Together with the observed effects on the PAX3-FOXO1 fusion protein, these data suggest SAHA as a possible therapeutic agent for clinical testing in patients with fusion protein-positive RMS.
This is supported in rhabdomyosarcoma models by characterization of molecular and phenotypic effects of reducing and inhibiting PLK1, including changes to the PAX3-FOXO1 fusion protein.
This study describes the in vitro and in vivo activity of PXD-101 (Belinostat), a novel hydroxamic acid-type pan-HDACs inhibitor characterized by a larger safety and efficacy, on myogenic-derived PAX3/FOXO1 fusion protein positive (RH30) or negative (RD) expressing rhabdomyosarcoma (RMS) cell lines.
We previously identified the class I-specific histone deacetylase inhibitor, entinostat (ENT), as a pharmacological agent that transcriptionally suppresses the PAX3:FOXO1 tumor-initiating fusion gene found in alveolar rhabdomyosarcoma (aRMS), and we further investigated the mechanism by which ENT suppresses PAX3:FOXO1 oncogene and demonstrated the preclinical efficacy of ENT in RMS orthotopic allograft and patient-derived xenograft (PDX) models.
Thus, we examined gene co-expression networks for rhabdomyosarcoma that were <i>FOXO1-PAX3</i> positive, <i>FOXO1-PAX7</i> positive, or fusion negative.
While RMS has been traditionally classified on the basis of its histological appearance (with embryonal and alveolar being most common), it is now clear that the PAX-FOXO1 fusion product drives prognosis.
Our findings identify a novel role of both PAX3-FOXO1 and its downstream effector miR-486-5p in exosome-mediated oncogenic paracrine effects of RMS, and suggest its possible use as a biomarker.
The rapid onset and increased penetrance of tumorigenesis in this model provide a powerful tool for interrogating aRMS biology and screening novel therapeutics.<b>Significance:</b> A novel mouse model sheds light on the critical role of Hippo/MST downregulation in PAX3-FOXO1-positive rhabdomyosarcoma tumorigenesis.<i></i>.
Rhabdomyosarcomas (RMSs) are the most frequent soft tissue sarcoma in children and adolescents, defined by skeletal muscle differentiation and the status of FOXO1 fusions.
In this article, we review the recent understanding of PAX3-FOXO1 as a transcription factor in the pathogenesis of this cancer and discuss recent developments to target this oncoprotein for treatment of RMS.
We find that PAX3-FOXO1 establishes a myoblastic super enhancer landscape and creates a profound subtype-unique dependence on BET bromodomains, the inhibition of which ablates PAX3-FOXO1 function, providing a mechanistic rationale for exploring BET inhibitors for patients bearing PAX-fusion rhabdomyosarcoma.<i>Cancer Discov; 7(8); 884-99.
In this study, we report overexpression of the nuclear receptor NR4A1 in rhabdomyosarcomas that is sufficient to drive high expression of PAX3-FOXO1A there.
In the present study, we applied fluorescent in situ hybridization (FISH) and found that the Forkhead box O1 (FOXO1) gene broke apart, amplified, and displayed an aneuploid signal that was related to the RMS pathological subtype.
Rhabdomyosarcomas (RMS) in children and adolescents are heterogeneous sarcomas broadly defined by skeletal muscle features and the presence/absence of PAX3/7-FOXO1 fusion genes.
Many findings have demonstrated that PAX/FOXO1-positive ARMS have a worse prognosis than PAX/FOXO1-negative ones and that distinct molecular features characterize RMS with different gene fusion statuses.
We compared the event-free survival (EFS) and overall survival by histology, PAX-FOXO1 fusion, and clinical risk factors (Oberlin score) for patients with metastatic RMS using the log-rank test.
A clinicopathologic study of head and neck rhabdomyosarcomas showing FOXO1 fusion-positive alveolar and MYOD1-mutant sclerosing are associated with unfavorable outcome.