Project description:The field of epitranscriptomics is growing in importance, with chemical modification of RNA being associated with a wide variety of biological phenomena. Mass spectrometry (MS) enables the identification of modified RNA residues within their sequence contexts, by using analogous approaches to shotgun proteomics. We have developed a free and open-source database search engine for RNA MS data, called NucleicAcidSearchEngine (NASE), as part of the OpenMS software framework. NASE allows the reliable identification of (modified) RNA sequences from LC-MS/MS data in a high-throughput fashion. For this validation dataset, we generated a sample of human total tRNA from a cellular extract - a complex mixture of highly modified RNAs. This sample was RNase-treated prior to nanoflow LC-MS/MS analysis.
Project description:The field of epitranscriptomics is growing in importance, with chemical modification of RNA being associated with a wide variety of biological phenomena. Mass spectrometry (MS) enables the identification of modified RNA residues within their sequence contexts, by using analogous approaches to shotgun proteomics. We have developed a free and open-source database search engine for RNA MS data, called NucleicAcidSearchEngine (NASE), as part of the OpenMS software framework. NASE allows the reliable identification of (modified) RNA sequences from LC-MS/MS data in a high-throughput fashion. For this validation dataset, we generated samples of human total tRNA from a cellular extract - a complex mixture of highly modified RNAs. The samples were RNase-treated prior to nanoflow LC-MS/MS analysis.
Project description:To define the role of MAGE-A1 in melanoma growth and metastasis, we performed RNA-seq analysis on MAGE-A1 overexpression (OE) and knockdown (KD) models in A375 human melanoma cell line. Our results revealed that overexpression of MAGE-A1 dramatically promoted proliferation, migration, and invasion of human melanoma cells in vitro and down-regulated of MAGE-A1 inhibited tumor cell proliferation and invasion. Furthermore, MAGE-A1 exerts its tumor promoting activity via activating including ERK-MAPK signaling pathway by RNA-seq analysis. mRNA profiles of MAGE-A1 over expression (OE), knockdown (KD), pcDNA-vector control, and pRNAT-scramble control in A375 cell line were generated using Ion torrent
Project description:MicroRNAs are important negative regulators of protein coding gene expression, and have been studied intensively over the last few years. To this purpose, different measurement platforms to determine their RNA abundance levels in biological samples have been developed. In this study, we have systematically compared 12 commercially available microRNA expression platforms by measuring an identical set of 20 standardized positive and negative control samples, including human universal reference RNA, human brain RNA and titrations thereof, human serum samples, and synthetic spikes from homologous microRNA family members. We developed novel quality metrics in order to objectively assess platform performance of very different technologies such as small RNA sequencing, RT-qPCR and (microarray) hybridization. We assessed reproducibility, sensitivity, quantitative performance, and specificity. The results indicate that each method has its strengths and weaknesses, which helps guiding informed selection of a quantitative microRNA gene expression platform in function of particular study goals.
Project description:In the pathogenic yeast Candida albicans, the zinc cluster transcription factor Upc2p has been shown to regulate expression of ERG11 and other genes involved in ergosterol biosynthesis upon exposure to azole antifungals. ERG11 encodes lanosterol demethylase, the target enzyme of this antifungal class. Over-expression of UPC2 reduces azole susceptibility, whereas its disruption results in hypersusceptibility to azoles and reduced accumulation of exogenous sterols. Constitutive up-regulation of ERG11 is a major cause of resistance to fluconazole in clinical isolates of C. albicans, yet the mechanism for this has yet to be determined. Using genome-wide gene expression profiling, we found UPC2 and other genes involved in ergosterol biosynthesis to be coordinately up-regulated with ERG11 in a fluconazole resistant clinical isolate as compared with a matched susceptible isolate from the same patient. Sequence analysis of the UPC2 alleles of these isolates revealed that the resistant isolate contained a single nucleotide substitution in one UPC2 allele that resulted in a G648D exchange in the encoded protein. Introduction of the mutated allele into a drug susceptible strain resulted in constitutive up-regulation of ERG11 and increased resistance to fluconazole. By comparing the gene expression profiles of the fluconazole resistant isolate and of strains carrying wild-type and mutated UPC2 alleles, we identified target genes that are controlled by Upc2p. Here we show for the first time that a gain-of-function mutation in UPC2 leads to increased expression of ERG11 and imparts resistance to fluconazole in clinical isolates of C. albicans. Keywords: genome-wide expression profiling Clinical isolates S1 (susceptible) and S2 (resistant), genome strain SC5314, UPC2 disruption strains (UPC2M4A and UPC2M4B), UPC2 re-integrant strains of non-mutated UPC2 allele (UPC2M2K21A and UPC2M2K21B), and UPC2 re-integrant strains of mutated UPC2 allele (UPC2M2K31A and UPC2M2K31B) were grown for 3 hours until log phase. RNA was extracted for each isolate/strain. Experiments were performed in duplicate.
Project description:Long non-coding RNAs (lncRNAs) are recently characterized players that are involved in the regulatory circuitry of self-renewal in human embryonic stem cells (hESCs). However, the specific roles of lncRNAs in this circuitry are poorly understood. Here, we determined that growth-arrest-specific transcript 5 (GAS5), which is a known tumor suppressor and growth arrest gene, is abundantly expressed in the cytoplasm of hESCs and essential for hESC self-renewal. GAS5 depletion in hESCs significantly impaired their pluripotency and self-renewal ability, whereas GAS5 overexpression in hESCs accelerated the cell cycle, enhanced their colony formation ability and increased pluripotency marker expression. By RNA sequencing and bioinformatics analysis, we determined that GAS5 activates NODAL-SMAD2/3 signaling by sustaining the expression of NODAL, which plays a key role in hESC self-renewal but not in somatic cell growth. Further studies indicated that GAS5 functions as a competing endogenous RNA (ceRNA) to protect NODAL mRNA against degradation and that GAS5 transcription is directly controlled by the core pluripotency transcriptional factors (TFs). Taken together, we suggest that the core TFs, GAS5 and NODAL-SMAD2/3 form a feed-forward loop to maintain the hESC self-renewal process. These findings are specific to ESCs and did not occur in the somatic cell lines we tested; therefore, our findings also provide evidence that the functions of lncRNAs vary in different biological contexts. We analyzed long non-coding RNAs in two hESC cell lines (X-01 and H1), and found GAS5 is highly expressed and functional in maintaining hESC self-renewal. We generate stable overexpressed or knockdown hESC cell lines using lentiviral approach. We transfected cells initialy after passage, and lentiviruses are added with daily medium change for three days (at a final concentration of 10^5 IU/ml). Puromycin is added for selection and supplied with daily medium change. Stable cell lines are established after two passages and verified under fluorescence scope. Total RNAs and miRNAs are extracted separately of all three cell lines (LV-NC, LV-GAS5 and LV-shGAS5) and put to sequencing.