Frontiers in Neuroscience (Nov 2015)

Metformin and Ara-a Effectively Suppress Brain Cancer by Targeting Cancer Stem/Progenitor Cells

  • Tarek H. Mouhieddine,
  • Amaly eNokkari,
  • Muhieddine M Itani,
  • Farah eChamaa,
  • Hisham eBahmad,
  • Alissar eMonzer,
  • Rabih eEl-Merahbi,
  • Georges eDaoud,
  • Assaad eEid,
  • Firas H Kobeissy,
  • Wassim eAbou-Kheir

DOI
https://doi.org/10.3389/fnins.2015.00442
Journal volume & issue
Vol. 9

Abstract

Read online

Background: Gliomas and neuroblastomas pose a great health burden worldwide with a poor and moderate prognosis, respectively. Many studies have tried to find effective treatments for these primary malignant brain tumors. Of interest, the AMP-activated protein kinase (AMPK) pathway was found to be associated with tumorigenesis and tumor survival, leading to many studies on AMPK drugs, especially Metformin, and their potential role as anti-cancer treatments. Cancer stem cells (CSCs) are a small population of slowly-dividing, treatment-resistant, undifferentiated cancer cells that are being discovered in a multitude of cancers. They are thought to be responsible for replenishing the tumor with highly proliferative cells and increasing the risk of recurrence. Methods: Metformin and 9-β-d-Arabinofuranosyl Adenine (Ara-a) were used to study the role of the AMPK pathway in vitro on U251 (glioblastoma) and SHSY-5Y (neuroblastoma) cell lines.Results: We found that both drugs are able to decrease the survival of U251 and SH-SY5Y cell lines in a 2D as well as a 3D culture model. Metformin and Ara-a significantly decreased the invasive ability of these cancer cell lines. Treatment with these drugs decreased the sphere-forming units (SFU) of U251 cells, with Ara-a being more efficient, signifying the extinction of the CSC population. However, if treatment is withdrawn before all SFUs are extinguished, the CSCs regain some of their sphere-forming capabilities in the case of Metformin but not Ara-a treatment. Conclusion: Metformin and Ara-a have proved to be effective in the treatment of glioblastomas and neuroblastomas, in vitro, by targeting their cancer stem/progenitor cell population, which prevents recurrence.

Keywords