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Updated: May 8, 2026
Ultra-Fast Amplicon-Based Next-Generation Sequencing in Non-Squamous Non-Small Cell Lung Cancer
Published on: September 8, 2023
A high-throughput screen identifies PARP1/2 inhibitors as a potential therapy for ERCC1-deficient non-small cell lung
S Postel-Vinay1, I Bajrami, L Friboulet
11] The Breakthrough Breast Cancer Research Centre and CRUK Gene Function Laboratory, Institute of Cancer Research, London, UK [2] Département de médecine-Unité INSERM 981, Institut Gustave Roussy, Villejuif, France.
Abstract:
Excision repair cross-complementation group 1 (ERCC1) is a DNA repair enzyme that is frequently defective in non-small cell lung cancer (NSCLC). Although low ERCC1 expression correlates with platinum sensitivity, the clinical effectiveness of platinum therapy is limited, highlighting the need for alternative treatment strategies. To discover new mechanism-based therapeutic strategies for ERCC1-defective tumours, we performed high-throughput drug screens in an isogenic NSCLC model of ERCC1 deficiency and dissected the mechanism underlying ERCC1-selective effects by studying molecular biomarkers of tumour cell response. The high-throughput screens identified multiple clinical poly (ADP-ribose) polymerase 1 and 2 (PARP1/2) inhibitors, such as olaparib (AZD-2281), niraparib (MK-4827) and BMN 673, as being selective for ERCC1 deficiency. We observed that ERCC1-deficient cells displayed a significant delay in double-strand break repair associated with a profound and prolonged G₂/M arrest following PARP1/2 inhibitor treatment. Importantly, we found that ERCC1 isoform 202, which has recently been shown to mediate platinum sensitivity, also modulated PARP1/2 sensitivity. A PARP1/2 inhibitor-synthetic lethal siRNA screen revealed that ERCC1 deficiency was epistatic with homologous recombination deficiency. However, ERCC1-deficient cells did not display a defect in RAD51 foci formation, suggesting that ERCC1 might be required to process PARP1/2 inhibitor-induced DNA lesions before DNA strand invasion. PARP1 silencing restored PARP1/2 inhibitor resistance in ERCC1-deficient cells but had no effect in ERCC1-proficient cells, supporting the hypothesis that PARP1 might be required for the ERCC1 selectivity of PARP1/2 inhibitors. This study suggests that PARP1/2 inhibitors as a monotherapy could represent a novel therapeutic strategy for NSCLC patients with ERCC1-deficient tumours.
Insights
Poly (ADP-ribose) polymerase 1 and 2 (PARP1/2) inhibitors show promise as a novel monotherapy for non-small cell lung cancer (NSCLC) with excision repair cross-complementation group 1 (ERCC1) deficiency. ERCC1-deficient tumors exhibit synthetic lethality with PARP1/2 inhibition.
Area of Science:
- Oncology
- Molecular Biology
- Cancer Therapeutics
Background:
- Excision repair cross-complementation group 1 (ERCC1) is crucial for DNA repair, and its deficiency is common in non-small cell lung cancer (NSCLC).
- While low ERCC1 expression predicts platinum sensitivity, platinum therapy efficacy is limited, necessitating alternative treatments for ERCC1-defective NSCLC.
Purpose of the Study:
- To identify novel, mechanism-based therapeutic strategies for ERCC1-deficient tumors.
- To investigate the molecular mechanisms underlying ERCC1-selective drug effects.
Main Methods:
- High-throughput drug screening in an isogenic NSCLC model of ERCC1 deficiency.
- Analysis of molecular biomarkers to understand tumor cell response.
- siRNA screening to assess synthetic lethality interactions.
Main Results:
- Poly (ADP-ribose) polymerase 1 and 2 (PARP1/2) inhibitors (olaparib, niraparib, BMN 673) demonstrated selectivity for ERCC1-deficient cells.
- ERCC1-deficient cells showed delayed double-strand break repair and prolonged G₂/M arrest after PARP1/2 inhibition.
- ERCC1 deficiency was epistatic with homologous recombination deficiency, but RAD51 foci formation was unaffected, suggesting a role for ERCC1 in processing PARP1/2 inhibitor-induced DNA lesions prior to strand invasion.
Conclusions:
- PARP1/2 inhibitors may offer a novel monotherapy for NSCLC patients with ERCC1-deficient tumors.
- ERCC1's role in DNA repair processing influences sensitivity to PARP1/2 inhibitors.
- PARP1 activity appears essential for the ERCC1 selectivity of PARP1/2 inhibitors.
