Mapping the oncogenic microenvironment throughout the establishment of bronchial pre-cancerous lesions and their progression to carcinoma

• Applicant: Dr. Roxana Pfefferkorn
• Subject Area: Hematology, Oncology ; Cell Biology
• Term: from 2021 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 453309893

About 30% of all lung cancers originate in the bronchial airways in the form of lung squamous cell carcinoma (LUSC). The development of LUSC is preceded by the successive progression of dysplastic pre-malignant lesions (PMLs). Over time most of these lesions will naturally regress, however, a subset progresses to frank carcinoma. To date biomedical researchers are unable to identify lesions that will require medical intervention. Understanding the molecular mechanisms determining lesion fate is critical to facilitate early identification of progressing lesions and to develop novel interventions to reverse dysplasia. Continuous smoke exposure creates promotes airway remodeling and is the main risk factor for LUSC. The earliest smoke-induced tissue abnormalities of the bronchial epithelium are regions of goblet cell hyperplasia (GCH). A novel pathway of goblet cell differentiation that gives rise to previously undescribed peri-goblet cells (PGCs) was recently identified in areas of GCH in smokers. With lesion progression, PGCs become increasingly abundant while differentiated goblet cells are depleted. I will expose differentiated bronchial-epithelial cell cultures to combinations of cigarette smoke, genomic mutations and immune stimulation to promote the transition of GCH to high-grade PMLs. Using multiplexed immunofluorescence and scRNA-sequencing, I will trace the trajectory of PGCs during lesion progression and identify the molecular drivers during smoking-dependent epithelial dysplasia. Besides inducing tissue remodeling, smoke exposure leads to a disruption of the innate and adaptive immune response. A recently identified molecular subtype of PMLs shows distinct down-regulation of various immune components, expresses high levels of growth related pathways and is strongly associated with high-grade lesions. Additionally, this proliferative subtype shows strong up-regulation of the PGC signature. I propose to utilize longitudinally collected biopsy samples to map the pre-malignant tumor microenvironment throughout PML development, providing unprecedented insights into progression-driving immune mechanisms by identifying activated immune cell populations, their tissue infiltration and the immuno-epithelial crosstalk.The objective of this study is to track smoke-associated lung lesions and their molecular drivers throughout lesion progression. I hypothesize that smoke exposure and immune dysregulation disrupt the genetic stability and epithelial homeostasis thereby modifying airway epithelial cell differentiation. The interaction of epithelial cells with the immune system creates immunological blind spots in which PMLs progress to frank carcinoma. I will test this hypothesis on the epithelial level in vitro by identifying the trajectory of PGC and their role in smoke-associated lesion progression (aim 1) and on the tissue level by imaging the immune activity and the immuno-epithelial crosstalk throughout each stage of dysplasia (aim 2).

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professorin Sarah Mazzilli, Ph.D.