Project description:HS-578T cells overexpressing EP300 show an increase in doxorubicin and paclitaxel resistance, up-regulation of EMT markers together with an increase in motility and invasion, and an increase in the percentage of cancer stem cells and mammosphere formation.
Project description:EP300, a transcriptional co-activator of E-cadherin, has been recently found by our group to regulate doxorubicin resistance via by-pass of senescence and paclitaxel resistance by overcoming apoptosis in a minimally transformed mammary epithelial cells (MTMEC). Moreover, EP300 deleted MTMEC cells exhibit an multi-drug resistant (MDR) phenotype independent of P-glycoprotein (ABCB1), an efflux pump or ABC drug transporter. This whole transcriptome array study was undertaken in order to explore the downstream targets in the EP300-mediated drug resistance, epidermal-to-mesenchymal transition and cancer stem cell phenotypes in breast cancer cell line MCF7.
Project description:Gene expression of different flocculent (HS 10 and HS 34) and powdery (HS 12 and HS 37) yeast strains compared to each other during exponential and stationary growth phase was analysed. The isolation of RNA was done by disruption of the cells under liquid nitrogen using mortar and pistil and then the Qiagen RNeasy Midi Kit with some modifications within the manufacturers´ protocol and the Qiagen RNase-Free DNase Set were applied. 6 µg of the total RNA per sample was used for each microarray experiments. The indirect labelling by the tyramide-signal-amplification method (MicromaxTM TSATM labelling and detection Kit from Perkin Elmer life sciences) was used to increase the Cy3 and Cy5 signals of microarray detection. Each cDNA containing Biotin- and Fluorescein-nucleotides respectively was purified with a QIAquick PCR purification kit and suspended in 11 µl of the formamide containing hybridization buffer. The slides were hybridized at 42°C over night under a cover slip. The microarrays were scanned by the Axon 4000B scanner; image intensity data were extracted and analysed with GenePix® Pro 6.0 software. Data from different scans of Dye-swap experiment were extracted by GenePix Pro 6.0 software, normalized and united. An outliertest has been applied in order to find outliers amongst the gene replicats. Subsequently, a t-test (1% and 5% probability of error) has been used in order to find regulated genes. Keywords: sorted yeast cells Microarray experiments were realised with dye swap.
Project description:Gene expression of different flocculent (HS 10 and HS 34) and powdery (HS 12 and HS 37) yeast strains compared to each other during exponential and stationary growth phase was analysed. The isolation of RNA was done by disruption of the cells under liquid nitrogen using mortar and pistil and then the Qiagen RNeasy Midi Kit with some modifications within the manufacturers´ protocol and the Qiagen RNase-Free DNase Set were applied. 6 µg of the total RNA per sample was used for each microarray experiments. The indirect labelling by the tyramide-signal-amplification method (MicromaxTM TSATM labelling and detection Kit from Perkin Elmer life sciences) was used to increase the Cy3 and Cy5 signals of microarray detection. Each cDNA containing Biotin- and Fluorescein-nucleotides respectively was purified with a QIAquick PCR purification kit and suspended in 11 µl of the formamide containing hybridization buffer. The slides were hybridized at 42°C over night under a cover slip. The microarrays were scanned by the Axon 4000B scanner; image intensity data were extracted and analysed with GenePix® Pro 6.0 software. Data from different scans of Dye-swap experiment were extracted by GenePix Pro 6.0 software, normalized and united. An outliertest has been applied in order to find outliers amongst the gene replicats. Subsequently, a t-test (1% and 5% probability of error) has been used in order to find regulated genes. Keywords: sorted yeast cells
Project description:We found that the bone marrow microenvironment of Crebbp+/- mice was unable to properly maintain the immature stem - and progenitor pools. Instead, it stimulates myeloid differentiation that progresses into a myeloproliferative-like disease. Since CREBBP is a transcriptional co-activator, we used gene expression analysis to globally assess functional deficiencies in Crebbp+/- bone marrow stroma cells at a molecular level. Ep300 encodes a protein which is highly similar in structure and function to CREBBP; nevertheless, Ep300+/- mice suffer neither excessive myeloid differentiation nor loss of HSCs. Therefore, to identify expression changes specifically related to Crebbp heterozygosity, we focused on genes that showed significant differences in expression levels between Crebbp+/- and wild-type bone marrow stroma but no difference between Ep300+/- and wild-type. Bone marrow stroma was established from wild-type, Crebbp+/- and Ep300+/- mice that were 3-4 months old for RNA extraction and hybridization on Affymetrix microarrays. There are 4 biological replicates for each genotype used.
Project description:Early placenta development involves cytotrophoblast differentiation into extravillous trophoblast (EVT) and syncytiotrophoblast (STB). Defective trophoblast development and function may result in severe pregnancy complications, including fetal growth restriction and pre-eclampsia. The incidence of these complications is increased in pregnancies of fetuses affected by Rubinstein–Taybi syndrome, a developmental disorder predominantly caused by heterozygous mutations in CREB-binding protein (CREBBP) or E1A-binding protein p300 (EP300). Although the acetyltransferases CREBBP and EP300 are paralogs with many overlapping functions, the increased incidence of pregnancy complications is specific for EP300 mutations. We hypothesized that these complications have their origin in early placentation and that EP300 is involved in that process. Therefore, we investigated the role of EP300 and CREBBP in trophoblast differentiation, using human trophoblast stem cells (TSCs) and trophoblast organoids. We found that pharmacological CREBBP/EP300 inhibition blocks differentiation of TSCs into both EVT and STB lineages, and results in an expansion of TSC-like cells under differentiation-inducing conditions. Specific targeting by RNA interference or CRISPR/Cas9-mediated mutagenesis demonstrated that knockdown of EP300 but not CREBBP, inhibits trophoblast differentiation, consistent with the complications seen in Rubinstein–Taybi syndrome pregnancies. By transcriptome sequencing, we identified transforming growth factor alpha (TGFA, encoding TGF-α) as being strongly upregulated upon EP300 knockdown. Moreover, supplementing differentiation medium with TGF-α, which is a ligand for the epidermal growth factor receptor (EGFR), likewise affected trophoblast differentiation and resulted in increased TSC-like cell proliferation. These findings suggest that EP300 facilitates trophoblast differentiation by interfering with at least EGFR signaling, pointing towards a crucial role for EP300 in early human placentation.