DUSP4 maintains the survival and LSD1 protein stability in esophageal squamous cell carcinoma cells by inhibiting JNK signaling-dependent autophagy.

DUSP4 is a biomarker of esophageal squamous cell carcinoma (ESCC), which is responsible for the prognosis in ESCC. However, the underlying mechanism of DUSP4-regulated ESCC carcinogenesis is unknown. As a negative regulator of JNK, DUSP4 can inhibit autophagy, which contributes to tumorigenesis. This study aimed to explore the role of autophagy in DUSP4-regulated ESCC carcinogenesis. Our results showed that DUSP4 overexpression inhibited autophagy and promoted LSD1 protein expression in ESCC cells, while DUSP4 silencing showed the opposite effects. However, DUSP4 overexpression and silencing did not affect LSD1 mRNA expression. But the regulatory ability of DUSP4 overexpression on autophagy, death level, and LSD1 protein was reversed by rapamycin. In addition, DUSP4 overexpression inhibited JNK and Bcl2 phosphorylation and the dissociation of Bcl2-Beclin1 complex, while DUSP4 silencing promoted JNK and Bcl2 phosphorylation. Moreover, the regulatory ability of DUSP4 overexpression on autophagy, death, and LSD1 protein was reversed by JNK activator anisomycin. The xenograft assays also showed that DUSP4 overexpression-promoted ESCC tumor growth in vivo and LC3II and LSD1 protein expression in tumor tissues were reversed by rapamycin or anisomycin. Overall, DUSP4 inhibits Bcl2-Beclin1-autophagy signal transduction through the negative regulation of JNK, thus suppressing autophagic death and the autophagic degradation of LSD1 in ESCC, by which DUSP4 promotes ESCC carcinogenesis.

[Retracted] MicroRNA­139­5p inhibits cell viability, migration and invasion and suppresses tumor growth by targeting HDGF in non­small cell lung cancer.

[This retracts the article DOI: 10.3892/ol.2020.11296.].

A one-step aptasensor for ultrasensitive detection of lung cancer marker homocysteine based on multifunctional carbon nanotubes by square-wave voltammetry.

In this work, a one-step aptasensor for ultrasensitive detection of homocysteine (HCY) is developed based on multifunctional carbon nanotubes, which is magnetic multi-walled carbon nanotubes (Fe3O4@MWCNTs) combined with the aptamer (Apt) for HCY (Fe3O4@MWCNTs-Apt). Fe3O4@MWCNTs-Apt have multiple functions as follows. (1) Apt immobilized could selectively capture all target molecules HCY in the sample; (2) Magnetic Fe3O4 nanoparticles could separate all target molecules HCY captured by Apt from the sample substrate to eliminate the background interference and achieve one-step preparation of the aptasensor; And (3), MWCNTs with good electrical conductivity become a new electrode surface, construct a three-dimensional electrode surface network, make the electron transfer easier and thus then enhance the signal response. Results show that there is a good linear relationship between peak current of square-wave voltammetry (SWV) and HCY concentration in the range of 0.01 µmol/L-1 µmol/L, with a limit of detection (LOD) 0.002 µmol/L. And, selectivity, reproducibility, precision and accuracy are all satisfactory. In addition, it could be applied to the detection of HCY in the plasma of lung cancer patients successfully, suggesting that this one-step aptasensor for HCY has a potential in practical clinical applications.

Role of exosomes in non-small cell lung cancer and EGFR-mutated lung cancer.

As an important mediator of information transfer between cells, exosomes play a unique role in regulating tumor growth, supporting vascular proliferation, tumor invasion, and metastasis. Exosomes are widely present in various body fluids, and therefore they can be used as a potential tool for non-invasive liquid biopsy. The present study reviews the role of exosomes in liquid biopsy, tumor microenvironment formation, and epithelial-mesenchymal transition in non-small cell lung cancer (NSCLC). By targeting epidermal growth factor receptor (EGFR) therapy as a first-line treatment for patients with NSCLC, this study also briefly describes the occurrence of EGRF+ exosomes and the role of exosomes and their contents in non-invasive detection and potential therapeutic targets in EGFR-mutated lung cancer.

Role of exosomal noncoding RNA in esophageal carcinoma.

Esophageal cancer is a common malignant tumor with a high degree of malignancy. Understanding its pathogenesis and identifying early diagnostic biomarkers can significantly improve the prognosis of esophageal cancer patients. Exosomes are small double-membrane vesicles found in various body fluids containing various components (DNA, RNA, and proteins) that mediate intercellular signal communication. Non-coding RNAs are a class of gene transcription products that encode polypeptide functions and are widely detected in exosomes. There is growing evidence that exosomal non-coding RNAs are involved in cancer growth, metastasis and angiogenesis, and can also be used as diagnostic and prognostic markers. This article reviews the recent progress in exosomal non-coding RNAs in esophageal cancer, including research progress, diagnostic value, proliferation, migration, invasion, and drug resistance, provide new ideas for the precise treatment of esophageal cancer.

APOC1 predicts a worse prognosis for esophageal squamous cell carcinoma and is associated with tumor immune infiltration during tumorigenesis.

Background: Esophageal carcinoma (ESCA), a common malignant tumor of the digestive tract with insidious onset, is a serious threat to human health. Despite multiple treatment modalities for patients with ESCA, the overall prognosis remains poor. Apolipoprotein C1 (APOC1) is involved in tumorigenesis as an inflammation-related molecule, and its role in esophageal cancer is still unknown. Methods: We downloaded documents and clinical data using The Cancer Genome Atlas (TCGA)and Gene Expression Omnibus (GEO) databases. We also conducted bioinformatics studies on the diagnostic value, prognostic value, and correlation between APOC1 and immune infiltrating cells in ESCA through STRING (https://cn.string-db.org/), the TISIDB (http://cis.hku.hk/TISIDB/) website, and various other analysis tools. Results: In patients with ESCA, APOC1 was significantly more highly expressed in tumor tissues than in normal tissues (p < 0.001). APOC1 could diagnose ESCA more accurately and determine the TNM stage and disease classification with high accuracy (area under the curve, AUC≥0.807). The results of the Kaplan-Meier curve analysis showed that APOC1 has prognostic value for esophageal squamous carcinoma (ESCC) (p = 0.043). Univariate analysis showed that high APOC1 expression in ESCC was significantly associated with worse overall survival (OS) (p = 0.043), and multivariate analysis shows that high APOC1 expression was an independent risk factor for the OS of patients with ESCC (p = 0.030). In addition, the GO (gene ontology)/KEGG (Kyoto encyclopedia of genes and genomes) analysis showed a concentration of gene enrichment in the regulation of T-cell activation, cornification, cytolysis, external side of the plasma membrane, MHC protein complex, MHC class II protein complex, serine-type peptidase activity, serine-type endopeptidase activity, Staphylococcus aureus infection, antigen processing and presentation, and graft-versus-host disease (all p < 0.001). GSEA (gene set enrichment analysis) showed that enrichment pathways such as immunoregulatory-interactions between a lymphoid and non-lymphoid cell (NES = 1.493, p. adj = 0.023, FDR = 0.017) and FCERI-mediated NF-KB activation (NES = 1.437, p. adj = 0.023, FDR = 0.017) were significantly enriched in APOC1-related phenotypes. In addition, APOC1 was significantly associated with tumor immune infiltrating cells and immune chemokines. Conclusion: APOC1 can be used as a prognostic biomarker for esophageal cancer. Furthermore, as a novel prognostic marker for patients with ESCC, it may have potential value for further investigation regarding the diagnosis and treatment of this group of patients.

Application of extracellular vesicles proteins in cancer diagnosis.

Early tumor diagnosis is crucial for its treatment and reduction of death, with effective tumor biomarkers being important tools. Extracellular vesicles (EVs) are small vesicles secreted by cells with various biomolecules, including proteins, nucleic acids, and lipids. They harbor a double membrane structure. Previous studies on EVs in cancer diagnosis and therapy focused on miRNAs. Nonetheless, EVs contain proteins that represent physiological and pathological state of their parental cells. EVs proteins can reflect the pathological state of some diseases, which provides a basis for diagnosis and treatment. This study describes the role of EVs in cancer and summarizes the use of EVs proteins as diagnostic markers in different cancer types. Specifically, we discuss the potential and shortcomings of EVs as tumor biomarkers.

Transcription factor Nrf2 binds to circRNAPIBF1 to regulate SOD2 in lung adenocarcinoma progression.

Emerging evidence indicates that circular RNAs (circRNAs) play important roles in disease development, especially in cancers. Analysis of circRNA expression microarrays from the Gene Expression Omnibus database revealed that circPIBF1 was highly upregulated in lung adenocarcinoma (LUAD). The main aim of this study was to probe the function of circPIBF1 in pyroptosis of LUAD cells and the signal transduction pathways involved. CircPIBF1 was significantly overexpressed in LUAD and was related to the dismal prognosis of patients with LUAD. CircPIBF1 could bind to nuclear factor erythroid 2-related factor 2 (Nrf2), which further promoted the expression of superoxide dismutase 2 (SOD2). In addition, Nrf2 was also observed to recruit histone acetyltransferase E1A binding protein p300 (EP300) to enhance H3K27ac modification of SOD2, thus modulating the Nrf2-Keap1 signaling pathway. Moreover, we found that knockdown of circPIBF1 significantly suppressed the expression of SOD2 in cells and LUAD cell growth, while enhanced the expression of pyroptosis-related factors, which were further reversed by overexpression of SOD2 or EP300. Collectively, our findings suggest a direct involvement of circPIBF1 in pyroptosis-related LUAD carcinogenesis and implicate a role of Nrf2/EP300/SOD2 signaling in this process.

CircFBXW7 Inhibits Proliferation, Migration, and Invasion of Nonsmall Cell Lung Cancer Cells by Regulating miR-492.

Background: CircFBXW7 has been determined to be involved in various cancers; however, its role in nonsmall cell lung cancer (NSCLC) remains unclear. This study examined the function and potential mechanism of circFBXW7 in NSCLC. Methods: The structure of circFBXW7 was verified via RT-PCR and Sanger sequencing. The expression of circFBXW7 in NSCLC was determined by qRT-PCR. The effect of circFBXW7 overexpression on the proliferation, migration, and invasion of NSCLC cells was examined by CCK-8 and Transwell assays. Furthermore, a circFBXW7-miRNA network was established to explore their interaction. Predicted miRNA was determined by qRT-PCR. Moreover, the miRNA mimics were synthesized, wherein its effect on proliferation, migration, and invasion of NSCLC cells overexpressed circFBXW7 was assessed. Results: The circularity of circFBXW7 was verified. The expression of circFBXW7 was found to be downregulated in NSCLC cells compared with that in normal human lung epithelial BEAS-2B cells. Overexpression of circFBXW7 reduced cell proliferation, migration, and invasion. Furthermore, according to the circFBXW7-miRNA network prediction and qRT-PCR validation, miR-492 was identified to be the target of circFBXW7. The inhibitory effect of circFBXW7 overexpression on cell proliferation, migration, and invasion was reversed by miR-492 mimics. Conclusion: CircFBXW7 is downregulated in NSCLC. CircFBXW7 inhibits NSCLC cells proliferation, migration, and invasion by regulating miR-492.

miR-181a-5p restrains non-small cell lung cancer cell invasion and migration by regulating the GTSE1/p53/NF-κB axis.

microRNAs (miRNAs) are relevant to metastasis and invasion of non-small cell lung cancer (NSCLC). This study investigated the role of miR-181a-5p in lung cancer. Expression patterns of miR-181a-5p and GTSE1 in the human NSCLC cell line A549 and normal lung epithelial cell line BASE-2B were detected. miR-181a-5p mimic was delivered into A549 cells utilizing Lipofectamine 2000 to overexpress miR-181a-5p, followed by analysis of cell viability, proliferation, apoptosis, invasion, and migration. GTSE1 (G2 and S phase-expressed-1) was predicted as the downstream target gene of miR-181a-5p using bioinformatics analysis software. Targeting relationship between miR-181a-5p and GTSE1 was validated via dual-luciferase assay, RIP assay, and RNA pull-down. Activation of the p53/NF-κB pathway was determined. miR-181a-5p was weakly-expressed in NSCLC cells relative to normal lung epithelial cells. miR-181a-5p overexpression prevented NSCLC cell proliferation, migration, and invasion. Mechanically, miR-181a-5p targeted GTSE1. GTSE1 overexpression partly annulled repression of miR-181a-5p overexpression on NSCLC cell malignant behavior. miR-181a-5p activated the p53 pathway and inhibited the NF-κB pathway by targeting GTSE1. Overall, this study for the first time validated that miR-181a-5p impeded NSCLC cell invasion and migration through activation of the p53 pathway and inhibition of the NF-κB pathway by targeting GTSE1, which may provide a potential novel insight into NSCLC treatment.

Low expression of miR-27b in serum exosomes of non-small cell lung cancer facilitates its progression by affecting EGFR.

Non-small cell lung cancer (NSCLC) is a malignant tumor. Serum exosomal miR-27b is related to tumor diagnosis. We explored the roles of serum exosomal miR-27b in NSCLC. NSCLC patients were assigned to NSCLC-early/terminal groups, with healthy subjects as controls. miR-27b expression was assessed using reverse transcription-quantitative polymerase chain reaction, and its diagnostic efficiency was analyzed using the receiver operating characteristic curve. The correlation between serum exosomal miR-27b expression and tumor markers carcinoembryonic antigen 125 (CA125), carcinoembryonic antigen (CEA), and cytokeratin 19-soluble fragment (CYFRA21-1) was analyzed using the Pearson analysis. The downstream target genes were predicted. Epidermal growth factor receptor (EGFR) level was assessed using enzyme-linked immunosorbent assay. Correlations of miR-27b expression with serum EGFR level and CA125, CEA, and CYFRA21-1 levels were analyzed using the Pearson analysis. Serum exosomal miR-27b was diminished in NSCLC and was further decreased in the NSCLS-terminal group. The sensitivity of miR-27b < 0.8150 for NSCLC diagnosis was 76.64%, and the specificity was 83.33%. Serum exosomal miR-27b was negatively correlated with CA125, CEA, and CYFRA21-1. miR-27b targeted EGFR. Serum EGFR was raised in NSCLC and was further elevated in the NSCLS-terminal group. miR-27b expression was negatively correlated with EGFR level. EGFR level was positively correlated with CA125, CEA, and CYFRA21-1 levels. Collectively, low expression of miR-27b assisted NSCLC diagnosis, and miR-27b exerted effects on NSCLC through EGFR.

miR-666-3p Mediates the Protective Effects of Mesenchymal Stem Cell-derived Exosomes Against Oxygen-glucose Deprivation and Reoxygenation- induced Cell Injury in Brain Microvascular Endothelial Cells via Mitogen-activated Protein Kinase Pathway.

BACKGROUND: Previous studies have reported that mesenchymal stem cell (MSC)- derived exosomes can protect primary rat brain microvascular endothelial cells (BMECs) against oxygen-glucose deprivation and reoxygenation (OGD/R)-induced injury. OBJECTIVE: The aim was to identify the key factors mediating the protective effects of MSC-derived exosomes. METHODS: Primary rat BMECs were either pretreated or not pretreated with MSC-derived exosomes before exposure to OGD/R. Naïve cells were used as a control. After performing small RNA deep sequencing, quantitative reverse transcription polymerase chain reaction was performed to validate microRNA (miRNA) expression. The effects of rno-miR-666-3p on cell viability, apoptosis, and inflammation in OGD/R-exposed cells were assessed by performing the Cell Counting Kit 8 assay, flow cytometry, and enzyme-linked immunosorbent assay, respectively. Moreover, the role of rno-miR-666-3p in regulating gene expression in OGD/R-exposed cells was studied using mRNA deep sequencing. Lastly, to evaluate whether mitogen-activated protein kinase 1 (MAPK1) was the target of rno-miR-666-3p, western blotting and the dual-luciferase assay were performed. RESULTS: MSC-derived exosomes altered the miRNA expression patterns in OGD/R-exposed BMECs. In particular, the expression levels of rno-miR-666-3p, rno-miR-92a-2-5p, and rnomiR- 219a-2-3p decreased in OGD/R-exposed cells compared with those in the control; however, MSC-derived exosomes restored the expression levels of these miRNAs under OGD/R conditions. rno-miR-666-3p overexpression enhanced cell viability and alleviated the apoptosis of OGD/R-exposed cells. Moreover, rno-miR-666-3p suppressed OGD/R-induced inflammation. mRNA deep sequencing revealed that rno-miR-666-3p is closely associated with the MAPK signaling pathway. Western blotting and the dual-luciferase assay confirmed that MAPK1 is the target of rnomiR- 666-3p. CONCLUSION: MSC-derived exosomes restore rno-miR-666-3p expression in OGD/R-exposed BMECs. Moreover, this specific miRNA exerts protective effects against OGD/R by suppressing the MAPK signaling pathway.

Advances in Mesenchymal Stem Cell-Derived Exosomes as Drug Delivery Vehicles.

Exosomes are tiny vesicles with a double membrane structure that cells produce. They range in diameter from 40 to 150 nm and may contain a variety of biomolecules including proteins and nucleic acids. Exosomes have low toxicity, low immunogenicity, and the ability to encapsulate a wide variety of substances, making them attractive drug delivery vehicles. MSCs secrete large amounts of exosomes and hence serve as an excellent source of exosomes. MSCs-derived exosomes have regenerative and tissue repair functions comparable to MSCs and can circumvent the risks of immune rejection and infection associated with MSC transplantation, indicating that they may be a viable alternative to MSCs' biological functions. In this review, we summarized the drug delivery methods and advantages of exosomes, as well as the advancement of MSC exosomes as drug carriers. The challenges and prospects of using exosomes as drug delivery vectors are presented.

MicroRNA-139-5p inhibits cell viability, migration and invasion and suppresses tumor growth by targeting HDGF in non-small cell lung cancer.

MicroRNA (miRNAs) serve key roles in the progress of various types of cancer. The expression of miRNA (miR)-139-5p is downregulated in several types of tumor and has been recognized as a tumor suppressor. However, the role of miR-139-5p in non-small cell lung cancer (NSCLC) has not been investigated in detail. In the present study, it was demonstrated that miR-139-5p was significantly downregulated in NSCLC cells and tissues, and the overexpression of miR-139-5p in vitro induced apoptosis and significantly inhibited the viability and proliferation of A549 and H1299 cells. In addition, upregulation of miR-139-5p significantly inhibited the migration and invasion of A549 and H1299 cells. Hepatoma-derived growth factor (HDGF) was identified as a direct target of miR-139-5p. Rescue experiments demonstrated that the inhibitory function of miR-139-5p on cell viability, migration and invasion was partially mediated by suppressing HDGF expression. Furthermore, miR-139-5p exhibited efficient inhibition of tumor growth in a xenograft tumor mouse model of A549 cells. In summary, the results from the present study suggested that miR-139-5p may serve an important role in NSCLC by targeting HDGF and causing inhibition of cell viability and metastasis, as well as induction of apoptosis. miR-139-5p may also have the potential to serve as a therapeutic target for the treatment of NSCLC.

Mesenchymal Stem Cell-derived Exosomes Rescue Oxygen-Glucose Deprivation-induced Injury in Endothelial Cells.

OBJECTIVE: The effects of mesenchymal stem cell (MSC)-derived exosomes on brain microvascular endothelial cells under oxygen-glucose deprivation (OGD), which mimic cells in deep hypothermic circulatory arrest (DHCA) in vitro, are yet to be studied. METHODS: MSCs were co-cultured with primary rat brain endothelial cells, which were then exposed to OGD. Cell viability, apoptosis, the inflammatory factors (IL-1ß, IL-6, and TNF-α), and the activation of inflammation-associated TLR4-mediated pyroptosis and the NF-κB signaling pathway were determined. Furthermore, exosomes derived from MSCs were isolated and incubated with endothelial cells to investigate whether the effect of MSCs is associated with MSCderived exosomes. Apoptosis, cell viability, and the inflammatory response were also analyzed in OGD-induced endothelial cells incubated with MSC-derived exosomes. RESULTS: OGD treatment promoted endothelial cell apoptosis, induced the release of inflammatory factors IL-1ß, IL-6, and TNF-α, and inhibited cell viability. Western blot analysis showed that OGD treatment-induced TLR4, and NF-κB p65 subunit phosphorylation and caspase-1 upregulation, while co-culture with MSCs could reduce the effect of OGD treatment on endothelial cells. As expected, the effect of MSC-derived exosomes on OGD-treated endothelial cells was similar to that of MSCs. MSC-derived exosomes alleviated the OGD-induced decrease in the viability of endothelial cells, and increased levels of apoptosis, inflammatory factors, and the activation of inflammatory and inflammatory focal pathways. CONCLUSION: Both MSCs and MSC-derived exosomes attenuated OGD-induced rat primary brain endothelial cell injury. These findings suggest that MSC-derived exosomes mediate at least some of the protective effects of MSCs on endothelial cells.

Knockdown of lncRNA MIAT inhibits proliferation and cisplatin resistance in non-small cell lung cancer cells by increasing miR-184 expression.

Accumulating evidence has demonstrated the important role of long non-coding RNA myocardial infarction-associated transcript (MIAT) in tumorigenesis as a potential oncogene. However, the function of MIAT in non-small cell lung cancer (NSCLC) has yet to be completely elucidated. The present study demonstrated that MIAT expression was significantly upregulated in NSCLC tissues, particularly in aggressive cases, and was highly associated with a poor prognosis. In addition, the upregulated expression of MIAT was observed in cisplatin (CDDP)-resistant H1299 cells. Knockdown of MIAT inhibited the proliferation of NSCLC cells and enhanced the sensitivity of NSCLC cells to CDDP in vitro and in vivo. Further functional analysis demonstrated that MIAT partially exerted its oncogenic effect by upregulating the expression of splicing factor 1 (SF1), by serving as a microRNA (miR)-184 sponge. In conclusion, the present study identified that MIAT functions as a competitive endogenous RNA of miR-184to modulate SF1 expression in NSCLC, which provides a novel insight into the potential therapeutic application of MIAT in NSCLC progression.