Project description:We show that oncogenesis in Wilms’ tumor - the most common pediatric renal cancer- is mediated by small non-coding RNAs miRNAs.Interestingly, several differentially expressed miRNAs target genes that are known to play important role in kidney development.
Project description:Gene expression analyses through cDNA microarray of unique Wilms tumor (WT) histological components, blastema (BL), epithelia (EP) and stroma (ST), from different patients were performed and compared with non-neoplastic mature and pool of fetal kidney (FK). We used a customized cDNA array containing 4 608 human genes and demonstrated that BL had over representation of genes with similar expression behavior to the earliest stage of normal renal development. Moreover, since WT is a result of loss of developmental control and gain of tumorigenic potential in a successive way, herein we identified genes whose expression level is altered during the kidney development and also in WT and classified as WT-kidney development set. From this set, a smaller group of 36 differentially expressed genes was derived, which was enriched by genes involved in signal transduction, such as APC, BZRP, MET, PLAU, GPR35 and TRADD. An over representation of genes belonging to the WNT signaling pathway were observed. Immunostaining assays of APC and beta-catenin were carried out in 108 specimens showing differential labeling localization in WT. Altogether our data show molecular evidences confirming the recapitulation of embryonic kidney by WT components and strongly suggest that the WNT signaling pathway plays a crucial role in Wilms tumorigenesis. Keywords: Wilms tumor, cDNA microarray, Histological components, WNT signaling pathway
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:The IGF2-intronic miR-483 selectively enhances transcription from IGF2 fetal promoters and enhances tumorigenesis. The expression levels of microRNAs were profiled in 20 human Wilms tumor samples (WT), 3 human normal adult kidney samples (AK) and 5 human fetal kidney samples (FK) using a Luminex bead platform.
Project description:Downregulation of specific microRNAs contribute to epithelial-mesenchymal transition of Wilms' tumor cancer initiating cells. In order to gain insight into the biology of initiating cells/cancer stem cells (CIC/CSCs) in Wilms' tumor, we compared the microRNA expression profile of un-sorted propagatable WT xenografts (p-WT Xn), p-WT NCAM+ALDH1+-derived Xn and human fetal kidneys (hFKs). Global microRNA expression analysis showed specific microRNAs to differentially express identifying a strong miRNA signature for the NCAM+ALDH1+ WT CICs. 3 different tissue types (described in 'summary') each with n=4 were homoginized and analyzed for their global miRNA expression profiles. Human Fetal Kidney tissues were used as a control.
Project description:ENL is an epigenetic acetylation reader and represents the most frequently mutated epigenetic regulator in Wilms tumor. In this study, we established an in vivo mouse model with the ENL hotspot mutation Enl-T1. We performed single-nuclei ATAC sequencing (snATAC-seq) analysis for the Enl-WT and T1 embryonic kidney to study the open chromatin dynamics and gene regulatory mechanism underlying the kidney developing defeat induced by the Enl mutation.
Project description:We show that oncogenesis in Wilms’ tumor - the most common pediatric renal cancer- is mediated by small non-coding RNAs miRNAs.Interestingly, several differentially expressed miRNAs target genes that are known to play important role in kidney development. miRNA profile of Wilm's tumor vs. normal kidney with two color microarray protocol