Perillyl alcohol induces apoptosis in human glioblastoma multiforme cells

Standard treatment of glioblastoma multiforme consisting of surgical resection, radiation and/or chemotherapy is rarely curative, emphasizing the need for new chemotherapeutic drugs. The monoterpene perillyl alcohol (POH) has preventive and therapeutic effects in a wide variety of pre-clinical tumor models and is currently under phase I and II clinical trials. In the present study, we analyzed its effect on human glioblastoma cell lines (U87 and A172) and a primary cell culture derived from a human glioblastoma tumor specimen (GBM-1). Using MTT, we showed that POH inhibits the viability of glioblastomas in a concentration-dependent way. Glioblastoma cell lines treated with POH showed morphological alterations characteristic of apoptosis. Analysis of cell cycle and quantification of DNA fragmentation, in cells stained with propidium iodide (PI), confirmed the apoptotic effect of POH on glioblastomas. These data support the potential usefulness of perillyl alcohol as an effective chemotherapeutic agent for patients with recurrent glioblastoma multiforme.