The 18S rRNA m6 A methyltransferase METTL5 promotes mouse embryonic stem cell differentiation.

RNA modifications represent a novel layer of regulation of gene expression. Functional experiments revealed that N6 -methyladenosine (m6 A) on messenger RNA (mRNA) plays critical roles in cell fate determination and development. m6 A mark also resides in the decoding center of 18S ribosomal RNA (rRNA); however, the biological function of m6 A on 18S rRNA is still poorly understood. Here, we report that methyltransferase-like 5 (METTL5) methylates 18S rRNA both in vivo and in vitro, which is consistent with previous reports. Deletion of Mettl5 causes a dramatic differentiation defect in mouse embryonic stem cells (mESCs). Mechanistically, the m6 A deposited by METTL5 is involved in regulating the efficient translation of F-box and WD repeat domain-containing 7 (FBXW7), a key regulator of cell differentiation. Deficiency of METTL5 reduces FBXW7 levels and leads to the accumulation of its substrate c-MYC, thereby delaying the onset of mESC differentiation. Our study uncovers an important role of METTL5-mediated 18S m6 A in mESC differentiation through translation regulation and provides new insight into the functional significance of rRNA m6 A.

Epstein-Barr virus (EBV) encoded microRNA BART8-3p drives radioresistance-associated metastasis in nasopharyngeal carcinoma.

Radiotherapy plays an important role in the treatment of nasopharyngeal carcinoma (NPC), however, 20% of patients with NPC exhibit unusual radioresistance. Patients with radioresistance are at risk of recurrence, so it is imperative to explore the mechanism of resistance to radiotherapy. In the past, studies on the mechanism of radioresistance have been restricted to DNA damage and related cell cycle remodeling or apoptosis. So far, no studies have explored the relationship between radioresistance and metastasis. Through the analysis of clinical samples, we observed that the metastasis rate of recurrent NPC was much higher than that of primary patients. In vitro and in vivo experiments showed that NPC cells with acquired radioresistance exhibited a stronger ability for invasion and metastasis. Mechanistically, we found that the Epstein-Barr virus (EBV)-encoded miRNA BART8-3p was increased in patients with NPC, and its expression was positively correlated with adverse prognostic factors, such as radioresistance. Besides this, miR-BART8-3p promoted the epithelial-mesenchymal transition, invasion, and metastasis of radioresistant NPC cells by targeting and inhibiting their PAG1 host gene. These findings suggested a novel role for EBV-miR-BART8-3p in promoting NPC radioresistance-associated metastasis and highlighted its potential value as a prognostic indicator or therapeutic target.

Endoplasmic Reticulum Stress Potentiates the Immunosuppressive Microenvironment in Hepatocellular Carcinoma by Promoting the Release of SNHG6-Enriched Small Extracellular Vesicles.

Endoplasmic reticulum (ER) stress leads to hepatocellular carcinoma (HCC) progression. Small extracellular vesicles (sEV) play a crucial role in modulating the tumor microenvironment (TME) by influencing cellular communication and immune responses. However, it is unclear whether ER stress modulates the TME through sEVs. In the current study, we investigated the effects and underlying mechanisms of ER stress on the HCC TME. In vivo and in vitro experiments showed that overactivated ER stress was a salient attribute of the immunosuppressive HCC TME. This was caused by the ATF4-promoted release of small nucleolar RNA host gene 6 (SNHG6)-carrying sEVs, which attenuated T cell-mediated immune responses. Overall, SNHG6 modulated the immunosuppressive TME and aggravated ER stress. Meanwhile, targeting SNHG6 facilitated M1-like macrophage and CD8+ T-cell infiltration and decreased the proportion of M2-like macrophages. In addition, SNHG6 knockdown enhanced anti-PD1 immunotherapeutic efficacy. Moreover, in HCC patients, overexpression of SNHG6 was associated with a lack of response to anti-PD1 therapy and poor prognosis, whereas low SNHG6 expression was associated with improved therapeutic efficacy and prognoses. These data indicate that a correlation exists among ER stress, sEVs, immunosuppressive HCC TME, and immunotherapeutic efficacy. Hence, SNHG6-targeted therapy may represent an effective strategy for patients with HCC.

NLRP3 Inflammasome: A key contributor to the inflammation formation.

Inflammation is an important part of the development of various organ diseases. The inflammasome, as an innate immune receptor, plays an important role in the formation of inflammation. Among various inflammasomes, the NLRP3 inflammasome is the most well studied. The NLRP3 inflammasome is composed of skeletal protein NLRP3, apoptosis-associated speck-like protein (ASC) and pro-caspase-1. There are three types of activation pathways: (1) "classical" activation pathway; (2) "non-canonical" activation pathway; (3) "alternative" activation pathway. The activation of NLRP3 inflammasome is involved in many inflammatory diseases. A variety of factors (such as genetic factors, environmental factors, chemical factors, viral infection, etc.) have been proved to activate NLRP3 inflammasome and promote the inflammatory response of the lung, heart, liver, kidney and other organs in the body. Especially, the mechanism of NLRP3 inflammation and its related molecules in its associated diseases remains not to be summarized, namely they may promote or delay inflammatory diseases in different cells and tissues. This article reviews the structure and function of the NLRP3 inflammasome and its role in various inflammations, including inflammations caused by chemically toxic substances.

A New Prognostic Strategy Based on four DNA Repair-Associated lncRNAs for Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a malignant tumour with a poor prognosis. The effect of DNA repair on prognosis cannot be ignored, and long non-coding RNA (lncRNA) can regulate the DNA repair process. OBJECTIVE: To obtain DNA repair-associated lncRNA (DR-lncRNA) prognostic signature for improving the ability to predict HCC prognosis. METHODS: Our study used the Cancer Genome Atlas database. Gene set variation analysis was performed to differentiate high and low levels of DNA repair to identify DR-lncRNAs. By performing univariate Cox regression, LASSO regression, and multivariate Cox regression analyses, we finally obtained a DR-lncRNA prognostic signature and constructed a nomogram prognostic model. Time-dependent receiver operating characteristic (ROC) curves, calibration plots, decision curve analysis (DCA), and clinical impact curves were used to assess predictive ability and clinical utility. Differentially expressed genes (DEGs) functional enrichment analysis was performed to further explore the underlying mechanisms that influence HCC prognosis. RESULTS: We obtained the following DR-lncRNA prognostic signature:AP002478.1, AC116351.1, LINC02580, and LINC00861. The ROC curves and calibration plots showed good discrimination and calibration properties. Combining the DR-lncRNA prognostic signature and tumour stages, we established a nomogram prognostic model. DCA and clinical impact curves showed the clinical utility of this model. DEGs of high-risk and low-risk groups predicted by the prognostic DRlncRNA were significantly associated with cell cycle, various metabolic pathways and biological processes, such as the oxidation-reduction process and cell division. CONCLUSION: We identified a DR-lncRNA prognostic signature and constructed a nomogram prognostic model, which could be a beneficial prognostic strategy for HCC.

Identification of a thirteen-gene signature predicting overall survival for hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a malignant tumor of the digestive system characterized by mortality rate and poor prognosis. To indicate the prognosis of HCC patients, lots of genes have been screened as prognostic indicators. However, the predictive efficiency of single gene is not enough. Therefore, it is essential to identify a risk-score model based on gene signature to elevate predictive efficiency. METHODS: Lasso regression analysis followed by univariate Cox regression was employed to establish a risk-score model for HCC prognosis prediction based on The Cancer Genome Atlas (TCGA) dataset and Gene Expression Omnibus (GEO) dataset GSE14520. R package 'clusterProfiler' was used to conduct function and pathway enrichment analysis. The infiltration level of various immune and stromal cells in the tumor microenvironment (TME) were evaluated by single-sample GSEA (ssGSEA) of R package 'GSVA'. RESULTS: This prognostic model is an independent prognostic factor for predicting the prognosis of HCC patients and can be more effective by combining with clinical data through the construction of nomogram model. Further analysis showed patients in high-risk group possess more complex TME and immune cell composition. CONCLUSIONS: Taken together, our research suggests the thirteen-gene signature to possess potential prognostic value for HCC patients and provide new information for immunological research and treatment in HCC.

HILPDA Is a Prognostic Biomarker and Correlates With Macrophage Infiltration in Pan-Cancer.

Background: The protein hypoxia-inducible lipid droplet-associated (HILPDA) is differentially expressed in various tumors. However, its role and correlation with immune cell infiltration in most tumors remain unclear. Methods: HILPDA expression was analyzed in pan-cancer data from The Cancer Genome Atlas (TCGA) database. The influence of HILPDA in clinical prognosis was evaluated using clinical survival data from TCGA. Enrichment analysis of HILPDA was conducted using the R package "clusterProfiler." We downloaded the immune cell infiltration score of TCGA samples from published articles and analyzed the correlation between the magnitude of immune cell infiltration and HILPDA expression. Results: HILPDA was highly expressed and associated with worse overall survival, disease-specific survival, and progression-free interval in most tumor types. In addition, HILPDA expression was significantly associated with the glycolysis pathway and infiltration of immune cells. Tumor-associated macrophage (TAM) infiltration increased in tissues with high HILPDA expression in most tumor types. Immunosuppressive genes, such as PD-L1, PD-1, TGFB1, and TGFBR1 were positively correlated with HILPDA. Conclusions: Our study suggests that HILPDA is a marker of poor prognosis. High HILPDA may contribute to TAM infiltration and be associated with tumor immunosuppression status.

Effects of Fruquintinib on the Pluripotency Maintenance and Differentiation Potential of Mouse Embryonic Stem Cells.

Mouse embryonic stem cells (mESCs) can maintain self-renewal and differentiate into any cell type of the three primary germ layers. The vascular endothelial growth factor (VEGF) is involved in the regulation of mESC differentiation and induces the activation of a series of kinase responses and several cell signaling pathways by binding to its respective transmembrane receptors, vascular endothelial growth factor receptor VEGFR1, and VEGFR2. Fruquintinib is a selective inhibitor of VEGFRs, and we used it to investigate the effects on the maintenance of pluripotency and differentiation potential of mESCs in this study. Our results showed that fruquintinib-treated cells expressed higher levels of pluripotent markers, including Oct4, Nanog, Sox2, and Esrrb under serum and leukemia inhibitory factor (LIF) condition, whereas the expression of phosphorylated Erk1/2 was restricted. Mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (MEK) signaling inhibitor (PD0325901) and glycogen synthase kinase 3 (GSK3) signaling inhibitor (CHIR99021) (also known as 2i) enable cells to maintain naive pluripotency with LIF, and fruquintinib can also promote cells to maintain naive pluripotent state even under serum/LIF condition, whereas VEGF addition limits the pluripotency characteristics in serum/LIF mESCs. Furthermore, fruquintinib could inhibit the three-germ layer establishment in embryoid body formation and maintain the undifferentiated characteristics of mESCs, indicating that fruquintinib could promote the maintenance of naive pluripotency and inhibit early differentiation programs.

A Pan-Cancer Analysis of CD161, a Potential New Immune Checkpoint.

Background: CD161, encoded by killer cell lectin-like receptor B1 gene, is a newly reported candidate inhibitor of tumour-infiltrating T cells. Antibody-mediated CD161 blockade enhances T cell-mediated killing of cancer cells in vitro and in vivo in several tumour types. We evaluated the role of CD161 using The Cancer Genome Atlas (TCGA) Pan-Cancer Data. Methods: CD161 expression was analysed using RNAseq data from TCGA and the Genotype-Tissue Expression (GTEx) database. HPA, GeneCards, and String database were used to explore the protein information of CD161. The prognostic value of CD161 was analysed using clinical survival data from the TCGA. Enrichment analysis of CD161 was conducted using the R package "clusterProfiler". We downloaded the immune cell infiltration score of TCGA samples from published articles and online databases and performed a correlation analysis between immune cell infiltration levels and CD161 expression. We further assessed the association between CD161 and immune checkpoints, immune activating genes, immunosuppressive genes, chemokines, and chemokine receptors. Findings: CD161 was differentially expressed and predicted better survival status in most tumour types in TCGA. In addition, CD161 expression was significantly associated with immunoregulatory interactions between lymphoid and non-lymphoid cells. CD161 expression was closely correlated with T cell infiltration, immune checkpoints, immune activating genes, immunosuppressive genes, chemokines, and chemokine receptors. Interpretation: Our results suggest that CD161 is a potential cancer biomarker. CD161 might synergize with other immune checkpoints to regulate the immune microenvironment, which could be applied in the development of new-targeted drugs for immunotherapy. Funding: This work was supported by the National Nature Science Foundation of China (grant numbers 81773008, 81672756, 81872399, 81972897), the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2015), the Natural Science Foundation of Guangdong Province (grant number 2017A030311023), the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program: 2017BT01S131 and the Guangzhou Technology Project (grant number 201804010044), National Key R&D Program of China (Grant Nos. 2020YFC2006400), Key-Area Research and Development Program of Guangdong Province (2019B020227004).

Small extracellular vesicles containing miR-30a-3p attenuate the migration and invasion of hepatocellular carcinoma by targeting SNAP23 gene.

Cancer cells under hypoxic, endoplasmic reticulum, and reactive oxygen species stress secrete copious amounts of small extracellular vesicles (sEVs) to promote tumor metastasis. The effects of blocking stress-induced sEV release on tumor metastasis remain unknown. We found that miR-30a-3p was selectively sorted into sEVs by hepatocellular carcinoma (HCC) cells under the influence of multiple stressors. miR-30a-3p removal from cancer cells through sEVs promoted HCC cell migration and invasion, whereas exogenous overexpression of miR-30a-3p could inhibit migration, invasion, and sEV release by directly targeting SNAP23. HCC cells efficiently absorbed hepatic stellate cell (HSC) sEVs, providing an advantage in the treatment of HCC using HSC sEVs. Treatment with HSC sEVs rich in miR-30a-3p cargo effectively attenuated HCC migration, invasion, and metastasis. Overall, sEVs containing miR-30a-3p decreased sEV secretion as well as the migration, invasion, and metastasis of HCC by directly targeting SNAP23, thereby providing an effective strategy to attenuate metastasis of HCC.

α-ketoglutarate promotes the specialization of primordial germ cell-like cells through regulating epigenetic reprogramming.

There is growing evidence that cellular metabolism can directly participate in epigenetic dynamics and consequently modulate gene expression. However, the role of metabolites in activating the key gene regulatory network for specialization of germ cell lineage remains largely unknown. Here, we identified some cellular metabolites with significant changes by untargeted metabolomics between mouse epiblast-like cells (EpiLCs) and primordial germ cell-like cells (PGCLCs). More importantly, we found that inhibition of glutaminolysis by bis-2- (5-phenylacetamido-1,3,4-thiadiazol-2-yl) ethyl sulfide (BPTES) impeded PGCLC specialization, but the impediment could be rescued by addition of α-ketoglutarate (αKG), the intermediate metabolite of oxidative phosphorylation and glutaminolysis. Moreover, adding αKG alone to the PGCLC medium accelerated the PGCLC specialization through promoting H3K27me3 demethylation. Thus, our study reveals the importance of metabolite αKG in the germ cell fate determination and highlights the essential role of cellular metabolism in shaping the cell identities through epigenetic events.

Clinical Characteristics of Patients With Progressive and Non-progressive Coronavirus Disease 2019: Evidence From 365 Hospitalised Patients in Honghu and Nanchang, China.

Background: Coronavirus disease (COVID-19) has swept around the globe and led to a worldwide catastrophe. Studies examining the disease progression of patients with non-severe disease on admission are scarce but of profound importance in the early identification of patients at a high risk of deterioration. Objectives: To elucidate the differences in clinical characteristics between patients with progressive and non-progressive COVID-19 and to determine the risk factors for disease progression. Study design: Clinical data of 365 patients with non-severe COVID-19 from 1 January 2020 to 18 March 2020 were retrospectively collected. Patients were stratified into progressive and non-progressive disease groups. Univariate and multivariate logistic regression analyses were performed to determine the independent risk factors for disease progression. Results: Compared with patients with non-progressive disease, those who progressed to severe COVID-19 were older and had significantly decreased lymphocyte and eosinophil counts; increased neutrophil and platelet counts; lower albumin levels; higher levels of lactate dehydrogenase, C-reactive protein (CRP), creatinine, creatinine kinase, and urea nitrogen; and longer prothrombin times. Hypertension, fever, fatigue, anorexia, bacterial coinfection, bilateral patchy shadowing, antibiotic and corticosteroid administration, and oxygen support had a significantly higher incidence among patients with progressive disease. A significantly longer duration of hospital stay was also observed in patients with progressive disease. Bilateral patchy shadowing (OR = 4.82, 95% CI: 1.33-17.50; P = 0.017) and elevated levels of creatinine (OR =6.24, 95% CI: 1.42-27.40; P = 0.015), and CRP (OR = 7.28, 95% CI: 2.56-20.74; P < 0.001) were independent predictors for disease progression. Conclusion: The clinical characteristics of patients with progressive and non-progressive COVID-19 were significantly different. Bilateral patchy shadowing and increased levels of creatinine, and CRP were independent predictors of disease progression.

The Potential Mutation of GAK Gene in the Typical Sporadic Parkinson's Disease from the Han Population of Chinese Mainland.

The genetic factors about the pathogenesis of sporadic Parkinson's disease (sPD) is not completely clear at present; therefore, we performed a genome-wide association study, high-throughput sequencing analysis (HTPSA) of all cyclin G-associated kinase (GAK) exons, loss-of-function assessment, and sorting intolerant from tolerant analysis of HTPSA data in 250 typical sPD and 250 controls, which found 55 candidate single nucleotide polymorphisms (SNPs). To further explore these SNPs, we sequenced the 30 most strongly associated SNPs in the 460 typical sPD cases and the 525 controls. All subjects were from the Han population of Chinese mainland and excluded the toxic exposure, the heavy coffee drinking, and the early- and late-onset sPD. The minor allele frequencies (MAFs) at c.3824T>G, c.3794T>C, and c.3819G>A were higher in the control. The TG of c.3824T>G, the TC of c.3794T>C, and the AG of c.3819G>A were associated with the decreased risk of sPD. The subjects carrying the minor C allele of c.3794T>C or the minor A allele of c.3819G>A exhibited a decreased risk of sPD. c.3824T>G negatively affected the binding affinity of heat shock protein 70 (HSP70). c.3794T>C increased the surface area exposed to substrates. c.3819G>A most likely reduced the expression level of GAK. Our data suggest that the multiple SNPs of GAK synergistically participate in the pathogenesis of sPD through multiple pathways.