Biology subjects

Larsson, C.

Publications and source records attributed to Larsson, C..

5 recordsLinked to original sources

bioRxiv2026

Sympathoadrenal Lineage Plasticity Drives Intratumoral Heterogeneity in Paraganglioma, Neuroblastoma and Composite Tumors Following KIF1Bb-NF1 Loss

Neuroblastoma (NB) and paraganglioma (PPGL) arise from the sympathoadrenal lineage, yet their developmental relationship and heterogeneity remain unclear. Single-cell and spatial transcriptomics revealed shared, spatially organized developmental states, including populations characteristic of the other tumor type, chromaffin-like cells in NB and neuroblast-like cells in PPGL and hybrids co-expressing adjacent states. Deconvolution of an independent PPGL cohort associated metastatic disease most strongly with chromaffin hybrid states, alongside connecting progenitor-like, cycling neuroblast, and early chromaffin identities, whereas non-metastatic tumors were enriched for differentiated late chromaffin identities. In mice, combined loss of the candidate 1p36 tumor suppressor KIF1B{beta} and NF1 recapitulates these developmental architectures by prolonging developmental plasticity, reactivating embryonic neurogenic programs, and driving chromaffin-to-neuroblast transitions generating pheochromocytoma, neuroblastoma and composite tumors. Mouse tumors contained discrete spatial domains of developmental and neoplastic states that mirrored those in human PPGL. Together, our findings establish chromaffin-neuroblast plasticity as a mechanism of sympathoadrenal tumor heterogeneity and identify hybrid developmental states as a potential indicator of plasticity associated with metastatic PPGL.

cancer biology↗

bioRxiv2021

Single-nuclei transcriptomes from human adrenal gland reveals distinct cellular identities of low and high-risk neuroblastoma tumors.

Childhood neuroblastoma has a remarkable variability in outcome. Age at diagnosis is one of the most important prognostic factors, with children less than 1 year old having favorable outcomes. We studied single-cell and single-nuclei transcriptomes of neuroblastoma with different clinical risk groups and stages, including healthy adrenal gland. We compared tumor cell populations with embryonic mouse sympatho-adrenal derivatives, and post-natal human adrenal gland. We provide evidence that low and high-risk neuroblastoma have different cell identities, representing two disease entities. Low-risk neuroblastoma presents a transcriptome that resembles sympatho- and chromaffin cells, whereas malignant cells enriched in high-risk neuroblastoma resembles an unknown subtype of TRKB+ cholinergic progenitor population identified in human post-natal gland. Analyses of these populations revealed different gene expression programs for worst and better survival in correlation with age at diagnosis. Our findings reveal two cellular identities and a composition of human neuroblastoma tumors reflecting clinical heterogeneity and outcome.

cancer biology↗

bioRxiv2021

The ratio of cytotoxic lymphocytes to M2-like macrophages is prognostic in immunogenic tumors

Immune cells in the microenvironment shape tumor development and progression. The prognostic value of T-cell-based immune scores exceeds those of clinical parameters in colon cancer, but reflects only a part of the anti-tumor immune response. Here, we assessed 15 distinct immune cell classes and identified a simple prognostic signature based on pro- and anti-tumoral immune cells in the tumor microenvironment. The ratio of cytotoxic lymphocytes to tumor supportive macrophages predicted survival better than the state-of-art immune score in colon cancer and had the highest relative contribution to survival prediction when compared to established clinical parameters. This signature was prognostic also in other cancers with high mutation burden, such as those of the lung, bladder, esophagus, and melanomas, supporting broad clinical applicability. One Sentence SummaryThe CD8/M2 ratio in tumor tissue defines prognosis in immunogenic cancers

cancer biology↗

bioRxiv2020

The Mutational Landscape of the SCAN-B Real-World Primary Breast Cancer Transcriptome

Breast cancer is a disease of genomic alterations, of which the complete panorama of somatic mutations and how these relate to molecular subtypes and therapy response is incompletely understood. Within the Sweden Cancerome Analysis Network-Breast project (SCAN-B; ClinicalTrials.gov NCT02306096), an ongoing study elucidating the tumor transcriptomic profiles for thousands of breast cancers prospectively, we developed an optimized pipeline for detection of single nucleotide variants and small insertions and deletions from RNA sequencing (RNA-seq) data, and profiled a large real-world population-based cohort of 3,217 breast tumors. We use it to describe the mutational landscape of primary breast cancer viewed through the transcriptome of a large population-based cohort of patients, and relate it to patient overall survival. We demonstrate that RNA-seq can be used to call mutations in important breast cancer genes such as PIK3CA, TP53, and ERBB2, as well as the status of key molecular pathways and tumor mutational burden, and identify potentially druggable genes in 86.8% percent of tumors. To make this rich and growing mutational portraiture of breast cancer available for the wider research community, we developed an open source web-based application, the SCAN-B MutationExplorer, accessible at http://oncogenomics.bmc.lu.se/MutationExplorer. These results add another dimension to the use of RNA-seq as a potential clinical tool, where both gene expression-based and gene mutation-based biomarkers can be interrogated simultaneously and in real-time within one week of tumor sampling.

cancer biology↗

bioRxiv2019

Splicing-sensitive fusion transcripts associated with key tumor characteristics occur at high frequency in neuroblastoma

The paucity of recurrent mutations has hampered efforts to understand and treat neuroblastoma. Alternative splicing and splicing-dependent RNA-fusions represent mechanisms able to increase the gene product repertoire but their role in neuroblastoma remains largely unexplored. Through analysis of RNA-sequenced neuroblastoma we here show that elevated expression of splicing factors is a strong predictor of poor clinical outcome. Furthermore, we identified >900 primarily intrachromosomal fusions containing canonical splicing sites. Fusions included transcripts from well-known oncogenes, were enriched for proximal genes and in chromosomal regions commonly gained or lost in neuroblastoma. As a proof-of-principle that these fusions can generate altered gene products, we characterized a ZNF451-BAG2 fusion, generating a truncated BAG2-protein which inhibited retinoic acid-induced differentiation. Spliceosome inhibition impeded neuroblastoma fusion expression, induced apoptosis and inhibited xenograft tumor growth. Our findings elucidate a splicing-dependent mechanism producing altered gene products in neuroblastoma and suggest that the spliceosome is a tractable therapeutical target.

cancer biology↗