Project description:Human colorectal cancer (CRC) cell lines are a used widely-used to model system for investigation investigate of tumour biology, experimental therapytherapeutic and biomarkers discovery. However, to what extent these established CRC cell lines represent and maintain the genetic diversity of primary cancers is uncertain. In this study, we analyzed 70 CRC cell lines were analysed for mutations using whole exome sequencing and DNA copy-number using by whole-exome sequencing and SNP microarray profilings, respectively. Presence of gGene expression was defined using RNA-Seq. Data from cellCell line datas were was compared to those that published from for primary CRCs published by in The the Cancer Genome Atlas Network. Notably, we found that The spectrum of exome mutations and DNA copy-number aberrations spectra in 70 CRC cell lines closely resembled those seen inat of primary colorectal tumours. Similarities included the presence of at least two hypermutation phenotypes, as defined by signatures of for defective DNA mismatch repair and DNA polymerase ? (POLE) proof-reading deficiency, and along with concordant mutation profiles in the broadly altered WNT, MAPK, PI3K, TGF? and p53 pathways. In additionFurther, we documented mutations were enriched in genes involved in chromatin remodelling (ARID1A, CHD6, SRCAP) and histone methylation or acetylation (ASH1L, EP300, EP400, MLL2, MLL3, PRDM2, TRRAP). Chromosomal instability was prevalent in non-hypermutated cases, with similar patterns of whole, partial and focal chromosomal aberrations and overlapping significant minimal regions ofchromosomal gains and losses. While paired cell lines derived from the same tumour were found to exhibited considerable mutation and DNA copy-number differences, in silico simulations suggest that these differenceslargely mainly reflected a pre-existing heterogeneity in the tumour cells heterogeneity. In conclusion, our results establish that human CRC lines are representative of the main subtypes of primary tumours at the genomic level, further validating underscoring their utility as tools for to investigating investigate CRC biology and drug responses. 69 colorectal cancer cell lines were analysed for DNA copy number profiles.
Project description:Background: Liver metastasis is the major cause of death following a diagnosis of colorectal cancer (CRC) and is a major health burden. Most molecular studies of CRC have profiled primary tumor samples and not the metastasis samples. In this study, we compared the copy number profiles of matched primary and liver metastatic CRC to better understand how the genomic structure of primary CRC differs from the metastasis. This has important implications for whether it is justified to base therapeutic approaches solely on data from the primary tumour. Methods: Paired primary and metastatic tumours from 16 patients and their adjacent normal tissue samples were analyzed using Single-Nucleotide-Polymorphism (SNP) arrays to determine copy number alterations. Nine patients had a synchronous liver metastasis at the time of CRC diagnosis and 7 patients developed a liver metastasis metachronously. Genome-wide chromosomal copy number alterations were assessed, with particular attention to 189 genes known to be somatically altered in CRC and 25 genes that are clinically actionable in CRC. These data were analyzed with respect to the timing of primary and metastatic tissue resection and with exposure to chemotherapy. Results: The genomic divergence with the whole genome duplication correction applied the average percent copy number discordance across all pairs of samples was 22.02%. The pairs of tumour samples collected prior to treatment revealed a significantly higher copy number differences compared to previously treated liver metastasis samples (P=0.024). However, loss of heterozygosity (LOH) acquired in metastasis was significantly higher in previously treated liver metastasis samples compared to treatment naïve liver metastasis samples (P= 0.0064) and which included where KRAS mutation was present in the primary cancers but was not detectable in the metastatic sample following chemotherapy. With regard to 25 genes that are clinically actionable in CRC, amplification of the genes ERBB2, FGFR1, CDK8 or PIK3CA was observed in the metastatic tissue of 4 patients but not in the matched primary CRC. In these cases, knowledge of these metastatic specific alterations could have informed therapeutic decision making and may have improved patient outcome. Conclusion: Intra-patient genomic discrepancies observed between primary and metastatic tissue
Project description:This is a genomic analysis of breast cancer metastasis using array based CGH and is part of a large study investigating the patterns and evolution of metastases from breast cancer using autopsy material accumulated over the last 50 years from a single institution. The samples used in the genomic profiling comprise the primary breast tumour and multiple matched metastases from each patient. The data demonstrate both the clonal nature of metastatic progression and the role of clonal evolution during progression. This study comprises six patients who died of metastatic breast cancer. For some patients the breast primary tumour and lymph node metastasis was obtained from previous surgical excision, otherwise material was obtained from a resulting autopsy. Each patient set of samples involves the primary breast tumour and multiple metastases, including from lung, liver, lymph node, adrenal gland, brain etc. DNA was extracted from formalin fixed paraffin embedded (FFPE) tissue blocks and analysed for DNA copy number alterations using an Agilent aCGH platform.
Project description:We performed whole exome sequencing and copy number analysis for 15 triplets, each comprising normal colorectal tissue, primary colorectal carcinoma, and its synchronous matched liver metastasis. We analyzed the similarities and differences between primary colorectal carcinoma and matched liver metastases in regards to somatic mutations and somatic copy number alterationss (SCNAs). The genomic profiling demonstrated mutations in APC(73%), KRAS (33%), ARID1A and PIK3CA (6.7%) genes between primary colorectal and metastatic liver tumors. TP53 mutation was observed in 47% of the primary samples and 67% in liver metastatic samples. The grouped pairs, in hierarchical clustering showed similar SCNA patterns, in contrast to the ungrouped pairs. Many mutations (including those of known key cancer driver genes) were shared in the grouped pairs. The ungrouped pairs exhibited distinct mutation patterns with no shared mutations in key driver genes. Four ungrouped liver metastasis samples had mutations in DNA mismatch repair genes along with hypermutations and a substantial number of copy number of alterations. Genomically, colorectal and metastatic liver tumors were very similar. However, in a subgroup of patients, there were genetic variations in liver metastases in the loss of DNA mismatch repair genes. Copy number analysis of Affymetrix CytoScanHD arrays was performed for 15 primary colorectal carcinoma and 15 samples of their matched liver metastases. 15 normal samples prepared from each of the patient was used as the reference for the study. Nexus Copy number 6.1 software was used for somatic copy number alteration analysis.
Project description:Medulloblastoma, the most common malignant pediatric brain tumour, disseminates by shedding cells into the cerebrospinal fluid, which then re-implant to cover the surface of the brain and spinal cord. Metastases are a very poor prognostic sign at presentation and are usually lethal at recurrence. Mechanisms driving dissemination have been described in the bulk primary tumour, with the underlying assumption that primary tumour and metastases are biologically similar. Here we show that in both mouse and human medulloblastoma, multiple metastases from a single animal are extremely similar, but are genetically highly divergent from the primary tumour. Clonal genetic events in the metastases can be demonstrated in a restricted sub-clone of the primary tumour, suggesting that only rare cells within the primary tumour have the ability to metastasize. Failure to account for the bicompartmental nature of primary and metastatic medulloblastoma represents a major barrier to the development of effective targeted therapies. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved human medulloblastoma tissue samples. Copy number analysis of Affymetrix SNP6 arrays was performed for 17 pediatric medulloblastoma samples. Samples comprise a series of 7 patient-matched primary/metastatic cases.
Project description:We used copy number analysis of paired primary and relapse ovarian tumours to identify genes associated with acquired resistance Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from ovarian tumours. Copy number profiles of 22 primary and matched ascites samples. Multiple biopsies of four samples were also profiled to assess the intra tumour heterogeneity in samples.
Project description:We performed whole exome sequencing and copy number analysis for 15 triplets, each comprising normal colorectal tissue, primary colorectal carcinoma, and its synchronous matched liver metastasis. We analyzed the similarities and differences between primary colorectal carcinoma and matched liver metastases in regards to somatic mutations and somatic copy number alterationss (SCNAs). The genomic profiling demonstrated mutations in APC(73%), KRAS (33%), ARID1A and PIK3CA (6.7%) genes between primary colorectal and metastatic liver tumors. TP53 mutation was observed in 47% of the primary samples and 67% in liver metastatic samples. The grouped pairs, in hierarchical clustering showed similar SCNA patterns, in contrast to the ungrouped pairs. Many mutations (including those of known key cancer driver genes) were shared in the grouped pairs. The ungrouped pairs exhibited distinct mutation patterns with no shared mutations in key driver genes. Four ungrouped liver metastasis samples had mutations in DNA mismatch repair genes along with hypermutations and a substantial number of copy number of alterations. Genomically, colorectal and metastatic liver tumors were very similar. However, in a subgroup of patients, there were genetic variations in liver metastases in the loss of DNA mismatch repair genes.
Project description:Human colorectal cancer (CRC) cell lines are a used widely-used to model system for investigation investigate of tumour biology, experimental therapytherapeutic and biomarkers discovery. However, to what extent these established CRC cell lines represent and maintain the genetic diversity of primary cancers is uncertain. In this study, we analyzed 70 CRC cell lines were analysed for mutations using whole exome sequencing and DNA copy-number using by whole-exome sequencing and SNP microarray profilings, respectively. Presence of gGene expression was defined using RNA-Seq. Data from cellCell line datas were was compared to those that published from for primary CRCs published by in The the Cancer Genome Atlas Network. Notably, we found that The spectrum of exome mutations and DNA copy-number aberrations spectra in 70 CRC cell lines closely resembled those seen inat of primary colorectal tumours. Similarities included the presence of at least two hypermutation phenotypes, as defined by signatures of for defective DNA mismatch repair and DNA polymerase ε (POLE) proof-reading deficiency, and along with concordant mutation profiles in the broadly altered WNT, MAPK, PI3K, TGFβ and p53 pathways. In additionFurther, we documented mutations were enriched in genes involved in chromatin remodelling (ARID1A, CHD6, SRCAP) and histone methylation or acetylation (ASH1L, EP300, EP400, MLL2, MLL3, PRDM2, TRRAP). Chromosomal instability was prevalent in non-hypermutated cases, with similar patterns of whole, partial and focal chromosomal aberrations and overlapping significant minimal regions ofchromosomal gains and losses. While paired cell lines derived from the same tumour were found to exhibited considerable mutation and DNA copy-number differences, in silico simulations suggest that these differenceslargely mainly reflected a pre-existing heterogeneity in the tumour cells heterogeneity. In conclusion, our results establish that human CRC lines are representative of the main subtypes of primary tumours at the genomic level, further validating underscoring their utility as tools for to investigating investigate CRC biology and drug responses.