MiR-937-3p promotes metastasis and angiogenesis and is activated by MYC in lung adenocarcinoma.

BACKGROUND: Non-small cell lung cancer (NSCLC) is still one of the diseases with the highest mortality and morbidity, and lung adenocarcinoma (LUAD) accounts for more than half of all NSCLC cases in most countries. miRNA can be used as a potential biological marker and treatment for lung adenocarcinoma. However, the effect of miR-937-3p to the invasion and metastasis of LUAD cells is not clear. METHODS: miRNA microarray is used to analyze the expression of miRNA in lung adenocarcinoma tissue. Transwell migration, Wound-healing assay and Western blot analysis are used to analyze cell migration, invasion and epithelial-mesenchymal transition (EMT) capabilities. Tube formation is used to assess angiogenesis ability. In addition, dual luciferase reporter gene detection is used to identify the potential binding between miRNA and target mRNA. In vivo experiments were performed on male NOD/SCID nude mice by tail vein injection to establish a transplanted tumor model. The CHIP experiment is used to verify the transcription factors of miRNA. RESULT: In our study, miR-937-3p was high-regulated in LUAD cell lines and tissues, and its expression level was related to tumor progression. We found that miR-937-3p high-expression has an effect on cell invasion and metastasis. In molecular mechanism, miR-937-3p causes SOX11 reduction by directly binding to the 3'-UTR of SOX11.In addition, MYC affects miR-937-3p transcription by binding to its promoter region. CONCLUSIONS: Our research shows that miR-937-3p is mediated by MYC and can control the angiogenesis, invasion and metastasis of LUAD by regulating SOX11, thereby promoting the progress of LUAD. We speculate that miR-937-3p can be used as a therapeutic target and potential biomarker for LUAD.

Exosome-mediated transfer of miR-1260b promotes cell invasion through Wnt/ß-catenin signaling pathway in lung adenocarcinoma.

Increasing evidence confirms that exosome-mediated transfer of microRNAs can influence cancer progression including tumor cell invasion, cell proliferation, and drug resistance via cell-cell communication. However, the potential role of exosomal-miR-1260b in lung adenocarcinoma (LAC) remains poorly understood. Thus, this study focused on investigating the function of exosomal-miR-1260b on cell invasion. Exosomal-miR-1260b was found to be higher in plasma of patients with LAC than that of healthy persons via quantitative real-time polymerase chain reaction assay. The sensitivity and specificity of exosomal-miR-1260b (cutoff point: 2.027) were 72% and 86%, and area under the curve of 0.845 (95% CI = 0.772-0.922). Elevated expression of miR-1260b in LAC tissues was positively correlated with exosomal-miR-1260b in plasma (r = .642, p < .05). Furthermore, ceramide biosynthesis regulated exosomal-miR-1260b secretion. Exosome-mediated transfer of miR-1260b promoted A549 cell invasion and was still functional inside A549 cells. Moreover, exosomal-miR-1260b regulated Wnt/ß-catenin signaling pathway by inhibiting sFRP1 and Smad4. This study identified a new regulation mechanism involving in cell invasion by exosome-mediated tumor-cell-to-tumor-cell communication. Targeting exosome-microRNAs may provide new insights into the diagnosis and treatment of LAC.

MicroRNA-1204 promotes cell proliferation by regulating PITX1 in non-small-cell lung cancer.

MicroRNA-1204 (miR-1204), a member of the PVT1 region, may improve B cell differentiation and metastasis in breast cancer. However, the role of miR-1204 in non-small-cell lung cancer (NSCLC) and its mechanism remain unclear. The GEO public database was first employed to find differentially expressed genes. The expression level of miR-1204 in patient tissues and NSCLC cell lines was determined using qRT-PCR. Cell proliferation assays were performed to investigate the impact of miR-1204 on cell growth. Bioinformatics analysis and dual-luciferase reporter assays were conducted to find potential target genes. Finally, we performed in vivo experiments to identify the effect of miR-1204 on tumor formation in nude mice. It was first found that miR-1204 was overexpressed in NSCLC tissues and cells. miR-1204 increased the proliferation of NSCLC cells and reduced cell cycle arrest in vitro. PITX1 (paired like homeodomain 1) was found as a potential target gene. In addition, PITX1 was also found to be low in expression in NSCLC tissues and cells. To show that PITX1 reversed the function of miR-1204 in promoting proliferation, confirmatory experiments were performed. Moreover, high miR-1204 and low PITX1 expression was highly correlated with tumor size, lymph node metastasis, and the TNM stage in patients diagnosed with NSCLC. Our results suggested that upregulated miR-1204 in NSCLC is associated with NSCLC progression and promotes NSCLC cell proliferation by downregulating PITX1. miR-1204 may act as a poor prognostic factor and a potential therapeutic target for NSCLC.

The long non-coding RNA AK001796 contributes to tumor growth via regulating expression of p53 in esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the prevalent and deadly cancers worldwide, especially in China. Considering the poor prognosis of ESCC, the aim of this study is to dissect the effects of long non-coding RNA (lncRNA) AK001796 on cell proliferation and cell cycle in vitro and tumorigenicity in vivo, providing therapeutic targets for ESCC. METHODS: We conducted quantitative real time PCR to detect the expression level of lncRNA AK001796 in human ESCC tumor and adjacent non-tumor tissues, and analyzed the correlation between lncRNA AK001796 expression and clinicopathologic feature of ESCC patients. Then we knocked down the expression of lncRNA AK001796 in human ESCC cell lines Eca-109 and TE-1, and next inspected cell cycle and apoptosis condition in these cells using flow cytometry. Subsequently, we used CCK-8 assay to test proliferation ability of the lncRNA AK001796-silenced ESCC cells, and the MDM2/p53 signaling pathway in these cells was analyzed by western blot analysis. At last, the ESCC xenograft models were established to verify the role of lncRNA AK001796 on the occurrence and development of ESCC. RESULTS: In this study, we demonstrated that lncRNA AK001796 was significantly upregulated in ESCC tumor tissues compared to adjacent non-tumor tissues. Knockdown of lncRNA AK001796 inhibited ESCC cell growth, cell cycle, and tumor growth in a xenograft mouse model via regulating MDM2/p53 signal pathway. The expression of lncRNA AK001796 was positively correlated with MDM2 levels in human ESCC samples. CONCLUSIONS: Overall, lncRNA AK001796 regulates cell proliferation and cell cycle via modulating MDM2/p53 signaling in ESCC, which provides a new insight into the treatment targets for ESCC.Trial registration This study was registrated in the Ethics Committee of the First Affiliated Hospital of Nanjing Medical University (Trial registration: 2012-SR-127, Registered 20 January 2012).

MiR-106b-5p Promotes Proliferation and Inhibits Apoptosis by Regulating BTG3 in Non-Small Cell Lung Cancer.

BACKGROUND/AIMS: MicroRNAs have been validated to play a crucial role in tumorigenesis of non-small cell lung cancer (NSCLC). Although miR-106b-5p has been reported to play a vital role in various malignancies the physiological function of miR-106b-5p in NSCLC still remain unknown. In this study, we investigated the role of miR-106b-5p in NSCLC. METHODS: Quantitative real-time polymerase chain reaction was conducted to estimate the expression of miR-106b-5p and BTG3 in both NSCLC tissues and cell lines. The effects of miR-106b-5p on proliferation were determined in vitro using CCK-8 proliferation assays, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, colony formation assays and cell-cycle assays and the in vivo effects were evaluated by a mouse tumorigenicity model. Cell apoptosis and cell cycle was investigated by flow cytometric analysis in vitro. The molecular mechanism underlying the relevance between miR-106b-5p and BTG3 was confirmed by luciferase assay and western blot. RESULTS: In current study, we found a relatively higher miR-106b-5p and lower BTG3 expression in NSCLC specimens and cell lines. BTG3 was verified as a direct target of miR-106b-5p by luciferase assay. In vitro, over-expression of miR-106b-5p promoted proliferation and inhibited apoptosis by down-regulating BTG3 expression. In vivo, miR-106b-5p promoted xenograft tumor formation. CONCLUSION: Our findings revealed for the first time that miR-106b-5p plays a tumorigenesis role in NSCLC progression by down-regulating BTG3 expression, which may lead to a novel insight to the potential biomarker and novel therapeutic strategies for NSCLC patients.

Long Noncoding RNA FAL1 Promotes Cell Proliferation, Invasion and Epithelial-Mesenchymal Transition Through the PTEN/AKT Signaling Axis in Non-Small Cell Lung Cancer.

BACKGROUND/AIMS: Recently, long non-coding RNAs (lncRNAs) have been found to have many biological effects in different cancer stages. Several studies have revealed that focally amplified lncRNA on chromosome 1 (FAL1) regulates cancer progression via p21. However, the expression and mechanism of FAL1 in non-small cell lung cancer (NSCLC) still remain unclear. METHODS: We detected the FAL1 level in NSCLC tissues and in established cell lines using quantitative real-time PCR and evaluated the clinical significance. FAL1 was silenced or overexpressed using siRNA or lentivirus to study whether FAL1 affected cell proliferation, invasion and migration. Xenograft growth and pulmonary metastasis were observed using nude mouse models. The mechanisms were explored with western blotting and immunohistochemistry. RESULTS: FAL1 was significantly overexpressed in NSCLC compared with adjacent normal tissues, and a high level of FAL1 correlated with poor histological grade, increased lymph node metastasis and advanced TNM stage. Loss- and gain-of-function experiments in vitro verified that knockdown of FAL1 inhibited cell proliferation, invasion, migration and EMT via the PTEN/AKT pathway. Furthermore, an in vivo assay confirmed that overexpression of FAL1 facilitated tumor growth and metastasis. CONCLUSION: FAL1 may promote tumorigenesis and progression of NSCLC through the PTEN/AKT axis, which could lead to lncRNA-related diagnostics and therapeutics in NSCLC.

MicroRNA-124 Functions as a Tumor Suppressor by Regulating CDH2 and Epithelial-Mesenchymal Transition in Non-Small Cell Lung Cancer.

BACKGROUND/AIMS: Abnormal expression of microRNA-124 (miR-124) was found in non-small cell lung cancer (NSCLC). However, the association between miR-124 and CDH2 has not been reported yet. This study aims to reveal the inhibiting effects of miR-124 on the expression of CDH2 in NSCLC. METHODS: Quantitative real-time polymerase chain reaction was used to evaluate the expression of miR-124 and CDH2 in NSCLC tissues. Cell viability, apoptosis and invasion assays were carried out in NSCLC cell lines after transfection. The regulation mechanism was confirmed by luciferase report assay and western blot (WB). RESULTS: Significantly decreased expression of miR-124 was found in NSCLC specimens and cell lines. Overexpression of miR-124 apparently suppressed the proliferation and invasion of NSCLC cell lines in vitro. Luciferase report assay and WB revealed that CDH2 was a target gene of miR-124. Furthermore, results of WB showed that epithelial-mesenchymal transition (EMT) could be inhibited by up-regulation of miR-124. CONCLUSIONS: Taken together, our findings present the first evidence that miR-124 could suppress the expression of CDH2 and regulate EMT, which might lead to a potential therapeutic strategy focusing on miR-124 and CDH2 for human lung cancer.

Up-Regulation of MiR-452 Inhibits Metastasis of Non-Small Cell Lung Cancer by Regulating BMI1.

BACKGROUND/AIMS: MicroRNAs (miRNAs) have been regarded as a new class of regulators in cellular processes in non-small cell lung cancer (NSCLC). However, the relationship between miR-452 and the development of NSCLC remains unclear. METHODS: qRT-PCR was used to detect the expression of miR-452 and its target gene in NSCLC samples (n=60). The transwell assay was used to test the cell invasion capability. The regulation mechanism was confirmed by luciferase reporter assay and western blot assay. RESULTS: In the current study, a relatively lower miR-452 and higher BMI1 expression levels were confirmed to be associated with advanced tumor stage and more extent of lymph nodes metastasis. In vitro, down-regulated miR-452 could enhance cell invasion capability. Furthermore, miR-452 modulated BMI1 expression by binding to its 3'-UTR. The enhancement of cell invasion capability induced by down-regulated miR-452 was eliminated by repression of BMI1. CONCLUSIONS: Our results suggest that miR-452 plays a vital role in development of NSCLC, and this miR-452-BMI1 pathway might generate a novel insight into the treatment of NSCLC.

Ubiquitin D promotes the progression of rheumatoid arthritis via activation of the p38 MAPK pathway.

Ubiquitin D (UBD), a member of the ubiquitin­like modifier family, has been reported to be highly expressed in various types of cancer and its overexpression is positively associated with tumor progression. However, the role and mechanism of UBD in rheumatoid arthritis (RA) remain elusive. In the present study, the gene expression profiles of GSE55457 were downloaded from the Gene Expression Omnibus database to assess differentially expressed genes and perform functional enrichment analyses. UBD was overexpressed by lentivirus transfection. The protein level of UBD, p­p38 and p38 in RA­fibroblast­like synoviocytes (FLSs) were examined by western blotting. Cell Counting Kit­8 and flow cytometry assays were used to detect the functional changes of RA­FLSs transfected with UBD and MAPK inhibitor SB202190. The concentrations of inflammatory factors (IL­2, IL­6, IL­10 and TNF­α) were evaluated using ELISA kits. The results revealed that UBD was overexpressed in RA tissues compared with in the healthy control tissues. Functionally, UBD significantly accelerated the viability and proliferation of RA­FLSs, whereas it inhibited their apoptosis. Furthermore, UBD significantly promoted the secretion of inflammatory factors (IL­2, IL­6, IL­10 and TNF­α). Mechanistically, elevated UBD activated phospohorylated­p38 in RA­FLSs. By contrast, UBD overexpression and treatment with the p38 MAPK inhibitor SB202190 not only partially relieved the UBD­dependent effects on cell viability and proliferation, but also reversed its inhibitory effects on cell apoptosis. Furthermore, SB202190 partially inhibited the effects of UBD overexpression on the enhanced secretion of inflammatory factors. The present study indicated that UBD may mediate the activation of p38 MAPK, thereby facilitating the proliferation of RA­FLSs and ultimately promoting the progression of RA. Therefore, UBD may be considered a potential therapeutic target and a promising prognostic biomarker for RA.

Clinical association study on the matrix metalloproteinase expression in the serum of patients with connective tissue disease complicated with interstitial lung disease.

Objectives: This study was implemented to reveal the expression and the clinical correlation of matrix metalloproteinases (MPSs) with connective tissue disease (CTD) complicated with interstitial lung disease (ILD). Patients and methods: This clinical study was conducted with 260 patients (151 males, 109 females; mean age: 47.3±12.5 years; range, 29 to 67 years) between October 2019 and October 2020. Among the subjects, 100 were CTD patients (CTD group), 80 were CTD patients with ILD (CTD-ILD group) and 80 were healthy individuals (control group). The MMP-2, -3, -7, and -9 levels in the serum of the three groups were detected by enzyme-linked immunosorbent assay. Results: Serum levels of MMP-3, -7, and -9 in the CTD-ILD group were higher, while the MMP-2 level was lower than those in the CTD group and the control group. The MMP-7 level in the serum of the CTD-ILD group was positively related to C-reactive protein, erythrocyte sedimentation rate, and rheumatoid factor and negatively correlated with immunoglobulin G and complement 3. The MMP-7 expression in the serum was positively correlated with forced expiratory volume in one second (FEV1%), FEV1/forced expiratory volume (FVC), and FVC in CTD-ILD patients. Pearson statistical analysis revealed that there was a significant positive correlation between the MMP-7 expression and the percentage of B cells in the serum of CTD-ILD patients. Conclusion: Expressions of MMP-3, -7, and -9 are significantly increased in the serum of patients with CTD and related interstitial lung lesions, and the high expression of MMP-7 indicates dynamic lung lesions, which is possible to be used as a possible biomarker for early diagnosis and assessment of disease progression.

LINC00668 promoted non-small lung cancer progression by miR-518c-3p/TRIP4 axis.

BACKGROUND: Non-small lung cancer ranks first in the cancer-related death of all malignant tumors. Exploring novel biological targets is of great significance for diagnosis and therapy of NSCLC. OBJECTIVE: In this study, we aimed to explore the effect of LINC00668 on the biological functions of NSCLC cells and the underlying mechanism. METHODS: RT-qPCR assays and western blot assays were utilized to estimate the relative gene expression at mRNA and protein levels, respectively. CCK8, colony formation, wound healing, transwell, and cell apoptosis assays were employed to assess cell function. IHC and FISH assays were used to determine the gene expression in NSCLC tissues. RIP and dual-luciferase assays were conducted to validate the combination between LINC00668 and miR-518c-3p. The correlation of expression between miR-518c-3p and LINC00668 or TRIP4 was determined by Pearson correlation analysis. RESULTS: LINC00668 was aberrantly upregulated in NSCLC tumor tissues and cell lines. Inhibition of LINC00668 significantly suppressed tumor proliferation, migration, invasion and promoted cell apoptosis. Mechanistically, LINC00668 could bind to miR-518c-3p, thus targeting the 3'UTR of TRIP4. TRIP4 overexpression rescued the weakened cell function mediated by LINC00668 silencing. CONCLUSIONS: LINC00668 acted as an oncogene in NSCLC progression through miR-518c-3p/TRIP4 axis. Our study disclosed a new mechanism of LINC00668 functioned in NSCLC and may give a deeper insight of the targeted therapy of NSCLC in the future.

Long noncoding RNA ArfGAP with RhoGAP domain, ankyrin repeat and PH domain 1 antisense RNA 1 recruits enhancer of zeste 2 polycomb repressive complex 2 subunit to promote the proliferation, migration and invasion of lung adenocarcinoma cells.

The detailed function of ARAP1-AS1, the antisense RNA of Arf-GAP with Rho-GAP domain, ANK repeat and PH domain-containing protein 1 (ARAP1), in lung adenocarcinoma (LUAD) has not been clearly elucidated and required further investigation. Our study is committed to exploring the role of ARAP1-AS1 in LUAD. Gene expression in LUAD was measured by real-time quantitative polymerase-chain reaction (RT-qPCR). The influence of ARAP1-AS1 on LUAD cell malignant behaviors was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, Transwell invasion assay and wound healing assay. Subcellular fractionation assay detected the cellular localization of ARAP1-AS1 in LUAD. The protein levels were subjected to western blotting. RNA immunoprecipitation (RIP) and luciferase reporter assay were employed to verify the interaction between ARAP1-AS1, ARAP1 and enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). Our investigation identified that ARAP1-AS1 was upregulated in LUAD cells and tissues. ARAP1-AS1 silencing repressed LUAD cell growth and migration. Furthermore, ARAP1-AS1 knockdown altered the expression of its sense mRNA, ARAP1. ARAP1-AS1 could recruit EZH2 to inhibit ARAP1 expression. Additionally, the downregulation of ARAP1 reversed ARAP1-AS1 downregulation-induced repression of cell growth and migration in LUAD. In conclusion, ARAP1-AS1 recruited EZH2 to silence ARAP1, facilitating cell proliferation, migration and invasion in LUAD. Our study demonstrated the possibility of ARAP1-AS1 to be a novel therapeutic target for LUAD. [Figure: see text].

lncRNA BBOX1-AS1 silencing inhibits esophageal squamous cell cancer progression by promoting ferroptosis via miR-513a-3p/SLC7A11 axis.

Long noncoding RNA BBOX1 antisense 1 (BBOX1-AS1) has been demonstrated to play important roles in several tumors. However, the expression and function of BBOX1-AS1 in esophageal squamous cell cancer (ESCC) have not been defined. Here, BBOX1-AS1 expression in 78 collected ESCC tissues, paired adjacent normal tissues, and ESCC cell lines were analyzed using quantitative real-time polymerase chain reaction. The overall survival of the patients was also studied. Cell proliferation, invasion, and migration were verified by constructing in vitro models. Additionally, cell apoptosis was determined by flow cytometry, and ferroptosis was examined using Ptgs2 detection and lipid-reactive oxygen species assays. The relationship between BBOX1-AS1 and downstream molecules was evaluated using RNA immunoprecipitation, western blotting, and luciferase reporter assays. The function of BBOX1-AS1 was studied in vivo using a xenograft model and immunohistochemistry. BBOX1-AS1 expression was significantly higher in ESCC tissues, indicating poor prognosis. Inhibition of BBOX1-AS1 reduced cell proliferation, slowed cell invasion and migration, and promoted apoptosis and ferroptosis in vitro. miR-513a-3p was verified as a specific target of BBOX1-AS1 in ESCC, whereas knockdown of miR-513a-3p reversed the suppressive function of BBOX1-AS1 silencing in TE-1 cells. Moreover, solute carrier family 7 member 11 (SLC7A11) is regulated by miR-513a-3p, which is mediated by BBOX1-AS1 in ESCC cells. In conclusion, downregulation of BBOX1-AS1 inhibits cell proliferation, and metastasis accelerates cell apoptosis and ferroptosis in ESCC by upregulating miR-513a-3p to reduce SLC7A11 expression. These findings may provide novel insights into the diagnosis and treatment of ESCC.

Identification and Quantification of Organic Contaminants and Evaluation of Their Effects on Amine Foaming in the Natural Gas Sweetening Industry.

Contamination is a leading cause of corrosion, foaming, and amine-absorption capacity limitation, predominantly foaming. There is currently an urgent need to identify the sources of amine foaming and eliminate them or reduce their impacts. Gas chromatography-mass spectrometry (GC-MS) and a sample pretreatment method were developed to identify and quantify the organic contaminants. Linear hydrocarbons (C12-C22), long-chain carboxylic acids and esters, alcohol ethoxylates, and benzene derivatives were detected, characterized, and quantified in amine solutions. Furthermore, the effects of the contaminant concentrations on foaming behavior were also investigated by adding those contaminants. The results reveal that the main issue of foaming is due to the presence of unsaturated fatty acids and alcohol ethoxylates, even with a small amount of 10 ppm, whereas benzene derivatives like methylpyridine, quinoline, methyl naphthalene, benzyl alcohol, octahydroacridine, and linear hydrocarbons have little effect on amine foaming, even with an amount up to 2000 ppm. Therefore, it is necessary to monitor the existence and content of these surface-active contaminants.

Adipose tissue macrophage-derived exosomes induce ferroptosis via glutathione synthesis inhibition by targeting SLC7A11 in obesity-induced cardiac injury.

Ferroptosis is an iron-dependent programmed cell death characterized by the accumulation of reactive oxygen species (ROS). Long-term high fat diet (HFD) was found to be associated with ferroptosis and cardiac injury. HFD-induced obesity is characterized by sustained, low-grade inflammation in adipose tissue, while macrophage infiltration plays a crucial role in inflammation. Exosomes (Exos) derived from adipose tissue macrophages (ATMs) participate in the physiological processes of recipient cells. In this study, we investigated the role of ATM-Exos in obesity-induced ferroptosis and cardiac injury. We found that HFD-induced obesity resulted in higher mRNA expression levels of specific markers, e.g., prostaglandin endoperoxide synthase 2 (PTGS2), and increased the levels of lipid peroxides, including malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Macrophages infiltrated the adipose tissues, as examined by flow cytometry. Exosomes derived from ATM-Exos were analyzed using transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Obese ATM-Exos administration induced higher levels of PTGS2, MDA, 4-HNE, lipid ROS, and mitochondrial injury. Obese ATM-Exos further provoked obvious cardiac injury, demonstrated by abnormal levels of cardiac enzymes and inflammatory factors. Systolic left ventricle (LV) function anomalies were induced by ATM-Exos in obese mice. miR-140-5p is abundant in obese ATM-Exos and promotes ferroptosis in cardiomyocytes. Solute carrier family 7 member 11 (SLC7A11) is a downstream target of miR-140-5p, which induces ferroptosis via inhibition of GSH synthesis by targeting SLC7A11. Attenuating exosomal-miR-140-5p expression alleviates ferroptosis and cardiac injury induced by obese ATM exosomes by alleviating GSH inhibition. In summary, the current study provides evidence that obese ATM-exosomal miR-140-5p promotes ferroptosis by regulating GSH synthesis and provides a novel therapeutic strategy for targeting obese ATM-Exos in obesity-induced cardiac injury.

CircP4HB regulates ferroptosis via SLC7A11-mediated glutathione synthesis in lung adenocarcinoma.

Background: Circular ribonucleic acids (circRNAs) play a key role in the development of different types of cancer. Ferroptosis is a type of programmed cell death that contributes to cancer progression. However, the role of circRNAs in lung adenocarcinoma (LUAD) ferroptosis remains unclear. Methods: The gene expression levels of circRNA P4HB (circP4HB), microRNA-1184 (miR-1184) and Solute carrier family 7 member 11 (Slc7a11), also known as Xct were detected using quantitative real-time polymerase chain reaction (qRT-PCR). Ferroptosis of established LUAD cells was induced by erastin. Cell viability was examined via Cell Counting Kit 8 assays. Ferroptosis was evaluated by malondialdehyde (MDA), Prostaglandin-endoperoxide Synthase 2 (Ptgs2), lipid reactive oxygen species (lipid ROS), and JC-1 detection. The mechanism of circP4HB/miR-1184/SLC7A11 was investigated by luciferase reporter assays, RNA immunoprecipitation, RNA pull-down, and western blot assays. A functional for circP4HB in vivo was determined using xenograft nude mice models. Results: CircP4HB expression levels were increased in LUAD. It triggered glutathione (GSH) synthesis and, therefore protected LUAD cells from ferroptosis induced by erastin. CircP4HB may function as a competing endogenous RNA by modulating miR-1184 to regulate SLC7A11. CircP4HB inhibited ferroptosis by regulating miR-1184/ SLC7A11-mediated GSH synthesis. In vivo, overexpression of circP4HB promoted tumor growth and inhibited ferroptosis. Conclusions: The circRNA, circP4HB acts as a novel ferroptosis suppressor in LUAD. Furthermore, circP4HB protects LUAD from ferroptosis via modulation of the miR-1184/SLC7A11 axis. Our findings identified circP4HB as a novel biomarker in LUAD and warrants further investigation in the early diagnosis and treatment of LUAD.

M2 macrophage-derived exosomes promote lung adenocarcinoma progression by delivering miR-942.

Tumor-associated macrophages (TAMs) are the major components of the tumor microenvironment that contribute to metastasis in lung adenocarcinoma (LUAD). The potential of TAM-derived exosomes for biomarker discovery in tumor initiation and progression has been recently reported. However, studies on macrophage-derived exosomes in LUAD remain limited. We investigated the role of M2 macrophage-derived exosomes in LUAD both in vivo and in vitro and its underlying mechanism. We showed that the infiltration of M2 macrophages was positively correlated with LUAD metastasis. M2 macrophage-derived exosomes could be taken up by LUAD cells to promote cell migration, invasion, and angiogenesis. Furthermore, miR-942 could be packaged into exosomes secreted by M2 macrophages. Mechanistically, exosomal miR-942 regulates FOXO1 protein expression by binding to the 3'-UTR region of FOXO1 and further alleviates ß-catenin inhibition in LUAD cells. Collectively, we demonstrated that M2 macrophage-derived miRNA-containing exosomes promote LUAD cell invasion and migration and facilitate angiogenesis, thereby providing a new therapeutic target for metastatic LUAD.

Tumor-derived exosomal miR-3157-3p promotes angiogenesis, vascular permeability and metastasis by targeting TIMP/KLF2 in non-small cell lung cancer.

Metastasis is the main cause of death in patients with advanced lung cancer. The exosomes released by cancer cells create tumor microenvironment, and then accelerate tumor metastasis. Cancer-derived exosomes are considered to be the main driving force for metastasis niche formation at foreign sites, but the mechanism in Non-small cell lung carcinoma (NSCLC) is unclear. In metastatic NSCLC patients, the expression level of miR-3157-3p in circulating exosomes was significantly higher than that of non-metastatic NSCLC patients. Here, we found that miR-3157-3p can be transferred from NSCLC cells to vascular endothelial cells through exosomes. Our work indicates that exosome miR-3157-3p is involved in the formation of pre-metastatic niche formation before tumor metastasis and may be used as a blood-based biomarker for NSCLC metastasis. Exosome miR-3157-3p has regulated the expression of VEGF/MMP2/MMP9 and occludin in endothelial cells by targeting TIMP/KLF2, thereby promoted angiogenesis and increased vascular permeability. In addition, exosome miR-3157-3p promoted the metastasis of NSCLC in vivo.

High-Dose Aluminum Exposure Further Alerts Immune Phenotype in Aplastic Anemia Patients.

This study explored the relationship between immunological status and clinical characteristics of aplastic anemia (AA) patients to plasma aluminum levels, which were increased after constant exposure to high levels of this metal. Sixty-two AA patients (33 cases with high and 29 cases with low or no exposure to aluminum) and 30 healthy controls were selected for this study. Aluminum in human albumin solution was measured by inductivity coupled plasma mass spectrometry. IL-10, IL-12, IL-17, and INF-γ levels were measured by enzyme-linked immunosorbent assay. The distribution of lymphocyte subsets were determined by flow cytometry. The expression levels of immunoglobulins and complement C3 and C4 were also measured. Exposure to high aluminum raised the levels of serum aluminum in AA patients (P < 0.01). The levels of hemoglobin and complement C4 were lower in AA patients with high aluminum exposure (P < 0.05 and < 0.01, respectively). The percentage of CD4+ T cells and the ratio of CD4+/ CD8+T cells in peripheral blood in AA patients with high aluminum exposure were higher compared with control AA patients (P < 0.05 in both cases), while the percentage of CD8+ T cells was significantly lower than that in non-aluminum-exposed AA patients (P < 0.05). Compared with non-aluminum-exposed AA patients, the level of IL-10 in the high aluminum-exposed AA group was significantly higher (P < 0.05 in both cases). The immunological and clinical characteristics of AA patients from regions of high aluminum exposure are different to those in from non-aluminum areas. These results suggest that high aluminum exposure alters the immune system in patients suffering from AA.

miR-550a-5p Functions as a Tumor Promoter by Targeting LIMD1 in Lung Adenocarcinoma.

Lung adenocarcinoma accounts for half of all lung cancer cases in most countries. Mounting evidence has demonstrated that microRNAs play important roles in cancer progression, and some of them can be identified as potential biomarkers. This study aimed to explore the role of miR-550a-5p, a lung adenocarcinoma-associated mature microRNA screened out from the TCGA database via R-studio and Perl, with abundant expression in samples and with 5-year survival prognosis difference, as well as having not been studied in lung cancer yet. Potential target genes were predicted by the online database. Gene ontology enrichment, pathway enrichment, protein-protein interaction network, and hub genes-microRNA network were constructed by FunRich, STRING database, and Cytoscape. Then, LIMD1, a known tumor suppressor gene reported by multiple articles, was found to have a negative correlation with miR-550a-5p. The expression of miR-550a-5p was up-regulated in tumor samples and tumor-associated cell lines. Its high expression was also correlated with tumor size. Cell line A549 treated with miR-550a-5p overexpression promoted tumor proliferation, while H1299 treated with miR-550a-5p knockdown showed the opposite result. Mechanically, miR-550a-5p negatively regulated LIMD1 by directly binding to its 3'-UTR validated by dual luciferase assay. In summary, a new potential prognostic and therapeutic biomarker, miR-550a-5p, has been identified by bioinformatics analysis and experimental validation in vitro and in vivo, which promotes lung adenocarcinoma by silencing a known suppressor oncogene LIMD1.