Project description:The aim of the study was to assess whether changes in the expression of miRs could be implicated in the modulation of the NOTCH pathway in head and neck paragangliomas. Several miRs, notably including families (miR-34s, miR-200s) that target the NOTCH signaling pathway, resulted differentially expressed in paragangliomas compared to the reference normal tissue, i.e., Jacobson's nerve.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:The aim of the study was to assess whether changes in the expression of miRs could be implicated in the modulation of the NOTCH pathway in head and neck paragangliomas. Several miRs, notably including families (miR-34s, miR-200s) that target the NOTCH signaling pathway, resulted differentially expressed in paragangliomas compared to the reference normal tissue, i.e., Jacobson's nerve. Total RNA from paraganglioma samples compared to total RNA from Jacobson's nerves (normal controls, chosen because Jacobson's nerve is a frequent site of origin of tympanic paraganglioma) and from SH-SY5Y cells (chosen based on their sympathoadrenal origin).
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:The similarity in gene-expression profiles suggest that PGL2, like SDHD, is involved in the functionality of the SDH complex, and that tumor formation in these three subgroups involves the same pathways as in SDH linked paragangliomas. We were not able to clarify the identity of PGL2 on 11q13. The lack of differential gene-expression of chromosome 11 genes might indicate that chromosome 11 loss, as demonstrated in SDHD-linked paragangliomas, is an important feature in the formation of a paraganglioma regardless of the genetic background. Keywords: disease state analysis We compared the gene expression profiles of sporadic (n=7), SDHD- (n=6) and PGL2-linked (n=4) head and neck paraganglioma.
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
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.