Project description:We have isolated Circulating Tumor Cells from four Small Cell Lung Cancer Patients at diagnosis and relapse using a two-step method developed in the laboratory. Subsequently, Whole-Exome sequencing was performed on these samples as well as on the corresponding biopsies.
Project description:Through whole-exome sequencing we identified somatic missense mutations in DICER1 and DROSHA in Wilms tumor, a childhood kidney cancer. DICER1 and DROSHA are key enzymes in the microRNA biogenesis pathway. To determine the effect of these mutations on microRNA expression, we prepared small RNAs from Wilms tumors and used next-generation sequencing to determine the expression levels of microRNAs in the tumors.
Project description:Here we characterize an association between disease progression and DNA methylation in Diffuse Large B cell Lymphoma (DLBCL). By profiling genome-wide DNA methylation at single base-pair resolution in thirteen DLBCL diagnosis-relapse sample pairs, we show DLBCL patients exhibit heterogeneous evolution of tumor methylomes during relapse. We identify differentially methylated regulatory elements and determine a relapse–associated methylation signature converging on key pathways such as transforming growth factor beta (TGF-beta) receptor activity. We also observe decreased intra-tumor methylation heterogeneity from diagnosis to relapsed tumor samples. Relapse-free patients display lower intra-tumor methylation heterogeneity at diagnosis compared to relapsed patients in an independent validation cohort. Furthermore, intra-tumor methylation heterogeneity is predictive of time to relapse. Therefore, we propose that epigenomic heterogeneity may support or drive the relapse phenotype and can be used to predict DLBCL relapse. Using ERRBS, we profiled genome-wide DNA methylation patterns of non-relapse DLBCL tumor samples at diagnosis, relaspe DLBCL patient samples at diagnosis and relaspe.
Project description:Through whole-exome sequencing we identified somatic missense mutations in DICER1 and DROSHA in Wilms tumor, a childhood kidney cancer. DICER1 and DROSHA are key enzymes in the microRNA biogenesis pathway. To determine the effect of these mutations on microRNA expression, we prepared small RNAs from Wilms tumors and used next-generation sequencing to determine the expression levels of microRNAs in the tumors. Comparison of miRNA expression in tumors with and without mutations in DICER1 or DROSHA.
Project description:Triple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer with high intra-tumoral heterogeneity, frequently resistant to treatment and no known targeted therapy available to improve patient outcomes. It has been hypothesized that the genomic architecture of a TNBC tumour evolves over time, both before, and during therapy, leading to therapy resistance and a high propensity to relapse. Whether this is an inherent property of the tumour or acquired over time is not well characterized. Despite this important clinical implication, limited studies have been carried out to unravel temporal evolution of TNBC over time. Herein, we report an OMICS based analysis of three TNBC patients who were longitudinally sampled during their treatment at different times of relapse. We recruited three TNBC patients at the time of their first relapse who were then followed-up through the course of their treatment. We obtained retrospective samples (tumour samples) from patient tumours at diagnosis (before neo-adjuvant chemotherapy - NACT) at surgery (post NACT) and prospectively sampled them at each subsequent relapse (tumour, blood plasma, and buffy coat) as determined by RECIST criteria. Tumor and buffy coat DNA were subjected to whole exome sequencing (WES) at 200x, and SNP arrays for copy number variation (CNV) analysis. RNA from tumour samples at relapse was subjected to whole transcriptome sequencing. Pathogenic germline BRCA1 variants identified in WES were validated using Sanger sequencing. 1084 somatic mutations identified in whole exome sequencing of all tumour tissues (n=13) from three patients, were subjected to a custom amplicon ultra-deep sequencing assay at 30,000X in their germline DNA (n=3), tumour DNA (n=10), and cfDNA from plasma samples at relapse (n=8). Copy number corrected allele frequencies, tumour ploidy, tumour purity, and ultra-deep sequencing assay derived variant allele frequencies were used to infer clonal and phylogenetic architecture of each patient as it evolved under selective pressure of therapy over time. Clonality analysis incorporating allele fractions from ultra-deep sequencing identified clones comprising of mutations that are present throughout the course of therapy which we term as founding clones and stem mutations respectively. Such founding clones comprising of stem mutations in all 3 patients were present throughout the course of treatment, irrespective of change in treatment modalities. These stem clones included well characterized cancer related genes like PDGFRB & ARID2 (Patient 02), TP53, BRAF & CSF3R (Patient 04) and ESR1, APC, EZH2 & TP53 (Patient 07). Such branching evolution is seen in all three patients wherein the dominant clone (stem clone) acquires additional mutations to form sub-clones, while persisting over time. These sub-clones may be chemo and radio resistant, while also providing for organ specific metastatic potential. Allele fractions of expressed variants inferred from RNA-Seq data co-related with allele fractions from WES data indicating that all somatic.
Project description:Triple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer with high intra-tumoral heterogeneity, frequently resistant to treatment and no known targeted therapy available to improve patient outcomes. It has been hypothesized that the genomic architecture of a TNBC tumour evolves over time, both before, and during therapy, leading to therapy resistance and a high propensity to relapse. Whether this is an inherent property of the tumour or acquired over time is not well characterized. Despite this important clinical implication, limited studies have been carried out to unravel temporal evolution of TNBC over time. Herein, we report an OMICS based analysis of three TNBC patients who were longitudinally sampled during their treatment at different times of relapse. We recruited three TNBC patients at the time of their first relapse who were then followed-up through the course of their treatment. We obtained retrospective samples (tumour samples) from patient tumours at diagnosis (before neo-adjuvant chemotherapy - NACT) at surgery (post NACT) and prospectively sampled them at each subsequent relapse (tumour, blood plasma, and buffy coat) as determined by RECIST criteria. Tumor and buffy coat DNA were subjected to whole exome sequencing (WES) at 200x, and SNP arrays for copy number variation (CNV) analysis. RNA from tumour samples at relapse was subjected to whole transcriptome sequencing. Pathogenic germline BRCA1 variants identified in WES were validated using Sanger sequencing. 1084 somatic mutations identified in whole exome sequencing of all tumour tissues (n=13) from three patients, were subjected to a custom amplicon ultra-deep sequencing assay at 30,000X in their germline DNA (n=3), tumour DNA (n=10), and cfDNA from plasma samples at relapse (n=8). Copy number corrected allele frequencies, tumour ploidy, tumour purity, and ultra-deep sequencing assay derived variant allele frequencies were used to infer clonal and phylogenetic architecture of each patient as it evolved under selective pressure of therapy over time. Clonality analysis incorporating allele fractions from ultra-deep sequencing identified clones comprising of mutations that are present throughout the course of therapy which we term as founding clones and stem mutations respectively. Such founding clones comprising of stem mutations in all 3 patients were present throughout the course of treatment, irrespective of change in treatment modalities. These stem clones included well characterized cancer related genes like PDGFRB & ARID2 (Patient 02), TP53, BRAF & CSF3R (Patient 04) and ESR1, APC, EZH2 & TP53 (Patient 07). Such branching evolution is seen in all three patients wherein the dominant clone (stem clone) acquires additional mutations to form sub-clones, while persisting over time. These sub-clones may be chemo and radio resistant, while also providing for organ specific metastatic potential. Allele fractions of expressed variants inferred from RNA-Seq data co-related with allele fractions from WES data indicating that all somatic.
Project description:Relapse of acute myeloid leukemia (AML) is highly aggressive and often treatment refractory. We analyzed previously published AML relapse cohorts and found that 40% of relapses occur without changes in driver mutations, suggesting that non-genetic mechanisms drive relapse in a large proportion of cases. We therefore characterized epigenetic patterns of AML relapse using 26 matched diagnosis-relapse samples with ATAC-seq. This analysis identified a relapse-specific chromatin accessibility signature for mutationally stable AML, suggesting that AML undergoes epigenetic evolution at relapse independent of mutational changes. Analysis of leukemia stem cell (LSC) chromatin changes at relapse indicated that this leukemic compartment underwent significantly less epigenetic evolution than non-LSCs, while epigenetic changes in non-LSCs reflected overall evolution of the bulk leukemia. Finally, we used single-cell ATAC-seq paired with mitochondrial sequencing (mtscATAC) to map clones from diagnosis into relapse along with their epigenetic features. We found that distinct mitochondrially-defined clones exhibit more similar chromatin accessibility at relapse relative to diagnosis, demonstrating convergent epigenetic evolution in relapsed AML. These results demonstrate that epigenetic evolution is a feature of relapsed AML and that convergent epigenetic evolution can occur following treatment with induction chemotherapy.
Project description:Triple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer with high intra-tumoral heterogeneity, frequently resistant to treatment and no known targeted therapy available to improve patient outcomes. It has been hypothesized that the genomic architecture of a TNBC tumour evolves over time, both before, and during therapy, leading to therapy resistance and a high propensity to relapse. Whether this is an inherent property of the tumour or acquired over time is not well characterized. Despite this important clinical implication, limited studies have been carried out to unravel temporal evolution of TNBC over time. Herein, we report an OMICS based analysis of three TNBC patients who were longitudinally sampled during their treatment at different times of relapse. We recruited three TNBC patients at the time of their first relapse who were then followed-up through the course of their treatment. We obtained retrospective samples (tumour samples) from patient tumours at diagnosis (before neo-adjuvant chemotherapy - NACT) at surgery (post NACT) and prospectively sampled them at each subsequent relapse (tumour, blood plasma, and buffy coat) as determined by RECIST criteria. Tumor and buffy coat DNA were subjected to whole exome sequencing (WES) at 200x, and SNP arrays for copy number variation (CNV) analysis. RNA from tumour samples at relapse was subjected to whole transcriptome sequencing. Pathogenic germline BRCA1 variants identified in WES were validated using Sanger sequencing. 1084 somatic mutations identified in whole exome sequencing of all tumour tissues (n=13) from three patients, were subjected to a custom amplicon ultra-deep sequencing assay at 30,000X in their germline DNA (n=3), tumour DNA (n=10), and cfDNA from plasma samples at relapse (n=8). Copy number corrected allele frequencies, tumour ploidy, tumour purity, and ultra-deep sequencing assay derived variant allele frequencies were used to infer clonal and phylogenetic architecture of each patient as it evolved under selective pressure of therapy over time. Clonality analysis incorporating allele fractions from ultra-deep sequencing identified clones comprising of mutations that are present throughout the course of therapy which we term as founding clones and stem mutations respectively. Such founding clones comprising of stem mutations in all 3 patients were present throughout the course of treatment, irrespective of change in treatment modalities. These stem clones included well characterized cancer related genes like PDGFRB & ARID2 (Patient 02), TP53, BRAF & CSF3R (Patient 04) and ESR1, APC, EZH2 & TP53 (Patient 07). Such branching evolution is seen in all three patients wherein the dominant clone (stem clone) acquires additional mutations to form sub-clones, while persisting over time. These sub-clones may be chemo and radio resistant, while also providing for organ specific metastatic potential. Allele fractions of expressed variants inferred from RNA-Seq data co-related with allele fractions from WES data indicating that all somatic.
Project description:Triple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer with high intra-tumoral heterogeneity, frequently resistant to treatment and no known targeted therapy available to improve patient outcomes. It has been hypothesized that the genomic architecture of a TNBC tumour evolves over time, both before, and during therapy, leading to therapy resistance and a high propensity to relapse. Whether this is an inherent property of the tumour or acquired over time is not well characterized. Despite this important clinical implication, limited studies have been carried out to unravel temporal evolution of TNBC over time. Herein, we report an OMICS based analysis of three TNBC patients who were longitudinally sampled during their treatment at different times of relapse. We recruited three TNBC patients at the time of their first relapse who were then followed-up through the course of their treatment. We obtained retrospective samples (tumour samples) from patient tumours at diagnosis (before neo-adjuvant chemotherapy - NACT) at surgery (post NACT) and prospectively sampled them at each subsequent relapse (tumour, blood plasma, and buffy coat) as determined by RECIST criteria. Tumor and buffy coat DNA were subjected to whole exome sequencing (WES) at 200x, and SNP arrays for copy number variation (CNV) analysis. RNA from tumour samples at relapse was subjected to whole transcriptome sequencing. Pathogenic germline BRCA1 variants identified in WES were validated using Sanger sequencing. 1084 somatic mutations identified in whole exome sequencing of all tumour tissues (n=13) from three patients, were subjected to a custom amplicon ultra-deep sequencing assay at 30,000X in their germline DNA (n=3), tumour DNA (n=10), and cfDNA from plasma samples at relapse (n=8). Copy number corrected allele frequencies, tumour ploidy, tumour purity, and ultra-deep sequencing assay derived variant allele frequencies were used to infer clonal and phylogenetic architecture of each patient as it evolved under selective pressure of therapy over time. Clonality analysis incorporating allele fractions from ultra-deep sequencing identified clones comprising of mutations that are present throughout the course of therapy which we term as founding clones and stem mutations respectively. Such founding clones comprising of stem mutations in all 3 patients were present throughout the course of treatment, irrespective of change in treatment modalities. These stem clones included well characterized cancer related genes like PDGFRB & ARID2 (Patient 02), TP53, BRAF & CSF3R (Patient 04) and ESR1, APC, EZH2 & TP53 (Patient 07). Such branching evolution is seen in all three patients wherein the dominant clone (stem clone) acquires additional mutations to form sub-clones, while persisting over time. These sub-clones may be chemo and radio resistant, while also providing for organ specific metastatic potential. Allele fractions of expressed variants inferred from RNA-Seq data co-related with allele fractions from WES data indicating that all somatic.
Project description:Background: The clonal basis of relapse in acute lymphoblastic leukemia (ALL) is complex and not fully understood. Methods: Next-generation sequencing (NGS), array comparative genomic hybridization (aCGH), and multiplex-ligation-dependent probe amplification (MLPA) were carried out in matched diagnosis-relapse samples from 13 B-cell precursor acute lymphoblastic leukemia (BCP-ALL) patients to identify patterns of genetic evolution that could account for the phenotypic changes associated with disease relapse. Findings: The integrative genomic analysis of aCGH, MLPA and NGS revealed that 100% of BCP-ALL patients showed at least one genetic alteration at diagnosis and relapse. In addition, there was a significant increase in the frequency of chromosomal lesions at the time of relapse (median, 6 alterations per sample) relative to that at diagnosis (median, 47 alterations) (p = 0.019). The combination of MLPA and aCGH techniques showed that IKZF1 was the most frequently deleted gene. Notably, TP53 was the most frequently mutated gene at relapse (31%). Two TP53 mutations were detected only at relapse, whereas the three others showed an increase of their mutational burden at relapse. Interpretation: Clonal evolution patterns were heterogeneous, involving acquisition, loss and maintenance of lesions at relapse. Therefore, this study confirmed that BCP-ALL is a genetically dynamic disease with distinct genetic profiles at diagnosis and relapse. The combination of the NGS, aCGH, and MLPA approaches enables better molecular characterization of the genetic profile in ALL patients during the evolution from diagnosis to relapse.