The RESPImmun Faculty

	Julia KARGL, PhD The role of neutrophil-derived myeloperoxidase in non-small-cell lung cancer metastasis
Otto Loewi Research Centre, Division of Pharmacology, Medical University of Graz, Neue Stiftingtalstraße 6, A-8010 Graz; phone: +43-316-385 74105, fax: +43-316-385 79613, ✉ e-mail
websites: [RESPImmun]
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Julia Kargl is a molecular biologist and immunologist with a strong expertise in immunologic mechanisms relevant to cancer biology. Recently she revealed that neutrophils are the predominant immune cells, and that COPD alters immune cell composition and response to checkpoint inhibitors, in non-small-cell lung carcinoma. In RESPImmun, she will investigate the role of myeloperoxidase and its significance as therapeutic target in lung cancer using human tumor samples (Horst Olschewski, Gerald Höfler), mouse models (Leigh Marsh), the biochemical mechanisms (Katharina Leithner).

Project

Project 13: The role of neutrophil-derived myeloperoxidase in non-small-cell lung cancer metastasis
Co-PI: Luka Brčić

Background

We have previously demonstrated that neutrophils are a prevalent immune cell type present in non-small cell lung cancer (NSCLC). Myeloperoxidase (MPO) is a peroxidase enzyme that generates reactive oxygen / nitrogen species and is most abundantly expressed in neutrophils. Upon neutrophil activation, during acute inflammation or in the tumor microenvironment (TME), MPO is secreted into the extracellular milieu during degranulation and utilizes H₂O₂ to hypochlorous acid that reacts with surrounding proteins and cell surface molecules and thereby can alter signaling pathways and cell function. Epithelial-mesenchymal transition (EMT) is a fundamental event for primary tumors to metastasize to distant sites. Altered gene and protein expression causes changes in cell morphology and behavior, resulting in the loss of attachment to neighboring cells, intravasation, and migration into distant tissue. However, the entities residing within the TME that drive EMT are poorly understood.

Hypothesis and objectives

The aim of this study is to identify neutrophil-derived molecules in the TME that affect tumor cell dissemination. We hypothesize that MPO, expressed and released by tumor-associated neutrophils, is affecting tumor cell propagation. Preliminary data in our lab suggest that MPO is capable of entering tumor cells and can alter tumor cell signaling and phenotype. Preliminary mouse experiments revealed reduced primary tumor burden and altered metastatic burden in the absence of MPO. Taken together, these preliminary data suggest a novel aspect of MPO in primary tumor growth and metastasis formation and form the rational to study MPO as a driver of EMT in NSCLC. Understanding the role of neutrophils and MPO in the TME and its role in metastasis may be a crucial step towards the potential clinical use of MPO inhibitors in lung cancer patients.

Methodology

Years 1– 2: The PhD candidate will investigate the mechanism by which MPO affects EMT using lung cancer cell lines in vitro (cell signaling, proliferation, migration, invasion and EMT marker expression and phenotype). Further, transplantable tumor models and LSL-K-ras model of lung adenocarcinoma in the setting of p53 deficiency, a well-established lung cancer mouse model to study metastasis (Kras^LSL-G12D / Trp53^fl/fl / MPO^−/−) will be used). Years 2 – 3: Mouse tumor tissue analysis includes immunohistochemistry, multiplex fluorescence microscopy, flow cytometry, and gene and protein expression analysis. Year 4: Furthermore, we will make use of NSCLC primary tumor and metastasis tissue from consented patients to validate our in vitro and in vivo findings.

Input from collaborations within the RESPImmun programme

Ákos Heinemann will support the student with his expertise in granulocyte biology and functional neutrophil assays,
with Katharina Leithner we will carry out cancer cell signaling experiments,
Gunther Marsche will support the project with his knowledge in MPO function,
Leigh Marsh will support with big data analysis,
Herbert Strobl will assist the student with in vitro co-culture methods,
Gerald Höfler will provide human samples.