Project description:The ADAR RNA-editing enzymes deaminate adenosine bases to inosines in cellular RNAs. Aberrant interferon expression occurs in patients in whom ADAR1 mutations cause Aicardi-Goutières syndrome (AGS) or dystonia arising from striatal neurodegeneration. Adar1 mutant mouse embryos show aberrant interferon induction and die by embryonic day E12.5. We demonstrate that Adar1 embryonic lethality is rescued to live birth in Adar1; Mavs double mutants in which the antiviral interferon induction response to cytoplasmic double-stranded RNA (dsRNA) is prevented. Aberrant immune responses in Adar1 mutant mouse embryo fibroblasts are dramatically reduced by restoring the expression of editing-active cytoplasmic ADARs. We propose that inosine in cellular RNA inhibits antiviral inflammatory and interferon responses by altering RLR interactions. Transfecting dsRNA oligonucleotides containing inosine-uracil base pairs into Adar1 mutant mouse embryo fibroblasts reduces the aberrant innate immune response. ADAR1 mutations causing AGS affect the activity of the interferon-inducible cytoplasmic isoform more severely than the nuclear isoform.
Project description:BackgroundArmadillo repeat-containing 10 (ARMC10) is involved in the progression of multiple types of tumors. Pancreatic adenocarcinoma (PAAD) is a lethal disease with poor survival and prognosis.MethodsWe acquired the data of ARMC10 in PAAD patients from the cancer genome atlas (TCGA) and gene expression omnibus (GEO) datasets and compared the expression level with normal pancreatic tissues. We evaluated the relevance between ARMC10 expression and clinicopathological factors, immune infiltration degree and prognosis in PAAD.ResultsHigh expression of ARMC10 was relevant to T stage, M stage, pathologic stage, histologic grade, residual tumor, primary therapy outcome (P < 0.05) and related to lower Overall-Survival (OS), Disease-Specific Survival (DSS), and Progression-Free Interval (PFI). Gene set enrichment analysis showed that ARMC10 was related to methylation in neural precursor cells (NPC), G alpha (i) signaling events, APC targets, energy metabolism, potassium channels and IL10 synthesis. The expression level of ARMC10 was positively related to the abundance of T helper cells and negatively to that of plasmacytoid dendritic cells (pDCs). Knocking down of ARMC10 could lead to lower proliferation, invasion, migration ability and colony formation rate of PAAD cells in vitro.ConclusionsOur research firstly discovered ARMC10 as a novel prognostic biomarker for PAAD patients and played a crucial role in immune regulation in PAAD.
Project description:BackgroundLung adenocarcinoma (LUAD) is a common subtype of non-small cell lung cancer with high morbidity and mortality rates and is usually detected at advanced stages because of the early onset of metastasis. Adenosine deaminase RNA-specific 1 (ADAR1) is an RNA editing enzyme that catalyzes the important physiological process of adenosine-to-inosine editing and has been shown to participate in the progression of LUAD. Increasing evidence has suggested that immune infiltration of the tumor immune microenvironment has prognostic value for most human solid organ malignancies; however, much is unknown about the functions of ADAR1.MethodsThe expression of ADAR1 was analyzed in The Cancer Genome Atlas -LUAD database and validated in our LUAD cohort. To assess the prognostic value of ADAR1, Kaplan-Meier survival analyses and Cox regression analyses were carried out in LUAD cohorts. The association between ADAR1 and LUAD immune infiltrates via analyses of cell-type identification by estimating relative subsets of known RNA transcripts. Furthermore, multiplex immunohistochemistry was used to confirm the relationship between ADAR1 expression and immune cells in the present cohort of patients with LUAD.ResultsADAR1 was highly expressed in LUAD tissues and closely correlated with lymph node metastasis (LNM) (p < 0.01), advanced tumor stage (p < 0.05), and poor patient prognosis (p < 0.01), thus indicating that increased ADAR1 contributed to the progression of LUAD. LUAD with high ADAR1 expression can metastasize to lymph nodes that express more ADAR1 than the primary lesion. In addition, M0 macrophages and M2 macrophages increased and CD4+ T cells decreased in LUAD tissues with high ADAR1 expression. And the expression of ADAR1 in lymph node metastases was negatively correlated with the contents of CD4+ T cells (p = 0.0017) and M1 macrophages (p = 0.0037).ConclusionThe findings of our study suggested that ADAR1 may be useful in predicting prognosis and LNM in LUAD, and may serve as a promising immune-related molecular target for LUAD patients.
Project description:Pancreatic ductal adenocarcinoma (PDAC) is one of the most refractory human malignancies. F-box only proteins (FBXO) are the core components of SKP1-cullin 1-F-box E3 ubiquitin ligase, which have been reported to play crucial roles in tumor initiation and progression via ubiquitination-mediated proteasomal degradation. However, the clinical implications and biological functions of FBXOs in PDAC have not been fully clarified. Herein we perform a comprehensive analysis for the clinical values and functional roles of FBXOs in PDAC using different public databases. We found that FBXO1 (CCNF), FBXO20 (LMO7), FBXO22, FBXO28, FBXO32, and FBXO45 (designated six-FBXOs) were robustly upregulated in PDAC tissues, which predicted an adverse prognosis of PDAC patients. There was a significant correlation between the expression levels of six-FBXOs and the clinicopathological features in PDAC. The transcriptional levels of six-FBXOs were subjected to the influence of promoter methylation levels. There were more than 40% genetic alterations and mutations of six-FBXOs, which affected the clinical outcome of PDAC patients. Furthermore, the expression of six-FBXOs was associated with immune infiltrations and activated status, including B cells, CD8+ T cells, CD4+ T cells, NK cells, macrophages, and dendritic cells. The functional prediction revealed that the six-FBXOs were involved in ubiquitination-related pathways and other vital signaling pathways, such as p53, PI3K/Akt, and Hippo pathway. Therefore, six-FBXOs are the promising prognostic biomarkers or potential targets for PDAC diagnosis and treatment.
Project description:BackgroundThe GSDM family includes six members, GSDMA, GSDMB, GSDMC, GSDMD, GSDME (DFNA5), and PJVK (Pejvakin, DFNB59), which can induce pyroptosis, thereby regulating the tumorigenesis of various cancers. However, the clinical characteristics and role of the GSDM family in LUAD are not well understood.MethodsIn this study, several important bioinformatics databases were used to integrate the analysis of the expression, prognostic value, and immune infiltration of GSDMs in LUAD. These databases include UALCAN, DiseaseMeth, GEPIA, THPA, cBioPortal, TIMER, WebGestalt, STRING database, and Cytoscape.ResultsThe findings from the UALCAN database revealed that the expression of all six GSDMs based on the tumor stage in LUAD was increased (particularly GSDMD). Our IHC results verified it. Additionally, the DiseaseMeth database showed that the methylation levels of GSDMA, GSDMB, GSDMC, and GSDMD were decreased. The expression of six GSDMs was related to shorter overall survival in patients with LUAD, according to the GEPIA database. The cBioPortal database was further used to explore the alteration rate and correlated genes in LUAD. Subsequently, these genes were subjected to functional enrichment and protein-protein interaction network analyses. We identified that the GSDM family regulate several signaling pathways, including immune-associated signaling pathways. According to tumor-infiltrating immune cell analysis from the TIMER database, GSDM family members are associated with the infiltration of important immune cells and their signature markers.ConclusionsGSDM family may be prognostic markers and novel strategies for the treatment of LUAD.
Project description:ADARs (adenosine deaminases that act on RNA) are RNA-editing enzymes that convert adenosines to inosines in structured or double-stranded RNAs. Expression and intracellular distribution of ADAR1 is controlled by a plethora of mechanisms suggesting that enzyme activity has to be tightly regulated. Mammalian ADAR1 is a shuttling protein, whereas Xenopus ADAR1 is exclusively nuclear. In oocytes, Xenopus ADAR1 associates with most nascent transcripts but is strongly enriched at a specific site on chromosome 3, termed the special loop. Enrichment at this site requires the presence of RNAs but is independent of ongoing transcription. Here we show that RNAs transcribed elsewhere in the genome accumulate at the special loop even in the absence of transcription. In situ hybridization experiments, however, indicate the absence of known editing substrates from this site. In the absence of transcription also other RNA binding and processing factors accumulate at the special loop, suggesting that ADAR1 is stored or assembled at the special loop in an RNA-containing complex. Nuclear injection of RNAs providing binding sites for ADAR1 dissociates the enzyme from the special loop, supporting the notion that the special loop represents a site where ADAR1 is stored, possibly for later use during development.
Project description:The RNA editing enzyme ADAR1 has been shown to be an essential molecule for hematopoietic cell differentiation, embryonic development, and regulation of immune responses. Here, we present evidence in a T-cell-specific gene knockout mouse model that ADAR1 is required for early T cell development. Loss of ADAR1 led to cell death of the progenitors at the double negative stage and prevented T cell maturation in the thymus. Furthermore, ADAR1 deletion in pre-T cells preferentially affected TCRβ-expressing cells causing TCRβ positive cell depletion. Interruption of IFN signaling occurred in the premature T cells, indicating a role of IFN signaling in the survival of TCRβ-expressing cells regulated by ADAR1. This study demonstrated an essential role for the RNA editing enzyme ADAR1 as a potential regulator for T-cell fate determination during clonal selection, which, in turn, contributes to immunologic homeostasis.
Project description:The ADAR RNA editing enzymes deaminate adenosine bases to inosines in cellular RNAs, recoding open reading frames. Human ADAR1 mutations cause Aicardi-Goutieres Syndrome (AGS) and Adar1 mutant mice showing an aberrant interferon response and death by embryonic day E12.5 model the human disease. Searches have not identified key ADAR1 RNA editing sites recoding immune/haematopoietic proteins but editing is widespread in Alu sequences. We show that Adar1 embryonic lethality is rescued in Adar1; Mavs double mutant mice in which general antiviral responses to cytoplasmic dsRNA are prevented. We propose that inosine bases are epigenetic marks identifying cellular RNA as innate immune ÒselfÓ. Consistent with this idea we show that an editing-active cytoplasmic ADAR is required to prevent aberrant immune responses in Adar1 mutant mouse embryo fibroblasts. No dramatic increase in repetitive transcripts is observed. AGS mutations in ADAR1 affect editing by the interferon-inducible cytoplasmic ADAR1 isoform. RNA-seq expression profiling in Adar1 and Adar1/Mavs knockout mice embryos.
Project description:BACKGROUND:Adenosine-to-inosine (A-to-I) RNA editing is catalyzed by adenosine deaminases acting on RNA (ADAR) enzymes. Recent evidence suggests that RNA editing of antizyme inhibitor 1 (AZIN1) RNA is emerging as a key epigenetic alteration underlying cancer pathogenesis. METHODS:We evaluated AZIN1 RNA editing levels, and the expression of its regulator, ADAR1, in 280 gastric tissues from 140 patients, using a RNA editing site-specific quantitative polymerase chain reaction assays. We also analyzed the clinical significance of these results as disease biomarkers in gastric cancer (GC) patients. RESULTS:Both AZIN1 RNA editing levels and ADAR1 expression were significantly elevated in GC tissues compared with matched normal mucosa (P < 0.0001, 0.0008, respectively); and AZIN1 RNA editing was positively correlated with ADAR1 expression. Elevated expression of ADAR1 significantly correlated with poor overall survival (P = 0.034), while hyper-edited AZIN1 emerged as an independent prognostic factor for OS and disease-free survival in GC patients [odds ratio (OR):1.98, 95% CI 1.17-3.35, P = 0.011, OR: 4.55, 95% CI 2.12-9.78, P = 0.0001, respectively]. Increased AZIN1 RNA editing and ADAR1 over-expression were significantly correlated with key clinicopathological factors, such as advanced T stage, presence of lymph node metastasis, distant metastasis, and higher TNM stages in GC patients. Logistic regression analysis revealed that hyper-editing status of AZIN1 RNA was an independent risk factor for lymph node metastasis in GC patients [hazard ratio (HR):3.03, 95% CI 1.19-7.71, P = 0.02]. CONCLUSIONS:AZIN1 RNA editing levels may be an important prognostic biomarker in GC patients, and may serve as a key clinical decision-making tool for determining preoperative treatment strategies in GC patients.
Project description:Pancreatic adenocarcinoma (PAAD) is a highly malignant tumor in the digestive system, with an increasing incidence and mortality rate globally. Recent genetic studies have revealed that the abnormal expression and functional dysregulation of various genes are involved in the occurrence and progression of pancreatic cancer. NIPA-like proteins (NIPAs) are expressed in a variety of cancer types, yet the role of NIPAL1 in cancer remains unclear. Therefore, further research is required to determine its diagnostic significance and understand its biological functions in cancer. Primitive RNA sequencing (RNA-seq) data of PAAD from The Cancer Genome Atlas (TCGA) was utilized for bioinformatics analysis to characterize the expression levels of NIPAL1 in tumor and normal tissues. Differentially expressed genes (DEGs) were identified, and Gene Set Enrichment Analysis (GSEA) was performed to elucidate potential biological mechanisms of NIPAL1 involved in PAAD development. Additionally, we analyzed the correlation between NIPAL1 expression, immune cell infiltration, and PAAD progression. The Genomics of Drug Sensitivity in Cancer (GDSC) database was utilized to investigate the relationship between NIPAL1 expression and the efficacy of common drugs used in chemotherapy and targeted therapy in patients with pancreatic cancer. Subsequently, we predicted five small-molecule drugs targeted at NIPAL1 using molecular docking. Finally, high expression of NIPAL1 in tumor tissues was validated through immunohistochemistry. In pancreatic cancer cell lines, changes in phenotypes such as proliferation, migration, and invasion following the knockdown of NIPAL1 were assessed. Finally, we established a subcutaneous tumor-bearing mouse model to further validate its therapeutic significance in vivo.