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Boch, T.

Publications and source records attributed to Boch, T..

6 recordsLinked to original sources

scIRES-seq reveals multimodal molecular heterogeneity in CTCs from small cell cervical cancer

Circulating tumor cells (CTCs) can provide a window into cellular and molecular mechanisms of cancer dissemination. However, the rarity and heterogeneity of CTCs complicate reliable identification and molecular characterization. Here, we introduce scIRES-seq, a framework linking immunophenotype, genetic variation, epigenomic profiles and gene expression within individual cells. In this proof-of-concept study, we coupled scIRES-seq to real-time imaging spectral flow cytometry and applied it to CTCs from a patient with metastatic cervical small cell neuroendocrine carcinoma. Tumor-matched copy-number alterations and targeted somatic variants established CTC identity, supported by DNA methylation profiles concordant with metastatic tissue and transcriptional features consistent with neuroendocrine differentiation. Genetic and DNA methylation analyses identified two largely concordant CTC subpopulations that were not clearly distinguished by their transcriptomes, highlighting the complementary information gained through single-cell multi-omics profiling. These findings demonstrate the feasibility of integrated CTC identification and characterization and provide a framework for investigating relationships between genetic diversity and molecular states in rare, heterogeneous cell populations.

cancer biology↗

Oncogenic RAS-Pathway Activation Drives Oncofetal Reprogramming and Creates Therapeutic Vulnerabilities in Juvenile Myelomonocytic Leukemia

Aberrant fetal gene expression facilitates tumor-specific cellular plasticity by hijacking molecular programs of embryogenesis1. Persistent fetal gene signatures in childhood malignancies are typically explained by their prenatal origins2-6. In contrast, reactivation of fetal gene expression is considered a consequence of oncofetal reprogramming (OFR) in adult malignancies and is associated with aggressive disease7-10. To date, OFR has not been described in the context of childhood malignancies. Here, we performed a comprehensive multi-layered molecular characterization of juvenile myelomonocytic leukemia (JMML) and identified OFR as a hallmark of aggressive JMML. We observed that hematopoietic stem cells (HSCs) aberrantly express mixed developmental programs in JMML. Expression of fetal gene signatures combined with a postnatal epigenetic landscape suggested OFR, which was validated in a JMML mouse model, demonstrating that postnatal activation of RAS signaling is sufficient to induce fetal gene signatures. Integrative analysis identified the fetal HSC maturation marker CD52 as a novel therapeutic target for aggressive JMML. Anti-CD52 treatment depleted human JMML HSCs and disrupted disease propagation in vivo. In summary, this study implicates OFR, defined as postnatal acquisition of fetal transcription signatures, in the pathobiology of a childhood malignancy. We provide evidence for the direct involvement of oncogenic RAS signaling in OFR. Finally, we demonstrate how OFR can be leveraged for the development of novel treatment strategies. Highlights{blacksquare} Epigenomic and transcriptomic landscape of juvenile myelomonocytic leukemia (JMML) in the context of hematopoietic development. {blacksquare}The presence of fetal transcription signatures in childhood malignancies is not indicative of a developmental maturation block. {blacksquare}High-risk JMML is characterized by oncofetal reprogramming of postnatal hematopoietic stem cells (HSCs). {blacksquare}RAS-pathway mutations induce fetal-like gene expression signatures in murine postnatal HSCs. {blacksquare}The fetal maturation marker CD52 is a novel therapeutic target in high-risk JMML.

cancer biology↗

Multiple myeloma long-term survivors display sustained immune alterations decades after first line therapy

The long-term consequences of cancer or cancer therapy on the patients immune system years after cancer-free survival remain poorly understood. Here, we have performed an in-depth characterization of the bone marrow ecosystem of multiple myeloma long-term survivors at initial diagnosis and up to 17 years following cancer-free survival. Using comparative single-cell analyses in combination with molecular, genomic and functional approaches, we demonstrate that multiple myeloma long-term survivors display pronounced alterations in their bone marrow microenvironment associated with impaired immunity. These immunological alterations were frequently driven by an inflammatory immune circuit fueled by the long-term persistence or resurgence of residual myeloma cells. Notably, even in the complete absence of any detectable residual disease for decades, sustained changes in the immune system were observed, suggesting an irreversible immunological scarring caused by the initial exposure to the cancer and therapy. Collectively, our study provides key insights into the molecular and cellular bone marrow ecosystem of multiple myeloma long-term survivors, revealing reversible and irreversible alterations of the immune compartment, which can serve as diagnostic and predictive tools. Statement of significanceLarge-scale single-cell profiling of a unique cohort of multiple myeloma long-term survivors uncovered that exposure to cancer and its treatment causes both reversible and irreversible immune alterations associated with impaired immunity. These findings have far-reaching implications for the understanding of long-term immune alterations in cancer, which need to be considered also in the context of immune therapeutic approaches. Furthermore, our study demonstrates how cancer-associated immune trafficking can be used to predict disease re-initiation in the bone marrow, opening new avenues for minimally invasive disease monitoring.

cancer biology↗

Comparison of extraction methods for intracellular metabolomics

Measurements of metabolic compounds inside cells or tissues are of high informative potential since they represent the endpoint of biological information flow and a snapshot of the integration of many regulatory processes. However, it requires careful extraction to quantify their abundance. Here we present a comprehensive study using ten extraction protocols on four human sample types (liver tissue, bone marrow, HL60 and HEK cells) targeting 630 metabolites of different chemical classes. We show that the extraction efficiency and stability is highly variable across protocols and tissues by using different quality metrics including the limit of detection and variability between replicates as well as the sum of concentration as a global estimate of extraction stability. The profile of extracted metabolites depends on the used solvents - an observation which has implications for measurements of different sample types and metabolic compounds of interest. To identify the optimal extraction method for future metabolomics studies, the benchmark dataset was implemented in an easy-to-use, interactive and flexible online resource (R/shiny app MetaboExtract).

biochemistry↗

Single-cell proteo-genomic reference maps of the hematopoietic system enable the purification and massive profiling of precisely defined cell states

Single-cell genomics has transformed our understanding of complex cellular systems. However, excessive costs and a lack of strategies for the purification of newly identified cell types impede their functional characterization and large-scale profiling. Here, we have generated high content single-cell proteo-genomic reference maps of human blood and bone marrow that quantitatively link the expression of up to 197 surface markers to cellular identities and biological processes across all major hematopoietic cell types in healthy aging and leukemia. These reference maps enable the automatic design of cost-effective high-throughput cytometry schemes that outperform state-of-the-art approaches, accurately reflect complex topologies of cellular systems, and permit the purification of precisely defined cell states. The systematic integration of cytometry and proteo-genomic data enables measuring the functional capacities of precisely mapped cell states at the single-cell level. Our study serves as an accessible resource and paves the way for a data-driven era in cytometry.

immunology↗

MutaSeq reveals the transcriptomic consequences of clonal evolution in acute myeloid leukemia

Cancer stem cells drive disease progression and relapse in many types of cancer. Despite this, a thorough characterization of these cells remains elusive and with i the ability to eradicate cancer at its source. In acute myeloid leukemia (AML), leukemic stem cells (LSCs) underlie mortality but are difficult to isolate due to their low abundance and high similarity to healthy hematopoietic stem cells (HSCs). Here, we demonstrate that LSCs, HSCs, and pre-leukemic stem cells can be identified and molecularly profiled by combining single-cell transcriptomics with lineage tracing using both nuclear and mitochondrial somatic variants. While mutational status discriminates between healthy and cancerous cells, gene expression distinguishes stem cells and progenitor cell populations. Our approach enables the identification of LSC-specific gene expression programs and the characterization of differentiation blocks induced by leukemic mutations. Taken together, we demonstrate the power of single-cell multi-omic approaches in characterizing cancer stem cells.

genomics↗