Project description:Colon polyps represent precursor lesions of colon cancers and their malignant potential varies according to histological subtype. A rare subtype of colon polyps is the Peutz-Jeghers (PJ) polyp. PJ polyps mostly occur in the context of Peutz-Jeghers Syndrome which is characterized by the development of multiple polyps in the intestinal tract and hyperpigmentation of oral mucosa and lips. Peutz-Jeghers Syndrome is an autosomal dominant disorder caused by germline mutations of the Serine Threonin Kinase STK11 (LKB1). PJ polyps very rarely occur outside of Peutz-Jeghers Syndrome and are then referred to as solitary PJ polyps. Contrary to Peutz-Jeghers Syndrome, the genetic basis and the malignant potential of solitary PJ polyps is currently unknown. To date, only one study described a sporadic PJ polyp finding no mutations of STK11, indicating that the molecular profile of solitary PJ polyps differs from Peutz-Jeghers syndrome. Methylome analysis revealed global hypomethylation and CpG island hypermethylation, two features that have been described as hallmarks of the colorectal cancer epigenome. These results provide a paradigm for a premalignant lesion that is defined by epigenetic changes.
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: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: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.
Project description:Individuals who present with premalignant endobronchial lesions are considered at high risk of lung cancer. Nonetheless, premalignant lesions behave erratically and only a minority progresses towards lung cancer. Therefore, biomarkers need to be discovered that can aid in assessing an individual’s risk for subsequent cancer to better tailor treatment choices and avoid unnecessary follow-up procedures. We recently proposed a classifier of DNA copy number alterations (CNAs) at 3p26.3-p11.1, 3q26.2-29, and 6p25.3-24.3 as risk predictor for endobronchial cancer. The current study was set out to validate the classifier among an independent series of premalignant endobronchial lesions with various histological grades. A series of 36 endobronchial premalignant lesions (8 squamous metaplasia, and 28 various grades of dysplasia) identified during autofluorescence bronchoscopy of 12 case subjects who had carcinoma in situ or carcinoma (≥CIS) during follow-up bronchoscopy at the initial site and 24 control subjects who remained cancer-free, was subjected to array Comparative Genomic Hybridization (arrayCGH). DNA copy number profiles were related to lesion outcome. Prediction accuracy of the previously defined molecular classifier to predict endobronchial cancer in this series was determined. Unsupervised hierarchical clustering analysis revealed a significant association between cluster assignment and lesion outcome (p< 0.001), independent of histological grade, with quiescent profiles in controls (24/24) and aberrant profiles in the majority of cases (9/12). Our pre-defined classifier demonstrated 92% accuracy for predicting cancer outcome in the current sample series. Our validated classifier holds great promise for stratification of patients with premalignant endobronchial lesions for risk of subsequent cancer. Fresh frozen specimens of 36 premalignant endobronchial biopsies. Test samples were compared to an external pool of normal male/female reference DNA.