1. Radio-sensitizing effect of MEK inhibition in glioblastoma in vitro and in vivo.
- Author
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Houweling, M., Abdul, U. K., Brahm, C., Lagerweij, T., Heukelom, S., Koken, P. W., Honeywell, R., Wedekind, L. E., Peters, G. J., Verheul, H., Sminia, P., Noske, D., Wurdinger, T., and Westerman, B. A.
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MITOGEN-activated protein kinases ,TUMOR growth ,GLIOBLASTOMA multiforme ,METHYLGUANINE ,BRAIN tumors ,BIOLUMINESCENCE - Abstract
Introduction: Glioblastoma (GBM) is an incurable cancer type. New therapeutic options are investigated, including targeting the mitogen-activated protein kinase (MAPK) pathway using MEK inhibitors as radio-sensitizers. In this study, we investigated whether MEK inhibition via PD0325901 leads to radio-sensitization in experimental in vitro and in vivo models of GBM. Materials and Methods: In vitro, GBM8 multicellular spheroids were irradiated with 3 fractions of 2 Gy, during 5 consecutive days of incubation with either PD0325901 or MEK-162. In vivo, we combined PD0325901 with radiotherapy in the GBM8 orthotopic mouse model, tumor growth was measured weekly by bioluminescence imaging and overall survival and toxicity were assessed. Results: Regrowth and viability of spheroids monitored until day 18, showed that both MEK inhibitors had an in vitro radio-sensitizing effect. In vivo, PD0325901 concentrations were relatively constant throughout multiple brain areas and temporal PD0325901-related adverse events such as dermatitis were observed in 4 out of 14 mice (29%). Mice that were treated with radiation alone or combined with PD0325901 had significantly better survival compared to vehicle (both P < 0.005), however, no significant interaction between PD0325901 MEK inhibition and irradiation was observed. Conclusion: The difference between the radiotherapy-enhancing effect of PD0325901 in vitro and in vivo urges further pharmacodynamic/pharmacokinetic investigation of PD0325901 and possibly other candidate MEK inhibitors. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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