Synergistic Effects of ATR Inhibition and Lurbinectedin in Soft-Tissue Sarcomas: The Predictive Role of SLFN11

Audrey Laroche-Clary1,2, Vanessa Chaire1,2, Veronica Valverde1,2

  • 1INSERM Bric U1312, Institut Bergonié, Bordeaux, France.

Abstract

Insights

Combining lurbinectedin with ataxia telangiectasia and Rad3-related (ATR) inhibitors shows synergistic effects in soft-tissue sarcoma (STS) treatment. Schlafen-11 (SLFN11) expression predicts response, supporting clinical evaluation.

Area of Science:

  • Oncology
  • Cancer Therapeutics
  • Molecular Biology

Background:

  • Soft-tissue sarcomas (STS) are a heterogeneous group of cancers with limited treatment options.
  • Targeted therapies and combination treatments are being explored to improve outcomes in STS.

Purpose of the Study:

  • To evaluate the synergistic effects of lurbinectedin combined with ataxia telangiectasia and Rad3-related (ATR) inhibition in STS.
  • To investigate the predictive value of Schlafen-11 (SLFN11) expression in determining treatment response to this combination therapy.

Main Methods:

  • STS cell lines were treated with lurbinectedin, the ATR inhibitor VE-822 (berzosertib), and their combination.
  • Cytotoxicity, DNA damage, cell-cycle progression, and apoptosis were assessed.
  • SLFN11 expression was modulated using CRISPR-Cas9, and in vivo efficacy was tested in patient-derived xenografts.

Main Results:

  • The combination of lurbinectedin and berzosertib demonstrated synergistic cytotoxicity, enhanced DNA damage, and induced apoptosis and cell-cycle arrest in STS cell lines.
  • SLFN11 expression correlated with sensitivity to lurbinectedin; knockdown confirmed its role in treatment response.
  • In vivo, the combination significantly inhibited tumor growth without observed toxicity.

Conclusions:

  • Combining lurbinectedin with ATR inhibitors shows promise for STS treatment.
  • SLFN11 is validated as a predictive biomarker for this combination therapy, supporting further clinical investigation.