Project description:Vessel co-option is an alternative mode of tumor vascularization, which contributes to resistance to anti-angiogenic therapy (AAT). In contrast to vessel sprouting (angiogenesis), knowledge about the mechanisms underlying vessel co-option is minimal, precluding therapeutic strategies. We therefore single-cell RNA-sequenced 31,964 cells from a murine lung metastasis model with vessel co-option, characterized by resistance to AAT. Unexpectedly, co-opted endothelial cells (ECs) were transcriptomically indistinguishable from healthy ECs and lacked an activation signature, while co-opted pericytes expressed a quiescence signature, in contrast to activated pericytes during angiogenesis. Compared with cancer cells during angiogenesis, co-opting cancer cells were phenotypically more diverse and enriched in invasive subpopulations. Together, these data reveal new insight into vessel co-option, with possible implications for the development of therapeutic targets.
Project description:Glioblastoma (GB) is one of the deadliest types of human cancer. Recurrence after chemoradiation is mostly caused by regrowth of highly invasive and resistant cells. There is an urgent need to better understand the underlying GB mechanisms of chemoradiation resistance and tumor spreading. Using a combination of transcriptomic analysis, longitudinal imaging, organotypic cultures, functional assays, animal studies and clinical data analyses, we demonstrated that chemoradiation and brain vasculature induce a transition to an invasive functional cell state that we named VC-Resist. Better cell survival, G2M-arrest, senescence/stemness pathways’ induction and YAP activation make this GB cell state more resistant to therapy. Notably, these persister GB cells are highly vessel co-opting, allowing homing to the perivascular niche, which in turn increases their transition to this cell state. These findings demonstrate how vessel co-option, the perivascular niche, and GB cell plasticity jointly drive resistance during GB recurrence.
Project description:The movement of repetitive elements in the germline creates widespread genomic alterations and pressure for resolution. Here we show that the Caenorhabditis clade took advantage of two transposon expansions by integrating hundreds of elements into its germline transcriptional network. We find that about one-third of C. elegans germline-specific promoters have been co-opted from CERP2 and CELE2 MITE elements and are regulated by HIM-17, a THAP domain-containing transcription factor related to a transposase. An ancestral CERP2 expansion took place in the common Caenorhabditis ancestor, concurrently with mutations in HIM-17 fixed by positive selection, whereas CELE2 expanded only in C. elegans. Through comparative analyses in C. briggsae, we find conservation as well as species-specific CERP2 co-option. Our work reveals the emergence of a novel transcriptional network driven by TE co-option and its impact on regulatory evolution.
Project description:The movement of repetitive elements in the germline creates widespread genomic alterations and pressure for resolution. Here we show that the Caenorhabditis clade took advantage of two transposon expansions by integrating hundreds of elements into its germline transcriptional network. We find that about one-third of C. elegans germline-specific promoters have been co-opted from CERP2 and CELE2 MITE elements and are regulated by HIM-17, a THAP domain-containing transcription factor related to a transposase. An ancestral CERP2 expansion took place in the common Caenorhabditis ancestor, concurrently with mutations in HIM-17 fixed by positive selection, whereas CELE2 expanded only in C. elegans. Through comparative analyses in C. briggsae, we find conservation as well as species-specific CERP2 co-option. Our work reveals the emergence of a novel transcriptional network driven by TE co-option and its impact on regulatory evolution.
Project description:The movement of repetitive elements in the germline creates widespread genomic alterations and pressure for resolution. Here we show that the Caenorhabditis clade took advantage of two transposon expansions by integrating hundreds of elements into its germline transcriptional network. We find that about one-third of C. elegans germline-specific promoters have been co-opted from CERP2 and CELE2 MITE elements and are regulated by HIM-17, a THAP domain-containing transcription factor related to a transposase. An ancestral CERP2 expansion took place in the common Caenorhabditis ancestor, concurrently with mutations in HIM-17 fixed by positive selection, whereas CELE2 expanded only in C. elegans. Through comparative analyses in C. briggsae, we find conservation as well as species-specific CERP2 co-option. Our work reveals the emergence of a novel transcriptional network driven by TE co-option and its impact on regulatory evolution.
Project description:The movement of repetitive elements in the germline creates widespread genomic alterations and pressure for resolution. Here we show that the Caenorhabditis clade took advantage of two transposon expansions by integrating hundreds of elements into its germline transcriptional network. We find that about one-third of C. elegans germline-specific promoters have been co-opted from CERP2 and CELE2 MITE elements and are regulated by HIM-17, a THAP domain-containing transcription factor related to a transposase. An ancestral CERP2 expansion took place in the common Caenorhabditis ancestor, concurrently with mutations in HIM-17 fixed by positive selection, whereas CELE2 expanded only in C. elegans. Through comparative analyses in C. briggsae, we find conservation as well as species-specific CERP2 co-option. Our work reveals the emergence of a novel transcriptional network driven by TE co-option and its impact on regulatory evolution.