The effect of tyrosine kinase inhibitors in high-grade glioma patient-derived cells

Abstract

Background: High-grade gliomas are the most frequently diagnosed malignant brain tumors in adults, with a very unfavorable prognosis. Although various strategies have been applied in the clinical setting, no significant progress has been made in the treatment of high-grade glioma. Clinical trials continue to expand into new approaches such as targeted agents and immunotherapy. Here, we performed pharmacological screening of tyrosine kinase inhibitors (TKIs) on patient-derived glioma cells ex vivo and assessed the expression of multidrug resistance (MDR) marker in glioma and stromal (non-glioma) cells. The effects of TKIs have been compared with chemotherapeutic agents approved for the treatment of high-grade glioma. Material and Methods: Primary patient-derived cell cultures were established from resections of high-grade gliomas. After short-term culturing (2-3 weeks), a mixed population of glioma and non-glioma cells was treated with 4 TKIs (alectinib, dabrafenib, trametinib, and nintedanib), as well as temozolomide (TMZ) and carmustine (BCNU). The maximum achieved concentration in human plasma during therapy (Cmax) was set as the upper limit and 4 lower concentrations were also used during the study. An immunofluorescence assay allowing discrimination of glial fibrillary acidic protein antibody-positive glioma cells versus negative non-glioma cells was performed using an ImageXpress Pico high-content imager (Molecular Devices) with CellReporterXpress 2.9 software. The MDR marker (ABCB1) was analyzed with the corresponding antibody in the same immunoassay. Results: Among the compounds tested, alectinib and TMZ did not affect cell growth and did not change the number of ABCB1-positive cells. Other compounds significantly inhibited the growth of glioma cells. However, they were not selective towards glioma cells, on the contrary, they showed greater cytotoxicity in non-glioma cells. The number of glioma cells positive for the ABCB1 marker increased significantly after treatment with dabrafenib, nintedanib, and BCNU, while trametinib and did not change ABCB1 expression in glioma cells. Stromal (non-glioma) cells generally followed the pattern of ABCB1 observed in glioma cells. Conclusions: Novel functional immunoassay may provide valuable information on the sensitivity of high-grade gliomas to different TKIs and possible treatment outcomes based on the expression of MDR marker.