Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases worldwide with an unclear mechanism. Long non-coding RNAs (lncRNAs) have recently emerged as important regulatory molecules. To better understand NAFLD pathogenesis, lncRNA and messenger RNA (mRNA) microarrays were conducted in an NAFLD rodent model. Potential target genes of significantly changed lncRNA were predicted using cis/trans-regulatory algorithms. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were then performed to explore their function. In the current analysis, 89 upregulated and 177 downregulated mRNAs were identified, together with 291 deregulated lncRNAs. Bioinformatic analysis of these RNAs has categorized these RNAs into pathways including arachidonic acid metabolism, circadian rhythm, linoleic acid metabolism, peroxisome proliferator-activated receptor (PPAR) signaling pathway, sphingolipid metabolism, steroid biosynthesis, tryptophan metabolism and tyrosine metabolism were compromised. Quantitative polymerase chain reaction (qPCR) of representative nine mRNAs and eight lncRNAs (named fatty liver-related lncRNA, FLRL) was conducted and this verified previous microarray results. Several lncRNAs, such as FLRL1, FLRL6 and FLRL2 demonstrated to be involved in circadian rhythm targeting period circadian clock 3 (Per3), Per2 and aryl hydrocarbon receptor nuclear translocator-like (Arntl), respectively. While FLRL8, FLRL3 and FLRL7 showed a potential role in PPAR signaling pathway through interaction with fatty acid binding protein 5 (Fabp5), lipoprotein lipase (Lpl) and fatty acid desaturase 2 (Fads2). Functional experiments showed that interfering of lncRNA FLRL2 expression affected the expression of predicted target, circadian rhythm gene Arntl. Moreover, both FLRL2 and Arntl were downregulated in the NAFLD cellular model. The current study identified lncRNA and corresponding mRNA in NAFLD, providing new insight into the pathogenesis of NAFLD. Moreover, we identified a new lncRNA FLRL2, that might participate NAFLD pathogenesis mediated by Arntl.
Afatinib is a second-generation of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor and has shown a significant clinical benefit in non-small cell lung cancer (NSCLC) patients with EGFR-activating mutations. However, the potential therapeutic effects of afatinib combining with other modalities, including ionizing radiation (IR), are not well understood. In this study, we developed a gefitinib-resistant cell subline (PC-9-GR) with a secondary EGFR mutation (T790M) from NSCLC PC-9 cells after chronic exposures to increasing doses of gefitinib. The presence of afatinib significantly increases the cell killing effect of radiation in PC-9-GR cells harboring acquired T790M, but not in H1975 cells with de novo T790M or in H460 cells that express wild-type EGFR. In PC-9-GR cells, afatinib remarkable blocks baseline of EGFR and ERK phosphorylations, and causes delay of IR-induced AKT phosphorylation. Afatinib treatment also leads to increased apoptosis and suppressed DNA damage repair in irradiated PC-9-GR cells, and enhanced tumor growth inhibition when combined with IR in PC-9-GR xenografts. Our findings suggest a potential therapeutic impact of afatinib as a radiation sensitizer in lung cancer cells harboring acquired T790M mutation, providing a rationale for a clinical trial with combination of afatinib and radiation in NSCLCs with EGFR T790M mutation.
Background and aimCaveolin1 (CAV1) is involved in lipid homeostasis and endocytosis, but little is known about the significance of CAV1 in the pathogenesis and development of nonalcoholic fatty liver disease (NAFLD). This study aimed to determine the role of CAV1 in NAFLD.MethodsExpression of CAV1 in the in vitro and in vivo models of NAFLD was analyzed. The effects of CAV1 knockdown or overexpression on free fatty acid (FFA)-induced lipid accumulation in L02 cells and AML12 cells were determined. CAV1 knockout (CAV1-KO) mice and their wild-type (WT) littermates were subjected to a high fat diet (HFD) for 4 weeks, and the functional consequences of losing the CAV1 gene and its subsequent molecular mechanisms were also examined.ResultsNoticeably, CAV1 expression was markedly reduced in NAFLD. CAV1 knockdown led to the aggravation of steatosis that was induced by FFA in both L02 cells and AML12 cells, while CAV1 overexpression markedly attenuated lipid accumulation in the cells. Consistent with CAV1 repression in the livers of HFD-induced mice, the CAV1-KO mice exhibited more severe hepatic steatosis upon HFD intake. In addition, increased cholesterol levels and elevated transaminases were detected in the plasma of CAV1-KO mice. The protein expression of SREBP1, a key gene involved in lipogenesis, was augmented following CAV1 suppression in FFA-treated hepatocytes and in the livers of HFD-fed CAV1-KO mice.ConclusionsCAV1 serves as an important protective factor in the development of NAFLD by modulating lipid metabolism gene expression.
Chalcomoracin (CMR) is a kind of Diels–Alder adduct extracted from the mulberry leaves. Recent studies showed that CMR has a broad spectrum of anticancer activities and induces paraptosis in breast cancer and prostate cancer cells. In this study, we investigated the effects of CMR against human non-small cell lung cancer cells and the underlying mechanisms. We found that CMR dose-dependently inhibited the proliferation of human lung cancer H460, A549 and PC-9 cells. Furthermore, exposure to low and median doses of CMR induced paraptosis but not apoptosis, which was presented as the formation of extensive cytoplasmic vacuolation with increased expression of endoplasmic reticulum stress markers, Bip and Chop, as well as activation of MAPK pathway in the lung cancer cells. Knockdown of Bip with siRNA not only reduced the cell-killing effect of CMR, but also decreased the percentage of cytoplasmic vacuoles in H460 cells. Moreover, CMR also increased the sensitivity of lung cancer cells to radiotherapy through enhanced endoplasmic reticulum stress. In lung cancer H460 cell xenograft nude mice, combined treatment of CMR and radiation caused greatly enhanced tumor growth inhibition with upregulation of endoplasmic reticulum stress proteins and activation of pErk in xenograft tumor tissue. These data demonstrate that the anticancer activity and radiosensitization effect of CMR result from inducing paraptosis, suggesting that CMR could be considered as a potential anticancer agent and radiation sensitizer in the future cancer therapeutics.
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