Screening 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 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 SamplesThis SuperSeries is composed of the SubSeries listed below.
Histone H3 lysine 9 di-methylation as an epigenetic signature of the interferon response.
Specimen part, Treatment
View SamplesEffective anti-viral immunity depends on the ability of infected cells or cells triggered with virus-derived nucleic acids to produce type I interferon (IFN), which activates transcription of numerous antiviral genes. However, disproportionately strong or chronic IFN expression is a common cause of inflammatory and autoimmune diseases. Here we describe an epigenetic mechanism that determines cell-type specific differences in IFN and IFN-stimulated gene expression in response to exogenous signals. We identify di-methylation of histone H3 at lysine 9 (H3K9me2) as a suppressor of IFN and IFN-inducible antiviral gene expression. We show that levels of H3K9me2 at IFN and IFN stimulated genes (ISG) correlate inversely with the scope and amplitude of IFN and ISG expression in fibroblasts and dendritic cells. Accordingly, genetic ablation or pharmacological inactivation of lysine methyltransferase G9a, which is essential for the generation of H3K9me2, resulted in phenotypic conversion of fibroblasts into highly potent IFN-producing cells and rendered these cells resistant to pathogenic RNA viruses. In summary, our studies implicate H3K9me2 and enzymes controlling its abundance as key regulators of innate antiviral immunity.
Histone H3 lysine 9 di-methylation as an epigenetic signature of the interferon response.
Treatment
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 SamplesPrevious studies have demonstrated that E-proteins induce AID expression in activated B cells. Here we have examined the role of Id3 in germinal center (GC) cells. We found that Id3 expression is high in follicular B-lineage cells but declines in GC cells. Immunized mice depleted for Id3 expression displayed a block in germinal center B cell maturation, showed reduced numbers of marginal zone B cells and class switched cells, were associated with decreased antibody titers and lower numbers of plasma cells. In vitro Id3-depleted B cells displayed a defect in class switch recombination. Whereas AID levels were not altered in Id3-depleted activated B cells, the expression of a subset of genes encoding for signaling components of antigen receptor, cytokine receptor and chemokine receptor mediated signaling was significantly impaired. We propose that during the GC reaction Id3 levels decline to activate the expression of genes encoding for signaling components that mediate B cell receptor and or cytokine-mediated signaling to promote the differentiation of GC B cells. Overall design: B cells derived from control and CD19-Cre;Id3loxP/loxP mice were activated in vitro in the presence of LPS and IL-4 for 24 or 48 hours. RNA was isolated from naïve as well as activated control and CD19-Cre;Id3loxP/loxP mice and analyzed by RNA-seq, in duiplicate.
Id3 Orchestrates Germinal Center B Cell Development.
Specimen part, Cell line, Subject
View SamplesThe tumor suppressor TP53 is mutated in the majority of human cancers, including over 70% of pancreatic ductal adenocarcinoma (PDAC). Wild-type p53 accumulates in response to cellular stress and regulates the expression of genes that alter cell fate and constrain tumorigenesis. p53 also modulates several cellular metabolic pathways, though it remains unclear whether particular p53-regulated metabolites contribute to tumor suppression or whether metabolic alterations driven by p53 mutation sustain cancer progression. Here, we show that restoring endogenous p53 function in cancer cells derived from a murine PDAC model driven by oncogenic Kras and a regulatable p53 short hairpin RNA (shRNA) rewires glucose and glutamine metabolism leading to the accumulation of a-ketoglutarate (aKG), an obligate substrate for several chromatin modifying enzymes. p53 induces transcriptional programs characteristic of premalignant differentiation, an effect that can be partially recapitulated by addition of cell permeable aKG. Similarly, enforcing aKG accumulation in p53-deficient PDAC cells though the inhibition of oxoglutarate (aKG) dehydrogenase (Ogdh), the enzyme that consumes aKG in the tricarboxylic acid cycle, reduces tumor-initiating capacity and promotes tumor cell differentiation. Decreases in 5-hydroxymethylcytosine (5hmC), an aKG-dependent chromatin modification, are associated with the appearance of p53 mutations in the transition from premalignant to de-differentiated malignant lesions, whereas increases in 5hmC accompany tumor cell differentiation triggered by either p53 restoration or Ogdh depletion. Together these data nominate aKG as an effector of p53-mediated tumor suppression whose accumulation in p53-deficient tumors can drive tumor cell differentiation and antagonize malignant progression. Overall design: 6 samples were analyzed in duplicates of 3 conditions. 1. Control, KPsh cells grown on dox, treated with vehicle DMSO for 72 hours. 2. KPsh cells grown on dox, treated with 4mM cell permeable dimethyl-alpha ketoglutarate for 72 hours. 3. KPsh cells grown off dox for 8 days, treated with DMSO vehicle for 72 hours.
α-Ketoglutarate links p53 to cell fate during tumour suppression.
Cell line, Treatment, Subject
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 Samples