Project description:In CRC, 1) to identify epigenetic changes at inter-tumor and intra-tumor level, and 2) to relate intra-tumor clonality to clinical, molecular and histopathologic parameters. From 79 FFPE tumors, 3 different regions were macrodissected: invasive front (IF), digestive tract surface (DTS) and central bulk (CB). Clinical, molecular, and histopathologic parameters were stablished. Epigenetic analysis was performed using Infinium 450K beadchip (Illumina) and R statistics. Intra-tumor regions clustered together by patient. The biggest epigenetic changes were in IF vs DTS/CB. By patient, the most often divergent region was IF (49.4%) comparing with DTS and CB (25.3% in both). It did not correlate with histopathologic, molecular and clinical parameters.Epigenetic clonality is higher at intra-tumor level. The highest changes are observed in IF vs DTS/CB. No association with histopathologic, molecular, and clinical characteristics was found. Cohort of CRC patients (N=17) who recieved quemotherapy (FOLFIRI)
Project description:In CRC, 1) to identify epigenetic changes at inter-tumor and intra-tumor level, and 2) to relate intra-tumor clonality to clinical, molecular and histopathologic parameters. From 79 FFPE tumors, 3 different regions were macrodissected: invasive front (IF), digestive tract surface (DTS) and central bulk (CB). Clinical, molecular, and histopathologic parameters were stablished. Epigenetic analysis was performed using Infinium 450K beadchip (Illumina) and R statistics. Intra-tumor regions clustered together by patient. The biggest epigenetic changes were in IF vs DTS/CB. By patient, the most often divergent region was IF (49.4%) comparing with DTS and CB (25.3% in both). It did not correlate with histopathologic, molecular and clinical parameters.Epigenetic clonality is higher at intra-tumor level. The highest changes are observed in IF vs DTS/CB. No association with histopathologic, molecular, and clinical characteristics was found.
Project description:In CRC, 1) to identify epigenetic changes at inter-tumor and intra-tumor level, and 2) to relate intra-tumor clonality to clinical, molecular and histopathologic parameters. From 79 FFPE tumors, 3 different regions were macrodissected: invasive front (IF), digestive tract surface (DTS) and central bulk (CB). Clinical, molecular, and histopathologic parameters were stablished. Epigenetic analysis was performed using Infinium 450K beadchip (Illumina) and R statistics. Intra-tumor regions clustered together by patient. The biggest epigenetic changes were in IF vs DTS/CB. By patient, the most often divergent region was IF (49.4%) comparing with DTS and CB (25.3% in both). It did not correlate with histopathologic, molecular and clinical parameters.Epigenetic clonality is higher at intra-tumor level. The highest changes are observed in IF vs DTS/CB. No association with histopathologic, molecular, and clinical characteristics was found. Technical replicates of 12 samples previously hybridized on the Infinium HumanMethylation450 to demonstrate technique robustness.
Project description:In CRC, 1) to identify epigenetic changes at inter-tumor and intra-tumor level, and 2) to relate intra-tumor clonality to clinical, molecular and histopathologic parameters. From 79 FFPE tumors, 3 different regions were macrodissected: invasive front (IF), digestive tract surface (DTS) and central bulk (CB). Clinical, molecular, and histopathologic parameters were stablished. Epigenetic analysis was performed using Infinium 450K beadchip (Illumina) and R statistics. Intra-tumor regions clustered together by patient. The biggest epigenetic changes were in IF vs DTS/CB. By patient, the most often divergent region was IF (49.4%) comparing with DTS and CB (25.3% in both). It did not correlate with histopathologic, molecular and clinical parameters.Epigenetic clonality is higher at intra-tumor level. The highest changes are observed in IF vs DTS/CB. No association with histopathologic, molecular, and clinical characteristics was found. SNP characterization of 9 patients of teh discovery cohort were hibridized on Infinium HumanOncoArray-500 v1 beadchip, to asses the genetic clonality of the samples among the three intratumoral regions studied.
Project description:Background: Glioblastoma (GBM) is the most aggressive and currently incurable brain tumor with a median survival of one year in adult patients. Elucidating novel transcriptomic and epigenetic contributors to the molecular heterogeneity underlying its aggressiveness may lead to improved clinical outcomes. Methods: To identify GBM-associated 5-hydroxymethylcytosine (5hmC) and transcriptomic features as well as their cross-talks, genome-wide 5hmC and transcriptomic profiles of tissue samples from 61 patients with GBM and 9 normal controls were obtained for differential and co-regulation/co-modification analyses. Prognostic models on overall survival (OS) based on transcriptomic features and the 5hmC modifications summarized over genic regions (promoters, gene bodies) and brain-derived histone marks were developed using machine learning algorithms. Results: Despite global reduction, the majority of differential 5hmC features showed higher modification levels in GBM tumors as compared to normal controls. In addition, the bi-directional correlations between 5hmC modifications over promoter regions or gene bodies and gene expression were greatly disturbed in GBM tumors regardless of IDH1 mutation status. Phenotype-associated co-regulated 5hmC-5hmC modules and 5hmC-mRNA modules not only are enriched with different molecular pathways that are indicative of the pathogenesis of GBM, but also are of prognostic significance comparable to IDH1 mutation status. Lastly, the best-performing 5hmC model can predict patient survival at a much higher accuracy (c-index = 74%) when compared to conventional prognostic factor IDH1 (c-index = 57%), capturing the molecular characteristics of tumors that are independent of IDH1 mutation status and gene expression-based molecular subtypes. Conclusions: The 5hmC-based prognostic model offers a robust tool to predict survival in GBM patients, outperforming existing prognostic factors such as IDH1 mutations. The crosstalk between 5hmC and gene expression revealed another layer of complexity underlying the molecular heterogeneity in GBM, offering opportunities for identifying novel therapeutic targets.