Abstract. Glioblastoma is the most aggressive primary brain malignancy, and the efficacy of multimodality treatments remains unsatisfactory. Phenethyl isothiocyanate (PEITC), one member of the isothiocyanate family, was found to inhibit the migration and invasion of many types of human cancer cells. In our previous study, PEITC induced the apoptosis of human brain glioblastoma GBM 8401 cells through the extrinsic and intrinsic signaling pathways. In the present study, we first investigated the effects of PEITC on the migration and invasion of GBM 8401 cells. PEITC decreased the migration of GBM 8401 cells in a dose-dependent manner as determined from scratch wound healing and Transwell migration assays. The percentage of inhibition ranged from 46.89 to 15.75%, and from 27.80 to 7.31% after a 48-h treatment of PEITC as determined from the Transwell migration assay and invasion assay, respectively. The western blot analysis indicated that PEITC decreased the levels of proteins associated with migration and invasion, Ras, uPA, RhoA, GRB2, p-p38, p-JNK, p-ERK, p65, SOS1, MMP-2, MMP-9 and MMP-13, in a dose-dependent manner. Real-time PCR analyses revealed that PEITC reduced the mRNA levels of MMP-2, MMP-7, MMP-9 and RhoA in a dose-and time-dependent manner. PEITC exhibited potent anticancer activities through the inhibition of migration and invasion in the GBM 8401 cells. Our findings elucidate the possible molecular mechanisms and signaling pathways of the anti-metastatic effects of PEITC on human brain glioblastoma cells, and PEITC may be considered as a therapeutic agent.
IntroductionGlioblastoma is the most aggressive primary brain malignancy with a median survival rate of 14.6 months from diagnosis in unselected patients, even following maximal, feasible surgical resection, radiotherapy and standard adjuvant temozolomide (TMZ) therapy (1). Only 0.4-0.5% of all GBM patients with extracranial metastasis has been reported, which may be attributable to the extremely shortened survival of these patients (2). Combining radiotherapy and TMZ provides better survival outcomes of glioblastoma patients than radiotherapy alone (3). Survival and recurrence are significantly associated with the extent of resection and residual volume (4). Gross total resection associated with survival improvement is not always possible as the preservation of neurological functions is necessary. The efficacy of current multimodality treatments including surgery, radiotherapy, chemotherapy for this tumor remains unsatisfactory.Phenethyl isothiocyanate (PEITC) is one of the most extensively studied isothiocyanates (5). PEITC can induce cell cycle arrest and apoptotic cell death in various tumor types (6-12). In our previous study, PEITC induced apoptosis through the extrinsic (death receptor) and intrinsic (mitochondrial) pathways, dysfunction of mitochondria and ROS-induced ER stress in GBM 8401 cells (13). PEITC displayed anti-metastatic PEITC inhibits human brain glioblastoma GBM 8401 cell migration and invasion through the inhibition of uPA,...