Inhibition of glioblastoma growth and invasion by 125I brachytherapy in rat glioma model.

Development of the novel targeted therapies for glioblastoma multiforme is very important. Brachytherapy has been proven to provide a good alternative to surgical removal of the prostate, breast and cervix with reduced risk of certain long-term side effects. Thus, 125I brachytherapy was used to effect on the growth and invasion of glioma cells in vitro and in vivo. The inhibitory effect of 125I seeds on C6 cells proliferation was determined by MTT assay. A rat intracranial glioma model was established and the 125I seeds were implanted into the glioma area. CD31 expression was determined by immunohistochemical method to evaluate the angiogenesis. The ΔΨm detection and cell invasion assays were performed to detect the mitochondrial-induced apoptosis and invasion signaling in tumor cells. 125I brachytherapy could significantly inhibit C6 rat glioma cells growth and reduce cell viability in vitro. The seeds implantation also inhibited tumor growth in the rat glioma model and improved survival rate. Analysis revealed that ROS production and the intrinsic mitochondrial pathway of apoptosis was activated by 125I brachytherapy. The HE staining results revealed that the rat glioma model treated with 125I seeds exhibited better defined tumor margins and fewer invasive cells to the lateral striatum compared with the untreated group. The comparison of expression of CD31 in treated or untreated groups was performed to show that the 125I brachytherapy has potential antiangiogenic activity. Meanwhile, 125I brachytherapy can inhibit the growth and invasion of glioma cells via decreasing the expression of MMP-2 and MMP-9.