Project description:Understanding intratumor heterogeneity is clinically important because it could cause therapeutic failure by fostering evolutionary adaptation. To this end, we profiled the genome and epigenome in multiple regions within each of nine colorectal tumors. Extensive intertumor heterogeneity is observed, from which we inferred the evolutionary history of the tumors. First, clonally shared alterations appeared, in which C>T transitions at CpG site and CpG island hypermethylation were relatively enriched. Correlation between mutation counts and patients’ ages suggests that the early-acquired alterations resulted from aging. In the late phase, a parental clone was branched into numerous subclones. Known driver alterations were observed frequently in the early-acquired alterations, but rarely in the late-acquired alterations. Consistently, our computational simulation of the branching evolution suggests that extensive intratumor heterogeneity could be generated by neutral evolution. Collectively, we propose a new model of colorectal cancer evolution, which is useful for understanding and confronting this heterogeneous disease.
Project description:Understanding intratumor heterogeneity is clinically important because it could cause therapeutic failure by fostering evolutionary adaptation. To this end, we profiled the genome and epigenome in multiple regions within each of nine colorectal tumors. Extensive intertumor heterogeneity is observed, from which we inferred the evolutionary history of the tumors. First, clonally shared alterations appeared, in which C>T transitions at CpG site and CpG island hypermethylation were relatively enriched. Correlation between mutation counts and patients’ ages suggests that the early-acquired alterations resulted from aging. In the late phase, a parental clone was branched into numerous subclones. Known driver alterations were observed frequently in the early-acquired alterations, but rarely in the late-acquired alterations. Consistently, our computational simulation of the branching evolution suggests that extensive intratumor heterogeneity could be generated by neutral evolution. Collectively, we propose a new model of colorectal cancer evolution, which is useful for understanding and confronting this heterogeneous disease.
Project description:Understanding intratumor heterogeneity is clinically important because it could cause therapeutic failure by fostering evolutionary adaptation. To this end, we profiled the genome and epigenome in multiple regions within each of eight colorectal tumors. Extensive intertumor heterogeneity is observed, from which we inferred the evolutionary history of the tumors. First, clonally shared alterations appeared, in which C>T transitions at CpG site and CpG island hypermethylation were relatively enriched. Correlation between mutation counts and patients’ ages suggests that the early-acquired alterations resulted from aging. In the late phase, a parental clone was branched into numerous subclones. Known driver alterations were observed frequently in the early-acquired alterations, but rarely in the late-acquired alterations. Consistently, our computational simulation of the branching evolution suggests that extensive intratumor heterogeneity could be generated by neutral evolution. Collectively, we propose a new model of colorectal cancer evolution, which is useful for understanding and confronting this heterogeneous disease.
Project description:A core task to understand the consequences of non-coding single nucleotide polymorphisms (SNP) is to identify their genotype specific binding of transcription factor (TF). Here, we generate a large-scale TF-SNP interaction map for a selection of 116 colorectal cancer (CRC) risk loci and validated TF binding to 10 putatively functional SNPs. Our data further revealed TF binding complexity adjacent to the 116 risk loci, adding an additional layer of understanding to regulatory networks associated with CRC relevant loci.
Project description:Structural changes of chromosomes play important roles in the carcinogenesis of colorectal carcinoma (CRC). Here, by using SNP-typing arrays, we have tried to screen for recurrent chromosome copy number changes and loss-of-heterozygosity in the genome of colorectal carcinoma. Genomic DNA was isolated from tumor and paired normal tissues of CRC (n=94), and was hybridized to Affymetrix Mapping 50K Xba 240 arrays. Chromosome copy number and LOH likelihood score was inferred at every SNP locus with CNAG2.0 software (http://www.genome.umin.jp). Keywords: Comparative genomic hybridization
Project description:Nasopharyngeal carcinoma (NPC) has extremely skewed ethnic and geographic distributions, is poorly understood at the genetic level and is in need of effective therapeutic approaches. We determined the genomic landscape of 52 NPC cases with SNP-array analysis. This approach identified multiple recurrent SCNVs, with the most frequent deletion peak spanning the CDKN2A gene on 9p21. Additional SCNVs involving established cancer genes including CCND1, AKT2, MYC and TP53 were observed. Notably, we identified that one component of the SWI/SNF complex, ARID1A, was frequently deleted in NPC. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from fresh frozen nasopharyngeal carcinoma biopsy tissues Copy number analysis of Affymetrix 250K SNP arrays was performed for 52 nasopharyngeal carcinoma samples. Please note that the sample characteristics 'primary tumor size, metastasis, and regional lymph node' represents T, M and N in WHO TNM staging of nasopharyngeal cancer (according to American Joint Committee on Cancer (AJCC)), respectively.
Project description:A core task to understand the consequences of non-coding single nucleotide polymorphisms (SNP) is to identify their genotype specific binding of transcription factor (TF). Here, we generate a large-scale TF-SNP interaction map for a selection of 116 colorectal cancer (CRC) risk loci and validated TF binding to 10 putatively functional SNPs. Our data further revealed TF binding complexity adjacent to the 116 risk loci, adding an additional layer of understanding to regulatory networks associated with CRC relevant loci.