Downregulated ferroptosis-related gene SQLE facilitates temozolomide chemoresistance, and invasion and affects immune regulation in glioblastoma

CNS Neurosci Ther. 2022 Dec;28(12):2104-2115. doi: 10.1111/cns.13945. Epub 2022 Aug 13.

Abstract

Chemoresistance in patients with glioblastoma multiforme (GBM) is a common reason hindering the success of treatment. Recently, ferroptosis has been reported to be associated with chemoresistance in different types of cancer, while the role of ferroptosis-related genes in GBM have not been fully elucidated. This study aimed to demonstrate the roles and mechanism of ferroptosis-related genes in chemoresistance and metastasis of GBM. First, two candidate genes, squalene epoxidase (SQLE) and FANCD2, were identified to be associated with ferroptosis-related chemoresistance in GBM from three temozolomide (TMZ) therapeutic datasets and one ferroptosis-related gene dataset. Then, comprehensive bio-informatics data from different databases testified that SQLE was significantly downregulated both in GBM tissue and cells and displayed a better prognosis in GBM. Clinical data identified lower expression of SQLE was significantly associated with WHO grade and 1p/19q codeletion. Moreover, through in vitro experiments, SQLE was confirmed to suppress ERK-mediated TMZ chemoresistance and metastasis of GBM cells. The KEGG analysis of SQLE-associated co-expressed genes indicated SQLE was potentially involved in the cell cycle. Furthermore, SQLE was found to have the most significant correlations with tumor-infiltrating lymphocytes and immunomodulators. These findings highlighted that SQLE could be a potential target and a biomarker for therapy and prognosis of patients with GBM.

Keywords: GBM; SQLE; TMZ; chemoresistance; ferroptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents, Alkylating / therapeutic use
  • Brain Neoplasms* / genetics
  • Cell Line, Tumor
  • Drug Resistance, Neoplasm
  • Ferroptosis*
  • Gene Expression Regulation, Neoplastic
  • Glioblastoma* / genetics
  • Humans
  • Squalene Monooxygenase* / genetics
  • Squalene Monooxygenase* / metabolism
  • Temozolomide / therapeutic use

Substances

  • Antineoplastic Agents, Alkylating
  • Squalene Monooxygenase
  • Temozolomide
  • SQLE protein, human