Ewing Sarcoma

P1, N=40, Active, not recruiting, Iovance Biotherapeutics, Inc. | Recruiting --> Active, not recruiting

Zebrafish with the MZ ewsr1a/ewsr1a genotype display an increased level of collagen type II protein in the notochord starting at 36 h post fertilization. We propose that Ewsr1a contributes to IVD formation by regulating the expression of col2a1a.

Comparative in vitro binding analyses demonstrated that the scFv containing the shorter 15-mer linker exhibits significantly enhanced affinity and specificity toward CD99-overexpressing Ewing sarcoma cells relative to the 18-mer variant, highlighting linker length as a critical determinant of scFv performance. These findings establish a rational design principle for optimizing CD99-targeting scFvs and support the potential application of the 15-mer scFv in CAR-T cell development and in targeting other CD99-overexpressing carcinomas.

Immunohistochemistry plays a crucial role in interpreting a specific diagnosis or narrowing the differential diagnosis of SRCTs. Molecular genetic investigations are essential, particularly in cases exhibiting atypical or overlapping histologic and immunohistological features.

After evaluation, he was found to have a rare diagnosis of ALES in this age group, specifically with this Ewing Sarcoma RNA binding protein 1 and nuclear factor of activated T cells cytoplasmic 2 (EWSR1::NFATC2) gene fusion. This case highlights the challenges of diagnosing and the multidisciplinary management of rare variants of ES with uncommon gene fusions and raises awareness for the future potential of molecular diagnostics and treatment-specific applications for improved access to care and better outcomes for this population.

We highlight an integrated diagnostic framework that combines morphology, broad immunohistochemical panels, and molecular testing. Accurate recognition of these tumors is essential, as correct classification directly informs prognosis and therapeutic decision-making.

These findings suggest that PI3Kα is the dominant isoform, whereas PI3Kβ and PI3Kδ cooperate with PI3Kα in cell survival, which appears to be a characteristic feature of TRS cells. Thus, triple-isoform inhibition might represent an effective therapy for TRSs.

In EFTs, EWSR1 gene rearrangement is most common, followed by FUS gene rearrangement. CD99 immunohistochemistry with additional molecular analysis is essential for further classification of EFTs. A detailed diagnostic algorithm including histology, IHC, and molecular studies is imperative for accurate subcategorization of EFTs.

The DPP4 inhibitor linagliptin, which is used clinically, consistently suppressed EwS viability with elevated sensitivity under hypoxia, where there was increased cell death of SK-ES-1 cells...These findings suggest that NPY and DPP4 enhance EwS survival through autocrine/paracrine signalling while reducing monocyte viability. Thus, targeting the NPY/DPP4 signalling axis may provide therapeutic benefit by directly suppressing EwS growth and enhancing efficacy of immunotherapy.

These findings suggest that functional impairment of GSK-3β and subsequent upregulation of Myc may promote the proliferation of Ewing sarcoma cells. Myc is normally phosphorylated by GSK-3β, which triggers its ubiquitination and proteasomal degradation. Although CDK5 is recognized as a cell-cycle-related kinase, our results demonstrate that CDK5 is associated with increased inhibitory phosphorylation of GSK-3β, resulting in functional suppression of its activity. As a result, GSK-3β-mediated phosphorylation of Myc is attenuated, leading to reduced ubiquitination and accumulation of Myc. Regulation of Myc expression through CDK5-mediated modulation of GSK-3β plays a critical role in controlling Ewing sarcoma cell proliferation and may represent a promising therapeutic target.

We tested these bifunctionals in a FKBP(F36V)-tagged transcription factor reporter system and found bifunctional induced transactivation is relatively common, being observed for bifunctionals with BET ligand JQ1, p300/CBP ligand GNE-781, CDK9 ligand SNS-032, and BRD9 ligand iBRD9. Together, these data establish bifunctionals targeting p300/CBP that toggle between a program of ultra-potent transactivation and repression depending on cellular context. Overall demonstrating that induced proximity with a given ligand does not encode a fixed functional outcome.

The authors provide an overview of the clinical features, pathologic findings, imaging characteristics, differential diagnosis, and treatment outcomes of each entity.