Project description:Purpose:The Vimentin gene plays a pivotal role in epithelial-to-mesenchymal transition (EMT) and is known to be over-expressed in the prognostically poor basal-like breast cancer subtype. Recent studies have reported Vimentin DNA methylation in association with poor clinical outcomes in other solid tumors, but not in breast cancer. We therefore quantified Vimentin DNA methylation in breast tumors and matched normal pairs in association with gene expression and survival in a cohort of 83 breast cancer patients. Materials and Methods:Vimentin methylation was quantified in 14 breast cell lines, 83 breast tumors, and 57 matched normal pairs using MALDI-TOF mass spectrometry. Gene expression data via qRT-PCR in cell lines, and oligo microarray data from breast tissues was correlated with percent methylation in the Vimentin promoter. A threshold of 20 percent average methylation was set for bivariate and multivariate tests of association between methylation and tumor subtype, tumor histopathology, and survival. Results:Vimentin was differentially methylated in luminal breast cancer cell lines, and in luminal A, luminal B and HER2+ breast tumor subtypes, but was rare in basal-like cell lines and tumors. Increased methylation was strongly correlated with decreased mRNA expression in cell lines, and had a moderate inverse correlation in breast tumors. Importantly, Vimentin methylation predicted poor overall survival independent of race, subtype, stage, nodal status or estrogen receptor positivity. Conclusion:Vimentin methylation predicts overall survival in breast cancer patients and holds promise as a prognostic biomarker for guiding treatment and prophylaxis. reference x sample
Project description:Purpose:The Vimentin gene plays a pivotal role in epithelial-to-mesenchymal transition (EMT) and is known to be over-expressed in the prognostically poor basal-like breast cancer subtype. Recent studies have reported Vimentin DNA methylation in association with poor clinical outcomes in other solid tumors, but not in breast cancer. We therefore quantified Vimentin DNA methylation in breast tumors and matched normal pairs in association with gene expression and survival in a cohort of 83 breast cancer patients. Materials and Methods:Vimentin methylation was quantified in 14 breast cell lines, 83 breast tumors, and 57 matched normal pairs using MALDI-TOF mass spectrometry. Gene expression data via qRT-PCR in cell lines, and oligo microarray data from breast tissues was correlated with percent methylation in the Vimentin promoter. A threshold of 20 percent average methylation was set for bivariate and multivariate tests of association between methylation and tumor subtype, tumor histopathology, and survival. Results:Vimentin was differentially methylated in luminal breast cancer cell lines, and in luminal A, luminal B and HER2+ breast tumor subtypes, but was rare in basal-like cell lines and tumors. Increased methylation was strongly correlated with decreased mRNA expression in cell lines, and had a moderate inverse correlation in breast tumors. Importantly, Vimentin methylation predicted poor overall survival independent of race, subtype, stage, nodal status or estrogen receptor positivity. Conclusion:Vimentin methylation predicts overall survival in breast cancer patients and holds promise as a prognostic biomarker for guiding treatment and prophylaxis.
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
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