Department of Radiology
Cancer Biology | Neoplasms | Oncology | Radiology | Therapeutics
Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor with poor survival. Cytoreduction in association with radiotherapy and temozolomide (TMZ) is the standard therapy, but response is heterogeneous and life expectancy is limited. The combined use of chemotherapeutic agents with drugs targeting cell metabolism is becoming an interesting therapeutic option for cancer treatment. Here, we found that metformin (MET) enhances TMZ effect on TMZ-sensitive cell line (U251) and overcomes TMZ-resistance in T98G GBM cell line. In particular, combined-treatment modulated apoptosis by increasing Bax/Bcl-2 ratio, and reduced Reactive Oxygen Species (ROS) production. We also observed that MET associated with TMZ was able to reduce the expression of glioma stem cells (GSC) marker CD90 particularly in T98G cells but not that of CD133. In vivo experiments showed that combined treatment with TMZ and MET significantly slowed down growth of TMZ-resistant tumors but did not affect overall survival of TMZ-sensitive tumor bearing mice. In conclusion, our results showed that metformin is able to enhance TMZ effect in TMZ-resistant cell line suggesting its potential use in TMZ refractory GBM patients. However, the lack of effect on a GBM malignancy marker like CD133 requires further evaluation since it might influence response duration.
glioblastoma multiforme, glioma stem cells, metabolism, metformin, temozolomide
Rights and Permissions
Copyright: Valtorta et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
DOI of Published Version
Oncotarget. 2017 Dec 6;8(68):113090-113104. doi: 10.18632/oncotarget.23028. eCollection 2017 Dec 22. Link to article on publisher's site
Valtorta S, Dico AL, Raccagni I, Gaglio D, Belloli S, Politi LS, Martelli C, Diceglie C, Bonanomi M, Ercoli G, Vaira V, Ottobrini L, Moresco RM. (2017). Metformin and temozolomide, a synergic option to overcome resistance in glioblastoma multiforme models. Radiology Publications. https://doi.org/10.18632/oncotarget.23028. Retrieved from https://escholarship.umassmed.edu/radiology_pubs/388
Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.