Cellular origin and clonal evolution of human dedifferentiated liposarcoma
Nadège Gruel, Chloé Quignot, Laëtitia Lesage, Sophie El Zein, Sylvie Bonvalot, Dimitri Tzanis, Khadija Aït Raïs, Fabien Quinquis, Bastien Manciot, Julien Vibert, Nadine El Tannir, Ahmed Dahmani, Héloïse Derrien, Didier Decaudin, Ivan Bièche, Laura Courtois, Odette Mariani, Laëtitia K. Linares, Laurie Gayte, Sylvain Baulande, Joshua J. Waterfall, Olivier Delattre, Gaëlle Pierron, Sarah Watson
Abstract
Dedifferentiated liposarcoma (DDLPS) is the most frequent high-grade soft tissue sarcoma subtype. It is characterized by a component of undifferentiated tumor cells coexisting with a component of well-differentiated adipocytic tumor cells. Both dedifferentiated (DD) and well-differentiated (WD) components exhibit MDM2 amplification, however their cellular origin remains elusive. Using single-cell RNA sequencing, DNA sequencing, in situ multiplex immunofluorescence and functional assays in paired WD and DD components from primary DDLPS tumors, we characterize the cellular heterogeneity of DDLPS tumor and micro-environment. We identify a population of tumor adipocyte stem cells (ASC) showing striking similarities with adipocyte stromal progenitors found in white adipose tissue. We show that tumor ASC harbor the ancestral genomic alterations of WD and DD components, suggesting that both derive from these progenitors following clonal evolution. Last, we show that DD tumor cells keep important biological properties of ASC including pluripotency and that their adipogenic properties are inhibited by a TGF-β-high immunosuppressive tumor micro-environment. Dedifferentiated liposarcomas (DDLPS) typically have dedifferentiated (DD) and well-differentiated (WD) components, although their cellular origins remain elusive. Here, the authors characterise primary DDLPS tumours using bulk and single-cell multi-omics and find adipocyte stem cells that could be a common ancestor of WD and DD components.