Micro (mi)RNAs are small non-coding RNAs with key regulatory functions. Recent advances in the field allowed researchers to identify their targets. However, much less is known regarding the regulation of miRNA themselves. The accumulation of these tiny regulators can be modulated at various levels during their biogenesis from the transcription of the primary transcript (pri-miRNA) to the stability of the mature miRNA. Here, we studied the importance of the pri-miRNA secondary structure for the regulation of mature miRNAs accumulation. To this end, we used the Kaposi’s sarcoma herpesvirus, which encodes a cluster of twelve pre-miRNAs. Using small RNA profiling and quantitative northern blot analysis, we measured the absolute amount of each mature miRNAs in different cellular context. We found that the difference in expression between the least and most expressed viral miRNA could be as high as 60-fold. Using high-throughput selective 2’-hydroxyl acylation analyzed by primer extension (hSHAPE), we then determined the secondary structure of the long primary transcript. We found that highly expressed miRNAs derived from optimally structured regions within the pri-miRNA. Finally, we confirmed the importance of the local structure by swapping stem-loops for highly and lowly expressed miRNAs, which resulted in a perturbed accumulation of the mature miRNA. Overall design: Examination of sRNA profiles in 3 independent B cell lines expressing KSHV miRNAs or infected with KSHV, without replicate
Importance of the RNA secondary structure for the relative accumulation of clustered viral microRNAs.
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View SamplesScreening small molecules and drugs for activity to modulate alternative splicing, we found that amiloride, distinct from four other intracellular pH-affecting analogues, could normalize the splicing of BCL-X, HIPK3 and RON/MISTR1 transcripts in human hepatocellular carcinoma Huh-7 cells. To elucidate the underlying mechanisms, our proteomic analyses of amiloride-treated cells detected hypo-phosphorylation of splicing factor SF2/ASF and also decreased levels of SRp20 and two un-identified SR proteins. We further observed decreased phosphorylation of AKT, ERK1/2 and PP1, while increased phosphorylation of p38 and JNK, suggesting that amiloride treatment down-regulated kinases and up-regulated phosphatases in the signal pathways known to affect the splicing factor protein phosphorylation. The amiloride effects of splicing factor protein hypo-phosphorylation andnormalizedoncogenic RNA splicing were both abrogated by pre-treatment with a PP1 inhibitor. We then performed global exon array analysis of Huh-7 cells treated with amiloride for 24 hours. Using gene array chips (Affymetrix GeneChip Human Exon 1.0 ST Array of >518000 exons of 42974 genes) for exon array analysis (set parameters of correlation coefficient 0.7, splicing index -1.585 , and log2 ratio -1.585), we found that amiloride influenced the splicing patterns of 551 genes involving at least 584 exons, which included 495 known protein-coding genes involving 526 exons, many of which play key roles in functional networks of ion transport, extracellular matrix, cytoskeletons and genome maintenance. Cellular functional analyses revealed subsequent invasion and migration defects, cell cycle disruption, cytokinesis impairment, and lethal DNA degradation in amiloride-treated Huh-7 cells. This study thus provides mechanistic underpinnings for exploiting small molecule modulation of abnormal RNA splicing for cancer therapeutics.
Small molecule amiloride modulates oncogenic RNA alternative splicing to devitalize human cancer cells.
Cell line
View SamplesCytomegaloviruses express large amounts of viral miRNAs during lytic infection, yet, they only modestly alter the cellular miRNA profile. The most prominent alteration upon lytic murine cytomegalovirus (MCMV) infection is the rapid degradation of the cellular miR-27a and miR-27b. Here, we report that this regulation is mediated by the <1.7 kb spliced and highly abundant MCMV m169 transcript. Specificity to miR-27a/b is mediated by a single, apparently optimized, miRNA binding site located in its 3''-UTR. This site is easily and efficiently retargeted to other cellular and viral miRNAs by target site replacement. Expression of the 3''-UTR of m169 by an adenoviral vector was sufficient to mediate its function, indicating that no other viral factors are essential in this process. Degradation of miR-27a/b was found to be accompanied by 3''-tailing and -trimming. Despite its dramatic effect on miRNA stability, we found this interaction to be mutual, indicating potential regulation of m169 by miR-27a/b. Most interestingly, three mutant viruses no longer able to target miR-27a/b, either due to miRNA target site disruption or target site replacement, showed significant attenuation in multiple organs as early as 4 days post infection, indicating that degradation of miR-27a/b is important for efficient MCMV replication in vivo. Overall design: Small RNA sequencing from total RNA or Ago2 associated small RNAs extracted from mock- or MCMV-infected NIH-3T3 cells
Degradation of cellular mir-27 by a novel, highly abundant viral transcript is important for efficient virus replication in vivo.
Specimen part, Cell line, Subject
View SamplesAlternative splicing is a mechanism for increasing the protein variety of a limited number of genes. Studies have shown that aberrant regulations of the alternative splicing of apoptotic gene transcripts may contribute to the development of cancer. In this study, we isolated 4ß-Hydroxywithanolide E (4bHWE) from the traditional herb Physalis peruviana, and analyzed its biological effects in cancer cells. The results demonstrated that 4bHWE modulates the alternative splicing of apoptotic genes (e.g., HIPK3, SMAC/DIABLO, and SURVIVIN), changes the expression level of splicing factors (e.g., hnRNP C1/C2, ASF/SF2, SRp20, and SRp55), and induces histone tail posttranslational modifications (e.g., H3K27me1, H3K27me2, H3K36me3, and H3K79me1). Pretreatment with okadaic acid to inhibit protein phosphatase-1 could partly relieve the effects of 4bHWE on the alternative splicing of HIPK3 and SMAC/DIABLO transcripts, as well as on the dephosphorylation of ASF/SF2. Genome-wide detection of alternative splicing further indicated that several other apoptosis-related genes are also regulated by 4bHWE, including APAF1, CARP-1, and RIPK1. Moreover, we extended our study to apoptosis-associated molecules, detecting an increasing level of CASPASE-3 activity and cleavage of poly ADP-ribose polymerase in 4bHWE-induced apoptosis. Furthermore, in vivo experiments showed that the treatment of tumor-bearing mice with 4bHWE resulted in a marked decrease of tumor size and weight. Taken together, this study is the first to show that 4bHWE affects alternative splicing through the modulations of splicing factors, providing a novel view of the antitumor mechanism of 4bHWE. Overall design: Examination of the global genes with altered alternative splicing in 4bHWE-treated Huh-7 cells.
4β-Hydroxywithanolide E Modulates Alternative Splicing of Apoptotic Genes in Human Hepatocellular Carcinoma Huh-7 Cells.
Specimen part, Treatment, Subject
View SamplesWe demonstrate that GLUT4 up-regulation significantly increased cell migration and invasion in lower magligance head and neck cancer cell lines in vitro.
Glucose transporter 4 promotes head and neck squamous cell carcinoma metastasis through the TRIM24-DDX58 axis.
Specimen part, Cell line
View SamplesThe orthotopic transplantation of human OEC-M1 cells in immune-compromised mice was established to feasibly study tumorigenesis and lymph node metastasis of OSCC.
Insulin-like growth factor-independent insulin-like growth factor binding protein 3 promotes cell migration and lymph node metastasis of oral squamous cell carcinoma cells by requirement of integrin β1.
Specimen part, Cell line
View SamplesTo exmaine the PTHLH stimulated genes in Ca9-22 cells, we preformed the Affymetrix Human Genome U133 Plus 2.0 Array with empty vector or PTHLH expression vector. The raw data were normalized by GeneSpring GX software and up-load with raw values.
Parathyroid Hormone-Like Hormone is a Poor Prognosis Marker of Head and Neck Cancer and Promotes Cell Growth via RUNX2 Regulation.
Cell line
View SamplesThe early-onset breast cancer patients (age 40) often display higher incidence of axillary lymph node metastasis, and poorer five-year survival than the late-onset patients. To identify the genes and molecules associated with poor prognosis of early-onset breast cancer, we examined gene expression profiles from paired breast normal/ tumor tissues, and coupled with Gene Ontology and public data base analysis. Our data showed that the expression of GAS7b gene was lower in the early-onset breast cancer patients as compared to the elder patients. We found that GAS7 was associated with CYFIP1 and WAVE2 complex to suppress breast cancer metastasis via blocking CYFIP1 and Rac1 protein interaction, actin polymerization, and 1-integrin/FAK/Src signaling. We further demonstrated that p53 directly regulated GAS7 gene expression, which was inversely correlated with p53 mutations in breast cancer specimens. Our study uncover a novel regulatory mechanism of p53 in early-onset breast cancer progression through GAS7-CYFIP1 mediated signaling pathways.
Wild-type p53 upregulates an early onset breast cancer-associated gene GAS7 to suppress metastasis via GAS7-CYFIP1-mediated signaling pathway.
Sex, Age, Specimen part, Subject
View SamplesTo examine the transcription targets of RUNX2 in OSCC cells, we preformed the Affymetrix Human Genome U133 Plus 2.0 Array with ectopic RUNX2 or empty vectors in Ca9-22 cells.
Dysregulation of RUNX2/Activin-A Axis upon miR-376c Downregulation Promotes Lymph Node Metastasis in Head and Neck Squamous Cell Carcinoma.
Specimen part, Cell line
View SamplesWe have developed a protocol to generate hematopoietic and cardiac derivatives in vitro by Mesp1 induction in ES cells. The goal of this study is to analyze the heterogeneity of Mesp1+ mesoderm by single-cell RNA-seq Overall design: 48 Mesp1-induced single cells were captured using the Fluidigm C1 microfluidic system. RNA extraction, RT and cDNA amplication were then performed according to the manufacturer's manual.
Heterogeneity of Mesp1+ mesoderm revealed by single-cell RNA-seq.
Specimen part, Cell line, Treatment, Subject
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