Project description:Nanomolar treatment with epigenetic drug combination induces genome-wide methylation and expression alterations in neuro-ectodermal cell lines [mRNA]
Project description:Nanomolar treatment with epigenetic drug combination induces genome-wide methylation and expression alterations in neuro-ectodermal cell lines [DNA methylation]
Project description:To study differentially expressed genes in neuro-ectodermal cell lines MYCN amplification (NMA) is the most important prognostic factor in neuroblastoma (NBL) patients, however 70% of advanced stage NBL are non-NMA and lack known driving oncogenic events. Gene expression profiles (HU133plus2.0 arrays, Affymetrix) of 17 NBL and 5 peripheral neuro-ectodermal cell lines were used to identify potential subgroups of NBL cell lines with a distinct gene signature. One group of non-NMA NBL cell lines was identified with a distinct gene expression profile and characterized by high expression of AXL. AXL is a tyrosine kinase receptor which plays a role in the metastatic process of cancer. We hypothesized that AXL contributes to the metastasizing potential of non-NMA NBL and tested if AXL silencing diminishes malignant properties of high AXL expressing cell lines. AXL was silenced in two non-NMA NBL cell lines by using a lentiviral shRNA construct that was able to transduce these cell lines with >90% infection efficiency. AXL mRNA expression level was efficiently knocked-down resulting in a severe decrease of migration of AXL positive cell lines GI-M-EN and SH-EP-2, and decreased invasion of GI-M-EN. Morphologically, AXL knockdown induced more rounded cells with a loss of contact. Intracellularly, we observed induction of stress fibers (immunofluorescence F-actin) in GI-M-EN. These changes in cytoskelet were associated with decreased migration. No effects were observed for cell proliferation, apoptosis or downstream pathways. In conclusion, AXL is identified as a possible mediator of NBL metastasis. Arrays were performed with 5 different PNET cell lines, which were used as controls for 17 NBL cell lines (GSE22771)
Project description:6 neuro-ectodermal cell lines were treated with 30 nM Decitabine (72 hour) and 25 nM trichostatin A (48 hour) and 6 were untreated 6 untreated and 6 treated, each sample labeled with Cy5 and normal blood pool with Cy3
Project description:To study differentially expressed genes in neuro-ectodermal cell lines MYCN amplification (NMA) is the most important prognostic factor in neuroblastoma (NBL) patients, however 70% of advanced stage NBL are non-NMA and lack known driving oncogenic events. Gene expression profiles (HU133plus2.0 arrays, Affymetrix) of 17 NBL and 5 peripheral neuro-ectodermal cell lines were used to identify potential subgroups of NBL cell lines with a distinct gene signature. One group of non-NMA NBL cell lines was identified with a distinct gene expression profile and characterized by high expression of AXL. AXL is a tyrosine kinase receptor which plays a role in the metastatic process of cancer. We hypothesized that AXL contributes to the metastasizing potential of non-NMA NBL and tested if AXL silencing diminishes malignant properties of high AXL expressing cell lines. AXL was silenced in two non-NMA NBL cell lines by using a lentiviral shRNA construct that was able to transduce these cell lines with >90% infection efficiency. AXL mRNA expression level was efficiently knocked-down resulting in a severe decrease of migration of AXL positive cell lines GI-M-EN and SH-EP-2, and decreased invasion of GI-M-EN. Morphologically, AXL knockdown induced more rounded cells with a loss of contact. Intracellularly, we observed induction of stress fibers (immunofluorescence F-actin) in GI-M-EN. These changes in cytoskelet were associated with decreased migration. No effects were observed for cell proliferation, apoptosis or downstream pathways. In conclusion, AXL is identified as a possible mediator of NBL metastasis.
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: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.