FTO up-regulation induced by MYC suppresses tumour progression in Epstein-Barr virus-associated gastric cancer.

BACKGROUND: Epstein-Barr virus-associated gastric cancer (EBVaGC) is regarded as a distinct molecular subtype of GC, accounting for approximately 9% of all GC cases. Clinically, EBVaGC patients are found to have a significantly lower frequency of lymph node metastasis and better prognosis than uninfected individuals. RNA N6-methyladenosine (m6A) modification has an indispensable role in modulating tumour progression in various cancer types. However, its impact on EBVaGC remains unclear. METHODS: Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and m6A dot blot were conducted to compare the m6A modification levels between EBVaGC and EBV-negative GC (EBVnGC) cells. Western blot, real-time quantitative PCR (RT-qPCR) and immunohistochemistry were applied to explore the underlying mechanism of the reduced m6A modification in EBVaGC. The biological function of fat mass and obesity-associated protein (FTO) was determined in vivo and in vitro. The target genes of FTO were screened by MeRIP-seq, RT-qPCR and Western blot. The m6A binding proteins of target genes were verified by RNA pulldown and RNA immunoprecipitation assays. Chromatin immunoprecipitation and Luciferase report assays were performed to investigate the mechanism how EBV up-regulated FTO expression. RESULTS: M6A demethylase FTO was notably increased in EBVaGC, leading to a reduction in m6A modification, and higher FTO expression was associated with better clinical outcomes. Furthermore, FTO depressed EBVaGC cell metastasis and aggressiveness by reducing the expression of target gene AP-1 transcription factor subunit (FOS). Methylated FOS mRNA was specifically recognized by the m6A 'reader' insulin-like growth factor 2 mRNA binding protein 1/2 (IGF2BP1/2), which enhanced its transcripts stability. Moreover, MYC activated by EBV in EBVaGC elevated FTO expression by binding to a specific region of the FTO promoter. CONCLUSIONS: Mechanistically, our work uncovered a crucial suppressive role of FTO in EBVaGC metastasis and invasiveness via an m6A-FOS-IGF2BP1/2-dependent manner, suggesting a promising biomarker panel for GC metastatic prediction and therapy.

Long noncoding RNA Regulating ImMune Escape regulates mixed lineage leukaemia protein-1-H3K4me3-mediated immune escape in oesophageal squamous cell carcinoma.

BACKGROUND: Predictive biomarkers for oesophageal squamous cell carcinoma (ESCC) immunotherapy are lacking, and immunotherapy resistance remains to be addressed. The role of long noncoding RNA (lncRNA) in ESCC immune escape and immunotherapy resistance remains to be elucidated. METHODS: The tumour-associated macrophage-upregulated lncRNAs and the exosomal lncRNAs highly expressed in ESCC immunotherapy nonresponders were identified by lncRNA sequencing and polymerase chain reaction assays. CRISPR-Cas9 was used to explore the functional roles of the lncRNA. RNA pull-down, MS2-tagged RNA affinity purification (MS2-TRAP) and RNA-binding protein immunoprecipitation (RIP) were performed to identify lncRNA-associated proteins and related mechanisms. In vivo, the humanized PBMC (hu-PBMC) mouse model was established to assess the therapeutic responses of specific lncRNA inhibitors and their combination with programmed cell death protein 1 (PD-1) monoclonal antibody (mAb). Single-cell sequencing, flow cytometry, and multiplex fluorescent immunohistochemistry were used to analyze immune cells infiltrating the tumour microenvironment. RESULTS: We identified a lncRNA that is involved in tumour immune evasion and immunotherapy resistance. High LINC02096 (RIME) expression in plasma exosomes correlates with a reduced response to PD-1 mAb treatment and poor prognosis. Mechanistically, RIME binds to mixed lineage leukaemia protein-1 (MLL1) and prevents ankyrin repeat and SOCS box containing 2 (ASB2)-mediated MLL1 ubiquitination, improving the stability of MLL1. RIME-MLL1 increases H3K4me3 levels in the promoter regions of programmed death-ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO-1), constitutively increasing the expression of PD-L1/IDO-1 in tumour cells and inhibiting CD8+ T cells infiltration and activation. RIME depletion in huPBMC-NOG mice significantly represses tumour development and improves the effectiveness of PD-1 mAb treatment by activating T-cell-mediated antitumour immunity. CONCLUSIONS: This study reveals that the RIME-MLL1-H3K4me3 axis plays a critical role in tumour immunosuppression. Moreover, RIME appears to be a potential prognostic biomarker for immunotherapy and developing drugs that target RIME may be a new therapeutic strategy that overcomes immunotherapy resistance and benefits patients with ESCC.

Genome-wide CRISPR/Cas9 screening identifies a targetable MEST-PURA interaction in cancer metastasis.

BACKGROUND: Metastasis is one of the most lethal hallmarks of esophageal squamous cell carcinoma (ESCC), yet the mechanisms remain unclear due to a lack of reliable experimental models and systematic identification of key drivers. There is urgent need to develop useful therapies for this lethal disease. METHODS: A genome-wide CRISPR/Cas9 screening, in combination with gene profiling of highly invasive and metastatic ESCC sublines, as well as PDX models, was performed to identify key regulators of cancer metastasis. The Gain- and loss-of-function experiments were taken to examine gene function. Protein interactome, RNA-seq, and whole genome methylation sequencing were used to investigate gene regulation and molecular mechanisms. Clinical significance was analyzed in tumor tissue microarray and TCGA databases. Homology modeling, modified ELISA, surface plasmon resonance and functional assays were performed to identify lead compound which targets MEST to suppress cancer metastasis. FINDINGS: High MEST expression was associated with poor patient survival and promoted cancer invasion and metastasis in ESCC. Mechanistically, MEST activates SRCIN1/RASAL1-ERK-snail signaling by interacting with PURA. miR-449a was identified as a direct regulator of MEST, and hypermethylation of its promoter led to MEST upregulation, whereas systemically delivered miR-449a mimic could suppress tumor metastasis without overt toxicity. Furthermore, molecular docking and computational screening in a small-molecule library of 1,500,000 compounds and functional assays showed that G699-0288 targets the MEST-PURA interaction and significantly inhibits cancer metastasis. INTERPRETATION: We identified the MEST-PURA-SRCIN1/RASAL1-ERK-snail signaling cascade as an important mechanism underlying cancer metastasis. Blockade of MEST-PURA interaction has therapeutic potential in management of cancer metastasis. FUNDING: This work was supported by National Key Research and Development Program of China (2021YFC2501000, 2021YFC2501900, 2017YFA0505100); National Natural Science Foundation of China (31961160727, 82073196, 81973339, 81803551); NSFC/RGC Joint Research Scheme (N_HKU727/19); Natural Science Foundation of Guangdong Province (2021A1515011158, 2021A0505030035); Key Laboratory of Guangdong Higher Education Institutes of China (2021KSYS009).

Anti-allergic drug azelastine suppresses colon tumorigenesis by directly targeting ARF1 to inhibit IQGAP1-ERK-Drp1-mediated mitochondrial fission.

This study aimed to screen novel anticancer strategies from FDA-approved non-cancer drugs and identify potential biomarkers and therapeutic targets for colorectal cancer (CRC). Methods: A library consisting of 1056 FDA-approved drugs was screened for anticancer agents. WST-1, colony-formation, flow cytometry, and tumor xenograft assays were used to determine the anticancer effect of azelastine. Quantitative proteomics, confocal imaging, Western blotting and JC-1 assays were performed to examine the effects on mitochondrial pathways. The target protein of azelastine was analyzed and confirmed by DARTS, WST-1, Biacore and tumor xenograft assays. Immunohistochemistry, gain- and loss-of-function experiments, WST-1, colony-formation, immunoprecipitation, and tumor xenograft assays were used to examine the functional and clinical significance of ARF1 in colon tumorigenesis. Results: Azelastine, a current anti-allergic drug, was found to exert a significant inhibitory effect on CRC cell proliferation in vitro and in vivo, but not on ARF1-deficient or ARF1-T48S mutant cells. ARF1 was identified as a direct target of azelastine. High ARF1 expression was associated with advanced stages and poor survival of CRC. ARF1 promoted colon tumorigenesis through its interaction with IQGAP1 and subsequent activation of ERK signaling and mitochondrial fission by enhancing the interaction of IQGAP1 with MEK and ERK. Mechanistically, azelastine bound to Thr-48 in ARF1 and repressed its activity, decreasing Drp1 phosphorylation. This, in turn, inhibited mitochondrial fission and suppressed colon tumorigenesis by blocking IQGAP1-ERK signaling. Conclusions: This study provides the first evidence that azelastine may be novel therapeutics for CRC treatment. ARF1 promotes colon tumorigenesis, representing a promising biomarker and therapeutic target in CRC.

Direct Targeting of CREB1 with Imperatorin Inhibits TGFß2-ERK Signaling to Suppress Esophageal Cancer Metastasis.

Metastasis accounts for 90% of cancer death worldwide, and effective therapeutic strategies are lacking. The aim of this work is to identify the key drivers in tumor metastasis and screen therapeutics for treatment of esophageal squamous cell carcinoma (ESCC). Gene Ontology analysis of The Cancer Genome Atlas (TCGA) gene expression datasets of ESCC patients with or without lympy metastasis identifies that TGFß2 is highly enriched in the pathways essential for tumor metastasis and upregulates in the metastatic ESCC tumors. High TGFß2 expression in ESCC correlates with metastasis and patient survival, and functionally contributes to tumor metastasis via activating extracellular signal-regulated kinases (ERK) signaling. By screening of a library consisting of 429 bioactive compounds, imperatorin is verified as a novel TGFß2 inhibitor, with robustly suppressive effect on tumor metastasis in multiple mice models. Mechanistically, direct binding of imperatorin and CREB1 inhibits phosphorylation, nuclear translocation of CREB1, and its interaction with TGFß2 promoter, represses TGFß2 expression and fibroblasts-secreted CCL2, and then inactivates ERK signaling to block cancer invasion and abrogates the paracrine effects of fibroblasts on tumor angiogenesis and metastasis. Overall, the findings suggest the use of TGFß2 as a diagnostic and prognostic biomarker and therapeutic target in ESCC, and supports the potential of imperatorin as a novel therapeutic strategy for cancer metastasis.

Echinatin suppresses esophageal cancer tumor growth and invasion through inducing AKT/mTOR-dependent autophagy and apoptosis.

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with poor survival. It is urgent to search for new efficient drugs with good stability and safety for clinical therapy. This study aims to identify potential anticancer drugs from a compound library consisting of 429 natural products. Echinatin, a compound isolated from the Chinese herb Glycyrrhiza uralensis Fisch, was found to markedly induce apoptosis and inhibit proliferation and colony-formation ability in ESCC. Confocal fluorescence microscopy data showed that echinatin significantly induced autophagy in ESCC cells, and autophagy inhibitor bafilomycinA1 attenuated the suppressive effects of echinatin on cell viability and apoptosis. Mechanistically, RNA sequencing coupled with bioinformatics analysis and a series of functional assays revealed that echinatin induced apoptosis and autophagy through inactivation of AKT/mTOR signaling pathway, whereas constitutive activation of AKT significantly abrogated these effects. Furthermore, we demonstrated that echinatin had a significant antitumor effect in the tumor xenograft model and markedly suppressed cell migration and invasion abilities of ESCC cells in a dose-dependent manner. Our findings provide the first evidence that echinatin could be a novel therapeutic strategy for treating ESCC.

Direct targeting of HSP90 with daurisoline destabilizes ß-catenin to suppress lung cancer tumorigenesis.

Lung cancer is the most frequent cancer worldwide with a poor prognosis. Identification of novel cancer targets and useful therapeutic strategies without toxicity are urgently needed. In this study, we screened natural products for anticancer bioactivity in a library consisting of 429 small molecules. We demonstrated for the first time that daurisoline, a constituent of Rhizoma Menispermi, repressed lung cancer cell proliferation by inducing cell cycle arrest at the G1 phase. Furthermore, daurisoline was found not only to suppress the growth of lung tumor xenografts in animals without obvious side effects, but also to inhibit cell migration and invasion. Mechanistically, quantitative proteomics and bioinformatics analyses, Western blotting and qRT-PCR confirmed that daurisoline exerted its anticancer effects by inhibiting the expression levels of ß-catenin and its downstream targets c-myc and cyclin D1. Furthermore, our data from Drug Affinity Responsive Target Stability (DARTS), isothermal titration calorimetry (ITC) and a series of functional assays demonstrated that daurisoline could target HSP90 directly and disrupt its interaction with ß-catenin, therefore increasing the ubiquitin-mediated proteasomal degradation of ß-catenin. This study reveals that daurisoline could be a promising therapeutic strategy for the treatment of lung cancer.

Inhibition of human thrombin by the constituents of licorice: inhibition kinetics and mechanistic insights through in vitro and in silico studies.

Thrombin inhibition therapy is a practical strategy to reduce thrombotic and cardiovascular risks via blocking the formation of blood clots. This study aimed to identify naturally occurring thrombin inhibitors from licorice (one of the most popular edible herbs), as well as to investigate their inhibitory mechanisms. Among all tested licorice constituents, licochalcone A was found as the most efficacious agent against human thrombin (IC50 = 7.96 µM). Inhibition kinetic analyses demonstrated that licochalcone A was a mixed inhibitor against thrombin-mediated Z-Gly-Gly-Arg-AMC acetate hydrolysis, with a K i value of 12.23 µM. Furthermore, mass spectrometry-based chemoproteomic assays and molecular docking simulations revealed that licochalcone A could bind to human thrombin at both exosite I and the catalytic site. In summary, our findings demonstrated that the chalcones isolated from licorice were a new class of direct thrombin inhibitors, also suggesting that licochalcone A was a promising lead compound for developing novel anti-thrombotic agents.

Adefovir dipivoxil sensitizes colon cancer cells to vemurafenib by disrupting the KCTD12-CDK1 interaction.

Vemurafenib is a B-Raf V600E inhibitor that exerts significant inhibitory effects in melanoma but not in colon cancer, and the mechanism of vemurafenib resistance remains unclear. In this study, bioinformatics analysis of gene profiles in cancer cells treated with vemurafenib or its analog revealed that cell cycle progression is significantly affected by vemurafenib. We found that CDK1 is stably activated in the vemurafenib-resistant (VR) colon cancer sublines that we established, indicating that CDK1 activation is responsible for vemurafenib resistance. As the KCTD12-CDK1 interaction is necessary for CDK1 activation, we screened an FDA-approved drug library consisting of 616 compounds and identified that adefovir dipivoxil (AD), a nucleoside analog for treatment of HBV infections, disrupts the CDK1-KCTD12 interaction and induces G2 phase arrest in the cell cycle. Functional assays demonstrated that AD significantly inhibited colon cancer cell proliferation and tumorigenesis both in vitro and in vivo with no observed side effects. Furthermore, AD sensitized vemurafenib-resistant colon cancer cells and tumor xenografts to vemurafenib. This study reveals that CDK1 activation induces vemurafenib resistance and that AD is a promising therapeutic strategy for colon cancer both as a single agent and in combination with vemurafenib.

Significance of integrin-linked kinase (ILK) in tumorigenesis and its potential implication as a biomarker and therapeutic target for human cancer.

Integrin-linked kinase (ILK), which is an ankyrin repeat-containing serine/threonine protein kinase, interacts with integrin ß1 and the ß3 cytoplasmic domain and phosphorylates integrin ß1. ILK has multiple functions in cells, such as cell-extracellular matrix interactions, cell cycle, apoptosis, cell proliferation and cell motility, which are associated with the interacting partners of ILK and downstream signaling pathways. Upregulation of ILK is frequently observed in cancer tissues compared to corresponding normal tissues. Emerging evidence has demonstrated that ILK plays an important role in biological processes associated with tumorigenesis, including cancer cell proliferation, angiogenesis, metastasis, and drug resistance. Furthermore, inhibition of ILK expression and activity using siRNA or chemical inhibitors has shown a significant suppressive effect on cancer development and progression, implicating the potential of ILK as a target for cancer treatment. In this review, we summarized the functional role of ILK in tumorigenesis, with the expectation that targeting ILK could provide more evidence for cancer therapy.

[Analysis of Epstein Barr virus infection in 761 hospitalized children].

OBJECTIVE: To study the status of EB virus (EBV) infection and the spectrum of EBV infection-related diseases. METHODS: A total of 761 plasma samples with suspected EBV infection were collected from 761 children (aged from 22 days to 14 years) admitted between August 2010 and July 2011. EBV-DNA of 761 plasma samples was detected by real-time PCR. The epidemiological characteristics and final clinical diagnosis were analyzed based on the clinical data of these EBV-positive hospitalized patients. RESULTS: A total of 109 cases with EBV infection were detected by real-time PCR, with a positive rate of 14.3%. There were significant differences in the positive rate of EBV-DNA among different age groups and between seasons (P<0.05). The positive rate of EBV-DNA in the baby group (<1 year old) was lowest (P<0.05), and the positive rate of EBV-DNA in summer was higher than in winter (P<0.05). The range of plasma EBV-DNA level in children with EBV-DNA positivity was 2.13 to 6.69 (median 3.72). Based on the final diagnosis of 62 EBV-positive hospitalized children, the most common disease was respiratory system infection (39%), such as acute bronchitis, acute upper respiratory infection and bronchopneumonia. CONCLUSIONS: The EBV-DNA positive rate is different among different age groups and between seasons. Respiratory system infection is a leading disease in hospitalized children who are EBV-DNA positive. Real-time PCR assay is useful for rapid and reliable clinical diagnosis of EBV in children.

[Detection of Mycoplasma pneumoniae, Chlamydia trachomatis and common respiratory viruses in children with acute respiratory infection in Nanjing].

OBJECTIVE: To investigate the nonbacterial pathogens in children with acute respiratory infection (ARI) in Nanjing. METHODS: The presence of Mycoplasma pneumoniae (MP) and Chlamydia trachomatis (CT) was determined by quantitative PCR in the nasopharyngeal samples from 1 592 hospitalized children with ARI. Common respiratory viruses, including respiratory syncytial virus (RSV), adenovirus (ADV), influenza virus types A and B (IVA and IVB), parainfluenza virus types 1, 2, 3(PIV-1, 2, 3) and human metapneumovirus (hMPV), were detected using direct immunofluorescence assay. RESULTS: MP and CT were detected in 25.7% and 2.4% of the 1 592 samples respectively. The overall positive rate of respiratory viruses was 40.9%. Among the viruses, the top detected virus was RSV (61.3%), followed by PIV-3 (6.7%) and hMPV (4.9%). Mixed infection among MP, CT and viruses was observed in 107 cases (6.7%). The infants under 1 year old were susceptible to mix-infection (68/107, 63.6%). CONCLUSIONS: Respiratory virus is the main pathogen responsible for ARI in children from Nanjing. RSV is the most commonly identified virus. MP is also the frequently identified pathogen for ARI in children. Mixed infection is common in infants under 1 year old.

Statistical analysis on 2213 inpatients with traffic injuries from January 2003 to September 2005 in Ningbo city.

OBJECTIVE: To analyze the epidemiological conditions and characteristics of inpatients with traffic trauma in order to provide objective data for basic research and clinical application of traffic trauma. METHODS: The data of 2213 inpatients with traffic trauma admitted to Lihuili Hospital, Ningbo Medical Centre, Ningbo, China, from January 2003 to September 2005 were studied retrospectively. According to the transportation ways, the patients were divided into four groups: pedestrians, bicyclists, motorcyclists, and automobilists. And the data of injured regions, combined injuries and causes of death were analyzed statistically. RESULTS: Among the 2213 patients, there were 550 pedestrians (23.5%), 521 bicyclists (24.9%), 738 motorcyclists (33.3%), and 404 automobilists (18.3%). Male patients were more than female ones, with the ratio of male to female of 2.8:1. Single region injury was found in 1663 patients (75.15%) and multiple injuries in 550 patients (24.85%). In total, 2849 regions were injured. Fracture of extremities (53.3%) occurred most often, craniocerebral trauma (19.4%) next, then followed in turn by thoraco-abdominal visceral injury (6.56%), spine fracture (5.37%), fracture of ribs (4.88%), and pelvic fracture (4.18%). The percentage of multiple injuries (33.2%) was highest and the percentage of thoraco-abdominal injury (18.0%) was higher in motorcyclists. The percentages of craniocerebral trauma in pedestrians and bicyclists were 27.8% and 28.2%, respectively. The incidence of fracture of extremities in motorcyclists reached 73.8%, but with the lowest case-fatality ratio of 1.4%. The incidence of traffic accidents caused by motorcyclists themselves (32.8%) was highest. A total of 56 patients died, with the case-fatality ratio of 2.53%. Among the deaths, 47 died from craniocerebral injury, 6 from multiple fractures combined with hemorrhagic shock, 2 from combined injury in the thoraco-abdominal region, and 1 from cervical cord injury. CONCLUSIONS: Nowadays, the patients with traffic trauma are mainly pedestrians, bicyclists and motorcyclists, and they suffer generally from fracture of extremities and craniocerebral injury. The main cause of death is craniocerebral injury. Another characteristic of traffic trauma is that the ratio of multiple injuries is higher.

[Existant quality problems and suggestions for quality control of medical absorbent cotton].

In the process of acid hydrolysis of medical absorbent cotton, we have discovered that some of the domestic manufactured medical absorbent cotton is mixed with wasted non-cotton chemical fiber. If the cotton is used in medical treatments, the chemical fiber will cause irritation, allergy and inflammation, so it's very harmful. But the non-cotton fiber content is not stipulated in the standard of YY0330-2002, and no testing method for it is available. In this paper we discuss the existent quality problems, the control and the test method for non-cotton chemical fiber in medical absorbent cotton.