Project description:Transcriptional profiling of hyperplastic, metaplastic, and dysplastic lesions of the bronchus in comparison with normal bronchial epithelium. The aim was to identify transcripts and cell signalling pathways associated with the development of isolated premalignant lesions and/or lesions combined with each other in the same bronchial epithelium.
Project description:The human bronchial epithelium is composed of multiple, distinct cell types that cooperate to defend against environmental insults. While studies have shown that smoking alters bronchial epithelial function and morphology, its precise effects on specific cell types and overall tissue composition are unclear. We used single-cell RNA sequencing to profile bronchial epithelial cells from six never- and six current smokers. Unsupervised analyses led to the characterization of a set of toxin metabolism genes that localized to smoker ciliated cells, tissue remodeling associated with a loss of club cells and extensive goblet cell hyperplasia, and a novel peri-goblet epithelial subpopulation in smokers that expressed a marker of bronchial premalignant lesions. Our data demonstrates that smoke exposure drives a complex landscape of cellular alterations that may prime the human bronchial epithelium for disease.
Project description:Bronchial premalignant lesions (PMLs) are composed of expanding bronchial basal cells that can progress to lung squamous cell carcinoma (LUSC) by evading immune responses. Despite ongoing efforts that have mapped gene expression and cell diversity across bronchial PML pathologies, signaling and transcriptional events driving malignancy are poorly understood. Evidence has suggested key roles for the Hippo pathway effectors YAP and TAZ and associated TEAD and TP63 transcription factor families in bronchial basal cell biology and LUSC. In this study we mapped target genes regulated by these factors by combined RNA-seq and ChIP-seq in primary human bronchial epithelial cells, revealing a converged transcriptional network that is strongly associated with bronchial PML progression. Our observations suggest that YAP/TAZ-TEAD-TP63 associate to cooperatively promote basal cell proliferation and repress signals associated with interferon responses and immune cell communication. Directly repressed targets include MHC Class II factors expressed in bronchial epithelium that correlate with adaptive immune Th1 cell activities known to contribute to the immunosuppressive microenvironment in lung cancers. Our findings provide a molecular mechanism for gene regulation in progressive PMLs that contributes to immune evasion, offering potential new avenues for lung cancer interception.
Project description:Lung squamous cell carcinoma (SCC) is thought to arise from premalignant lesions in the airway epithelium, therefore studying these lesions is critical for understanding lung carcinogenesis. We performed RNA sequencing on laser-microdissected representative cell populations along the SCC pathological continuum of patient-matched normal basal cells, premalignant lesions, and tumor cells. We discovered transcriptomic changes and identified genomic pathways altered with initiation and progression of SCC within individual patients. We used immunofluorescent staining to confirm gene expression changes in premalignant lesions and tumor cells, including increased expression of SLC2A1, CEACAM5, and PTBP3 at the protein level and increased activation of MYC via nuclear translocation. Cytoband enrichment analysis revealed coordinated loss and gain of expression in chromosome 3p and 3q regions, respectively, during carcinogenesis. This is the first gene expression profiling of airway premalignant lesions with patient-matched samples that provides insight into the mechanisms of stepwise lung carcinogenesis. Profiling of mRNA expression in laser-microdissected normal airway basal cells, premalignant airway lesions, and lung SCC tumor cells by massively parallel RNA sequencing.
Project description:Bronchial premalignant lesions (PMLs) are composed of expanding bronchial basal cells that can progress to lung squamous cell carcinoma (LUSC) by evading immune responses. Despite ongoing efforts that have mapped gene expression and cell diversity across bronchial PML pathologies, signaling and transcriptional events driving malignancy are poorly understood. Evidence has suggested key roles for the Hippo pathway effectors YAP and TAZ and associated TEAD and TP63 transcription factor families in bronchial basal cell biology and LUSC. In this study we mapped target genes regulated by these factors by combined RNA-seq and ChIP-seq in primary human bronchial epithelial cells, revealing a converged transcriptional network that is strongly associated with bronchial PML progression. Our observations suggest that YAP/TAZ-TEAD-TP63 associate to cooperatively promote basal cell proliferation and repress signals associated with interferon responses and immune cell communication. Directly repressed targets include MHC Class II factors expressed in bronchial epithelium that correlate with adaptive immune Th1 cell activities known to contribute to the immunosuppressive microenvironment in lung cancers. Our findings provide a molecular mechanism for gene regulation in progressive PMLs that contributes to immune evasion, offering potential new avenues for lung cancer interception.