Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Genome-wide methylation profiling of multiple sporadic colorectal cancer

ABSTRACT: Background an Aim: Epigenetics are thought to play a major role in the carcinogenesis of patients that develop multiple colorectal cancers (CRC) in the non-hereditary setting. Previous studies have suggested concordant DNA hypermethylation between tumor pairs. However, only a few methylation markers have been analyzed. This study was aimed at describing the underlying epigenetic signature that differentiates multiple from solitary colorectal cancer tumors using a genome-scale DNA methylation profiling. Patients and Methods: We used a population-based cohort (EPICOLON II) of 12 patients with synchronous CRC and 29 age- sex- and tumor location-paired solitary CRC patients. DNA methylation profiling was performed using the Illumina Infinium HM27 DNA methylation assay. The most significantly hypermethylated CpG sites results were validated by Methylight. Tumors samples were also analyzed for the CpG Island Methylator Phenotype (CIMP) using the Infinium DNA methylation data; KRAS and BRAF mutations; microsatellite instability; and immunohistochemistry for MLH1/MSH2/MSH6/PMS2. Functional annotation clustering of differentially methylated genes between multiple and solitary CRCs was performed. Results: We identified 102 CpG sites that showed significant DNA hypermethylation in multiple versus solitary tumors (difference in M-NM-2 value >0.1 and p<0.05). Methylight assays validated the array results for 4 selected significantly hypermethylated genes (MAP1B, HTRA1, ALOX15, TIMP3) identified in the profiling (p=0.0002). Based on the Infinium data, 8/12 (66.6%) of multiple tumors were classified as CIMP-high, as compared to 5/29 (17%) solitary tumors (p=0.004). CIMP-high tumors displayed significant hypermethylation in 301 CpG sites (difference in M-NM-2 value >0.1; p value <0.05). Interestingly, 76/102 (74.5%) of the hypermethylated CpG sites found in multiple vs. solitary tumors were also seen to be hypermethylated in CIMP-H tumors. Functional analysis of hypermethylated genes found in multiple vs. solitary tumors showed the presence and enrichment of genes involved in different tumorigenic functions. Conclusions: Multiple colorectal cancers are associated with a distinct methylation phenotype, with a close association between tumor multiplicity and CIMP-high. Our results may be important to unravel the underlying mechanism of tumor multiplicity in the non-hereditary scenario, and provide novel potential biomarkers for identifying high-risk patients and tailoring surveillance strategies. We used a population-based cohort (EPICOLON II) of 12 patients with synchronous CRC and 29 solitary CRC patients. DNA methylation profiling was performed using the Illumina Infinium HM27 DNA methylation assay.

ORGANISM(S): Homo sapiens

SUBMITTER: Juanjo Lozano

PROVIDER: E-GEOD-52573 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

Multiple sporadic colorectal cancers display a unique methylation phenotype.

Gonzalo Victoria V Lozano Juan Jose JJ Alonso-Espinaco Virginia V Moreira Leticia L Muñoz Jenifer J Pellisé Maria M Castellví-Bel Sergi S Bessa Xavier X Andreu Montserrat M Xicola Rosa M RM Llor Xavier X Ruiz-Ponte Clara C Carracedo Angel A Jover Rodrigo R Castells Antoni A Balaguer Francesc F

PloS one 20140318 3

Epigenetics are thought to play a major role in the carcinogenesis of multiple sporadic colorectal cancers (CRC). Previous studies have suggested concordant DNA hypermethylation between tumor pairs. However, only a few methylation markers have been analyzed. This study was aimed at describing the epigenetic signature of multiple CRC using a genome-scale DNA methylation profiling. We analyzed 12 patients with synchronous CRC and 29 age-, sex-, and tumor location-paired patients with solitary tumo ...[more]

PMID: 24643221

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Project description:Background an Aim: Epigenetics are thought to play a major role in the carcinogenesis of patients that develop multiple colorectal cancers (CRC) in the non-hereditary setting. Previous studies have suggested concordant DNA hypermethylation between tumor pairs. However, only a few methylation markers have been analyzed. This study was aimed at describing the underlying epigenetic signature that differentiates multiple from solitary colorectal cancer tumors using a genome-scale DNA methylation profiling. Patients and Methods: We used a population-based cohort (EPICOLON II) of 12 patients with synchronous CRC and 29 age- sex- and tumor location-paired solitary CRC patients. DNA methylation profiling was performed using the Illumina Infinium HM27 DNA methylation assay. The most significantly hypermethylated CpG sites results were validated by Methylight. Tumors samples were also analyzed for the CpG Island Methylator Phenotype (CIMP) using the Infinium DNA methylation data; KRAS and BRAF mutations; microsatellite instability; and immunohistochemistry for MLH1/MSH2/MSH6/PMS2. Functional annotation clustering of differentially methylated genes between multiple and solitary CRCs was performed. Results: We identified 102 CpG sites that showed significant DNA hypermethylation in multiple versus solitary tumors (difference in β value >0.1 and p<0.05). Methylight assays validated the array results for 4 selected significantly hypermethylated genes (MAP1B, HTRA1, ALOX15, TIMP3) identified in the profiling (p=0.0002). Based on the Infinium data, 8/12 (66.6%) of multiple tumors were classified as CIMP-high, as compared to 5/29 (17%) solitary tumors (p=0.004). CIMP-high tumors displayed significant hypermethylation in 301 CpG sites (difference in β value >0.1; p value <0.05). Interestingly, 76/102 (74.5%) of the hypermethylated CpG sites found in multiple vs. solitary tumors were also seen to be hypermethylated in CIMP-H tumors. Functional analysis of hypermethylated genes found in multiple vs. solitary tumors showed the presence and enrichment of genes involved in different tumorigenic functions. Conclusions: Multiple colorectal cancers are associated with a distinct methylation phenotype, with a close association between tumor multiplicity and CIMP-high. Our results may be important to unravel the underlying mechanism of tumor multiplicity in the non-hereditary scenario, and provide novel potential biomarkers for identifying high-risk patients and tailoring surveillance strategies.

Project description:Purpose: The long-term follow-up results from the EORTC-26951 trial showed that the addition of PCV after radiotherapy increases survival in anaplastic oligodendrogliomas/oligoastrocytomas (AOD/AOA). However, some patients appeared to benefit more from PCV treatment than others. Experimental Design: We performed genome-wide methylation profiling of 115 samples included in the EORTC-26951 trial and extracted the CpG island hypermethylated phenotype (CIMP) and MGMT promoter methylation (MGMT-STP27) status. Results: We first demonstrate that methylation profiling can be performed on archival tissues with a performance that is similar to snap frozen tissue samples. We then performed methylation profiling on EORTC-26951 clinical trial samples. Univariate analysis indicated that CIMP+ or MGMT-STP27 methylated tumors had an improved survival compared to CIMP- and/or MGMT-STP27 unmethylated tumors (median overall survival (OS) 1.05 v. 6.46 years and 1.06 v. 3.8 years, both P<0.0001 for CIMP and MGMT-STP27 status respectively). Multivariable analysis indicates that CIMP and MGMT-STP27 are significant prognostic factors for survival in presence of age, sex performance score and review diagnosis in the model.Multivariate analysis indicates that CIMP and MGMT-STP27 status are prognostic factors for survival independent of age, sex, performance score and review diagnosis. CIMP+ and MGMT-STP27 methylated tumors showed a clear benefit from adjuvant PCV chemotherapy: the median OS of CIMP+ samples in the RT and RT-PCV arms was 3.27 and 9.51 years respectively P=0.0033; for MGMT-STP27 methylated samples it was 1.98 and 8.65 years. There was no such benefit for CIMP- or for MGMT-STP27 unmethylated tumors. MGMT-STP27 status remained significant in an interaction test (P=0.003). Statistical analysis of microarray (SAM) identified 259 novel CpGs associated with treatment response. Conclusions: MGMT-STP27 may be used to guide treatment decisions in this tumor type. Bisulphite converted DNA from the 58 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip The following sample characteristics are provided; OS: overall survival; PFS: progression free survival; CIMP: CpG Island Methylator phenotype; IGS: Intrinsic Glioma subtype; MGMT: O6-methylguanine-DNA-methyltransferase; OR diagn: original diagnosis; Rev diag: review diagnosis; Tum loc: Tumor location; Perf: Performance score; TRT: treatment Performance is based on the ECOG performance status Tum loc: tumor location indicated by 1: Biopsy; 2: Partial Resection; 3: Total Resection. The MGMT promoter methylation status was determined previously (van den Bent et al, J. Clin Oncol 27: 5881-6, 2009) using MS-MLPA and may differ from the MGMT-SPT27 status.

Project description:Purpose: The long-term follow-up results from the EORTC-26951 trial showed that the addition of PCV after radiotherapy increases survival in anaplastic oligodendrogliomas/oligoastrocytomas (AOD/AOA). However, some patients appeared to benefit more from PCV treatment than others. Experimental Design: We performed genome-wide methylation profiling of 115 samples included in the EORTC-26951 trial and extracted the CpG island hypermethylated phenotype (CIMP) and MGMT promoter methylation (MGMT-STP27) status. Results: We first demonstrate that methylation profiling can be performed on archival tissues with a performance that is similar to snap frozen tissue samples. We then performed methylation profiling on EORTC-26951 clinical trial samples. Univariate analysis indicated that CIMP+ or MGMT-STP27 methylated tumors had an improved survival compared to CIMP- and/or MGMT-STP27 unmethylated tumors (median overall survival (OS) 1.05 v. 6.46 years and 1.06 v. 3.8 years, both P<0.0001 for CIMP and MGMT-STP27 status respectively). Multivariable analysis indicates that CIMP and MGMT-STP27 are significant prognostic factors for survival in presence of age, sex performance score and review diagnosis in the model.Multivariate analysis indicates that CIMP and MGMT-STP27 status are prognostic factors for survival independent of age, sex, performance score and review diagnosis. CIMP+ and MGMT-STP27 methylated tumors showed a clear benefit from adjuvant PCV chemotherapy: the median OS of CIMP+ samples in the RT and RT-PCV arms was 3.27 and 9.51 years respectively P=0.0033; for MGMT-STP27 methylated samples it was 1.98 and 8.65 years. There was no such benefit for CIMP- or for MGMT-STP27 unmethylated tumors. MGMT-STP27 status remained significant in an interaction test (P=0.003). Statistical analysis of microarray (SAM) identified 259 novel CpGs associated with treatment response. Conclusions: MGMT-STP27 may be used to guide treatment decisions in this tumor type. Bisulphite converted DNA from the 59 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip The following sample characteristics are provided; OS: overall survival; PFS: progression free survival; CIMP: CpG Island Methylator phenotype; IGS: Intrinsic Glioma subtype; MGMT: O6-methylguanine-DNA-methyltransferase; OR diagn: original diagnosis; Rev diag: review diagnosis; Tum loc: Tumor location; Perf: Performance score; TRT: treatment Performance is based on the ECOG performance status Tum loc: tumor location indicated by 1: Biopsy; 2: Partial Resection; 3: Total Resection. The MGMT promoter methylation status was determined previously (van den Bent et al, J. Clin Oncol 27: 5881-6, 2009) using MS-MLPA and may differ from the MGMT-SPT27 status.

Dataset Information

Genome-wide methylation profiling of multiple sporadic colorectal cancer

Publications

Multiple sporadic colorectal cancers display a unique methylation phenotype.

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