TTFields, an approved treatment modality for glioblastoma, are delivered via continuous, noninvasive application of low intensity, intermediate frequency alternating electric fields. The antimitotic effects of TTFields have been extensively investigated. We investigated other processes that may be affected by TTFields such as human glioma cell migration and cellular invasion properties. Four human glioma cell lines were treated with TTFields using the inovitro system. Cell migration rates were measured using wound healing assays. Invasion assays were performed using a modified Matrigel coated Boyden chamber. Cell adhesion assays were performed during TTFields treatment and compared to untreated controls. At the end of TTFields’ treatment, adhered cells were trypsinized and counted. A cells de-adhesion assay was performed following 24 and 72 hours of TTFields application with the outcome being the number of cells removed after varying times of trypsinization. Application of TTFields in-vitro led to a significant reduction in cell migration velocity compared with untreated control cells. Furthermore, comparison of the anti-migratory efficacy of TTFields applied from 2 directions vs. a single direction revealed that the single direction approach applied perpendicularly to the course of migration was more effective than TTFields applied in 2 directions or in a single parallel direction. Glioma cells invasion was significantly reduced compared to untreated cells in all tested cell lines. Cell adhesion to the substrate (fibronectin) was significantly reduced when exposed to TTFields. On the other hand, cell de-adherence following TTFields treatment took significantly longer time of trypsinization. Our results suggest that human glioma cell motility is impaired by exposure to TTFields. Both alterations in cells adherence and de-adherence during exposure to TTFields may contribute to reduction in cell motility. Further studies are needed to elucidate the mechanism by which TTFields disrupts cellular motility in glioma cancer cells.

Citation Format: Dario Garcia-Carracedo, Rosa S. Schneiderman, Einav Zeevi, Anna Shteingauz2, Moshe Giladi, Tali Voloshin, Yaara Porat, Mijal Munster, Roni Blat, Eilon D. Kirson, Uri Weinberg, Yoram Palti. Tumor Treating Fields (TTFields) affect human glioma cell migration, invasion and adherence properties in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 900. doi:10.1158/1538-7445.AM2017-900

©2017 American Association for Cancer Research.
2017
American Association for Cancer Research.