTI β over-expression on cell migration and invasion was abolished by HIF-1α down-regulation. In summary, our study showed, for the first time, that HIF-1α was regulated by protein prenylation transferase GGTI and mediated the effect of GGTI on glioma cell migration and invasion.