Project description:This is a hypothesis driven, open label, single-arm, multiple centers, Phase II trial. The trial has been designed to prove or disprove whether a rechallenge with panitumumab can achieve an objective response rate (ORR= CR+PR) of 30% or more in a population of RAS wild type mCRC patients selected on the basis of RAS extended clonal evolution in their plasma.
Project description:Clonal diversity contributes to treatment resistance and cancer recurrence. Precise delineation of clonal substructure is essential to understand the resistance mechanism, however, bulk DNA sequencing cannot accurately resolve the complex clonal architectures. Here we report the single-cell DNA sequencing of 123 acute myeloid leukemia (AML) patients and provide cell-level evidence of co-occurrence and mutual exclusivity among driver mutations. Reconstruction of tumor phylogeny uncovers linear and branching clonal evolution patterns, with the latter involving functional convergence. Single-cell DNA sequencing of xenotransplanted samples reveales clonal diversity in leukemia initiating cell populations. Simultaneous single-cell profiling of mutations and cell surface proteins provides cellular genotype-phenotype associations. Analysis of longitudinal samples visualizes the behavior of each individual clone in response to therapy, illustrating the underlying evolutionary process of therapeutic resistance and disease recurrence. Together, these data portray clonal diversity, architecture, and evolution of AML, and highlight their clinical relevance in the era of precision medicine.
Project description:Divergence of K-562 genomes through in vitro clonal evolution revealed by comparing three sublines. Comparison of three K-562 sublines
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.
Project description:Recurrences of diffuse large B-cell lymphomas (DLBCL) result in significant morbidity and mortality, but their underlying genetic and biological mechanisms are unclear. Clonal relationship in DLBCL relapses so far is mostly addressed by the investigation of immunoglobulin (IG) rearrangements, therefore lacking deeper insights into genome-wide lymphoma evolution. We studied mutations and copy number aberrations in 20 paired relapsing and 20 non-relapsing DLBCL cases aiming to test the clonal relationship between primaries and relapses, to track tumors’ genetic evolution and to investigate the genetic background of DLBCL recurrence. Three clonally-unrelated DLBCL relapses were identified (15%). Also, two distinct patterns of genetic evolution in clonally-related relapses were detected: (1) early-divergent/branching evolution from a common progenitor in 6 patients (30%), and (2) late-divergent/linear progression of relapses in 11 patients (65%). Analysis of recurrent genetic events identified potential early drivers of lymphomagenesis (KMT2D, MYD88, CD79B and PIM1). The most frequent relapse-specific events were additional mutations in KMT2D and alterations of MEF2B. SOCS1 mutations were exclusive to non-relapsing DLBCL, whereas primaries of relapsing DLBCL more commonly displayed gains of 10p15.3-p12.1 containing the potential oncogenes PRKCQ, GATA3, MLLT10 and ABI1. Altogether, our study expands knowledge on clonal relationship, genetic evolution and mutational basis of DLBCL relapses.
Project description:Understanding clonal evolution and cancer development requires experimental approaches for characterizing the consequences of somatic mutations on gene regulation. However, no methods currently exist that efficiently link chromatin accessibility with genotype in single cells. To address this, we developed Genotyping with the Assay for Transposase-Accessible Chromatin (GTAC), enabling accurate mutation detection at multiple amplified loci, coupled with robust chromatin accessibility readout. We applied GTAC to primary acute myeloid leukemia, obtaining high-quality chromatin accessibility profiles and clonal identities for multiple mutations in 88% of cells. We traced chromatin variation throughout clonal evolution, showing the restriction of different clones to distinct differentiation stages. Furthermore, we identified switches in transcription factors motif accessibility associated with a specific combination of driver mutations, which biased transformed progenitors towards a leukemia stem cell-like chromatin state. GTAC is a powerful tool to study clonal heterogeneity across a wide spectrum of pre-malignant and neoplastic conditions.
Project description:Clonal and subclonal evolution is involved in the progression of chronic lymphocytic leukemia (CLL). Evolution can work to select not only genetic mutations, but also epigenetic states. Here we performed a long-term longitudinal DNA methylation profiling study of CLL patients to look for associations of epigenetic evolution to different disease courses. In line with the genetic data, large-scale methylation evolution was not present in any of the evaluated long-term untreated (n = 3) and relapsed (n = 2) patients displaying clonal changes of linear type while 3 of the 5 examined refractory patients featured profound changes in DNA methylation.
Project description:Hereditary endocrine neoplasias, including phaeochromocytoma/paraganglioma (PPGL) and medullary thyroid cancer (MTC), are caused by autosomal dominant mutations in a multitude of familial cancer genes. A common feature of these diseases is the presentation of multiple primary tumours or multifocal disease representing independent tumour clones that have arisen from the same initiating genetic lesion but have undergone independent clonal evolution. Such tumours provide a unique opportunity to discover common co-operative changes required for tumorigenesis while controlling for the genetic background of the individual. We performed an in-depth genomic analysis of synchronous and metachronous tumours from five patients harbouring germline mutations in the genes SDHB, RET and MAX. Using whole exome sequencing and high-density SNP-arrays we analyzed between two and four primary tumours from each patient. Furthermore, we applied multi-regional sampling to assess intra-tumoral heterogeneity and clonal evolution in two cases involving PPGL and MTC, respectively. Heterogeneous patterns of genomic change existed between synchronous or metachronous tumours with evidence of branching evolution. We observed striking examples of evolutionary convergence involving the same rare somatic copy-number events in synchronous primary PPGL. Convergent events also occurred during clonal evolution of metastatic MTC. These observations suggest that genetic or epigenetic changes acquired early within precursor cells, or pre-existing within the genetic background of the individual, create contingencies that determine the evolutionary trajectory of the tumour.