Targeting Squalene Epoxidase Confers Metabolic Vulnerability and Overcomes Chemoresistance in HNSCC

Adv Sci (Weinh). 2023 Sep;10(27):e2206878. doi: 10.1002/advs.202206878. Epub 2023 Jul 25.

Abstract

Cisplatin resistance poses a substantial hurdle in effectively treating head and neck squamous cell carcinoma (HNSCC). Utilizing multiple tumor models and examining an internal HNSCC cohort, squalene epoxidase (SQLE) is pinpointed as a key driver of chemoresistance and tumorigenesis, operating through a cholesterol-dependent pathway. Comprehensive transcriptomic analysis reveals that SQLE is essential for maintaining c-Myc transcriptional activity by stabilizing the c-Myc protein and averting its ubiquitin-mediated degradation. Mechanistic investigation demonstrates that SQLE inhibition diminishes Akt's binding affinity to lipid rafts via a cholesterol-dependent process, subsequently deactivating lipid raft-localized Akt, reducing GSK-3β phosphorylation at S9, and increasing c-Myc phosphorylation at T58, ultimately leading to c-Myc destabilization. Importantly, employing an Sqle conditional knockout mouse model, SQLE's critical role in HNSCC initiation and progression is established. The preclinical findings demonstrate the potent synergistic effects of combining terbinafine and cisplatin in arresting tumor growth. These discoveries not only provide novel insights into the underlying mechanisms of SQLE-mediated cisplatin resistance and tumorigenesis in HNSCC but also propose a promising therapeutic avenue for HNSCC patients unresponsive to conventional cisplatin-based chemotherapy.

Keywords: c-Myc; cholesterol; cisplatin resistance; lipid raft; squalene epoxidase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinogenesis
  • Cell Transformation, Neoplastic
  • Cholesterol
  • Cisplatin / pharmacology
  • Cisplatin / therapeutic use
  • Drug Resistance, Neoplasm
  • Glycogen Synthase Kinase 3 beta
  • Head and Neck Neoplasms* / drug therapy
  • Humans
  • Mice
  • Proto-Oncogene Proteins c-akt
  • Squalene Monooxygenase* / genetics
  • Squalene Monooxygenase* / metabolism
  • Squamous Cell Carcinoma of Head and Neck / drug therapy

Substances

  • Squalene Monooxygenase
  • Cisplatin
  • Proto-Oncogene Proteins c-akt
  • Glycogen Synthase Kinase 3 beta
  • Cholesterol