Project description:To explore the role of small nucleolar RNA (snoRNA) on self-renewal of liver cancer stem cells (CSCs), we isolated liver CSCs (CD133+CD13+) and Non-CSCs (CD133-CD13-) from huamn liver tumor tissues.
Project description:Leukemogenesis requires enhanced self-renewal activity, which is induced by specific oncogenes. The underlying molecular mechanisms remain incompletely understood. We measured snoRNA expression in human primary AML samples that contained determined leukemia stem cells frequency. We identified that expression of C/D box snoRNAs was closely associated with leukemia stem cell frequency.
Project description:Background: Small nucleolar RNAs (snoRNAs) are mid-size non-coding RNAs required for ribosomal RNA modification, implying a ubiquitous tissue distribution linked to ribosome synthesis. However, increasing numbers of studies identify extra-ribosomal roles of snoRNAs in modulating gene expression, suggesting more complex snoRNA abundance patterns. Therefore, there is a great need for mapping the snoRNome in different human tissues as the blueprint for snoRNA functions. Results: We used a low structure bias RNA-Seq approach to accurately quantify snoRNAs and compare them to the entire transcriptome in seven healthy human tissues (breast, ovary, prostate, testis, skeletal muscle, liver and brain). We identify 475 expressed snoRNAs categorized in two abundance classes that differ significantly in their function, conservation level and correlation with their host gene: 390 snoRNAs are uniformly expressed and 85 are enriched in the brain or reproductive tissues. Most tissue-enriched snoRNAs are embedded in lncRNAs and display strong correlation of abundance with them, whereas uniformly expressed snoRNAs are mostly embedded in protein-coding host genes and are mainly non- or anticorrelated with them. 59% of the non-correlated or anticorrelated protein-coding host gene/snoRNA pairs feature dual-initiation promoters, compared to only 16% of the correlated non-coding host gene/snoRNA pairs. Conclusions: Our results demonstrate that snoRNAs are not a single homogeneous group of housekeeping genes but include highly regulated tissue-enriched RNAs. Indeed, our work indicates that the architecture of snoRNA host genes varies to uncouple the host and snoRNA expressions in order to meet the different snoRNA abundance levels and functional needs of human tissues.
Project description:Background: In recent years, a variety of small RNAs derived from other RNAs with well-known functions such as tRNAs and snoRNAs, have been identified. The functional relevance of these RNAs is largely unknown. To gain insight into the complexity of snoRNA processing and the functional relevance of snoRNA-derived small RNAs, we sequenced long and short RNAs, small RNAs that co-precipitate with the Argonaute 2 protein and RNA fragments obtained in photoreactive nucleotide-enhanced crosslinking and immunoprecipitation (PAR-CLIP) of core snoRNA-associated proteins. Results: Analysis of these data sets revealed that many loci in the human genome reproducibly give rise to C/D box-like snoRNAs, whose expression and evolutionary conservation are typically less pronounced relative to the snoRNAs that are currently catalogued. We further found that virtually all C/D box snoRNAs are specifically processed inside the regions of terminal complementarity, retaining in the mature form only 4-5 nucleotides upstream of the C box and 2-5 nucleotides downstream of the D box. Sequencing of the total and Argonaute 2-associated populations of small RNAs revealed that despite their cellular abundance, C/D box-derived small RNAs are not efficiently incorporated into the Ago2 protein. Conclusions: We conclude that the human genome encodes a large number of snoRNAs that are processed along the canonical pathway and expressed at relatively low levels. Generation of snoRNA-derived processing products with alternative, particularly miRNA-like, functions appears to be uncommon. PAR-CLIP profiling for snoRNP core proteins NOP56, NOP58, Fibrillarin, and Dyskerin in HEK293 cells. Small RNA profiling using RNA-seq in HEK293 and HeLa cells, small RNA profiling using IP-seq of Ago2 associated small RNAs.
Project description:We evaluated the profile of miRNA and snoRNA expression in 7 solitary CRC and matched normal colorectal tissues using the Affymetrix GeneChip miRNA 1.0 array. We found that global dysregulated miRNAs and snoRNAs between cancer tissue and normal mucosa in solitary CRC. Our findings firstly implicates that dysregulation of snoRNAs and miRNA may play important role in the cancinogenesis and present therapeutic targets for solitary CRC. Examination of microRNA and snoRNA expression in cancer and matched normal tissues of solitary CRC
Project description:This study aimed to determine whether the spaceflight-induced snoRNA changes in plasma extracellular vesicles (EV) and astronauts' peripheral blood mononuclear cells (PBMCs) can be utilized as potential biomarkers. Using unbiased small RNA sequencing, we evaluated the EV snoRNA changes in peripheral blood (PB) plasma of astronauts (n=5/group) who underwent median 12-day long Shuttle missions between 1998-2001. Using stringent cutoff (> log 2-fold change, FDR < 0.05), we detected 21 down-regulated snoRNAs and 9 upregulated in PB-EVs at three days after return (R+3) compared to ten days before launch (L-10). Our findings unveiled that spaceflight induced changes in EV and PBMCs snoRNA expression, thus suggesting snoRNAs may serve as novel biomarkers for monitoring astronauts' health.
Project description:We evaluated the profile of miRNA and snoRNA expression in 5 synchronous CRC and matched normal colorectal tissues using the Affymetrix GeneChip miRNA 1.0 array. A total of 24 miRNA differential expressed transcripts which represent 27 mature miRNAs, including an oncogenic miR-17-92a and oncosuppressive miR-143-145 cluster, and a global up-regulation of snoRNAs were revealed in cancer tissues compared with matched normal tissues. Global miRNA expression could distinguish synchronous cancer from normal mucosa. Our findings represent the first comprehensive miRNA and snoRNA expression signatures for synchronous CRC, which increase the understanding of the molecular basis of synchronous CRC, and firstly implicate that dysregulation of snoRNAs and miRNA clusters may present therapeutic targets for synchronous CRC. Examination of microRNA and snoRNA expression in synchronous CRC and matched normal colorectal tissues
Project description:Comparison of mRNA transcriptome after differential expression of U17 snoRNA. We hypothesiaed that if U17 snoRNA regulates cholesterol homeostasis by modulating the expression of target mRNAs, genes that are differentially expressed by the loss-of-function or gain-of-function of U17 snoRNA would be candidate U17 targets. Results revealed negative regulation of target genes by U17 snoRNA, in which increasing dosage of U17 snoRNA from U17 knockdown to WT to U17 overexpression lead to decreases in target levels. Total RNA were isolated by TRIzol reagent (Invitrogen) from WT, U17 snoRNA KD (ShSnhg3 stable clone), and U17 snoRNA OE (pMDβglobinU17b stable clone) cells grown in LPDS media for 24 hours.
Project description:We applied small RNA Solexa sequencing technology to identify microRNA expression in human liver samples from surgically removed liver tissues including three normal liver tissues (distal normal liver tissue of liver hemangioma), an hepatitis B virus (HBV)-infected liver, a severe chronic hepatitis B liver, two HBV-related hepatocellular carcinoma (HCC), an hepatitis C virus (HCV)-related HCC, and an HCC without HBV or HCV infection. All samples were collected with the informed consent of the patients and the experiments were approved by the ethics committee of Second Military Medical University, Shanghai, China. We investigated the miRNome in human normal liver and suggested some deregulated abundantly expressed microRNAs in HCC. center_name: National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai, China.