Project description:Tumor associated miRNAs in hereditary breast cancer. In this study we investigated the role of miRNAs in hereditary breast tumors comparing with normal breast tissue. Global miRNA expression profiling was performed on 22 hereditary breast tumors and 15 non-tumoral breast tissues. We identified 19 miRNAs differentially expressed, most of them down-regulated in tumors. An important proportion of deregulated miRNAs in hereditary tumors were previously identified commonly deregulated in sporadic breast tumors. Our results identify miRNAs associated to hereditary breast cancer, as well as miRNAs commonly miss-expressed in hereditary and sporadic tumors, suggesting common underlying mechanisms of tumor progression. In addition, we provide evidence that KRAS is a target of miR-30c, and that this miRNA suppresses breast cancer cell growth potentially through inhibition of KRAS signaling.
Project description:Tumor associated miRNAs in hereditary breast cancer. In this study we investigated the role of miRNAs in hereditary breast tumors comparing with normal breast tissue. Global miRNA expression profiling was performed on 22 hereditary breast tumors and 15 non-tumoral breast tissues. We identified 19 miRNAs differentially expressed, most of them down-regulated in tumors. An important proportion of deregulated miRNAs in hereditary tumors were previously identified commonly deregulated in sporadic breast tumors. Our results identify miRNAs associated to hereditary breast cancer, as well as miRNAs commonly miss-expressed in hereditary and sporadic tumors, suggesting common underlying mechanisms of tumor progression. In addition, we provide evidence that KRAS is a target of miR-30c, and that this miRNA suppresses breast cancer cell growth potentially through inhibition of KRAS signaling. Single color experiments in a pairwise comparison design.
Project description:The objective of the study was to characterize hereditary breast tumors based on their miRNA expression profiles. To this end, we performed global miRNA expression analysis of more than 800 human miRNA genes in a large series of 80 FFPE breast tissue samples. The series included 66 hereditary breast primary tumors from 13 BRCA1 mutation carriers, 10 BRCA2 mutation carriers and 43 non-BRCA12 tumors denominated hereafter as BRCAX tumors. In addition we have analyzed 10 sporadic breast carcinomas and 4 normal breast tissues obtained after breast reduction surgery from healthy donors with no family history of breast cancer. To avoid contamination with normal breast tissue, tumoral area on FFPE blocks was marked by a pathologist and macrodissected for subsequent total RNA extraction.
Project description:The objective of the study was to characterize hereditary breast tumors based on their miRNA expression profiles. To this end, we performed global miRNA expression analysis of more than 800 human miRNA genes in a large series of 80 FFPE breast tissue samples. The series included 66 hereditary breast primary tumors from 13 BRCA1 mutation carriers, 10 BRCA2 mutation carriers and 43 non-BRCA12 tumors denominated hereafter as BRCAX tumors. In addition we have analyzed 10 sporadic breast carcinomas and 4 normal breast tissues obtained after breast reduction surgery from healthy donors with no family history of breast cancer. To avoid contamination with normal breast tissue, tumoral area on FFPE blocks was marked by a pathologist and macrodissected for subsequent total RNA extraction. Microarray expression profiling was performed using miRCURY LNATM microRNA Array v.11 (Exiqon A/S, Denmark), in a single color experiments in a pairwise comparison experimantal design.
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: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.