Project description:Analyses of gene expression profiling in sinonasal sarcoma (SNS) harboring PAX3-MAML3 fusion gene or PAX3 rearrangement and other types of tumors without having such fusion or rearrangement. The results provide important information for further investigations of the PAX3-MAML3 fusion functions in SNS.
Project description:Analyses of gene expression profiling in sinonasal sarcoma (SNS) harboring PAX3-MAML3 fusion gene or PAX3 rearrangement and other types of tumors without having such fusion or rearrangement. The results provide important information for further investigations of the PAX3-MAML3 fusion functions in SNS. Total RNA was obtained from FFPE tissues of 41 tumors including 8 SNS (6 with PAX3-MAML3 fusion and 2 with PAX3 rearrangement only) and 33 cases from other 10 different types of tumors. Gene expression profiling of fusion group including 8 SNA vs.non-fusion group including 33 control tumors were analyszed.
Project description:Chimeric transcription factors drive lineage-specific oncogenesis but are notoriously difficult to target. Alveolar rhabdomyosarcoma (RMS) is an aggressive childhood soft tissue sarcoma transformed by the pathognomonic PAX3–FOXO1 fusion protein, which governs a core regulatory circuitry transcription factor (CRC TF) network. Here we show that the histone lysine demethylase KDM4B is a therapeutic vulnerability for PAX3–FOXO1+ RMS. Genetic and pharmacologic inhibition of KDM4B significantly delays tumor growth by disrupting the expression of CRC TFs caused by epigenetic alterations of PAX3–FOXO1-governed super enhancers. Combining KDM4B inhibition with cytotoxic chemotherapy leads to significant tumor regression in preclinical PAX3–FOXO1+ RMS models. In summary, we have identified a targetable mechanism required for maintenance of PAX3-FOXO1-related CRC TF network, which may translate to a novel therapeutic approach for fusion-positive RMS.
Project description:Chimeric transcription factors drive lineage-specific oncogenesis but are notoriously difficult to target. Alveolar rhabdomyosarcoma (RMS) is an aggressive childhood soft tissue sarcoma transformed by the pathognomonic PAX3–FOXO1 fusion protein, which governs a core regulatory circuitry transcription factor (CRC TF) network. Here we show that the histone lysine demethylase KDM4B is a therapeutic vulnerability for PAX3–FOXO1+ RMS. Genetic and pharmacologic inhibition of KDM4B significantly delays tumor growth by disrupting the expression of CRC TFs caused by epigenetic alterations of PAX3–FOXO1-governed super enhancers. Combining KDM4B inhibition with cytotoxic chemotherapy leads to significant tumor regression in preclinical PAX3–FOXO1+ RMS models. In summary, we have identified a targetable mechanism required for maintenance of PAX3-FOXO1-related CRC TF network, which may translate to a novel therapeutic approach for fusion-positive RMS.
Project description:Chimeric transcription factors drive lineage-specific oncogenesis but are notoriously difficult to target. Alveolar rhabdomyosarcoma (RMS) is an aggressive childhood soft tissue sarcoma transformed by the pathognomonic PAX3–FOXO1 fusion protein, which governs a core regulatory circuitry transcription factor (CRC TF) network. Here we show that the histone lysine demethylase KDM4B is a therapeutic vulnerability for PAX3–FOXO1+ RMS. Genetic and pharmacologic inhibition of KDM4B significantly delays tumor growth by disrupting the expression of CRC TFs caused by epigenetic alterations of PAX3–FOXO1-governed super enhancers. Combining KDM4B inhibition with cytotoxic chemotherapy leads to significant tumor regression in preclinical PAX3–FOXO1+ RMS models. In summary, we have identified a targetable mechanism required for maintenance of PAX3-FOXO1-related CRC TF network, which may translate to a novel therapeutic approach for fusion-positive RMS.
Project description:Chimeric transcription factors drive lineage-specific oncogenesis but are notoriously difficult to target. Alveolar rhabdomyosarcoma (RMS) is an aggressive childhood soft tissue sarcoma transformed by the pathognomonic PAX3–FOXO1 fusion protein, which governs a core regulatory circuitry transcription factor (CRC TF) network. Here we show that the histone lysine demethylase KDM4B is a therapeutic vulnerability for PAX3–FOXO1+ RMS. Genetic and pharmacologic inhibition of KDM4B significantly delays tumor growth by disrupting the expression of CRC TFs caused by epigenetic alterations of PAX3–FOXO1-governed super enhancers. Combining KDM4B inhibition with cytotoxic chemotherapy leads to significant tumor regression in preclinical PAX3–FOXO1+ RMS models. In summary, we have identified a targetable mechanism required for maintenance of PAX3-FOXO1-related CRC TF network, which may translate to a novel therapeutic approach for fusion-positive RMS.
Project description:Chimeric transcription factors drive lineage-specific oncogenesis but are notoriously difficult to target. Alveolar rhabdomyosarcoma (RMS) is an aggressive childhood soft tissue sarcoma transformed by the pathognomonic PAX3–FOXO1 fusion protein, which governs a core regulatory circuitry transcription factor (CRC TF) network. Here we show that the histone lysine demethylase KDM4B is a therapeutic vulnerability for PAX3–FOXO1+ RMS. Genetic and pharmacologic inhibition of KDM4B significantly delays tumor growth by disrupting the expression of CRC TFs caused by epigenetic alterations of PAX3–FOXO1-governed super enhancers. Combining KDM4B inhibition with cytotoxic chemotherapy leads to significant tumor regression in preclinical PAX3–FOXO1+ RMS models. In summary, we have identified a targetable mechanism required for maintenance of PAX3-FOXO1-related CRC TF network, which may translate to a novel therapeutic approach for fusion-positive RMS.
Project description:Alveolar rhabdomyosarcoma (ARMS) is a highly aggressive pediatric soft tissue sarcoma driven by the PAX3::FOXO1 fusion protein. Despite multipronged treatment approaches, survival rates for patients with fusion-positive (FP) ARMS remain poor, underscoring the need for novel therapeutic strategies. Here, we employ sequential multimodal CRISPR/Cas9 genetic screens to identify essential genes in FP ARMS, revealing FANCM, a key component of the Fanconi Anemia pathway, as a critical dependency. FANCM loss selectively impairs FP ARMS cell growth in vitro and in vivo, reduces PAX3::FOXO1 levels, and induces myogenic differentiation. Mechanistically, FANCM depletion exacerbates replication stress, particularly at PAX3::FOXO1 target gene loci, which leads to ATR/ATM-mediated DNA damage signaling and selective downregulation of the fusion-driven oncogenic program. CRISPR exon-tiling screens highlighted FANCM's helicase and DNA-binding domains as essential for its FP-specific dependency, linking FANCM-mediated replication fork binding and downstream ATR signaling to FP ARMS survival. This study positions FANCM as a promising therapeutic target in FP ARMS and introduces a novel paradigm for exploiting replication stress vulnerabilities in oncofusion-driven malignancies.
Project description:Alveolar rhabdomyosarcoma (aRMS) is an aggressive sarcoma of skeletal muscle characterized by expression of the PAX3-FOXO1 fusion gene. Despite its discovery over almost 20 years ago, PAX3-FOXO1 remains an enigmatic tumor driver. Previously, we reported that PAX3-FOXO1 supports aRMS initiation by enabling bypass of cellular senescence. Here, we show that bypass occurs in part by PAX3-FOXO1-mediated upregulation of RASSF4, a Ras-association domain family (RASSF) member, which then suppresses the evolutionarily conserved mammalian Hippo/Mst1 pathway. RASSF4 loss-of-function activates Hippo/Mst1 and inhibits downstream YAP, causing aRMS cell cycle arrest and senescence. This is the first evidence for an oncogenic role for RASSF4, and a novel mechanism for Hippo signaling suppression in human cancer. Human skeletal muscle myoblasts (HSMMs) were retrovirally transduced with either an empty vector (Vp, pK1) or PAX3-FOXO1 (PFp, pK1-PAX3-FOXO1) and selected on puromycin. Presenescent (presen) cells were harvested before the senescence checkpoint. Since cells expressing PAX3-FOXO1 can bypass the senescence checkpoint, postsenescent (postsen) cells expressing PAX3-FOXO1 were also harvested. the gene expression affected by the introduction of PAX3-FOXO1
Project description:Fusion-positive alveolar rhabdomyosarcoma (FP-RMS) is an aggressive pediatric sarcoma driven primarily by the PAX3-FOXO1 fusion oncogene, for which therapies targeting PAX3-FOXO1 are lacking. We screened 62,643 compounds using an engineered cell line that monitors PAX3-FOXO1 transcriptional activity identifying a hitherto uncharacterized compound, PFI-63. RNA-seq, ATAC-seq, and docking analyses implicated histone lysine demethylases (KDMs) as its targets. Enzymatic assays confirmed the inhibition of multiple KDMs with highest selectivity for KDM3B. Structural similarity search of PFI-63 identified PFI-90 with improved solubility and potency. Biophysical binding of PFI-90 to KDM3B was demonstrated using NMR and SPR. PFI-90 suppressed the growth of FP-RMS in vitro and in vivo through downregulating PAX3-FOXO1 activity, and combined knockdown of KDM3B and KDM1A phenocopied PFI-90 effects. Thus, we report novel KDM inhibitors with highest specificity for KDM3B. Its potent suppression of PAX3-FOXO1 activity can be exploited as a new therapeutic approach for FP-RMS and other transcriptionally driven cancers.