Project description:<p>BRCA1 mutations are a hallmark of hereditary ovarian cancer, strongly linked to deficiencies in homologous recombination (HR) DNA repair and impaired DNA replication fork protection. However, its roles in cancer progression beyond maintaining genomic integrity remain poorly understood. Through metabolomics approaches, we found BRCA1-deficiency strikingly increased choline metabolism. Loss of BRCA1 promotes choline uptake through upregulating choline transporter-like protein 4 (CTL4). BRCA1 directly binds and recruits EZH2-mediated H3K27Me3 deposition to CTL4 promoter. CTL4 was therefore overexpressed in ovarian cancer tissues with BRCA1 mutations. Furthermore, BRCA1-deficiency significantly promotes ovarian cancer invasion, while inhibition of CTL4 reverses the high metastatic potential of BRCA1-deficient ovarian cancer cells, suggesting the functionality and specificity of CTL4 as a therapeutic target. Additionally, we discovered that phosphocholine, the choline metabolite increased by CTL4 overexpression, interacted with and stabilized the epithelial-to-mesenchymal transition inducer FAM3C in BRCA1-deficient ovarian cancer cells. Importantly, we identified a potent CTL4 inhibitor, DT-13, which significantly reduces choline metabolism and effectively suppresses metastasis in BRCA1-deficient ovarian cancers. Therefore, our study uncovers a mechanism underlying metastasis in BRCA1-deficient cancers and identifies CTL4 as a therapeutic target for metastatic ovarian cancer patients with BRCA1 mutations.</p>
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:Gene expression profiling on 63 stage III-IV papillary serous ovarian cancer samples resected during primary debulking at the University of Turin, Italy. Only the primary ovarian mass and no metastases were included in this analysis. The study focused on ovarian cancer chemokine expressions Only the primary ovarian mass and no metastases were included in this analysis.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:Tumor cell extravasation takes place, similar to leukocytes, in a multi-step process by which cells emigrate from the blood stream through the vascular endothelium into the tissue. Selectins are regarded as the most important molecules for the first capturing step of the cascade. Whether all tumor cells employ selectin dependent adhesion to metastasize or there is an alternative mechanism still is an open question. Comparative transcriptomic analysis of OVCAR8 and SKOV3 cultured cells and revealed that one third of genes encoding proteins involved in the selectin dependent leukocyte like adhesion cascade show lower expression levels in OVCAR8 cultured cells in comparison to that in SKOV3 cultured cells. In contrast to SKOV3 cells, c-Fos overexpression in OVCAR8 cells does not significantly influence expression of the leukocyte like adhesion cascade genes leaving them at similar levels as in control OVCAR8 cells. The intraperitoneal xenograft model of OVCAR8 cells demonstrated that aggressiveness of OVCAR8-derived tumors is not dependent of c-Fos expression level and comparable with that for SKOV3 control tumors. Based on transcriptome array data we analyzed in details expression of genes encoding proteins involved in the leukocyte like adhesion cascade, E- and P-selectin ligands, as well as glycosylation enzymes in both type of tumors. Our results suggest that selectin-dependent mechanism is not the only for adhesion of OVCAR8 ovarian cancer cells. There is at least one additional mechanism of extravasation that does not rely on selectins.
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: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. Two-condition experiment, Normoxic MSCs vs. Hypoxic MSCs.