76P - Circadian control of neutrophil extracellular trap formation temporally regulates metastatic lung cancer progression

Background

Neutrophils are the first responders of the innate immune system and have been implicated in lung cancer progression and metastasis to secondary organs. Neutrophil trafficking and effector functions are temporally controlled by the chemokine receptor CXCR2 and the circadian rhythm. Due to their diurnal regulation, it remains elusive whether neutrophils can be effectively targeted in lung cancer.

Methods

To study the role of tumor-derived CXCR2 ligands in neutrophil chemoattraction in vitro, we designed a migration assay using microfluidic chips. We developed orthotopic and liver metastasis models of lung cancer using intrathoracic and intrasplenic injections of syngeneic lung adenocarcinoma cells. We combined spectral flow cytometry, immunofluorescence and imaging mass cytometry to assess changes to the immune response. To study the role of the CXCR2 axis in our cancer models, we generated a neutrophil-specific CXCR2 knock-out mouse model or blocked CXCR2 signaling using a small molecule inhibitor.

Results

We show that neutrophil maturation programs, including CXCR2 expression and neutrophil extracellular traps (NETs) formation, accurately predict adverse outcomes in lung adenocarcinoma patients. Using primary and metastatic lung cancers models, we found that tumor-supplied CXCR2 ligands dictate neutrophil recruitment and activation during disease progression. Interestingly, we discovered that lung cancer liver metastases followed a diurnal pattern that coincided with circadian oscillations in circulating neutrophils and NETs. Moreover, quantitative systems modelling identified optimal posological schedules to curb diurnal surges in neutrophil trafficking using CXCR2 inhibitors, which were functionally validated in vivo. Finally, highly multiplexed histological analyses of human lung adenocarcinoma by imaging mass cytometry revealed a robust time-dependent oscillation in neutrophil infiltration, confirming that circadian control of the tumor microenvironment is also present in patients.

Conclusions

Our findings suggest that NET-mediated metastases are time-dependent and support the need for the temporal optimization of immune-based cancer treatments targeting neutrophils.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

The authors.

Funding

The Canadian Institutes of Health Research, the Canadian Cancer Society, the Rosalind and Morris Goodman Cancer Institute, the Brain Tumor Funders’ Collaborative, the McGill Interdisciplinary Initiative in Infection and Immunity, the Montreal General HospitalFoundation Ray Chiu Award, the American Surgical Association, the Cancer Research Society.

Disclosure

P. Fiset: Financial Interests, Personal, Advisory Role: Amgen, Bristol Myers Squibb, F. Hoffmann-La Roche, Merck, Novartis, Pfizer; Financial Interests, Personal, Invited Speaker: Precision Rx-Dx. J. Spicer: Financial Interests, Personal, Advisory Role: Bristol Myers Squibb, Merck, Amgen, AstraZeneca, Protalix, TransHit Bio; Financial Interests, Personal, Sponsor/Funding: AstraZeneca, CLS Therapeutics, Merck, F. Hoffman La Roche. All other authors have declared no conflicts of interest.