Anti-JAG1 (aa 1197-1210) polyclonal antibody

Background: Undifferentiated pleomorphic sarcomas are one of the most common subtypes of soft tissue sarcomas. These are aggressive mesenchymal tumors and are devoid of the major known biomarkers except vimentin. Our objective was to establish and characterize a primary cell population from a mandibular UPS specimen. Methods: The tumor was surgically removed from the right mandible of a 24-year-old male with IRB approved signed consent. Tumor was dissected, cultured ex vivo, and a cell population, MUPS-1, were isolated from outgrowths. Gene and protein expression profiles of both the primary tumor and the derived there from cells were obtained by quantitative RT-PCR and immunohistochemistry and included markers of epithelial, endothelial, and mesenchymal differentiation. To better define potential biomarkers, MUPS-1 cells were additionally characterized by RNA sequencing analysis. Results: Pathological analysis of primary tumor tissue revealed a sarcoma demonstrating multiple pathways of differentiation simultaneously with myxoid, fibrous, and osseous tissue. The isolated cells had a spindle cell-like morphology, were maintained in culture for greater than 20 passages, and formed colonies in soft agar indicating tumorigenicity. The cells, similar to the primary tumor, were strongly positive for vimentin and moderately expressed alkaline phosphatase. RNA-seq analysis revealed the tumor over-expressed several genes compared to normal tissue, including components of the Notch signaling pathway, NOTCH3 and JAG1. Conclusions: We have successfully established an undifferentiated pleomorphic sarcoma cell population, which will provide a valuable resource for studying fundamental processes and potentially serving as a platform for exploring therapeutic strategies for sarcomas.

Nephron induction during kidney development is driven by reciprocal interactions between progenitor cells (NPCs) of the cap mesenchyme (CM) and the ureteric bud (UB). The prorenin receptor (PRR) is a receptor for renin and prorenin, and an accessory subunit of the vacuolar proton pump V-ATPase. Previously, we demonstrated that conditional ablation of the PRR in Six2(+) NPCs in mice (Six2(PRR-/-)) causes early neonatal death. Here, we identified genes that are regulated by PRR in Six2(+)NPCs FACS-isolated from Six2(PRR-/-) and control kidneys on embryonic day E15.5 using whole-genome expression analysis. Seven genes with expression in CM cells previously shown to direct kidney development, including Notch1, beta-catenin, Lef1, Lhx1, Jag1, and p53, were downregulated. The functional groups within the downregulated gene set included genes involved in embryonic and cellular development, renal regeneration, cellular assembly and organization, cell morphology, death and survival. Double-transgenic Six2(PRR-/-)/BatGal(+) mice, a reporter strain for beta-catenin transcriptional activity, showed decreased beta-catenin activity in the UB invivo. Reduced PRR gene dosage in heterozygous Six2(PRR+/-) mice was associated with decreased glomerular number, segmental thickening of the glomerular basement membrane with focal podocyte foot process effacement, development of hypertension and increased soluble PRR (sPRR) levels in the urine at 2 months of age. Together, these data demonstrate that NPC PRR performs essential functions during nephrogenesis via control of hierarchy of genes that regulate critical cellular processes. Both reduced nephron endowment and augmented urine sPRR likely contribute to programming of hypertension in Six2(PRR+/-) mice.