Project description:Primary tumor recurrence occurs commonly after surgical resection of lung squamous cell carcinoma (SCC). The aim of this study was to identify genes involved in recurrence in lung squamous cell carcinoma patients. Array comparative genomic hybridization (aCGH) was performed on DNA extracted from tumour tissue from 62 patients with primary lung squamous cell carcinomas. aCGH data was analysed to identify genes affected by copy number alterations that may be involved in SCC recurrence. Candidate genes were then selected for technical validation based on differential copy number between recurrence and non-recurrence SCC tumour samples. Genes technically validated advanced to tests of biological replication by qPCR using an independent test set of 72 primary lung SCC tumour samples. 18q22.3 loss was identified by aCGH as significantly associated with recurrence (p=0.038). Although aCGH copy number loss associated with recurrence was found for seven genes within 18q22.3, only SOCS6 copy number loss was both technically replicated by qPCR and biologically validated in the test set. DNA copy number profiling using 44K element array comparative genomic hybridization microarrays of 62 primary lung squamous cell carcinomas.
Project description:Primary tumor recurrence occurs commonly after surgical resection of lung squamous cell carcinoma (SCC). The aim of this study was to identify genes involved in recurrence in lung squamous cell carcinoma patients. Array comparative genomic hybridization (aCGH) was performed on DNA extracted from tumour tissue from 62 patients with primary lung squamous cell carcinomas. aCGH data was analysed to identify genes affected by copy number alterations that may be involved in SCC recurrence. Candidate genes were then selected for technical validation based on differential copy number between recurrence and non-recurrence SCC tumour samples. Genes technically validated advanced to tests of biological replication by qPCR using an independent test set of 72 primary lung SCC tumour samples. 18q22.3 loss was identified by aCGH as significantly associated with recurrence (p=0.038). Although aCGH copy number loss associated with recurrence was found for seven genes within 18q22.3, only SOCS6 copy number loss was both technically replicated by qPCR and biologically validated in the test set.
Project description:Lung cancer is the leading cause of preventable death globally and is broadly classified into adenocarcinoma and squamous cell carcinoma depending upon cell type. In this study, we carried out mass spectrometry based quantitative proteomic analysis of lung adenocarcinoma and squamous cell carcinoma primary tissue by employing the isobaric tags for relative and absolute quantitation (iTRAQ) approach. Proteomic data was analyzed using SEQUEST search algorithm which resulted in identification of 25,998 peptides corresponding to 4,342 proteins of which 610 proteins were differentially expressed (≥ 2-fold) between adenocarcinoma and squamous cell carcinoma samples. These differentially expressed proteins were further classified by gene ontology for their localizations and biological processes. Pathway analysis of differentially expressed proteins revealed distinct alterations in networks and pathways in both adenocarcinoma and squamous cell carcinoma samples. In this study, we identified a subset of proteins that shows converse expression between lung adenocarcinoma and squamous cell carcinoma samples. Such proteins may serve as signature markers to distinguish between the two subtypes.
Project description:Lung cancer remains the leading cause of cancer death worldwide. Overall 5-year survival is about 10-15% and despite curative intent surgery, treatment failure is primarily due to recurrent disease. Conventional prognostic markers are unable to determine which patients with completely resected disease within each stage group are likely to relapse. To identify a gene signature associated with recurrent squamous cell carcinoma (SCC) of lung, we analyzed primary tumour gene expression for a total of fifty-one SCCs (stage I-III) on 22,323 element microarrays, comparing expression profiles for individuals who remained disease-free for a minimum of 36 months with those from individuals whose disease recurred within 18 months of complete resection. Cox proportional hazards modeling with leave-one-out cross-validation identified a 70-gene capable of predicting the likelihood of tumor recurrence and a 79-gene signature predictive for overall survival. These two signatures were pooled to generate a 111-gene classifier which achieved an overall predictive accuracy for disease recurrence of 72% (77% sensitivity, 67% specificity) in an independent set of fifty-eight stage I-III SCCs. This classifier also predicted differences in survival (log-rank P=0.0008, hazard ratio (HR), 3.8 [95% confidence interval, 1.6-8.7]), and was superior to conventional prognostic markers such as TNM stage or N stage in predicting patient outcome. Genome-wide profiling has revealed a distinct gene expression profile for recurrent lung SCC which may be clinically useful as a prognostic tool. Keywords: non-small cell lung carcinoma, squamous cell, tumor recurrence, expression profiling
Project description:Lung cancer remains the leading cause of cancer death worldwide. Overall 5-year survival is about 10-15% and despite curative intent surgery, treatment failure is primarily due to recurrent disease. Conventional prognostic markers are unable to determine which patients with completely resected disease within each stage group are likely to relapse. To identify a gene signature associated with recurrent squamous cell carcinoma (SCC) of lung, we analyzed primary tumour gene expression for a total of fifty-one SCCs (stage I-III) on 22,323 element microarrays, comparing expression profiles for individuals who remained disease-free for a minimum of 36 months with those from individuals whose disease recurred within 18 months of complete resection. Cox proportional hazards modeling with leave-one-out cross-validation identified a 70-gene capable of predicting the likelihood of tumor recurrence and a 79-gene signature predictive for overall survival. These two signatures were pooled to generate a 111-gene classifier which achieved an overall predictive accuracy for disease recurrence of 72% (77% sensitivity, 67% specificity) in an independent set of fifty-eight stage I-III SCCs. This classifier also predicted differences in survival (log-rank P=0.0008, hazard ratio (HR), 3.8 [95% confidence interval, 1.6-8.7]), and was superior to conventional prognostic markers such as TNM stage or N stage in predicting patient outcome. Genome-wide profiling has revealed a distinct gene expression profile for recurrent lung SCC which may be clinically useful as a prognostic tool. Expression profiling using 22K element microarrays of 51 primary lung squamous cell carcinomas.