Prediction of prognosis for small cell lung cancer based on genome-wide methylation analyses with surgical materials and robust clustering methods
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE62021 | GEO | 2014/10/04
SECONDARY ACCESSION(S): PRJNA262968
REPOSITORIES: GEO
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Project description:Methylation is closely involved in the development of various carcinomas. However, little datasets are available for small cell lung carcinoma (SCLC) due to the scarcity of fresh tumor samples. The aim of this study is to investigate the comprehensive genome-wide methylation profile of SCLC to predict the prognosis after surgical treatment. We investigated the high DNA methylated and low gene expression sites using 25 SCLC tumor tissues. First, we selected most differentially methylated CpG sites across the tumor tissues. Following hierarchical clustering (HC) and non-negative matrix factorization (NMF), gene ontology analysis was performed using DAVID software. Clustering of SCLC tumors led to the important identification of a CpG island methylator phenotype (CIMP) of SCLC, and showed that CIMP-high tumors had a significantly poorer prognosis (p = 0.001). Multivariate analysis revealed that postoperative chemotherapy, low neuroendocrine expression and the CIMP-low state were significantly good prognostic factors. Association analyses of methylation and gene expression provided 46 genes with significant correlation. Ontology studies to these genes showed that genes involved in extrinsic apoptosis pathway were suppressed, including TNFRSF1A, TNFRSF10A and TRADD, in CIMP-high tumors, prognosis of which was poorer. By comprehensive DNA methylation profiling, two distinct subgroups were identified to evoke a CIMP of SCLC as a useful marker for determination of treatment. Delineation of this phenotype may also be useful for the development of novel apoptosis-related chemotherapeutic agents for the treatment of an aggressive subtype of SCLC. Comprehensive genome-wide methylation analyses
2014-10-04 | E-GEOD-62021 | biostudies-arrayexpress
Project description:We analyzed 28 fresh frozen samples from pure SCLC patients and 13 noncancerous lung tissues, using the Illumina Infinium 27k Human DNA methylation Beadchip v1.2 Background: Small cell lung cancer (SCLC) accounts for 13-15% of new lung cancer cases in worldwide and has the poor therapeutic outcomes with a median survival of just over one year. A CpG island methylate phenotype (CIMP) is well known as a methylator phenotype with characteristic promoter DNA methylation alterations, in colorectal cancers, glioblastoma and breast cancers, although there has been no report about any CIMP of SCLC. We investigated whether DNA methylation profiles can provide useful molecular subtyping of SCLC in terms of etiology and prognosis of SCLC. Results: We selected a total of 1741 most differentially methylated CpG sites (s.d. > 0.20) across the 28 SCLC tumor tissues in each DNA methylation platform, after an elimination of the probes related with the X- and Y- chromosome. Unsupervised hierarchical clustering of methylation data from SCLC samples reveals two major subgroups with different prognosis: the 5 years disease-free interval (DFI) rate of patients in cluster 1 (11.1%) was lower than that of patients in cluster 2 (61.57%) (p = 0.001). By multivariate analysis for DFI, both postoperative chemotherapy and cluster 1 were a significant prognostic factor (p = 0.002 and 0.002; respectively). Next, among 1220 genes with methylation and expression data both available, the CpG sites were ranked on the basis of the spearman’s correlation coefficient between cluster 1 and cluster 2 into an ascending order. Finally, we identified that fifty-five CpG sites were nagetively correlated and found that apoptosis pathway was a most differentially expressed. Conclusion: By comprehensive DNA methylation profiling, two distinct subgroups with different molecular and clinical phenotype were identified to evoke a CIMP of SCLC. We found some promoter markers in the apoptosis pathway could make a difference between the two groups, and we hope that our data can contribute to provide a useful resource for the construction of therapeutic strategy and the development of a new chemotherapeutic agent. After genomic DNA was treated with sodium bisulfite, bisulfite-converted genomic DNA was analyzed using Illumina’s Infinium HumanMethylation27 BeadChip.
2013-08-29 | E-GEOD-50412 | biostudies-arrayexpress
Project description:We analyzed 28 fresh frozen samples from pure SCLC patients and 13 noncancerous lung tissues, using the Illumina Infinium 27k Human DNA methylation Beadchip v1.2 Background: Small cell lung cancer (SCLC) accounts for 13-15% of new lung cancer cases in worldwide and has the poor therapeutic outcomes with a median survival of just over one year. A CpG island methylate phenotype (CIMP) is well known as a methylator phenotype with characteristic promoter DNA methylation alterations, in colorectal cancers, glioblastoma and breast cancers, although there has been no report about any CIMP of SCLC. We investigated whether DNA methylation profiles can provide useful molecular subtyping of SCLC in terms of etiology and prognosis of SCLC. Results: We selected a total of 1741 most differentially methylated CpG sites (s.d. > 0.20) across the 28 SCLC tumor tissues in each DNA methylation platform, after an elimination of the probes related with the X- and Y- chromosome. Unsupervised hierarchical clustering of methylation data from SCLC samples reveals two major subgroups with different prognosis: the 5 years disease-free interval (DFI) rate of patients in cluster 1 (11.1%) was lower than that of patients in cluster 2 (61.57%) (p = 0.001). By multivariate analysis for DFI, both postoperative chemotherapy and cluster 1 were a significant prognostic factor (p = 0.002 and 0.002; respectively). Next, among 1220 genes with methylation and expression data both available, the CpG sites were ranked on the basis of the spearman’s correlation coefficient between cluster 1 and cluster 2 into an ascending order. Finally, we identified that fifty-five CpG sites were nagetively correlated and found that apoptosis pathway was a most differentially expressed. Conclusion: By comprehensive DNA methylation profiling, two distinct subgroups with different molecular and clinical phenotype were identified to evoke a CIMP of SCLC. We found some promoter markers in the apoptosis pathway could make a difference between the two groups, and we hope that our data can contribute to provide a useful resource for the construction of therapeutic strategy and the development of a new chemotherapeutic agent.
2013-08-29 | GSE50412 | GEO
Project description:The outcome of patients with anaplastic gliomas varies considerably depending on histology and single molecular markers such as codeletion of 1p/19q and mutations of the isocitrate dehydrogenase (IDH) gene. Whether a molecularly-based classification of anaplastic gliomas based on large scale genomic or epigenomic analyses is superior to histopathology, may reflect distinct biological subtypes, predict outcome and guide therapy decisions had yet to be determined. Epigenome-wide DNA methylation analysis, which also allows for the detection of copy-number aberrations, was performed in a cohort of 228 patients with anaplastic gliomas (astrocytomas, oligoastrocytomas and oligodendrogliomas), including 115 patients of the NOA-04 trial. We further compared these tumors with a group of 55 glioblastomas. Unsupervised clustering demonstrated two main groups based on IDH mutation status: CpG island methylator phenotype (CIMP) positive (77.5%) or negative (22.5%). CIMP+ (IDH mutant) tumors showed a further separation based on copy-number status of chromosome arms 1p and 19q, but not based on histopathology. CIMP- (IDH wild type) tumors on the other hand showed hallmark copy-number alterations of glioblastomas. These tumors clustered together with CIMP- glioblastomas without forming separate groups based on WHO grade. There was no Tumor classification based on CIMP and 1p/19q status was significantly associated with survival allowing a better prediction of outcome than the current histopathological classification alone: Patients with CIMP+ tumors with 1p/19q codeletion had the best prognosis, followed by patients with CIMP+ but intact 1p/19q status. Patients with CIMP- anaplastic gliomas had the worst prognosis. Collectively, our data suggest that anaplastic gliomas can be grouped into three molecular subtypes with clear association to underlying biology and clinical outcome based on IDH and 1p/19q status. The data do not provide a molecular basis for the diagnosis of anaplastic oligoastrocytoma. We investigated a subset of 228 anaplastic gliomas using the Illumina 450k methylation array.
2014-06-06 | E-GEOD-58218 | biostudies-arrayexpress
Project description:Aberrant DNA methylation, one of the major epigenetic alterations in cancer, has been reported to accumulate in a subset of colorectal cancer (CRC), so-called CpG island methylator phenotype (CIMP), which was known to correlate with microsatellite instability (MSI)-high CRC. To select new methylation markers genome-widely and epigenotype CRC by DNA methylation comprehensively, we performed methylated DNA immunoprecipitation-on-chip analysis using MSI-high CRC cell line HCT116 and microsatellite-stable SW480, and re-expression array analysis by 5-aza-2-deoxycytidine/Trichostatin A. Methylation levels of 44 new markers selected and 16 previously reported markers were analyzed quantitatively in 149 clinical CRC samples using MALDI-TOF mass spectrometry. By unsupervised two-way hierarchical clustering, CRC was clustered into high-, intermediate-, and low-methylation epigenotypes. Methylation markers were clustered into two groups: Group-1 showing methylation in high-methylation epigenotype and including all the 11 CIMP-related markers except NEUROG1, and Group-2 showing methylation in high- and intermediate-methylation epigenotypes. Marker panel deciding methylation epigenotypes with the highest accuracy was developed: 1st-Panel consisting of Group-1 genes (CACNA1G, LOX, SLC30A10) to extract high-methylation epigenotype, and 2nd-Panel consisting of Group-2 genes (ELMO1, FBN2, THBD, HAND1) and SLC30A10 again to divide the remains into intermediate- and low-methylation epigenotypes. High-methylation epigenotype correlated significantly with BRAF mutation, MSI, proximal tumor location, and mucinous component, in concordance with reported CIMP. Intermediate- and low-methylation epigenotypes significantly correlated with KRAS-mutation(+) and KRAS-mutation(-), respectively. KRAS-mutation(+) intermediate-methylation epigenotype showed worse prognosis than KRAS-mutation(-) low-methylation epigenotype (p=0.030). These three epigenotypes with different genetic characteristics suggested different molecular CRC genesis, and the markers might be useful to predict prognosis.
2010-01-05 | GSE14526 | GEO
Project description:The CpG island methylator phenotype (CIMP) in colorectal tumors can be recognized by an increased frequency of aberrant methylation in a specific set of genomic loci. Because of the strong association of CIMP with high microsatellite instability (MSI-H), the identification of CIMP+ tumors within microsatellite stable (MSS) colorectal cancers may not be straightforward. To overcome this potential limitation, we have built an improved 7-loci set of methylation markers that includes CACNA1G, IGF2, RUNX3, HTR6, RIZ1, MINT31 and MAP1B. This new set of CIMP markers revealed a bimodal distribution of methylation frequencies in a group of 95 MSS colorectal cancers, which allowed a clearer separation between CIMP classes. Correlation of CIMP+ tumors with bio-pathological traits revealed significant associations with location to the proximal colon, mucinous histology and chromosomal stability. Although not statistically significant, a trend toward an adverse prognosis for CIMP+ cases was observed. Microarray analysis revealed that CIMP+ tumors are characterized by a unique expression profile, a result that confirms that CIMP+ tumors represent a distinct molecular class within MSS colorectal cancers. Moreover, our results suggest that this expression pattern may represent the molecular background for the development of CIMP+ tumors that, in turn, develop MSI when aberrant methylation occurs at the MLH1 gene promoter.
2008-01-01 | E-TABM-328 | biostudies-arrayexpress
Project description:The outcome of patients with anaplastic gliomas varies considerably depending on histology and single molecular markers such as codeletion of 1p/19q and mutations of the isocitrate dehydrogenase (IDH) gene. Whether a molecularly-based classification of anaplastic gliomas based on large scale genomic or epigenomic analyses is superior to histopathology, may reflect distinct biological subtypes, predict outcome and guide therapy decisions had yet to be determined. Epigenome-wide DNA methylation analysis, which also allows for the detection of copy-number aberrations, was performed in a cohort of 228 patients with anaplastic gliomas (astrocytomas, oligoastrocytomas and oligodendrogliomas), including 115 patients of the NOA-04 trial. We further compared these tumors with a group of 55 glioblastomas. Unsupervised clustering demonstrated two main groups based on IDH mutation status: CpG island methylator phenotype (CIMP) positive (77.5%) or negative (22.5%). CIMP+ (IDH mutant) tumors showed a further separation based on copy-number status of chromosome arms 1p and 19q, but not based on histopathology. CIMP- (IDH wild type) tumors on the other hand showed hallmark copy-number alterations of glioblastomas. These tumors clustered together with CIMP- glioblastomas without forming separate groups based on WHO grade. There was no Tumor classification based on CIMP and 1p/19q status was significantly associated with survival allowing a better prediction of outcome than the current histopathological classification alone: Patients with CIMP+ tumors with 1p/19q codeletion had the best prognosis, followed by patients with CIMP+ but intact 1p/19q status. Patients with CIMP- anaplastic gliomas had the worst prognosis. Collectively, our data suggest that anaplastic gliomas can be grouped into three molecular subtypes with clear association to underlying biology and clinical outcome based on IDH and 1p/19q status. The data do not provide a molecular basis for the diagnosis of anaplastic oligoastrocytoma.
2014-06-06 | GSE58218 | GEO
Project description:Ependymomas are common childhood brain tumors that occur throughout the nervous system, but are most common in the pediatric hindbrain. Current standard therapy comprises surgery and radiation, but not cytotoxic chemotherapy as it does not further increase survival. Whole-genome and whole-exome sequencing of 47 hindbrain ependymomas reveals an extremely low mutation rate, and zero significant recurrent somatic SNVs. While devoid of recurrent SNVs and focal copy number aberrations, poor prognosis hindbrain ependymomas exhibit a CpG island methylator phenotype (CIMP). Transcriptional silencing driven by CpG methylation converges exclusively on targets of the polycomb repressor complex 2 (PRC2) that represses expression of differentiation genes through tri-methylation of H3K27. CIMP-positive (CIMP+) hindbrain ependymomas are responsive to clinical drugs that target either DNA or H3K27 methylation both in vitro and in vivo. We conclude that epigenetic modifiers are the first rational therapeutic candidates for this deadly malignancy, which is epigenetically de-regulated but genetically bland. 10 primary posterior fossa ependymomas have been analyzed
2014-03-15 | E-GEOD-55920 | biostudies-arrayexpress
Project description:Small cell lung cancer (SCLC) is a disease characterized by aggressive clinical behavior and lack of effective therapy. Due to its high tendency of early dissemination, only a third of patients have limited-stage disease at the time of diagnosis. SCLC is thought to derive from neuroendocrine cells of the lung. Although several molecular abnormalities in SCLC have been described, there are relatively few studies on epigenetic alterations in this type of tumor. Here, we have used methylation profiling with the methylated CpG island recovery assay (MIRA) in combination with microarrays and conducted the first genome-scale analysis of methylation changes that occur in primary SCLC and SCLC cell lines. Among hundreds of tumor-specifically methylated genes, we identified 73 gene targets that are methylated in more than 77% of primary SCLC tumors, most of which have never been linked to aberrant methylation in tumors. These targets have excellent potential for development of biomarkers for early detection of SCLC. SCLC cell lines had an ~3-fold greater number of hypermethylated genes than primary tumors. Gene ontology analysis indicated a significant enrichment of methylated genes functioning as transcription factors and in processes of neuronal differentiation. Motif analysis of tumor-specific methylated regions identified enrichment of binding sites for several neural cell fate-specifying transcription factors including NEUROD1, HAND1, ZNF423 and REST. We hypothesize that functional inactivation of their corresponding binding sites by DNA methylation can lead to an escape route for early progenitor cells towards the malignant state and may contribute to the origin of SCLC. Comparison between healthy and SCLC tumor DNA methylation profiles
2012-01-26 | E-GEOD-35341 | biostudies-arrayexpress
Project description:Ependymomas are common childhood brain tumors that occur throughout the nervous system, but are most common in the pediatric hindbrain. Current standard therapy comprises surgery and radiation, but not cytotoxic chemotherapy as it does not further increase survival. Whole-genome and whole-exome sequencing of 47 hindbrain ependymomas reveals an extremely low mutation rate, and zero significant recurrent somatic SNVs. While devoid of recurrent SNVs and focal copy number aberrations, poor prognosis hindbrain ependymomas exhibit a CpG island methylator phenotype (CIMP). Transcriptional silencing driven by CpG methylation converges exclusively on targets of the polycomb repressor complex 2 (PRC2) that represses expression of differentiation genes through tri-methylation of H3K27. CIMP-positive (CIMP+) hindbrain ependymomas are responsive to clinical drugs that target either DNA or H3K27 methylation both in vitro and in vivo. We conclude that epigenetic modifiers are the first rational therapeutic candidates for this deadly malignancy, which is epigenetically de-regulated but genetically bland.
2014-03-15 | GSE55920 | GEO