lncRNAs can exert many biological effects in several cancer types. MALAT1 is a kind of lncRNA which is greatly overexpressed in several tumors including non-small cell lung cancer (NSCLC). However, the mechanism of MALAT1 in NSCLC still remains unclear. In our current study, we concentrated on the biological mechanism of MALAT1 in NSCLC. It was observed that MALAT1 was significantly upregulated in five human NSCLC cells including A549, H23, H522, H1299, and H460 cells compared to normal bronchial epithelial cell line 16HBE cells. On the contrary, miR-124 was remarkably downregulated, which indicated a potential negative correlation between miR-124 and MALAT1. MALAT1 inhibition can increase miR-124 expression in A549 and H460 cells. In addition, miR-124 mimics were able to repress MALAT1 expression and miR124 inhibitors can promote MALAT1 levels. Then it was found that shMALAT1 can inhibit NSCLC cell proliferation, colony formation and apoptosis, which can be reversed by miR-124 inhibitors. Bioinformatic analysis predicted the correlation between miR-124 and MALAT1. In addition, STAT3 was found to be a novel mRNA target of miR-124. Downregulation of MALAT1 can inhibit NSCLC development by enhancing miR-124 and decreasing STAT3 expression. We speculated that MALAT1can act as a competing endogenous lncRNA (ceRNA) to modulate miR-124/STAT3 in NSCLC. Taken these together, we revealed that MALAT1/miR-124/STAT3 was involved in NSCLC development.
Recently, long noncoding RNAs (lncRNAs) have been widely reported to play pivotal roles in the regulation of human cancers. Although the oncogenic property of lncRNA small nucleolar RNA host gene 3 (SNHG3) has been revealed in a variety of cancers, functions and regulatory mechanism of SNHG3 in non-small-cell lung cancer (NSCLC) remain to be investigated. In this study, we detected the upregulated expression of SNHG3 in NSCLC tissues as well as cells through quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis. Using Kaplan-Meier analysis, we determined that a high-level of SNHG3 was associated with a low overall survival rate of patients with NSCLC.Through gain and loss of function experiments, we demonstrated that SNHG3 had a significantly positive effect on NSCLC cell proliferation and migration.Mechanistic investigations revealed that SNHG3 was a predicted direct transcriptional target of E2F1. We observed that the transcriptional activation of SNHG3 could be induced by E2F1. To explore the mechanism, rescue experiments were carried out, which revealed that the cotreatment with SB-431542, JSI-124, or JSI-124 + SB-431542 rescued the effects brought by the overexpression of SNHG3 on NSCLC cell proliferation, migration, and epithelial-mesenchymal transition process. Our results suggested that E2F1 activated SNHG3 and promoted cell proliferation and migration in NSCLC via transforming growth factor-β pathway and interleukin-6/janus-activated kinase 2/signal transducer and activator of transcription 3 pathway, which implied that SNHG3 may be a biomarker for the treatment of patients with NSCLC.
The dysregulation of microRNAs (miRNAs) is crucially implicated in the development of various cancers. In this study, we explored the biological role of miR‐141 in non‐small cell lung cancer (NSCLC). miR‐141 expression was significantly up‐regulated in NSCLC tissues, and its overexpression accelerated NSCLC cell proliferation in vitro and tumor growth in vivo. We subsequently identified the antagonists of PI3K/AKT signaling, PH domain leucine‐rich‐repeats protein phosphatase 1 (PHLPP1) and PHLPP2, as direct targets of miR‐141. Re‐introduction of PHLPP1 and PHLPP2 abrogated miR‐141‐induced proliferation of NSCLC cells. Together, the results of this study suggest that miR‐141 and its targets PHLPP1 and PHLPP2 play critical roles in NSCLC tumorigenesis, and provide potential therapeutic targets for NSCLC treatment.
Background: Chronic obstructive pulmonary disease (COPD) is an obstinate pulmonary disease, causing irreversible alveoli collapse and increasing the risk for cardiovascular disease. Accumulating evidence has shown that the dysregulation of miRNAs is crucially involved in the pathogenesis and development of COPD. However, the effects and role of microRNA-181c (miR-181c) have not been investigated in a murine model of COPD.
To investigate the role of TGF-β and IL-6 in myofibroblasts (MFs) — lung cancer cell interactions, lung cancer cells (Lewis and CTM-167 cell lines) were stimulated by IL-6, MF-conditioned medium (MF-CM) or MFs, with or without TGF-β signaling inhibitor — SB431542 and/or JAK2/STAT3 inhibitor — JSI-124. MFs were stimulated by TGF-β, cancer cell-CM or cancer cells, with or without SB431542 and JSI-124. Cell proliferation, the levels of cytokines, expression of mRNA and protein were determined. Mice bearing xenograft tumors were intraperitoneally treated with SB431542 or JSI-124 and monitored for up to 45 days. In co-culture systems, MFs secreted high levels of IL-6, while cancer cells produced high levels of TGF-β. Recombinant IL-6 and MF-CM activated STAT3 and upregulated TGF-β in cancer cells. In contrast, cancer cell-CM or TGF-β stimulated MFs to produce IL-6. Blockade of JAK2/STAT3 and TGF-β signaling by specific inhibitors significantly inhibited cell proliferation in vitro and tumor growth in vivo of lung cancer cells. Our study demontrated that the TGF-β and IL-6/JAK2/STAT3 signaling pathways form a positive feedback signaling loop that mediated the interactions between MFs and lung cancer cells. Targeted inhibiton of this signaling loop could be a new approach for lung cancer prevention and therapy.
Viral infection was an important pathogen in AECOPD patients; the most common viruses included FluA, HRV and FluB. It was very difficult to diagnose the viral infection according to clinical characteristics. The increased of serum IP-10 and IFN-γ levels might be value to indicate viral infection in AECOPD.
BackgroundChronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by incomplete reversible airflow limitation, which is associated with emphysema and chronic inflammation. Oxidative/antioxidant imbalance is one of the mechanisms of the current pathogenesis of COPD and several recent studies have attempted to uncover genetic causes of COPD and its progression. GST, HO-1, and SOD-3 are important susceptibility genes related to COPD.MethodsA total of 300 blood samples were included in two groups: Control group and COPD group. We genotyped 4 single nucleotide polymorphisms (SNPs) from these 3 genes in 150 COPD patients and 150 controls to analyze genetic polymorphisms and interactions with COPD-related quantitative traits using correlation analysis and multivariate logistic regression analysis.ResultsThe results indicated that genotype distributions and allele frequencies of GSTP1, HO-1, and SOD-3 were significantly different between the COPD and the control group, while there is no correlation between the polymorphism of GSTP1, HO-1, SOD3, and the different stages of COPD. Furthermore, multivariate logistic regression analysis indicated that COPD GSTP1-exon5 SNP and HO-1 (GT)n SNP are high-risk factors for COPD and there was interaction between GSTP1 exon5 SNPS and HO-1 (GT)n SNP. More important, the genotypes, AG, GG of GSTP1 exon5 and L/M*S, L/L of HO-1 (GT)n associated with increased 8-iso-prostaglandin F (2 alpha) (8-iso-PGF2) and malondialdehyde (MDA) concentration and decreased catalase (CAT) activity.ConclusionCollectively, this study shows that genetic polymorphisms of GSTP1, HO-1, and SOD-3 are associated with COPD susceptibility.
The results suggested that genetic polymorphisms in XPD-751, XRCC1-194 and XRCC1-399 were related to the risk of NSCLC, among which XPD-751SNP was responsible for adenocarcinoma, while XRCC1-194SNP was closely linked to squamous carcinoma. Smoking and XRCC1-194SNP were risk factors of NSCLC.
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