scRNA-seq of patient-derived PDAC organoids
We derived PDAC organoids from primary tumors of 18 patients, together with two matched samples from liver metastases. By single-cell RNA sequencing, we show that PDAC organoids consist of ductal cells with patient-specific expression of several gene groups, including genes which encode cell surface proteins. We report ‘classical’ and ‘basal-like’ cells coexisting within single primary tumors or metastases, with greater intratumor subtype heterogeneity linked to higher tumor grade. Single-cell transcriptome analysis of PDAC organoids and primary PDAC identified distinct tumor cell states shared across patients, including a cycling progenitor cell state and a differentiated secretory state. We show that these cell states are connected by a differentiation hierarchy, with ‘classical’ subtype cells concentrated at the endpoint of this hierarchy.
Study
EGAS00001004661
Whole genome sequencing of Sinonasal hemangiopericytoma and patient derived cell line model
Solitary fibrous tumor/Hemangiopericytoma (SFT/HPC) is a rare subtype of soft tissue sarcoma associated with NAB2-STAT6 gene fusions. This study established and characterized a novel SFT/HPC patient-derived cell line called SFT-S1 using whole genome sequencing.
Study
EGAS50000000025
ICARUS-LUNG01-RNAseq
Bulk RNA-seq was carried out on 20 pairs of frozen tumor biopsies. Differential gene expression (DGE) analyses was conducted, looking at the fold change of gene expression of matched on-T/BL samples in the overall population and, then, separately in responders and non-responders.
Study
EGAS50000000732
Circulating tumor cells for comprehensive and multiregional non-invasive genetic characterization of multiple myeloma
Study
EGAS00001004288
Pancreatic, Small-intestinal and Pulmonary Neuroendocrine Tumors
Purpose: The primary origin of neuroendocrine tumor metastases can be difficult to determine by histopathology alone, but is critical for therapeutic decision making. DNA methylation-based profiling is now routinely used in the diagnostic workup of brain tumors. This has been enabled by the availability of cost-efficient array-based platforms. We have extended these efforts to augment histopathological diagnosis in neuroendocrine tumors.
Experimental Design and Results: We compiled data of 69 small-intestinal, pulmonary, and pancreatic neuroendocrine tumors. These data were used to build a ridge regression calibrated random forest classification algorithm (NEN-ID) that predicts the origin of tumor samples with high accuracy (> 95%). The model was validated during 3x3 nested cross validation and tested in a local (n=26) and external (n=172) cohort. In addition, we show that our diagnostic approach is robust across a range of possible confounding experimental parameters such as tumor purity and array quality. A software infrastructure and online user interface was built to make the model available to the scientific community.
Conclusions: This DNA methylation-based prediction model can be used in the workup for patients with neuroendocrine tumors of unknown primary. To facilitate validation and clinical implementation, we provide a user-friendly, publicly available web-based version of NEN-ID.
Study
EGAS00001004878
The Spatial Heterogeneity in Multiple Myeloma - from the Subclonal Architecture to the Immune Microenvironment (partly hipo_K08K)
Multiple myeloma (MM) cells show pronounced heterogeneity not only within a given patient but also between spatially separated tumor loci in the bone marrow. Understanding this spatial heterogeneity is emerging as a critical challenge for the successful treatment of the disease. Yet, our understanding of spatial differences in the subclonal architecture, molecular signatures and interactions with the tumor microenvironment remains very limited.
To address this shortcoming, we performed bulk and single-cell multi-region sequencing, including random bone marrow samples from the iliac crest and paired imaging-guided focal lesion specimens from 15 newly diagnosed MM patients. We found a median of 5 subclones per patient and unique subclones in focal lesions. Central features of spatial heterogeneity included a consistent down-regulation of the chemoattractant cytokines CXCL7 and CXCL12 in focal lesion tumor cells as well as a significant depletion of macrophages in the focal lesion microenvironment. In contrast, a site-specific expansion of T-cell clones was not detected in focal lesions. In conclusion, our results demonstrate the relevance of considering spatial heterogeneity with potential implications for immunotherapies and molecular studies analyzing the role of gene signatures and MM-microenvironment interactions in disease progression.
Study
EGAS00001006090
Defective Homologous Recombination DNA Repair as Therapeutic Target in Advanced-Stage Chordoma (HIPO_021)
HIPO project: HIPO_021
Importance: Chordomas are rare tumors of the axial skeleton and skull base with few therapeutic options and no clinically validated molecular drug targets. The value of comprehensive genomic analyses for guiding medical therapy of patients with advanced-stage chordoma is unknown.Objective: To identify therapeutically tractable genetic lesions in a cohort of chordoma patients within a genomics-guided precision oncology program and to document the outcome of individualized, molecularly targeted chordoma therapy.Design, Setting, and Participants: We performed whole-exome sequencing of tumor and matched germline control samples from seven patients with locally advanced or metastatic chordoma who were enrolled in a cross-institutional molecular stratification registry trial for younger adults with advanced-stage cancer across all histologies and patients with rare tumors. All patients were heavily pretreated and had progressive disease prior to molecular analysis.Interventions: Individualized medical therapy was administered according to the patients’ molecular profiles.Main Outcomes and Measures: Candidate therapeutic targets identified by whole-exome sequencing and response to genotype-directed therapy.Results: All patients harbored alterations of two or more genes known to be involved in DNA repair via homologous recombination (HR), including heterozygous deletions of ERCC6, FANC family members, RAD51L (n = 6), BRCA2 (n = 5), ATR, CHEK2, RAD18, RAD51B, and XRCC3 (n = 4); inactivating PTEN mutations coupled with loss of heterozygosity (n = 2); and pathogenic germline variants in BRCA2 (n = 1), NBN (n = 1), and CHEK2 (n = 1) that were accompanied by somatic deletion of the corresponding wild-type alleles. Consistently, a mutational signature associated with defective HR was enriched in all samples and co-occurred with extensive genomic instability, as evidenced by HR deficiency scores and high numbers of large-scale state transitions. These results prompted off-label treatment with the poly(ADP-ribose) polymerase (PARP) inhibitor olaparib in a patient whose tumor was refractory to irradiation and systemic treatment with imatinib, which led to a prolonged response and substantial clinical improvement.Conclusions and Relevance: Advanced-stage chordomas are frequently characterized by genomic imprints of defective HR DNA repair. HR deficiency represents a new therapeutic opportunity in this intractable disease through repositioning of PARP inhibitors that warrants further exploration in clinical trials.
Study
EGAS00001002720
THE GENOMIC LANDSCAPE OF ACTINIC KERATOSIS
Actinic keratoses (AK) are lesions of epidermal keratinocyte dysplasia and are pre-cursor lesions to invasive cutaneous squamous cell carcinoma (cSCC). Identifying the specific genomic alterations driving the progression of normal skin to AK and invasive cSCC is challenging due to the massive, ultraviolet radiation-induced mutational burden characteristic to these lesions. Here, we present the largest whole exome sequencing study to date on AK with matched cSCC and demonstrate that AK and cSCC are almost indistinguishable at the genomic level, in terms of mutational burden, patterns of driver gene mutations and copy number alterations. We identified 44 significantly mutated AK driver genes through our established bioinformatics pipeline and demonstrate these genes are similarly mutated in cSCC. We also identified mutational signature-32 exclusively in AK from patients exposed to azathioprine, providing further, compelling evidence for this drug’s role in keratinocyte carcinogenesis, likely through its blocking of transcription coupled repair. We demonstrated that cSCC had higher levels of intra-sample heterogeneity than AK and that several signaling pathways, including immune-related signaling and TGF-beta signaling were significantly more mutated in cSCC. Integrating our findings with independent gene expression data confirms that dysregulated TGF-beta signaling may represent the critical pathway in the progression from AK to cSCC.
Study
EGAS00001004243
Immune infiltrate and tumor microenvironment transcriptional programs stratify pediatric osteosarcoma into prognostic groups at diagnosis
Study
EGAS00001005326
Integrated single-cell profiling dissects cell-state-specific enhancer landscapes of human tumor infiltrating T cells.
Study
EGAS00001006141
