Targeting FOXP1 phase separation in small cell lung cancer mechanisms of chemotherapy resistance

Commun Biol. 2025 Mar 13;8(1):431. doi: 10.1038/s42003-025-07804-7.

Abstract

Our study elucidates the role of FOXP1 in chemoresistance in small cell lung cancer(SCLC). FOXP1 enhances chemoresistance by regulating SP8 expression through its super-enhancer (SP8-SE), with SP8 mediating resistance via the homologous recombination repair (HRR) pathway. We also discovered that FOXP1 forms punctate nuclear structures indicative of liquid-liquid phase separation, crucial for its transcriptional regulation. Targeting the FOXP1-SP8-HR axis with BRD4 and PARP inhibitors showed synergistic effects in reducing tumor growth in vitro and in patient-derived xenograft models. These findings identify FOXP1 as a critical mediator and marker of chemoresistance in SCLC, providing a foundation for developing targeted therapies to overcome this resistance.

MeSH terms

  • Animals
  • Bromodomain Containing Proteins
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • Drug Resistance, Neoplasm* / genetics
  • Forkhead Transcription Factors* / genetics
  • Forkhead Transcription Factors* / metabolism
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Lung Neoplasms* / drug therapy
  • Lung Neoplasms* / genetics
  • Lung Neoplasms* / metabolism
  • Lung Neoplasms* / pathology
  • Mice
  • Phase Separation
  • Poly(ADP-ribose) Polymerase Inhibitors / pharmacology
  • Repressor Proteins* / genetics
  • Repressor Proteins* / metabolism
  • Small Cell Lung Carcinoma* / drug therapy
  • Small Cell Lung Carcinoma* / genetics
  • Small Cell Lung Carcinoma* / metabolism
  • Small Cell Lung Carcinoma* / pathology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Xenograft Model Antitumor Assays

Substances

  • Forkhead Transcription Factors
  • FOXP1 protein, human
  • Repressor Proteins
  • Transcription Factors
  • Cell Cycle Proteins
  • BRD4 protein, human
  • Poly(ADP-ribose) Polymerase Inhibitors
  • Bromodomain Containing Proteins