Deletion of TMEM268 inhibits growth of gastric cancer cells by downregulating the ITGB4 signaling pathway

Mediterranean diet protects against a neuroinflammatory cortical transcriptome: Associations with brain volumetrics, peripheral inflammation, social isolation, and anxiety in nonhuman primates (Macaca fascicularis)

Mediterranean diets may be neuroprotective and prevent cognitive decline relative to Western diets; however, the underlying biology is poorly understood. We assessed the effects of Western versus Mediterranean-like diets on RNAseq-generated transcriptional profiles in lateral temporal cortex and their relationships with longitudinal changes in neuroanatomy, circulating monocyte gene expression, and observations of social isolation and anxiety in 38 socially-housed, middle-aged female cynomolgus macaques (Macaca fascicularis). Diet resulted in differential expression of seven transcripts (FDR < 0.05). Cyclin dependent kinase 14 (CDK14), a proinflammatory regulator, was lower in the Mediterranean group. The remaining six transcripts [i.e., "lunatic fringe" (LFNG), mannose receptor C type 2 (MRC2), solute carrier family 3 member 2 (SLCA32), butyrophilin subfamily 2 member A1 (BTN2A1), katanin regulatory subunit B1 (KATNB1), and transmembrane protein 268 (TMEM268)] were higher in cortex of the Mediterranean group and generally associated with anti-inflammatory/neuroprotective pathways. KATNB1 encodes a subcomponent of katanin, important in maintaining microtubule homeostasis. BTN2A1 is involved in immunomodulation of γδ T-cells which have anti-neuroinflammatory and neuroprotective effects. CDK14, LFNG, MRC2, and SLCA32 are associated with inflammatory pathways. The latter four differentially expressed cortex transcripts were associated with peripheral monocyte transcript levels, neuroanatomical changes determined by MRI, and with social isolation and anxiety. These results provide important insights into the potential mechanistic processes linking diet, peripheral and central inflammation, and behavior. Collectively, our results provide evidence that, relative to Western diets, Mediterranean diets confer protection against peripheral and central inflammation which is reflected in preserved brain structure and socioemotional behavior. Ultimately, such protective effects may confer resilience to the development of neuropathology and associated disease.

Deletion of Tmem268 in mice suppresses anti-infectious immune responses by downregulating CD11b signaling

Transmembrane protein 268 (TMEM268) is a novel, tumor growth-related protein first reported by our laboratory. It interacts with the integrin subunit β4 (ITGB4) and plays a positive role in the regulation of the ITGB4/PLEC signaling pathway. Here, we investigated the effects and mechanism of TMEM268 in anti-infectious immune response in mice. Tmem268 knockout in mice aggravated cecal ligation and puncture-induced sepsis, as evidenced by higher bacterial burden in various tissues and organs, congestion, and apoptosis. Moreover, Tmem268 deficiency in mice inhibited phagocyte adhesion and migration, thus decreasing phagocyte infiltration at the site of infection and complement-dependent phagocytosis. Further findings indicated that TMEM268 interacts with CD11b and inhibits its degradation via the endosome-lysosome pathway. Our results reveal a positive regulatory role of TMEM268 in β2 integrin-associated anti-infectious immune responses and signify the potential value of targeting the TMEM268-CD11b signaling axis for the maintenance of immune homeostasis and immunotherapy for sepsis and related immune disorders.

ING3 inhibits the malignant progression of lung adenocarcinoma by negatively regulating ITGB4 expression to inactivate Src/FAK signaling

Lung adenocarcinoma (LUAD) is the most commonly diagnosed subtype of lung cancer worldwide. Inhibitor of growth 3 (ING3) serves as a tumor suppressor in many cancers. This study aimed to elucidate the role of ING3 in the progression of LUAD and investigate the underlying mechanism related to integrin β4 (ITGB4) and Src/focal adhesion kinase (FAK) signaling. ING3 expression in LUAD tissues and the correlation between ING3 expression and prognosis were analyzed by bioinformatics databases. After evaluating ING3 expression in LUAD cells, ING3 was overexpressed to assess the proliferation, cell cycle arrest, migration and invasion of LUAD cells. Then, ITGB4 was upregulated to observe the changes of malignant activities in ING3-overexpressed LUAD cells. The transplantation tumor model of NCI-H1975 cells in nude mice was established to analyze the antineoplastic effect of ING3 upregulation in vivo. Downregulated ING3 expression was observed in LUAD tissues and cells and lower ING3 expression predicated the poor prognosis. ING3 upregulation restrained the proliferation, migration, invasion and induced the cell cycle arrest of NCI-H1975 cells. Additionally, ITGB4 expression was negatively correlated with ING3 expression in LUAD tissue. ING3 led to reduced expression of ITGB4, Src and p-FAK. Moreover, ITGB4 overexpression alleviated the effects of ING3 upregulation on the malignant biological properties of LUAD cells. It could be also found that ING3 upregulation limited the tumor volume, decreased the expression of ITGB4, Src and p-FAK, which was restored by ITGB4 overexpression. Collectively, ING3 inhibited the malignant progression of LUAD by negatively regulating ITGB4 expression to inactivate Src/FAK signaling.

N6-methyladenosine (m6A) methylation in kidney diseases: Mechanisms and therapeutic potential

The N6-methyladenosine (m6A) modification is regulated by methylases, commonly referred to as "writers," and demethylases, known as "erasers," leading to a dynamic and reversible process. Changes in m6A levels have been implicated in a wide range of cellular processes, including nuclear RNA export, mRNA metabolism, protein translation, and RNA splicing, establishing a strong correlation with various diseases. Both physiologically and pathologically, m6A methylation plays a critical role in the initiation and progression of kidney disease. The methylation of m6A may also facilitate the early diagnosis and treatment of kidney diseases, according to accumulating research. This review aims to provide a comprehensive overview of the potential role and mechanism of m6A methylation in kidney diseases, as well as its potential application in the treatment of such diseases. There will be a thorough examination of m6A methylation mechanisms, paying particular attention to the interplay between m6A writers, m6A erasers, and m6A readers. Furthermore, this paper will elucidate the interplay between various kidney diseases and m6A methylation, summarize the expression patterns of m6A in pathological kidney tissues, and discuss the potential therapeutic benefits of targeting m6A in the context of kidney diseases.

Mediterranean Diet Protects Against a Neuroinflammatory Cortical Transcriptome: Associations with Brain Volumetrics, Peripheral Inflammation, Social Isolation and Anxiety

INTRODUCTION

Mediterranean diets may be neuroprotective and prevent cognitive decline relative to Western diets, however the underlying biology is poorly understood.

METHODS

We assessed the effects of Western vs. Mediterranean-like diets on RNAseq generated transcriptional profiles in temporal cortex and their relationships with changes in MRI neuroimaging phenotypes, circulating monocyte gene expression, and observations of social isolation and anxiety in 38 socially-housed, middle-aged female cynomolgus macaques.

RESULTS

Diet resulted in differential expression of seven transcripts (FDR<0.05). Cyclin dependent kinase 14 ( CDK14 ), a proinflammatory regulator, was lower in the Mediterranean group. The remaining six transcripts [i.e., "lunatic fringe" ( LFNG ), mannose receptor C type 2 ( MRC2 ), solute carrier family 3 member 2 ( SLCA32 ), butyrophilin subfamily 2 member A1 ( BTN2A1 ), katanin regulatory subunit B1 ( KATNB1 ), and transmembrane protein 268 ( TMEM268 )] were higher in cortex of the Mediterranean group and generally associated with anti-inflammatory/neuroprotective pathways. KATNB1 encodes a subcomponent of katanin, important in maintaining microtubule homeostasis. BTN2A1 is involved in immunomodulation of γδ T-cells which have anti-neuroinflammatory and neuroprotective effects. CDK14 , LFNG , MRC2, and SLCA32 are associated with inflammatory pathways. The latter four differentially expressed cortex transcripts were associated with monocyte transcript levels, changes in AD-relevant brain volumes determined by MRI over the course of the study, and social isolation and anxiety. CDK14 was positively correlated with monocyte inflammatory transcripts, changes in total brain, gray matter, cortical gray matter volumes, and time alone and anxious behavior, and negatively correlated with changes in total white matter and cerebrospinal fluid (CSF) volumes. In contrast, LFNG , MRC2 , and SLCA32 were negatively correlated with monocyte inflammatory transcripts and changes in total gray matter volume, and positively correlated with CSF volume changes, and SLCA32 was negatively correlated with time alone.

DISCUSSION

Collectively, our results suggest that relative to Western diets, Mediterranean diets confer protection against peripheral and central inflammation which is reflected in preserved brain structure and behavior.

SPTBN2 regulates endometroid ovarian cancer cell proliferation, invasion and migration via ITGB4‑mediated focal adhesion and ECM receptor signalling pathway

Ovarian cancer is as a major contributor to gynaecologic death globally. The present study aimed to investigate the regulatory role of spectrin β non-erythrocytic 2 gene (SPTBN2) in endometroid ovarian cancer and its mechanism of action. According to the Gene Expression Profiling Interactive Analysis (GEPIA) database, SPTBN2 expression is elevated in ovarian cancer tissues and higher SPTBN2 expression indicated a worse prognosis. The present study assessed SPTBN2 mRNA and protein expression levels by reverse transcription-quantitative PCR and western blotting, respectively. Cell viability, proliferation, migration and invasion were assessed with Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine incorporation, wound healing and Transwell assays, respectively. SPTBN2 expression was notably enhanced in ovarian cancer cell lines, especially in A2780 cells compared with HOSEPiC cells (P<0.001). Following transfection with small interfering (si)RNA targeting SPTBN2, the viability, proliferation, migration and invasion of A2780 cells were decreased compared with those of A2780 cells transfected with siRNA-NC (P<0.001). Gene Set Enrichment Analysis database revealed that SPTBN2 was primarily enriched in 'focal adhesion' and 'extracellular matrix (ECM)-receptor interaction', whereas SPTBN2 was significantly associated with integrin β4 (ITGB4) in the GEPIA database. In addition, rescue experiments were performed to determine the mechanism of SPTBN2 in endometroid ovarian cancer. ITGB4 overexpression reversed the inhibitory effects of the SPTBN2 knockdown on viability, proliferation, migration and invasion of A2780 cells (P<0.05). The impacts of SPTBN2 on the expression of focal adhesion and downstream ECM receptor signalling-related proteins, including Src and p-FAK/FAK, were significantly reversed by ITGB4 overexpression (P<0.01). Collectively, SPTBN2 may regulate endometroid ovarian cancer cell proliferation, invasion and migration through the ITGB4-mediated focal adhesion and ECM receptor signalling pathway.

Inhibition of the SLC35B2-TPST2 Axis of Tyrosine Sulfation Attenuates the Growth and Metastasis of Pancreatic Ductal Adenocarcinom

BACKGROUND & AIMS

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer deaths in the United States. Tyrosine sulfation, catalyzed by the tyrosylprotein sulfotransferase 2 (TPST2), is a post-translational modification essential for protein-protein interactions and cellular functions. Solute carrier family 35 member B (SLC35B2) is a key transporter that transports the universal sulfate donor 3'-phosphoadenosine 5'-phosphosulfate into the Golgi apparatus where the protein sulfation occurs. The goal of this study was to determine whether and how the SLC35B2-TPST2 axis of tyrosine sulfation plays a role in PDAC.

METHODS

Gene expression was analyzed in PDAC patients and mice. Human PDAC MIA PaCa-2 and PANC-1 cells were used for in vitro studies. TPST2-deficient MIA PaCa-2 cells were generated to assess xenograft tumor growth in vivo. Mouse PDAC cells derived from the KrasLSL-G12D/+;Tp53L/+;Pdx1-Cre (KPC) mice were used to generate Tpst2 knockout KPC cells to evaluate tumor growth and metastasis in vivo.

RESULTS

High expressions of SLC35B2 and TPST2 were correlated with poor PDAC patient survival. Knocking down SLC35B2 or TPST2, or pharmacologicically inhibiting sulfation, resulted in the inhibition of PDAC cell proliferation and migration in vitro. TPST2-deficient MIA PaCa-2 cells showed inhibited xenograft tumor growth. Orthotopic inoculation of Tpst2 knockout KPC cells in mice showed inhibition of primary tumor growth, local invasion, and metastasis. Mechanistically, the integrin β4 was found to be a novel substrate of TPST2. Inhibition of sulfation destabilizes integrin β4 protein, which may have accounted for the suppression of metastasis.

CONCLUSIONS

Targeting the SLC35B2-TPST2 axis of tyrosine sulfation may represent a novel approach for therapeutic intervention of PDAC.

Regulation of Kinase Signaling Pathways by α6β4-Integrins and Plectin in Prostate Cancer

Hemidesmosomes (HDs) are adhesive structures that ensure stable anchorage of cells to the basement membrane. They are formed by α6β4-integrin heterodimers and linked to intermediate filaments via plectin. It has been reported that one of the most common events during the pathogenesis of prostate cancer (PCa) is the loss of HD organization. While the expression levels of β4-integrins are strongly reduced, the expression levels of α6-integrins and plectin are maintained or even elevated, and seem to promote tumorigenic properties of PCa cells, such as proliferation, invasion, metastasis, apoptosis- and drug-resistance. In this review, we discuss the potential mechanisms of how HD components might contribute to various cellular signaling pathways to promote prostate carcinogenesis. Moreover, we summarize the current knowledge on the involvement of α6β4-integrins and plectin in PCa initiation and progression.

Activation of GRP78 ATPase suppresses A549 lung cancer cell migration by promoting ITGB4 degradation

Hypochlorous acid (HOCl) is an essential signal molecule in cancer cells. Activated GRP78 ATPase by a HOCl probe named ZBM-H inhibits lung cancer cell growth. However, the role and underlying mechanism of GRP78 ATPase in lung cancer cell migration have not been established. Here, we reported that activation of GRP78 ATPase by ZBM-H suppressed A549 cell migration and inhibited EMT process. Notably, ZBM-H time-dependently decreased the protein level of integrin β4 (ITGB4) in A549 cells. Combinatorial treatment of 3BDO (an autophagy inhibitor) and ZBM-H partially rescued the protein level of ITGB4. Consistently, 3BDO partially reversed ZBM-H-inhibited cell migration. Furthermore, ZBM-H promoted the interaction between ANXA7 and Hsc70, which participated in the regulation of selective autophagy and degradation of ITGB4.

METTL14-mediated N6-methyladenosine modification of ITGB4 mRNA inhibits metastasis of clear cell renal cell carcinoma

Background

Integrin β4 (ITGB4) participates in tumorigenesis and progression of several malignancies, but its role and related mechanisms in clear cell renal cell carcinoma (ccRCC) remain unclear.

Methods

Quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry were used to detect mRNA and protein levels of relevant genes. Biological functions of ITGB4 and methyltransferase-like 14 (METTL14) were determined by in vitro and in vivo experiments. The levels of N6-methyladenosine (m6A) in ccRCC tissues and adjacent normal tissues were calculated via total RNA m6A quantification assay. The m6A modification of ITGB4 was demonstrated via m6A RNA immunoprecipitation (MeRIP), RIP and luciferase reporter assays.

Results

ITGB4 was significantly overexpressed in ccRCC tissues and high level of ITGB4 predicted poor prognosis as well as metastasis. Functionally, ITGB4 stimulated ccRCC cell migration and invasion in vitro and metastasis in vivo with epithelial–mesenchymal transition (EMT) strengthened. Mechanically, the total levels of m6A were reduced in ccRCC tissues. METTL14, a favorable factor for ccRCC patients’ prognosis, facilitated m6A modification on ITGB4 3′UTR and subsequently accelerated ITGB4 mRNA degradation, leading to its declined expression. Furthermore, the METTL14-mediated inhibition of ITGB4 expression was dependent on the YTH domain family protein 2 (YTHDF2), which acted as an m6A reader to bind to ITGB4 mRNA and to promote its decay. In addition, we demonstrated that knockdown of METTL14 promoted ccRCC cell migration, invasiveness and metastasis as well as stimulating the EMT process and the PI3K/AKT signal by overexpressing ITGB4.

Conclusion

Our study reveals that METTL14 inhibits ITGB4 expression via m6A modification to attenuate metastasis and EMT of ccRCC cells, suggesting the METTL14/ITGB4 axis as a potential prognostic biomarker and therapeutic target for ccRCC.

Targeting ferroptosis suppresses osteocyte glucolipotoxicity and alleviates diabetic osteoporosis

Diabetic osteoporosis (DOP) is the leading complication continuously threatening the bone health of patients with diabetes. A key pathogenic factor in DOP is loss of osteocyte viability. However, the mechanism of osteocyte death remains unclear. Here, we identified ferroptosis, which is iron-dependent programmed cell death, as a critical mechanism of osteocyte death in murine models of DOP. The diabetic microenvironment significantly enhanced osteocyte ferroptosis in vitro, as shown by the substantial lipid peroxidation, iron overload, and aberrant activation of the ferroptosis pathway. RNA sequencing showed that heme oxygenase-1 (HO-1) expression was notably upregulated in ferroptotic osteocytes. Further findings revealed that HO-1 was essential for osteocyte ferroptosis in DOP and that its promoter activity was controlled by the interaction between the upstream NRF2 and c-JUN transcription factors. Targeting ferroptosis or HO-1 efficiently rescued osteocyte death in DOP by disrupting the vicious cycle between lipid peroxidation and HO-1 activation, eventually ameliorating trabecular deterioration. Our study provides insight into DOP pathogenesis, and our results provide a mechanism-based strategy for clinical DOP treatment.

A Pan-Cancer Analysis of the Oncogenic Role of Integrin Beta4 (ITGB4) in Human Tumors

Background

Integrin beta4 (ITGB4) is a transmembrane receptor that plays a key role in tumorigenesis and tumor development. However, there are no pan-cancer analyses of ITGB4.

Methods

This study demonstrates the first potential oncogenic roles of ITGB4 across 33 tumors based on the dataset of the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO).

Results

ITGB4 is highly expressed in many cancers, and distinct correlations exist between ITGB4 expression and the prognosis of tumor patients. We also found that the methylation and genetic alteration level of ITGB4 was associated with some cancer prognosis. Furthermore, we found a reduced phosphorylation of ITGB4 at S1457 in several tumors, such as breast and ovarian cancers. Finally, ITGB4 expression was correlated with cancer-associated fibroblasts in liver hepatocellular carcinoma and prostate adenocarcinoma, and the infiltration level of NK cells and neutrophils was observed in other cancers, such as breast invasive carcinoma and lung adenocarcinoma. Moreover, RNA metabolism and protein processing-associated functions are involved in the functional mechanism of ITGB4.

Conclusion

Our first pan-cancer study may offer a relatively comprehensive understanding of the oncogenic roles of ITGB4 across different tumors.

Roles of Integrins in Gastrointestinal Cancer Metastasis

Integrins are a large family of heterodimeric transmembrane receptors which mediate cell adhesion and transmit signals to the cell interior. The mechanistic roles of integrins have long been an enigma in cancer, given its complexity in regulating different cellular behaviors. Recently, however, increasing research is providing new insights into its function and the underlying mechanisms, which collectively include the influences of altered integrin expression on the aberrant signaling pathways and cancer progression. Many studies have also demonstrated the potentiality of integrins as therapeutic targets in cancer treatment. In this review, we have summarized these recent reports and put a particular emphasis on the dysregulated expression of integrins and how they regulate related signaling pathways to facilitate the metastatic progression of gastrointestinal cancer, including gastric cancer (GC) and colorectal cancer (CRC), which will address the crucial roles of integrins in gastrointestinal cancer.

Synthetic Evaluation of MicroRNA-1-3p Expression in Head and Neck Squamous Cell Carcinoma Based on Microarray Chips and MicroRNA Sequencing

Background

MicroRNA-1-3p (miR-1-3p) exerts significant regulation in various tumor cells, but its molecular mechanisms in head and neck squamous cell carcinoma (HNSCC) are still ill defined. This study is aimed at detecting the expression of miR-1-3p in HNSCC and at determining its significant regulatory pathways.

Methods

Data were obtained from the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), Oncomine, ArrayExpress, Sequence Read Archive (SRA) databases, and additional literature. Expression values of miR-1-3p in HNSCC were analyzed comprehensively. The R language software was employed to screen differentially expressed genes, and bioinformatics assessment was performed. One sequence dataset (HNSCC: n = 484; noncancer: n = 44) and 18 chip datasets (HNSCC: n = 656; noncancer: n = 199) were obtained.

Results

The expression of miR-1-3p in HNSCC was visibly decreased in compare with noncancerous tissues. There were distinct differences in tumor state (P = 0.0417), pathological stage (P = 0.0058), and T stage (P = 0.0044). Comprehensive analysis of sequence and chip data also indicated that miR-1-3p was lowly expressed in HNSCC. The diagnostic performance of miR-1-3p in HNSCC is reflected in the sensitivity and specificity of the collection, etc. Bioinformatics analysis showed the possible biological process, cellular component, molecular function, and KEGG pathways of miR-1-3p in HNSCC. And ITGB4 was a possible target of miR-1-3p.

Conclusions

miR-1-3p's low expression may facilitate tumorigenesis and evolution in HNSCC through signaling pathways. ITGB4 may be a key gene in targeting pathways but still needs verification through in vitro experiments.

ITGB4 as a novel serum diagnosis biomarker and potential therapeutic target for colorectal cancer

Purpose

To develop new and effective biomarkers for the diagnosis of colorectal cancer (CRC).

Experimental design

The serum expression of ITGB4 (49 CRC and 367 HC) was detected by enzyme‐linked immunosorbent assay (ELISA), and its diagnostic value was analyzed using the receiver operating characteristic (ROC) curve. The sensitivity and specificity of ITGB4 in CRC diagnosis were calculated through statistical analysis. The optimal clinical cutoff value was calculated using the Youden index, and diagnostic efficacy was analyzed in a larger serum sample (98 CRC and 1631 non‐CRC). The expression of ITGB4 was measured by CyTOF (cell experimental technology) at the single‐cell level, and characteristics were analyzed using viSNE and SPADE TREE.

Results

Serum ITGB4 and CEA levels were significantly higher in CRC patients than in HC and non‐CRC patients. The use of serum ITGB4 levels for the diagnosis of CRC has a high sensitivity (79%) but not high specificity when the clinical cutoff value was 0.70 ng/mL. However, the optimal cutoff value was 1.6 ng/mL with 86.2% specificity and 52.0% sensitivity, and the diagnostic efficacy was greatly improved with high specificity (82.0%) and sensitivity (71.4%) when combined with CEA. ITGB4 expression characteristics were measured and related to the expression of EpCAM, Ck8/18, and perforin at the single‐cell level. Single‐cell analysis showed that cell clusters with low expression of CK8/18 and ITGB4 were more sensitive to 5FU and radiotherapy (RT).

Conclusions

ITGB4 is an effective diagnostic serum biomarker and a potential therapeutic target for CRC.

MicroRNA-328-3p facilitates the progression of gastric cancer via KEAP1/NRF2 axis

Gastric cancer is a common lethal malignancy and causes great cancer-related mortality worldwide. MicroRNA (miR)-328-3p is implicated in the progression of various human cancers; however, its role and mechanism in the progression of gastric cancer remain unclear.Human gastric cancer cells were incubated with miR-328-3p mimic, inhibitor or the matched negative control. Cell viability, colony formation, migrative and invasive capacity, cell apoptosis and oxidative stress were measured. To clarify the involvement of nuclear factor-E2-related factor 2 (NRF2) and kelch-like ECH-associated protein 1 (KEAP1), small interfering RNA was used. miR-328-3p was upregulated in human gastric cancer cells and tissues, and its level positively correlated with the progression of gastric cancer. miR-328-3p promoted cell viability, colony formation, migration and invasion, thereby facilitating the progression of gastric cancer. miR-328-3p mimic reduced, while miR-328-3p inhibitor increased apoptosis and oxidative stress of human gastric cancer cells. Mechanistically, miR-328-3p upregulated NRF2 via targeting KEAP1to attenuate excessive free radical production and cell apoptosis. miR-328-3p functions as an oncogenic gene and inhibiting miR-328-3p may help to develop novel therapeutic strategies of human gastric cancer.

Immune Infiltration Subtypes Characterization and Identification of Prognosis-Related lncRNAs in Adenocarcinoma of the Esophagogastric Junction

The incidence of adenocarcinoma of the esophagogastric junction (AEG) has markedly increased worldwide. However, the precise etiology of AEG is still unclear, and the therapeutic options thus remain limited. Growing evidence has implicated long non-coding RNAs (lncRNAs) in cancer immunomodulation. This study aimed to examine the tumor immune infiltration status and assess the prognostic value of immune-related lncRNAs in AEG. Using the ESTIMATE method and single-sample GSEA, we first evaluated the infiltration level of 28 immune cell types in AEG samples obtained from the TCGA dataset (N=201). Patients were assigned into high- and low-immune infiltration subtypes based on the immune cell infiltration’s enrichment score. GSEA and mutation pattern analysis revealed that these two immune infiltration subtypes had distinct phenotypes. We identified 1470 differentially expressed lncRNAs in two immune infiltration subtypes. From these differentially expressed lncRNAs, six prognosis-related lncRNAs were selected using the Cox regression analysis. Subsequently, an immune risk signature was constructed based on combining the values of the six prognosis-associated lncRNAs expression levels and multiple regression coefficients. To determine the risk model’s prognostic capability, we performed a series of survival analyses with Kaplan–Meier methods, Cox proportional hazards regression models, and the area under receiver operating characteristic (ROC) curve. The results indicated that the immune-related risk signature could be an independent prognostic factor with a significant predictive value in patients with AEG. Furthermore, the immune-related risk signature can effectively predict the response to immunotherapy and chemotherapy in AEG patients. In conclusion, the proposed immune-related lncRNA prognostic signature is reliable and has high survival predictive value for patients with AEG and is a promising potential biomarker for immunotherapy.

Effects of propofol and sevoflurane on tumor killing activity of peripheral blood natural killer cells in patients with gastric cancer

Objective

This study aimed to investigate the effects of propofol and sevoflurane on cytotoxicity of natural killer (NK) cells in patients with gastric cancer.

Methods

Patients with gastric cancer were anesthetized by propofol or sevoflurane. Peripheral blood NK cells were isolated and co-cultured with BGC-823 gastric cancer cell culture supernatant, and the rate of apoptosis and effector molecules were analyzed by flow cytometry. Effects of propofol and sevoflurane on NK cell function and SMAD4 protein expression were investigated.

Results

Cytotoxicity of NK cells in patients with gastric cancer was inhibited before surgery, but it was enhanced in patients who were anesthetized by propofol compared with those who had sevoflurane. In vitro co-culture with BGC-823 cells significantly inhibited the cytotoxicity of NK cells, which was abolished by treatment of propofol or transforming growth factor (TGF)-β1. SMAD4 protein expression in the NK cell nucleus was significantly downregulated by TGF-β1 treatment and BGC-823 supernatant co-culture, and this expression could be restored by propofol.

Conclusions

Cytotoxicity of NK cells in patients with gastric cancer is low, but it can be promoted by propofol. Propofol regulates cytotoxicity in NK cells by promoting SMAD4, thereby affecting cellular function.

Astrocytes increase exosomal secretion of oligodendrocyte precursor cells to promote their proliferation via integrin β4-mediated cell adhesion

Many degenerative diseases of the central nervous system (CNS) are associated with demyelination. Oligodendrocyte precursor cells (OPCs) are potential stem cells that can differentiate into oligodendrocytes (OLs) and promote myelination. Promoting the proliferation of OPCs is key to stimulating remyelination and treating neurodegenerative diseases. Herein, we report that astrocytes (ASTs) could increase exosomal secretion of OPCs to promote their proliferation via ITGB4-mediated cell adhesion. Our results demonstrate that ASTs can regulate the proliferation of OPCs through ITGB4-mediated exosomal secretion. OPC proliferation is significantly increased after direct-contact culture with ASTs. Gene ontology (GO) and KEGG pathway analyses reveal that ITGB4/extracellular exosome are closely related to OPC proliferation. siRNA ITGB4 decreases exosomal secretion and OPC proliferation. ITGB4/exosomes remarkably promote OPC transition from G1 to S phase. Furthermore, exosomes can alleviate the inhibitory effect of ITGB4 knockdown on OPC proliferation. Collectively, ASTs regulate OPC exosomal secretion via ITGB4, which could be a valuable approach for promoting OPC proliferation. This strategy may represent a potential treatment for neurological diseases caused by demyelination.

The clinical significance and potential molecular mechanism of integrin subunit beta 4 in laryngeal squamous cell carcinoma

The relationship between integrin beta 4 (ITGB4) expression and laryngeal squamous cell carcinoma (LSCC) remains unclarified. The object of the present study was to explore the clinical significance and potential molecular mechanism of ITGB4 in LSCC. The protein level of ITGB4 was significantly higher in 46 LSCC patients than in 26 non-LSCC tissues detected by in-house immunohistochemistry. Consistently, ITGB4 mRNA level was also greatly upregulated based on microarray and RNA-seq data (standard mean difference, SMD = 1.62, 95 % CI: 1.23-2.00). And the area under curves (AUC) of summary receiver operator characteristic (SROC) was 0.87 (95 % CI: 0.84-0.90) based on 172 cases of LSCC and 59 cases of non-cancerous controls. Ninety genes were intersected by the ITGB4 related genes and LSCC differential expressed genes (DEGs) from all available microarray and RNA-seq datasets. Based on Gene Ontology (GO) analysis, the top terms of biological process (BP), cellular component (CC) and molecular function (MF) for the 90 ITGB4 related DEGs were extracellular matrix organization, basement membrane and extracellular matrix structural constituent, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that ITGB4 related DEGs mainly participated in the pathways of ECM-receptor interaction, Focal adhesion and Small cell lung cancer. Moreover, the Protein-Protein Interaction (PPI) network indicated that ITGA3, ITGA5, ITGB4, MET, LAMA3, and COL4A1 might be the core genes of LSCC development related to ITGB4. In conclusion, high ITGB4 expression may lead to the occurrence and development of LSCC via various signaling pathways.

MiR-876-5p regulates gastric cancer cell proliferation, apoptosis and migration through targeting WNT5A and MITF

MicroRNAs (miRNAs) are reported to play critical roles in various cancers. Recently, mounting miRNAs are found to exert oncogenic or tumor inhibitory role in gastric cancer (GC), however, their potential molecular mechanism in GC remains ill-defined. Currently, we aimed to elucidate the functional and mechanistic impacts of a novel miRNA on GC cellular process. The significant down-regulation of miR-876-5p in GC cells attracted our attention. In function, we performed gain-of-function assays and found that miR-876-5p overexpression repressed proliferative, anti-apoptotic and migratory abilities and epithelial-mesenchymal transition (EMT) of GC cells. By applying bioinformatics prediction and mechanism experiments, we verified that miR-876-5p could double-bind to the 3' untranslated regions (3'UTRs) of Wnt family member 5A (WNT5A) and melanogenesis associated transcription factor (MITF), thus regulating their mRNA and protein levels. Both WNT5A and MITF were highly expressed in GC cells. Additionally, we conducted loss-of-function assays and confirmed the oncogenic roles of WNT5A and MITF in GC. Finally, rescue assay uncovered a fact that miR-876-5p suppressed GC cell viability and migration, but induced cell apoptosis via targeting WNT5A and MITF. Taken together, we might offer a valuable evidence for miR-876-5p role in GC development.

Reciprocal regulation of integrin β4 and KLF4 promotes gliomagenesis through maintaining cancer stem cell traits

BACKGROUND

The dismal prognosis of patients with glioma is largely attributed to cancer stem cells that display pivotal roles in tumour initiation, progression, metastasis, resistance to therapy, and relapse. Therefore, understanding how these populations of cells maintain their stem-like properties is critical in developing effective glioma therapeutics.

METHODS

RNA sequencing analysis was used to identify genes potentially involved in regulating glioma stem cells (GSCs). Integrin β4 (ITGB4) expression was validated by quantitative real-time PCR (qRT-PCR) and immunohistochemical (IHC) staining. The role of ITGB4 was investigated by flow cytometry, mammosphere formation, transwell, colony formation, and in vivo tumorigenesis assays. The reciprocal regulation between Integrin β4 and KLF4 was investigated by chromatin immunoprecipitation (ChIP), dual-luciferase reporter assay, immunoprecipitation, and in vivo ubiquitylation assays.

RESULTS

In this study, we found that ITGB4 expression was increased in GSCs and human glioma tissues. Upregulation of ITGB4 was correlated with glioma grades. Inhibition of ITGB4 in glioma cells decreased the self-renewal abilities of GSCs and suppressed the malignant behaviours of glioma cells in vitro and in vivo. Further mechanistic studies revealed that KLF4, an important transcription factor, directly binds to the promoter of ITGB4, facilitating its transcription and contributing to increased ITGB4 expression in glioma. Interestingly, this increased expression enabled ITGB4 to bind KLF4, thus attenuating its interaction with its E3 ligase, the von Hippel-Lindau (VHL) protein, which subsequently decreases KLF4 ubiquitination and leads to its accumulation.

CONCLUSIONS

Collectively, our data indicate the existence of a positive feedback loop between KLF4 and ITGB4 that promotes GSC self-renewal and gliomagenesis, suggesting that ITGB4 may be a valuable therapeutic target for glioma.