Project description:MicroRNAs (miRNAs), a class of short non-coding RNAs, often act post-transcriptionally to inhibit gene expression. We used a bead-based flow cytometric profiling method to obtain miRNA expression data for 93 primary human breast tumours, 21 cell lines and five normal breast samples. Of 309 human miRNAs assayed we identify 133 miRNAs expressed in human breast and breast tumours. We used mRNA expression profiling to classify the breast tumours into Luminal A, Luminal B, Basal-like, HER2+/ER- and Normal-like. A number of miRNAs are differentially expressed between these molecular tumour subtypes and individual miRNAs are associated with clinicopathological factors. Furthermore, we find that miRNAs could classify basal versus luminal tumour subtypes in an independent data set. Keywords = miRNA Keywords = microRNA Keywords = normal Keywords = tumour Keywords = cell line Keywords = breast Keywords = cancer Keywords: Bead-based flow cytometric profiling
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:Due to their role in tumorigenesis and remarkable stability in body fluids, microRNAs (miRNAs) are emerging as a promising diagnostic tool. The aim of this study was to identify tumor miRNA signatures for the discrimination of breast cancer and the intrinsic molecular subtypes, and the study in plasma of the status of the most significant ones in order to identify potential circulating biomarkers for breast cancer detection. MiRNA expression profiling of 1919 human miRNAs was conducted in 122 FFPE breast tumors (31 luminal A, 33 luminal B, 27 Her2 and 31 triple negative) and 11 normal breast tissues using LNA based miRNA microarrays. Breast tumors were divided into a training (n=61) and a test set (n=61). Both series comprised a similar number of samples from each molecular subtype. Differential expression analysis was performed and microarray classifiers were developed with samples from the training set and validated in samples from the test set. The most relevant miRNAs were validated by quantitative PCR and analyzed in plasma from 36 pretreated patients, 47 postreated patients and 26 healthy individuals. In addition, further validation in 114 pretreated patients and 116 healthy individuals was performed.
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:MicroRNAs (miRNAs), a class of short non-coding RNAs, often act post-transcriptionally to inhibit gene expression. We used a bead-based flow cytometric profiling method to obtain miRNA expression data for 93 primary human breast tumours, 21 cell lines and five normal breast samples. Of 309 human miRNAs assayed we identify 133 miRNAs expressed in human breast and breast tumours. We used mRNA expression profiling to classify the breast tumours into Luminal A, Luminal B, Basal-like, HER2+/ER- and Normal-like. A number of miRNAs are differentially expressed between these molecular tumour subtypes and individual miRNAs are associated with clinicopathological factors. Furthermore, we find that miRNAs could classify basal versus luminal tumour subtypes in an independent data set. Keywords = miRNA Keywords = microRNA Keywords = normal Keywords = tumour Keywords = cell line Keywords = breast Keywords = cancer Keywords: Bead-based flow cytometric profiling miRNA expression data for 93 primary human breast tumours, 21 cell lines and five normal breast samples
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:Recent analyses have identified heterogeneity in estrogen receptor (ER)-positive breast cancer. There are so-called luminal A and luminal B subtypes, and the characteristics, such as response to endocrine therapy and chemotherapy and prognosis, are different in these two subtypes of breast cancer. In this study, expression profiles of microRNAs (miRNAs) and mRNAs in ER-positive breast cancer tissues were compared between highly and incompletely endocrine responsive tumors by miRNA and mRNA microarrays. Unsupervised hierarchical clustering analyses revealed distinct expression patterns of miRNAs and mRNAs in these two groups. We identified one miRNA that was downregulated in highly endocrine responsive tumors and 8 miRNAs that were downregulated in incompletely endocrine responsive tumors, and target genes of these miRNAs were predicted using TargetScan and MiRanda. Protein expression patterns of the predicted target genes and the genes that were identified by mRNA expression profiling were analyzed in ER-positive breast cancer samples by immunohistochemistry. We identified a novel protein that might be associated with characteristics of ER-positive breast cancer.