Decreased eukaryotic initiation factors expression upon temozolomide treatment-potential novel implications for eIFs in glioma therapy

J Neurooncol. 2023 Oct;165(1):91-100. doi: 10.1007/s11060-023-04451-y. Epub 2023 Oct 31.

Abstract

Purpose: Since glioma therapy is currently still limited until today, new treatment options for this heterogeneous group of tumours are of great interest. Eukaryotic initiation factors (eIFs) are altered in various cancer entities, including gliomas. The purpose of our study was to evaluate the potential of eIFs as novel targets in glioma treatment.

Methods: We evaluated eIF protein expression and regulation in 22 glioblastoma patient-derived xenografts (GBM PDX) after treatment with established cytostatics and with regards to mutation profile analyses of GBM PDX.

Results: We observed decreased expression of several eIFs upon temozolomide (TMZ) treatment independent from the phosphatidylinositol 3-kinase (PI3K)/ AKT/ mammalian target of the rapamycin (mTOR) signalling pathway. These effects of TMZ treatment were not present in TMZ-resistant PDX. Combination therapy of regorafenib and TMZ re- established the eIF/AKT/mTOR axis.

Conclusion: Our study provides novel insights into chemotherapeutic effects on eIF regulation in gliomas and suggests that eIFs are interesting candidates for future research to improve glioma therapy.

Keywords: Astrocytoma; Eukaryotic initiation factors; Glioma; Glioma therapy; Temozolomide.

MeSH terms

  • Brain Neoplasms* / genetics
  • Cell Line, Tumor
  • Dacarbazine / pharmacology
  • Dacarbazine / therapeutic use
  • Glioblastoma* / drug therapy
  • Glioblastoma* / pathology
  • Glioma* / drug therapy
  • Glioma* / pathology
  • Humans
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • TOR Serine-Threonine Kinases / metabolism
  • Temozolomide / pharmacology
  • Temozolomide / therapeutic use

Substances

  • Temozolomide
  • Proto-Oncogene Proteins c-akt
  • Phosphatidylinositol 3-Kinases
  • Dacarbazine
  • TOR Serine-Threonine Kinases