The fate of orally administered sialic acid: First insights from patients with -acetylneuraminic acid synthase deficiency and control subjects.

Background: In NANS deficiency, biallelic mutations in the -acetylneuraminic acid synthase () gene impair the endogenous synthesis of sialic acid (-acetylneuraminic acid) leading to accumulation of the precursor, -acetyl mannosamine (ManNAc), and to a multisystemic disorder with intellectual disability. The aim of this study was to determine whether sialic acid supplementation might be a therapeutic avenue for NANS-deficient patients.

Methods: Four adults and two children with NANS deficiency and four adult controls received oral NeuNAc acid (150 mg/kg/d) over three days.

A live single-cell reporter assay links intratumor heterogeneity to metastatic proclivity in Ewing sarcoma.

Targeting of the most aggressive tumor cell subpopulations is key for effective management of most solid malignancies. However, the metastable nature of tumor heterogeneity, which allows cells to transition between strong and weak tumorigenic phenotypes, and the lack of reliable markers of tumor-promoting properties hamper identification of the most relevant cells. To overcome these obstacles, we designed a functional microRNA (miR)-based live-cell reporter assay to identify highly tumorigenic cells in xenotransplants of primary Ewing sarcoma (EwS) 3D cultures.

LIN28B Underlies the Pathogenesis of a Subclass of Ewing Sarcoma LIN28B Control of EWS-FLI1 Stability.

Ewing sarcoma (EwS) is associated with poor prognosis despite current multimodal therapy. Targeting of EWS-FLI1, the fusion protein responsible for its pathogenesis, and its principal downstream targets has not yet produced satisfactory therapeutic options, fueling the search for alternative approaches. Here, we show that the oncofetal RNA-binding protein LIN28B regulates the stability of EWS-FLI1 mRNA in ~10% of EwSs.

Targeting cancer stem-like cells as an approach to defeating cellular heterogeneity in Ewing sarcoma.

Plasticity in cancer stem-like cells (CSC) may provide a key basis for cancer heterogeneity and therapeutic response. In this study, we assessed the effect of combining a drug that abrogates CSC properties with standard-of-care therapy in a Ewing sarcoma family tumor (ESFT). Emergence of CSC in this setting has been shown to arise from a defect in TARBP2-dependent microRNA maturation, which can be corrected by exposure to the fluoroquinolone enoxacin.