PD-L1 and IFN-γ modulate Non-Small Cell Lung Cancer (NSCLC) cell plasticity associated to immune checkpoint inhibitor
Stefania Angelicola1,2, Francesca Giunchi3, Francesca Ruzzi2
1Medical Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
Background:
Non-Small Cell Lung Cancer (NSCLC) is the leading cause of cancer death worldwide. Although immune checkpoint inhibitors (ICIs) have shown remarkable clinical efficacy, they can also induce a paradoxical cancer acceleration, known as hyperprogressive disease (HPD), whose causative mechanisms are still unclear.
Methods:
This study investigated the mechanisms of ICI resistance in an HPD-NSCLC model. Two primary cell cultures were established from samples of a NSCLC patient, before ICI initiation ("baseline", NSCLC-B) and during HPD ("hyperprogression", NSCLC-H). The cell lines were phenotypically and molecularly characterized through immunofluorescence, Western Blotting and RNA-Seq analysis. To assess cell plasticity and aggressiveness, cellular growth patterns were evaluated both in vitro and in vivo through 2D and 3D cell growth assays and patient-derived xenografts establishment. In vitro investigations, including the evaluation of cell sensitivity to interferon-gamma (IFN-γ) and cell response to PD-L1 modulation, were conducted to explore the influence of these factors on cell plasticity regulation.
Results:
NSCLC-H exhibited increased expression of specific CD44 isoforms and a more aggressive phenotype, including organoid formation ability, compared to NSCLC-B. Plastic changes in NSCLC-H were well described by a deep transcriptome shift, that also affected IFN-γ-related genes, including PD-L1. IFN-γ-mediated cell growth inhibition was compromised in both 2D-cultured NSCLC-B and NSCLC-H cells. Further, the cytokine induced a partial activation of both type I and type II IFN-pathway mediators, together with a striking increase in NSCLC-B growth in 3D cell culture systems. Finally, low IFN-γ doses and PD-L1 modulation both promoted plastic changes in NSCLC-B, increasing CD44 expression and its ability to produce spheres.
Conclusions:
Our findings identified plasticity as a relevant hallmark of ICI-mediated HPD by demonstrating that ICIs can modulate the IFN-γ and PD-L1 pathways, driving tumor cell plasticity and fueling HPD development.
Insights
Immune checkpoint inhibitors (ICIs) can paradoxically accelerate cancer, causing hyperprogressive disease (HPD). This study reveals that tumor cell plasticity, driven by interferon-gamma (IFN-γ) and PD-L1 pathway modulation, is a key mechanism fueling HPD in Non-Small Cell Lung Cancer (NSCLC).
Area of Science:
- Oncology
- Immunotherapy
- Cancer Biology
Background:
- Non-Small Cell Lung Cancer (NSCLC) is a leading cause of cancer mortality globally.
- Immune checkpoint inhibitors (ICIs) are effective but can paradoxically cause hyperprogressive disease (HPD).
- The mechanisms underlying HPD development remain largely unknown.
Purpose of the Study:
- To investigate the mechanisms driving ICI resistance and HPD in a Non-Small Cell Lung Cancer (NSCLC) model.
- To explore the role of tumor cell plasticity in the development of hyperprogressive disease (HPD) under ICI treatment.
Main Methods:
- Established and characterized two NSCLC cell lines from patient samples: one before ICI treatment (NSCLC-B) and one during HPD (NSCLC-H).
- Utilized immunofluorescence, Western Blotting, and RNA-Seq for molecular and phenotypic characterization.
- Assessed cell plasticity and aggressiveness using in vitro (2D/3D cultures) and in vivo (patient-derived xenografts) models, including sensitivity to interferon-gamma (IFN-γ) and PD-L1 modulation.
Main Results:
- NSCLC-H cells exhibited increased CD44 isoform expression and enhanced aggressiveness, including organoid formation, compared to NSCLC-B.
- Transcriptome analysis revealed significant shifts in NSCLC-H, impacting IFN-γ-related genes and PD-L1.
- Both NSCLC-B and NSCLC-H showed compromised IFN-γ-mediated growth inhibition; low IFN-γ doses and PD-L1 modulation promoted plasticity and aggressive phenotypes in NSCLC-B.
Conclusions:
- Tumor cell plasticity is a critical hallmark of ICI-mediated HPD.
- ICIs can modulate IFN-γ and PD-L1 pathways, thereby increasing tumor cell plasticity and promoting HPD development in NSCLC.
