Nuclear respiratory factor 1 promotes the progression of EBV-associated gastric cancer and maintains EBV latent infection

This study aimed to investigate the association of Epstein-Barr virus (EBV) with nuclear respiratory factor 1 (NRF1) and the biological function of NRF1 in EBV-associated gastric cancer (EBVaGC). Western blot and qRT-PCR were used to assess the effect of latent membrane protein 2A (LMP2A) on NRF1 expression after transfection with LMP2A plasmid or siLMP2A. The effects of NRF1 on the migration and apoptosis ability of GC cells were investigated by transwell assay and flow cytometry apoptosis analysis in vitro, respectively. In addition, we determined the regulatory role of NRF1 in EBV latent infection by western blot and droplet digital PCR (ddPCR). LMP2A upregulated NRF1 expression by activating the NF-κB pathway. Moreover, NRF1 upregulated the expression of N-Cadherin and ZEB1 to promote cell migration. NRF1 promoted the expression of Bcl-2 to increase the anti-apoptotic ability of cells. In addition, NRF1 maintained latent infection of EBV by promoting the expression of the latent protein Epstein-Barr nuclear antigen 1 (EBNA1) and inhibiting the expression of the lytic proteins. Our data indicated the role of NRF1 in EBVaGC progression and the maintenance of EBV latent infection. This provided a new theoretical basis for further NRF1-based anti-cancer therapy.

First Report of Root Rot Caused by Ilyonectria robusta in the Medicinal Herb Aconitum carmichaelii in China

Aconitum carmichaelii Debeaux is used as a traditional Chinese medicine with antiarrhythmic, antiinflammatory and other pharmacological functions. It is widely cultivated in China. According to our survey, about 60% of A. carmichaelii in Qingchuan, Sichuan, suffered from root rot, reducing yields by 30% in the past five years. Symptomatic plants exhibited stunted growth, dark brown roots, reduced root biomass, and fewer root hairs. The disease caused root rot and plant death in 50% of the infected plants. In October 2019, ten symptomatic 6-month-old plants were collected from fields in Qingchuan. Diseased pieces of the roots were surface sterilized with sodium hypochlorite solution (2%), rinsed three times in sterile water, plated on potato dextrose agar (PDA), and incubated at 25°C in the dark. Six single-spore isolates of a Cylindrocarpon-like anamorp were obtained. The colonies on PDA were 35 to 37 mm diam after seven days with regular margins. The plates were covered with felty aerial mycelium, white to buff, and the reverse side chestnut near center with a ochre to yellowish leading edge. On spezieller nährstoffarmer agar (SNA), macroconidia were 1 to 3 septate, straight or slightly curved, cylindrical, with rounded ends, and varied in size: 1-septate 15.1 to 33.5 × 3.7 to 7.3 μm (n=250), 2-septate 16.5 to 48.5 × 3.7 to 7.6 μm (n=85), and 3-septate 22.0 to 50.6 × 4.9 to 7.4 μm (n=115). Microconidia were ellipsoid to ovoid, and 0 to 1 septate; aseptate spores were 4.5 to 16.8 × 1.6 to 4.9 μm (n=200), and 1-septate spores were 7.4 to 20.0 × 2.4 to 5.1 μm (n=200). The chlamydospores were brown, thick-walled, globose to subglobose, 7.9 to 15.9 μm (n=50). The morphology of these isolates was consistent with the previous description of Ilyonectria robusta (Cabral et al. 2012). Isolate QW1901 was characterized by sequencing the ITS, TUB, H3, and tef1α loci using previously reported primer pairs: ITS1/ITS4 (White et al. 1990), T1/Bt-2b (O'Donnell and Cigelnik 1997), CYLH3F/CYLH3R (Crous et al. 2004), and EF1/EF2 (O'Donnell et al. 1998). A Blastn search of the sequences of ITS, TUB, H3, and tef1α showed that QW1901 shared 99.26, 97.89, 97.79, and 99.17 % identities, respectively, with the ex-type strain of I. robusta (CBS308.35). The ITS, TUB, H3, and tef1α sequences were deposited in GenBank under accession nos. MW534715, and MW880180 to MW880182, respectively. A phylogenetic tree was constructed from a neighbor-joining analysis on the alignment of the combined ITS, TUB, H3, and tef1α sequence. QW1901 was clustered with the ex-type strain of I. robusta. To confirm the pathogenicity of I. robusta, bare roots of healthy 6-month-old A. carmichaelii were inoculated with mycelial plugs of 7-day-old QW1901 colonies selected randomly (Lu et al. 2015). Five needle-wound lateral roots and five intact roots were inoculated as replicates with pathogen-free agar plugs as a control. Then, all plants were grown in sterile soil in a growth chamber at 20±1°C and watered regularly. Pathogenicity assays were repeated twice. After 20 days of cultivation, infected plants exhibited symptoms similar to those observed in the field. All control plants remained asymptomatic. Sequencing confirmed the re-isolation of I. robusta from the inoculated plants, satisfying Koch's hypothesis. Ilyonectria robusta has been reported to cause root rot of plants such as Codonopsis tangshen and Panax ginseng ( Lu et al. 2015; Zheng et al. 2021), and has also been reported to be isolated from Aconitum kongboense in China (Wang et al. 2015). However, this is the first report of the pathogen causing root rot of A. carmichaelii. Management measures, such as growing disease-free seedlings in sterile soil, should be used to minimize the risk of this pathogen.

The enhanced photocatalytic and photothermal effects of Ti3C2 Mxene quantum dot/macroscopic porous graphitic carbon nitride heterojunction for Hydrogen Production

A new heterostructure between Ti₃C₂ MXene quantum dot and 3D macroscopic porous graphitic carbon nitride (PGCN) was successfully obtained by integrating Ti₃C₂ quantum dots onto porous graphitized carbon nitride (Ti₃C₂QDs/PGCN) using in situ electrostatic self-assembly techniques. The photocatalytic H₂ evolution rate of optimized 5.5 wt% Ti₃C₂ QD/PGCN composites is nearly 15.24 and 3.53 times higher than pristine CN, and PGCN, respectively. Ti₃C₂ quantum dots can significantly enhance the hydrogen production activity of PGCN. In addition, their good photothermal conversion ability accelerates the overall reaction process and enhances the light absorption and carrier density. Furthermore, to elucidate the photocatalytic mechanism, a series of tests involving electron spin resonance (ESR) and density functional theory (DFT) calculations were performed. The results confirmed that the Schottky barrier between PGCN and Ti₃C₂ QD can effectively promote spatial charge separation and significantly improve the photocatalytic performance. This work provides a new approach for the construction of photocatalytic systems and the application of MXene QD.

[Serum lipoprotein-associated phospholipase A2 level is positively correlated with the recurrence risk of acute ischemic cerebral infarction in hypertensive patients]

OBJECTIVE

To explore the relationship between serum lipoprotein-associated phospholipase A2 (Lp-PLA2) level and the risk of acute ischemic stroke (AIS) recurrence in hypertensive patients.

METHODS

This retrospective case-control study was conducted among 211 hypertensive patients with AIS treated in Foshan First People's Hospital, including 35 patients with recurrence of AIS during the 1-year follow-up as confirmed by head CT/MR. In the overall patients, 60 had grade 1 hypertension (including 5 recurrent cases), 76 had grade 2 hypertension (with 11 recurrent cases), and 75 had grade 3 hypertension (with 19 recurrent cases). Univariate analysis, multivariate logistic regression analysis, trend analysis, and smooth curve fitting analysis were performed to explore the correlation between serum Lp-PLA2 level within 24 h after admission and the risk of AIS recurrence. The predictive efficacy of serum Lp-PLA2 level for AIS recurrence in different hypertension grades was evaluated using ROC curve analysis.

RESULTS

Serum Lp-PLA2 level, age, NIHSS score at admission, mRS scores at 7 days, homocysteine level and smoking status differed significantly between patients with and without AIS recurrence (P < 0.05). After adjustment for confounding factors, multivariate regression analysis showed that the highest tertile of Lp-PLA2 level was associated with a 4.13-fold increase of AIS recurrence risk compared with the lowest tertile (OR=5.13, 95% CI: 1.35-19.40), and each 1 ng/mL increase of Lp-PLA2 level was associated with a 1% increase of AIS recurrence risk (OR= 1.01, 95% CI: 1.01-1.02). Serum Lp-PLA2 level was shown to positively correlate with AIS recurrence risk, and in patients with grade 3 hypertension, its areas under the ROC curve for predicting AIS recurrence was 0.869 with a specificity of 0.893 and a sensitivity of 0.737.

CONCLUSION

Serum Lp-PLA2 concentration is an independent risk factor and potentially an effective predictor for AIS recurrence in patients with grade 3 hypertension.

Epstein-Barr Virus Regulates Endothelin-1 Expression through the ERK/FOXO1 Pathway in EBV-Associated Gastric Cancer

Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is one of the four subtypes of gastric carcinoma and its unique clinicopathological mechanism is unclear. Herein, the expression of endothelin-1 (ET-1) in EBVaGC was lower than of Epstein-Barr virus-negative gastric carcinoma (EBVnGC) and associated with a low frequency of lymph node metastasis of EBVaGC. Functional studies showed that the activation of ET-1/endothelin receptor type A (ETAR) axis could promote cell growth, migration, and antiapoptosis. The expression of the ET-1 gene was unrelated to methylation of its promoter region and miRNAs (-1, -125a, -125b). After being treated with MEK1/2 inhibitor (PD0325901), the inactivation of ERK1/2 pathway resulted in downregulation of ET-1 and forkhead box O1 (FOXO1) expression. Further, FOXO1 knockdown decreased the ET-1 expression. These findings indicated that ET-1 could be involved in development of gastric cancer and EBV could suppress the expression of ET-1 via the regulation of the transcription factor FOXO1 through the MAPK/ERK pathway. IMPORTANCE The relationship between Epstein-Barr virus and gastric cancer has been relatively clear. However, there are still many unresolved mechanisms of the virus in tumorigenesis. In recent years, activation of the endothelin-1 signaling axis has been found to play an important role in tumorigenesis, which is involved in tumor angiogenesis and epithelial-mesenchymal transition. EBV genes. In our study, we found that ET-1 was low-expressed in EBV-positive gastric cancer cells, which was due to the inhibition of ERK signaling by EBNA1 through the repression of FOXO1 expression. The low expression of ET-1 limits the proliferation, migration, and anti-apoptotic ability of tumor cells. These findings contribute to further understanding of the role of EBV in EBV-associated gastric cancer.

The role and molecular mechanism of gut microbiota in Graves' orbitopathy

PURPOSE

Graves' orbitopathy (GO) is an autoimmune orbital disorder. Gut microbiota dysfunction plays a vital role in autoimmune diseases, including Graves' disease (GD) and GO. In the present study, we aimed to investigate the change of gut microbiota in GD/GO using mouse model.

METHODS

The murine model of GD/GO was established by the challenge of adenovirus expressing thyroid-stimulating hormone (TSH) receptor (TSHR) (Ad-TSHR). The histological changes of orbital and thyroid tissues were analyzed by hematoxylin and eosin (H&E), Masson staining, and immunohistochemistry (IHC) staining. The fecal samples were collected for 16S rRNA gene sequencing and bioinformatics analysis.

RESULTS

The GD/GO model was established successfully, as manifested as the broadened eyelid, exophthalmia and conjunctive redness, severe inflammatory infiltration among thyroid glands and between extraocular muscle space, hypertrophic extraocular muscles, elevated thyroxine (T4) and decreased TSH, and positive CD34, CD40, collagen I, and α-SMA staining. A total of 222 operational taxonomic units (OUTs) were overlapped between mice in the Ad-NC and Ad-TSHR groups. The microbial composition of the samples in the two groups was mainly Bacteroidia and Clostridia, and the Ad-NC group had a significantly lower content of Bacteroidia and higher content of Clostridia. KEGG orthology analysis results revealed differences in dehydrogenase, aspartic acid, bile acid, chalcone synthase, acetyltransferase, glutamylcyclotransferase, glycogenin, and 1-phosphatidylinositol-4-phosphate 5-kinase between two groups; enzyme commission (EC) analysis results revealed differences in several dehydrogenase, oxidase, thioxy/reductase between two groups; MetaCyc pathways analysis results revealed differences in isoleucine degradation, oxidation of C1 compounds, tricarboxylic acid (TCA) cycle IV, taurine degradation, and biosynthesis of paromamine, heme, colonic acid building blocks, butanediol, lysine/threonine/methionine, and histidine/purine/pyrimidine between two groups.

CONCLUSION

This study induced a mouse model of GD/GO by Ad-TSHR challenge, and gut microbiota characteristics were identified in the GD/GO mice. The Bacteroidia and Clostridia abundance was changed in the GD/GO mice. These findings may lay a solid experimental foundation for developing personalized treatment regimens for GD patients according to the individual gut microbiota. Given the potential impact of regional differences on intestinal microbiota, this study in China may provide a reference for the global overview of the gut-thyroid axis hypothesis.

Epstein-Barr virus miR-BART2-5p and miR-BART11-5p regulate cell proliferation, apoptosis, and migration by targeting RB and p21 in gastric carcinoma

Epstein-Barr virus (EBV) was the first tumor virus discovered in humans and can cause various types of tumors. Molecular classification suggests that EBV-associated gastric cancer (EBVaGC) is a unique subtype of gastric cancer.EBV was also the first virus found to encode its own microRNAs. However, the functions of many miRNAs remain unknown. This study investigated the roles and targets of miR-BART2-5p (BART2-5p) and miR-BART11-5p (BART11-5p) in EBVaGC. The expression of RB and p21 in EBVaGC and EBV negative GC (EBVnGC) cells was evaluated by western blotting. Expression of BART2-5p and BART11-5p in EBVaGC cells was evaluated by droplet digital PCR. The effects of BART2-5p or BART11-5p and their potential mechanisms were further investigated using cell counting kit-8, colony formation assay, flow cytometry analysis, and transwell assay. BART2-5p and BART11-5p were abundantly expressed and RB and p21 were downregulated in EBVaGC cells. BART2-5p regulates RB and p21 expression by directly targeting them. BART11-5p regulates RB expression by directly targeting RB. Both BART2-5p and BART11-5p promoted proliferation and migration of gastric cancer cells, while inhibiting apoptosis and promoting S-phase arrest of the cell cycle. Thus, BART2-5p and BART11-5p play important roles in promoting proliferation and migration, and inhibiting apoptosis in EBVaGC by targeting RB and p21, thus providing new potential therapeutic targets for EBVaGC.

Sequence analysis of Epstein-Barr virus RPMS1 gene in malignant hematopathy of Northern China

The RPMS1 gene is the only member of the BamHI-A rightward transcripts (BARTs) family for which a full-length complementary DNA has been identified, and RPMS1 transcript has been confirmed in many Epstein-Barr virus (EBV)-positive malignancies. However, the effects of sequence variations of RPMS1 in hematological malignancies and their biological significance are unclear. To explore the association between RPMS1 gene variations and hematological malignancy, the RPMS1 gene of 391 EBV-positive samples from patients with EBV-positive leukemia, myelodysplastic syndromes and lymphoma in northern China were sequenced. On the basis of phylogenetic tree and mutation characteristics of RPMS1, all the sequences were divided into five major types: RPMS1-A, RPMS1-B, RPMS1-C, RPMS1-E, and RPMS1-F. RPMS1-A type, similar to the prototype B95-8, was identified in 71.87% (281/391) of samples and was the major type in all subpopulations. The frequency of RPMS1-F type was significantly higher in all malignant hematopathy groups than in healthy donors. The Hodgkin lymphoma group contained more RPMS1-F than other malignant hematopathy groups, and acute myeloid leukemia contained more RPMS1-C type than other malignant hematopathy groups. Therefore, RPMS1-A is the main type of RPMS1 gene in northern China, and RPMS1-F may be associated with hematologic malignancies.

Effects of methylation and imprinting expression of Insulin-like growth factor 2 gene in gastric cancer

BACKGROUND

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a common malignant tumor associated with EBV infection. Insulin-like growth factor 2 (IGF2) is an imprinted gene and a key protein that regulates growth, especially during normal fetal development. Loss of imprinting (LOI), is a common epigenetic anomaly in a variety of human cancers. However, the promoter methylation, imprinting status and function of IGF2 gene in GC are unclear.

OBJECTIVE

To explore the role of IGF2 in the occurrence and development of gastric cancer.

METHODS

The biological function of IGF2 in gastric cancer was investigated by Transwell, wound healing, CCK-8 and flow cytometry assays. IGF2 imprinting status and gene promoter methylation in gastric cancer tissues were detected by PCR-RFLP and BGS.

RESULTS

The results showed that the expression of IGF2 was higher in GC tissues than adjacent tissues. IGF2 gene promoter methylation and LOI were significantly higher in EBVaGC tissues than in EBV-negative gastric cancer (EBVnGC) tissues. The high expression of IGF2 in gastric cancer can promote the migration and proliferation of gastric cancer cells.

CONCLUSION

Our data suggest that IGF2 is involved in the occurrence and development of gastric cancer. Targeting IGF2 may be a potential therapeutic target for gastric cancer.

Federated learning enables big data for rare cancer boundary detection

Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing.

Molecular mechanism of aquaporin 3 (AQP3) regulating by LMP2A and its crosstalk with 4E-BP1 via ERK signaling pathway in EBV-associated gastric cancer

Aquaporin 3(AQP3) is involved in epithelial-mesenchymal transformation of tumor cells and is closely related to the occurrence and development of tumors. However, the regulatory mechanism and function of AQP3 in EBV-associated gastric cancer (EBVaGC) are still poorly understood. This study aims to explore the regulatory effect of EBV on AQP3 and the cross talk of AQP3 with EIF4E-binding proteins 1(4E-BP1) in EBVaGC. The effect of LMP2A on the expression of AQP3 and 4E-BP1 was analyzed using real-time PCR and western blotting. The biological functions of AQP3 and 4E-BP1 in gastric cancer cells were detected by cell biological experiments. In addition, we examined the role of mTOR and ERK signaling pathways in the LMP2A/AQP3/4E-BP1 regulatory axis. We found that LMP2A could down-regulate AQP3 expression by inhibiting the activation of mTOR signaling pathway, and further promote autophagy and migration of gastric cancer cells. AQP3 up-regulated the expression of 4E-BP1 and its phosphorylated protein by activating ERK signaling pathway, thus promoting the autophagy and proliferation of gastric cancer cells. In conclusion, EBV-encoded LMP2A inhibits AQP3 expression, and further participates in cell proliferation, migration and autophagy through the mTOR/AQP3/ERK/4E-BP1 axis.

Analysis of the relationship between the expression of EBV-related antibodies and ET-1 axis in gastric cancer

BACKGROUND AND OBJECTIVE: EBV-associated gastric cancer (EBVaGC) is a distinct subtype of GC, and EBV plays an important role in tumor progress. The standard method to identify EBV-positive tumor is determined by in situ hybridization for EBV-encoded EBERs in tumor tissues. The present study aims to detect the serological expression of EBV-related antibodies and ET-1 axis to provide a noninvasive method for diagnosis of EBVaGC. METHODS: The content of EBV-related antibodies and ET-1 axis in preoperative peripheral blood of GC was performed by Chemiluminescence and ELISA assay. The EBV DNA copy number was measured by qRT-PCR. RESULTS: The results showed that the levels of anti-EBV early antigen (EA) IgG, viral capsid antigen (VCA) IgA, nuclear antigen (NA) IgG, and EBV DNA copy number were significantly higher in EBVaGC. The ET-1 axis level was much lower in EBVaGC than EBVnGC. CONCLUSIONS: The combined detection of specific anti-EBV antibodies and ET-1 axis might provide new molecular markers for the identification of EBVaGC.

[Correlation analysis between drought and outpatient visits for diarrhea in children aged 0-6 in Lanzhou city and Tianshui city, Gansu Province]

In this study, the data of pediatric diarrhea clinic of Gansu Provincial Maternal and Child Health Hospital from January 1, 2014 to December 31, 2018 and Tianshui First Hospital from January 1, 2015 to December 31, 2018 were collected. Standardized precipitation index (SPI) and meteorological drought composite index (MCI) were used as drought indicators. Quasi-Poisson generalized additive model was used to analyze the correlation between drought and pediatric diarrhea outpatient visits. During the study period, the dry days in Lanzhou city and Tianshui city were 298 and 379 days according to SPI-1, 303 and 398 days according to MCI, respectively. There were 57 147 and 18 703 cases of diarrhea in children aged 0-6 years in Gansu Provincial Maternal and Child Health Hospital and Tianshui First Hospital, respectively. MCI and SPI (SPI-1) based on monthly precipitation were negatively correlated with the number of pediatric diarrhea outpatients. Compared with the non-drought period, SPI-1 showed the strongest correlation between middle drought and pediatric diarrhea outpatients, with an increase of 13.4% (95%CI: 7.9%-19.3%) and 20.0% (95%CI: 12.7%-27.8%) in Lanzhou city and Tianshui city, respectively. According to MCI, the outpatients with diarrhea in Tianshui children increased by 60.5% (95%CI: 3.4%-149.0%) due to extreme drought.

Preparation of Porous Ellipsoidal Bismuth Oxyhalide Microspheres and Their Photocatalytic Performances

Well-dispersed and uniform porous ellipsoidal-shaped bismuth oxyhalides (nominal composition: 80%BiOCl/20%BiOI) microspheres were obtained by a facile solvothermal method, in which process the use of polyvinylpyrrolidone (PVP) as template agent was found to be crucial. At 150 °C, elliptical porous particles with a particle size of 0.79 μm were formed. Instead of forming solid solutions, the study of X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) shows that the prepared 80%BiOCl/20%BiOI microspheres are composite of BiOCl and BiOI in nature and the obtained crystallite size is about 5.6 nm. The optical bandgap of 80%BiOCl/20%BiOI was measured to be 2.93 eV, which is between the bandgap values of BiOCl and BiOI. The 80%BiOCl/20%BiOI microspheres were able to decompose various organic dyes (rhodamine B-RhB, methyl orange-MO, methylene blue-MB, methyl violet-MV) under an illuminated condition with the degradation rate in the order of RhB > MB > MV > MO, and 98% of RhB can be degraded in 90 min. Radical scavenger tests showed that photogenerated holes are the main active species for the photocatalytic decomposition of all of the tested organic dyes. Our results show that the obtained porous ellipsoidal-shaped 80%BiOCl/20%BiOI microspheres are promising for the degradation of various organic pollutants under the illumination of visible light.

Polymer Photoelectrodes for Solar Fuel Production: Progress and Challenges

Converting solar energy to fuels has attracted substantial interest over the past decades because it has the potential to sustainably meet the increasing global energy demand. However, achieving this potential requires significant technological advances. Polymer photoelectrodes are composed of earth-abundant elements, e.g. carbon, nitrogen, oxygen, hydrogen, which promise to be more economically sustainable than their inorganic counterparts. Furthermore, the electronic structure of polymer photoelectrodes can be more easily tuned to fit the solar spectrum than inorganic counterparts, promising a feasible practical application. As a fast-moving area, in particular, over the past ten years, we have witnessed an explosion of reports on polymer materials, including photoelectrodes, cocatalysts, device architectures, and fundamental understanding experimentally and theoretically, all of which have been detailed in this review. Furthermore, the prospects of this field are discussed to highlight the future development of polymer photoelectrodes.

Transcriptome sequencing of LMP2A-transfected gastric cancer cells identifies potential biomarkers in EBV-associated gastric cancer

Epstein-barr virus (EBV) is a well-known human oncogenic virus. However, its molecular mechanisms in the initiation and development of EBV-associated gastric cancer (EBVaGC) remain poorly understood. Latent membrane protein 2A (LMP2A) is an EBV latency-associated protein expressed in part of EBVaGC cases. This study analyzed the effect of LMP2A on the gene expression of gastric cancer cells by transcriptome sequencing on the gastric cancer cell line SGC7901 that expresses LMP2A. The study monitored a total of 238 genes with significant differences in expression, including 101 upregulated genes and 137 downregulated genes. Using the KEGG pathway analysis, it was found that more genes were enriched in the Steroid biosynthesis, Axon guidance, and Terpenoid backbone biosynthesis pathway, and there were 5 genes each enriched in PI3K-Akt and AMPK signaling pathway, all of which were significant. This indicates that LMP2A may be involved in cell biosynthesis, and affects downstream genes and cell biological behavior through AKT and AMPK signaling pathway. Further evaluation confirmed that LMP2A induces ETV5 transcription, but repress GATA6 and NOTCH3 expression. ETV5, GATA6 and NOTCH3 are the candidate targets of LMP2A in gastric cancer.

Sequence analysis of Epstein–Barr virus BALF2 gene in associated tumors and healthy individuals from southern and northern China

Aim: The purpose of this study is to investigate the polymorphism and distribution characteristics of BALF2 gene in Epstein–Barr virus (EBV)-associated tumors (gastric cancer, nasopharyngeal carcinoma and lymphoma). Materials & methods: DNA sequences of 349 EBV-related samples were analyzed by nested PCR combined with DNA sequencing. Results: According to the phylogenetic tree, BALF2 was divided into six genotypes ( BALF2-A–F). Statistically, the incidence of BALF2-E in nasopharyngeal carcinoma was higher than that in healthy people, and the incidence of BALF2-E in nasopharyngeal carcinoma in South China was higher than that in North China (p = 0.001). Conclusion: BALF2 variants in EBV-associated samples are not only tumor-specific, but also differ between northern and southern regions.

Activation of DNA methyltransferase 3a by Epstein-Barr nuclear antigen 1 in gastric carcinoma

BACKGROUND

Epstein-Barr nuclear antigen 1 (EBNA1) is expressed in all Epstein-Barr virus (EBV)-infected cells. It interacts with a variety of cellular proteins and activates the transcription of other EBV latency genes, which plays an important role in the persistence of the EBV genome during latent infection.

AIM

Several studies have shown that EBV infection induces the expression of DNA methyltransferases (DNMTs) and causes extensive methylation of the whole genome in EBV-associated gastric carcinoma (EBVaGC). However, the specific mechanism by which EBV regulates DNMTs expression is still unclear.

METHODS AND RESULTS

EBNA1 plasmid and siRNA were transfected to evaluate the effect of EBNA1 on DNMT3a expression. Molecular biology experiments were used to detect the biological function of DNMT3a and its effect on EBV latency in gastric carcinoma cells. We showed that EBNA1 upregulated DNMT3a expression through the E2F1 transcription factor (E2F1) in EBVaGC. DNMT3a knockdown restrained cell proliferation, induced cell cycle arrest, promoted cell apoptosis and suppressed cell migration in vitro.

CONCLUSIONS

Our results showed a new mechanism for EBV to regulate the expression of DNMT3a. Targeting the EBNA1/E2F1/DNMT3a axis may provide an alternative therapeutic strategy in the treatment of EBVaGC with high DNMT3a expression.

Efficient photothermal-assisted photocatalytic hydrogen production over a plasmonic CuNi bimetal cocatalyst

It is challenging to maximize the utilization of solar energy using photocatalysis or photothermal catalysis alone. Herein, we report a full spectrum solar energy driven photothermal-assisted photocatalytic hydrogen production over CuNi bimetallic nanoparticles co-loaded with graphitized carbon nitride nanosheet layers (Cu_xNi_y/CN) which are prepared by a facile in-situ reduction method. Cu₅Ni₅/CN shows a high hydrogen production rate of 267.8 μmol g^-1 h^-1 at room temperature, which is 70.5 and 1.34 times of that for pure CN (3.8 μmol g^-1 h^-1) and 0.5 wt% Pt/CN (216 μmol g^-1 h^-1), respectively. The photothermal catalytic hydrogen activity can be further increased by 3.7 times when reaction solution is external heated to 100 °C. For the photothermal catalytic system, the local surface plasmon resonance (LSPR) effect over active Cu nanoparticles can absorb near-infrared light to generate hot electrons, which are partially quenched to generate heat for heating of the reaction system and partially transported to the active sites, where the Ni nanoparticles as another functional component couple the electrons and heat to finally promote the photothermal catalytic activity. Our result suggests that a rational design of the catalyst with bifunctional atomic components can photothermocatalysis-assisted photocatalysis to maximize utilization solar energy for efficient full spectrum conversion.

LMP1 Induces p53 Protein Expression via the H19/miR-675-5p Axis

Epstein-Barr virus (EBV), a ubiquitous oncogenic herpesvirus, infects more than 90% of the adult population worldwide. The long noncoding RNA H19 is downregulated in EBV-positive gastric cancer (EBVaGC) and nasopharyngeal cancer (NPC). In this study, we found that loss of H19 is caused by hypermethylation status of the H19 promoter in EBV-positive GC and NPC cell lines. Furthermore, latent membrane protein 1 (LMP1), encoded by EBV, induced H19 promoter hypermethylation and deregulated the expression of H19 by upregulating DNMT1 expression. Transwell assays showed that H19 promoted cell migration. Furthermore, H19 promoted cell proliferation and inhibited apoptosis in CCK-8 and flow cytometry assays, respectively. p53, a well-known tumor suppressor, was upregulated in EBVaGC and NPC cell lines. miR-675-5p derived from H19 inhibited p53 protein expression by targeting the 3' untranslated region of the gene. Overall, we found that LMP1 induced p53 protein expression via the H19/miR-675-5p axis in EBVaGC and NPC. LMP1 induced H19 promoter hypermethylation, which repressed the expression of H19 and miR-675-5p and caused p53 protein overexpression in EBVaGC and NPC cells. IMPORTANCE Epstein-Barr virus (EBV) is the first virus to be known to have direct association with human cancer and to be considered as an important DNA tumor virus. The EBV life cycle consists of both latent and lytic modes of infection in B lymphocytes and epithelial cells. The persistence of EBV genomes in malignant cells promoted cell growth. p53, acting as a critical gatekeeper tumor suppressor, is involved in multiple virus-mediated tumorigeneses. Overexpression of p53 inhibits the ability of BZLF1 (EBV-encoded immediate early gene) to disrupt viral latency. In our study, we found LMP1 induces H19 promoter hypermethylation, which represses the expression of H19 and miR-675-5p and results in p53 protein overexpression in EBVaGC and NPC cells. These observations suggest a new mechanism of aberrant expression of p53 by LMP1, which facilitates EBV latency.