Project description:Adrenocortical tumors are common; their prevalence may reach up to 5-7% in pathological series. Most of them are benign and hormonally inactive, however, rare hormone-secreting (aldosterone and cortisol) and malignant forms are associated with significant morbidity and mortality. The prognosis of adrenocortical cancer (ACC) is poor with an overall five-year survival below 30 %. In this study, CGH analysis was performed on 4 ACC (adrenocortical carcinoma), 4 IA (hormonally inactive adrenocortical adenoma) and 3 CPA (cortisol producing adrenocortical adenoma) samples. Tissue digestion, labeling, hybridization and data analysis of genomic DNA were performed according to the Agilent Technologies (Santa Clara, CA) protocol version 2.0 for 105 K arrays. As expected, many of the observed aberrations were generally consistent with those of other preciously published data and will provide the basis for determination how genomic diversity impacts biological function and human diseases, such as cancer.
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