ABSTRACT
BACKGROUND AND AIMS: Peroxisome proliferator-activated receptor-gamma (PPARγ) coactivator-1α (PGC1α) is a key regulator of mitochondrial biogenesis and respiration. PGC1α is involved in the carcinogenesis, progression, and metabolic state of cancer. However, its role in the progression of hepatocellular carcinoma (HCC) remains unclear. APPROACH AND RESULTS: In this study, we observed that PGC1α was down-regulated in human HCC. A clinical study showed that low levels of PGC1α expression were correlated with poor survival, vascular invasion, and larger tumor size. PGC1α inhibited the migration and invasion of HCC cells with both in vitro experiments and in vivo mouse models. Mechanistically, PGC1α suppressed the Warburg effect through down-regulation of pyruvate dehydrogenase kinase isozyme 1 (PDK1) mediated by the WNT/ß-catenin pathway, and inhibition of the WNT/ß-catenin pathway was induced by activation of PPARγ. CONCLUSIONS: Low levels of PGC1α expression indicate a poor prognosis for HCC patients. PGC1α suppresses HCC metastasis by inhibiting aerobic glycolysis through regulating the WNT/ß-catenin/PDK1 axis, which depends on PPARγ. PGC1α is a potential factor for predicting prognosis and a therapeutic target for HCC patients.
Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Hepatocellular/secondary , Liver Neoplasms/pathology , Lung Neoplasms/secondary , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Biomarkers, Tumor/blood , Carcinogenesis/genetics , Carcinogenesis/pathology , Carcinoma, Hepatocellular/blood , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/mortality , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Disease Progression , Female , Gene Expression Regulation, Neoplastic , Humans , Liver/pathology , Liver/surgery , Liver Neoplasms/blood , Liver Neoplasms/genetics , Liver Neoplasms/mortality , Male , Middle Aged , Neoplasm Invasiveness/genetics , Neoplasm Invasiveness/pathology , PPAR gamma/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/blood , Prognosis , Pyruvate Dehydrogenase Acetyl-Transferring Kinase/metabolism , Warburg Effect, Oncologic , Wnt Signaling Pathway/genetics , Xenograft Model Antitumor AssaysABSTRACT
Metastasis is the main reason for high recurrence and poor survival of hepatocellular carcinoma (HCC). The molecular mechanism underlying HCC metastasis remains unclear. In this study, we found that argininosuccinate synthase 1 (ASS1) expression was significantly decreased and down-regulation of ASS1 was closely correlated with poor prognosis in HCC patients. DNA methylation led to the down-regulation of ASS1 in HCC. Stable silencing of ASS1 promoted migration and invasion of HCC cells, whereas overexpression of ASS1-inhibited metastasis of HCC cells in vivo and in vitro. We also revealed that ASS1-knockdown increased the phosphorylation level of S727STAT3, which contributed to HCC metastasis by up-regulation of inhibitor of differentiation 1 (ID1). These findings indicate that ASS1 inhibits HCC metastasis and may serve as a target for HCC diagnosis and treatment.
Subject(s)
Argininosuccinate Synthase/physiology , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/pathology , STAT3 Transcription Factor/antagonists & inhibitors , Animals , Argininosuccinate Synthase/antagonists & inhibitors , Argininosuccinate Synthase/genetics , Carcinoma, Hepatocellular/enzymology , Cell Line, Tumor , Cell Movement , DNA Methylation , Humans , Inhibitor of Differentiation Protein 1/genetics , Liver Neoplasms/enzymology , Mice , Neoplasm Invasiveness , Neoplasm Metastasis/prevention & control , STAT3 Transcription Factor/physiology , Signal Transduction/physiologyABSTRACT
Emerging evidence has indicated that deregulation of long non-coding RNAs (lncRNAs) can contribute to the progression and metastasis of human cancer, including hepatocellular carcinoma (HCC). However, the roles of most lncRNAs in HCC remain largely unknown. Here we found a long noncoding RNA termed SchLAH (seven chromosome locus associated with HCC; also called BC035072) was generally downregulated in HCC. Low expression of SchLAH was significantly correlated with shorter overall survival of HCC patients. In vitro and in vivo assays indicated that overexpression of SchLAH inhibited the migration and lung metastasis of HCC cells. Knockdown of SchLAH by siRNA pool promoted the migration of HCC cells. RNA pull-down and RNA immunoprecipitation assays demonstrated SchLAH physically interacted with fused in sarcoma (FUS). PCR array analysis showed that RhoA and Rac1 were the downstream effector molecules of SchLAH during HCC metastasis. Knockdown of FUS rescued the mRNA levels of RhoA and Rac1 that were repressed by SchLAH. These results suggest that SchLAH may suppress the metastasis of HCC cells by interacting with FUS, which indicates potential of SchLAH for the prognosis and treatment of HCC.
Subject(s)
Carcinoma, Hepatocellular/genetics , Gene Expression Regulation, Neoplastic , Liver Neoplasms/genetics , RNA, Long Noncoding/genetics , RNA-Binding Protein FUS/genetics , Animals , Blotting, Western , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Cell Movement/genetics , Hep G2 Cells , Humans , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Mice, Inbred BALB C , Mice, Nude , Neoplasm Metastasis , Prognosis , Protein Binding , RNA Interference , RNA, Long Noncoding/metabolism , RNA-Binding Protein FUS/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Transplantation, Heterologous , rac1 GTP-Binding Protein/genetics , rac1 GTP-Binding Protein/metabolism , rhoA GTP-Binding Protein/genetics , rhoA GTP-Binding Protein/metabolismABSTRACT
BACKGROUND/AIMS: Circulating long non coding RNAs (lncRNAs) have emerged recently as major players in tumor biology and may be used for cancer diagnosis, prognosis, and as potential therapeutic targets. We explored circulating lncRNA as a predictor for the tumorigenesis of non-small-cell lung cancer (NSCLC). METHODS: In this study, we applied a lncRNA microarray to screen for a potential biomarker for NSCLC, utilizing RT-PCR (ABI 7900HT). A multi-stage validation and risk score formula detection analysis was used. RESULTS: We discovered that three lncRNAs (RP11-397D12.4, AC007403.1, and ERICH1-AS1) were up regulated in NSCLC, compared with cancer-free controls, with the merged area under the curve in the training and validation sets of 0.986 and 0.861. Furthermore, the positive predictive value and negative predictive value of the three merged factors were 0.72 and 0.87. We confirmed stable detection of the three lncRNAs by three cycles of freezing and thawing. CONCLUSIONS: RP11-397D12.4, AC007403.1, and ERICH1-AS1 may be potential biomarkers for predicting the tumorigenesis of NSCLC in the future.
Subject(s)
Biomarkers, Tumor/blood , Carcinoma, Non-Small-Cell Lung/genetics , Gene Expression Profiling/methods , Lung Neoplasms/genetics , RNA, Long Noncoding/blood , Biomarkers, Tumor/genetics , Carcinoma, Non-Small-Cell Lung/blood , Carcinoma, Non-Small-Cell Lung/pathology , China , Female , Gene Expression Regulation, Neoplastic , Genetic Predisposition to Disease , Humans , Lung Neoplasms/blood , Lung Neoplasms/pathology , Male , Middle Aged , Oligonucleotide Array Sequence Analysis/methods , Prognosis , Reverse Transcriptase Polymerase Chain Reaction/methods , Up-RegulationABSTRACT
Resveratrol, a natural polyphenolic compound found in foods and beverages, has attracted increasing attention in recent years because of its potent chemopreventive and anti-tumor effects. In this study, the effects of resveratrol on the expression of P-glycoprotein/multi-drug resistance protein 1 (P-gp/MDR1), and the underlying molecular mechanisms, were investigated in oxaliplatin (L-OHP)-resistant colorectal cancer cells (HCT116/L-OHP). Resveratrol downregulated MDR1 protein and mRNA expression levels and reduced MDR1 promoter activity. It also enhanced the intracellular accumulation of rhodamine 123, suggesting that resveratrol can reverse multi-drug resistance by downregulating MDR1 expression and reducing drug efflux. Resveratrol treatment also reduced nuclear factor-κB (NF-κB) activity, reduced phosphorylation levels of IκBα, and reduced nuclear translocation of the NF-κB subunit p65. Moreover, downregulation of MDR1 expression and promoter activity was mediated by resveratrol-induced AMP-activated protein kinase (AMPK) phosphorylation. The inhibitory effects of resveratrol on MDR1 expression and cAMP-responsive element-binding protein (CREB) phosphorylation were reversed by AMPKα siRNA transfection. We found that the transcriptional activity of cAMP-responsive element (CRE) was inhibited by resveratrol. These results demonstrated that the inhibitory effects of resveratrol on MDR1 expression in HCT116/L-OHP cells were closely associated with the inhibition of NF-κB signaling and CREB activation in an AMPK-dependent manner.
Subject(s)
AMP-Activated Protein Kinases/biosynthesis , Colorectal Neoplasms/genetics , Stilbenes/administration & dosage , eIF-2 Kinase/genetics , AMP-Activated Protein Kinases/genetics , ATP Binding Cassette Transporter, Subfamily B/biosynthesis , ATP Binding Cassette Transporter, Subfamily B/genetics , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Cyclic AMP Response Element-Binding Protein/genetics , Doxorubicin/administration & dosage , Drug Resistance, Multiple/genetics , Drug Resistance, Neoplasm/genetics , Gene Expression Regulation, Neoplastic/drug effects , HCT116 Cells , Humans , I-kappa B Proteins/biosynthesis , I-kappa B Proteins/genetics , NF-KappaB Inhibitor alpha , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Resveratrol , Signal Transduction/drug effects , Transcriptional Activation/drug effects , eIF-2 Kinase/biosynthesisABSTRACT
BACKGROUND: Hepatic stellate cell (HSC) activation is activated mainly by endotoxin and transforming growth factor (TGF-ß1) in chronic liver injury, consequently, can be important therapeutic targets. Xia-yu-xue decoction (XYXD), a classical recipe used in China to treat liver fibrosis, and has been revealed to inhibit hepatic fibrosis in animal models, the mechanism of action of XYXD remains elusive. In the present study, we evaluated whether XYXD reduced endotoxin and pro-fibrogenic pathways induced by lipopolysaccharide (LPS) and TGF-ß1 in HSCs. METHODS: The in vivo effect of XYXD on fibrosis progression was assessed in mice model induced by carbon tetrachloride (CCl4), The in vitro effect of XYXD on mice GFP-Col-HSC cells was evaluated using LPS and TGF-ß1 stimulation. RESULTS: XYXD treatment reduced CCl4-induced liver fibrosis and decreased hepatic hydroxyproline (Hyp) content, the mRNA levels of smooth muscle actin (α-SMA) and Col 1(α1) in fibrotic liver. XYXD suppressed nuclear factor-κB (NF-κB) activation induced by LPS and TGF-ß1 assessed by using NF-κB-luciferase reporter. The expression of NF-κB target genes, chemokine (C-C motif) ligand 2 (CCL2) and chemokine (C-X-C motif) ligand 2 (CXCL2) induced by LPS was suppressed after XYXD treatment. The expression of TGF-ß1 targets genes, Col1(α1) and tissue inhibitor of metalloproteinases (TIMP1) induced by TGF-ß1 was inhibit after XYXD treatment. CONCLUSION: XYXD treatment attenuates liver fibrosis by inhibiting HSC activation via inhibition of NF-κB and TGF-ß1 signaling pathway, thereby blocking the synthesis of Col1 (α1) and TIMP-1. These findings from present study suggest that XYXD may be a therapeutic decoction for liver fibrosis in which NF-κB and TGF-ß1 are thought to take part.
Subject(s)
Carbon Tetrachloride/adverse effects , Drugs, Chinese Herbal/pharmacology , Hepatic Stellate Cells/drug effects , Liver Cirrhosis , NF-kappa B/metabolism , Signal Transduction/drug effects , Transforming Growth Factor beta1/metabolism , Animals , Cells, Cultured , Liver Cirrhosis/chemically induced , Liver Cirrhosis/metabolism , MiceABSTRACT
Myasthenia gravis (MG) are T-cell dependent antibody-mediated autoimmune disorders, microRNAs are important regulators of human autoimmune disease pathogenesis. Here, we investigated the miRNAs expression profiles in MG for the first time and found that miR-320a was significantly downregulated in MG patients compared to normal healthy people. Meanwhile, pro-inflammatory cytokins in MG patients were overexpressed. Furthermore, we identified MAPK1 as a direct target of miR-320a. Downregulation of miR-320a induced the overexpression of pro-inflammatory cytokins through promoting COX-2 expression. This process was modulated by ERK/ NF-κB pathways. Taken together, our findings suggested that miR-320a could play a role in modulation of inflammatory cytokins production.
Subject(s)
Cytokines/genetics , Inflammation Mediators , MicroRNAs/genetics , Mitogen-Activated Protein Kinase 1/genetics , Myasthenia Gravis/genetics , Adult , Aged , Base Sequence , Case-Control Studies , Cell Line, Tumor , Cluster Analysis , Cytokines/metabolism , Female , Gene Expression Profiling , Gene Expression Regulation , Humans , Male , MicroRNAs/chemistry , Middle Aged , Mitogen-Activated Protein Kinase 1/metabolism , Myasthenia Gravis/metabolism , NF-kappa B/metabolism , RNA Processing, Post-Transcriptional , Signal TransductionABSTRACT
Previous studies have reported that 8-c [6-(2-(2-(dimethylamino)ethylamino)ethylamino)-2-octyl-1H-benzo[de]isoquinoline-1,3(2H)-dione], a novel amonafide analogue, was generated as a new anticancer candidate. However, little is known about its activity in chemoresistant cells. In this study, the antitumor effects of 8-c on the multi-drug-resistant human colorectal carcinoma cancer cell lines HCT-116/L-OHP and HCT-8/VCR have been investigated for the first time. 8-c showed similar concentration-dependent inhibitory activities against multi-drug-resistant cells and corresponding parental cell lines by the MTT assay after 48 h of treatment. 8-c treatment resulted in the induction of apoptosis, as evidenced by fluorescent staining analysis, comet assay data, and the increase in the number of apoptotic cells as detected by flow cytometry. Western blot, qPCR, and siRNA techniques were used to elucidate the molecular mechanism. Our study suggested that the apoptotic effect of 8-c can be attributed to the upregulation of p53, caspase-3, and cleaved poly(ADP-ribose) polymerase (PARP) and the downregulation of Bcl-2. Furthermore, ERCC1 is essential for nucleotide excision repair. ERCC1 expression was correlated with sensitivity to chemotherapy in various colon cancer cell lines. It is intriguing that decreases in ERCC1 protein and mRNA levels were also observed in the HCT-116/L-OHP and HCT-8/VCR cells after exposure to 8-c. Further transient transfection of multi-drug-resistant cells with ERCC1 siRNA enhanced 8-c-induced cytotoxicity. In contrast, epidermal growth factor-induced increase in ERCC1 protein levels was shown to rescue cell viability upon 8-c treatment. These findings suggest that 8-c has a strong potential to be developed as a new antitumor agent for the treatment of multi-drug-resistant colon cancer cells, and is worthy of further studies.
Subject(s)
Adenocarcinoma/pathology , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Colorectal Neoplasms/pathology , DNA-Binding Proteins/biosynthesis , Endonucleases/biosynthesis , Gene Expression Regulation, Neoplastic/drug effects , Naphthalimides/pharmacology , Neoplasm Proteins/biosynthesis , Adenocarcinoma/genetics , Adenocarcinoma/metabolism , Apoptosis Regulatory Proteins/biosynthesis , Apoptosis Regulatory Proteins/genetics , Cell Line, Tumor/drug effects , Cell Line, Tumor/metabolism , Cell Shape/drug effects , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Comet Assay , DNA Damage , DNA Repair , DNA-Binding Proteins/genetics , Dose-Response Relationship, Drug , Drug Resistance, Multiple/drug effects , Drug Resistance, Neoplasm/drug effects , Drug Screening Assays, Antitumor , Endonucleases/genetics , Humans , Neoplasm Proteins/genetics , RNA Interference , RNA, Small Interfering/pharmacology , Single-Cell AnalysisABSTRACT
Extra copies of centrosomes are frequently observed in cancer cells. To survive and proliferate, cancer cells have developed strategies to cluster extra-centrosomes to form bipolar mitotic spindles. The aim of this study was to investigate whether centrosome clustering (CC) inhibition (CCi) would preferentially radiosensitize non-small cell lung cancer (NSCLC). Griseofulvin (GF; FDA-approved treatment) inhibits CC, and combined with radiation treatment (RT), resulted in a significant increase in the number of NSCLC cells with multipolar spindles, and decreased cell viability and colony formation ability in vitro. In vivo, GF treatment was well tolerated by mice, and the combined therapy of GF and radiation treatment resulted in a significant tumor growth delay. Both GF and radiation treatment also induced the generation of micronuclei (MN) in vitro and in vivo and activated cyclic GMP-AMP synthase (cGAS) in NSCLC cells. A significant increase in downstream cGAS-STING pathway activation was seen after combination treatment in A549 radioresistant cells that was dependent on cGAS. In conclusion, GF increased radiation treatment efficacy in lung cancer preclinical models in vitro and in vivo. This effect may be associated with the generation of MN and the activation of cGAS. These data suggest that the combination therapy of CCi, radiation treatment, and immunotherapy could be a promising strategy to treat NSCLC.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Animals , Mice , Griseofulvin/pharmacology , Griseofulvin/metabolism , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/radiotherapy , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/pathology , Centrosome , NucleotidyltransferasesABSTRACT
Background & Aims: Exploiting key regulators responsible for hepatocarcinogenesis is of great importance for the prevention and treatment of hepatocellular carcinoma (HCC). However, the key players contributing to hepatocarcinogenesis remain poorly understood. We explored the molecular mechanisms underlying the carcinogenesis and progression of HCC for the development of potential new therapeutic targets. Methods: The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) and Genotype-Tissue Expression (GTEx) databases were used to identify genes with enhanced expression in the liver associated with HCC progression. A murine liver-specific Ftcd knockout (Ftcd-LKO) model was generated to investigate the role of formimidoyltransferase cyclodeaminase (FTCD) in HCC. Multi-omics analysis of transcriptomics, metabolomics, and proteomics data were applied to further analyse the molecular effects of FTCD expression on hepatocarcinogenesis. Functional and biochemical studies were performed to determine the significance of loss of FTCD expression and the therapeutic potential of Akt inhibitors in FTCD-deficient cancer cells. Results: FTCD is highly expressed in the liver but significantly downregulated in HCC. Patients with HCC and low levels of FTCD exhibited worse prognosis, and patients with liver cirrhosis and low FTCD levels exhibited a notable higher probability of developing HCC. Hepatocyte-specific knockout of FTCD promoted both chronic diethylnitrosamine-induced and spontaneous hepatocarcinogenesis in mice. Multi-omics analysis showed that loss of FTCD affected fatty acid and cholesterol metabolism in hepatocarcinogenesis. Mechanistically, loss of FTCD upregulated peroxisome proliferator-activated receptor (PPAR)γ and sterol regulatory element-binding protein 2 (SREBP2) by regulating the PTEN/Akt/mTOR signalling axis, leading to lipid accumulation and hepatocarcinogenesis. Conclusions: Taken together, we identified a FTCD-regulated lipid metabolic mechanism involving PPARγ and SREBP2 signaling in hepatocarcinogenesis and provide a rationale for therapeutically targeting of HCC driven by downregulation of FTCD. Impact and implications: Exploiting key molecules responsible for hepatocarcinogenesis is significant for the prevention and treatment of HCC. Herein, we identified formimidoyltransferase cyclodeaminase (FTCD) as the top enhanced gene, which could serve as a predictive and prognostic marker for patients with HCC. We generated and characterised the first Ftcd liver-specific knockout murine model. We found loss of FTCD expression upregulated peroxisome proliferator-activated receptor (PPAR)γ and sterol regulatory element-binding protein 2 (SREBP2) by regulating the PTEN/Akt/mTOR signalling axis, leading to lipid accumulation and hepatocarcinogenesis, and provided a rationale for therapeutic targeting of HCC driven by downregulation of FTCD.
ABSTRACT
Lung cancer is the most common cancer and the leading cause of cancer deaths worldwide. In addition to coding genes, the contribution of long noncoding RNA (lncRNA) to non-small cell lung cancer (NSCLC) remains unclear. Here, we explored lncRNA expression profiles by Affymetrix Gene Chip Human Transcriptome Array 2.0 in 37 paired samples of tumorous NSCLC tissues and adjacent nontumorous tissues. We showed that LHFPL3-AS2 is a novel lncRNA, significantly decreased in NSCLC tissues. LHFPL3-AS2 was further validated in an additional 93 paired samples of NSCLC. Low levels of LHFPL3-AS2 expression were highly correlated with poor overall survival, TNM stage, and metastasis of NSCLC patients. Enhanced expression of LHFPL3-AS2 inhibited NSCLC invasion and metastasis in vitro and in vivo. Moreover, downregulation of LHFPL3-AS2 reduced its specific interaction with SFPQ, resulting in more SFPQ binding to the promoter of TXNIP and causing the transcriptional repression of TXNIP, thus finally promoting the migration and invasion of NSCLC cells. Furthermore, LHFPL3-AS2 was shown to be regulated by EGR1 under hypoxia.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , RNA, Long Noncoding , Carcinoma, Non-Small-Cell Lung/pathology , Carrier Proteins/genetics , Carrier Proteins/metabolism , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Humans , Lung Neoplasms/metabolism , Membrane Proteins , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolismABSTRACT
BACKGROUND: Numerous studies have used multi-region sampling approaches to characterize intra-tumor heterogeneity (ITH) in hepatocellular carcinoma (HCC). However, conventional multi-region sampling strategies do not preserve the spatial details of samples, and thus, the potential influences of spatial distribution on patient-wise ITH (represents the overall heterogeneity level of the tumor in a given patient) have long been overlooked. Furthermore, gene-wise transcriptional ITH (represents the expression pattern of genes across different intra-tumor regions) in HCC is also under-explored, highlighting the need for a comprehensive investigation. METHODS: To address the problem of spatial information loss, we propose a simple and easy-to-implement strategy called spatial localization sampling (SLS). We performed multi-region sampling and sequencing on 14 patients with HCC, collecting a total of 75 tumor samples with spatial information and molecular data. Normalized diversity score and integrated heterogeneity score (IHS) were then developed to measure patient-wise and gene-wise ITH, respectively. RESULTS: A significant correlation between spatial and molecular heterogeneity was uncovered, implying that spatial distribution of sampling sites did influence ITH estimation in HCC. We demonstrated that the normalized diversity score had the ability to overcome sampling location bias and provide a more accurate estimation of patient-wise ITH. According to this metric, HCC tumors could be divided into two classes (low-ITH and high-ITH tumors) with significant differences in multiple biological properties. Through IHS analysis, we revealed a highly heterogenous immune microenvironment in HCC and identified some low-ITH checkpoint genes with immunotherapeutic potential. We also constructed a low-heterogeneity risk stratification (LHRS) signature based on the IHS results which could accurately predict the survival outcome of patients with HCC on a single tumor biopsy sample. CONCLUSIONS: This study provides new insights into the complex phenotypes of HCC and may serve as a guide for future studies in this field.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Liver Neoplasms/genetics , Carcinoma, Hepatocellular/genetics , High-Throughput Nucleotide Sequencing , Risk Assessment , Tumor Microenvironment/geneticsABSTRACT
Circular RNAs (circRNA) are a class of covalently closed single-stranded RNAs that have been implicated in cancer progression. Here we identify circNDUFB2 to be downregulated in non-small cell lung cancer (NSCLC) tissues, and to negatively correlate with NSCLC malignant features. Elevated circNDUFB2 inhibits growth and metastasis of NSCLC cells. Mechanistically, circNDUFB2 functions as a scaffold to enhance the interaction between TRIM25 and IGF2BPs, a positive regulator of tumor progression and metastasis. This TRIM25/circNDUFB2/IGF2BPs ternary complex facilitates ubiquitination and degradation of IGF2BPs, with this effect enhanced by N6-methyladenosine (m6A) modification of circNDUFB2. Moreover, circNDUFB2 is also recognized by RIG-I to activate RIG-I-MAVS signaling cascades and recruit immune cells into the tumor microenvironment (TME). Our data thus provide evidences that circNDUFB2 participates in the degradation of IGF2BPs and activation of anti-tumor immunity during NSCLC progression via the modulation of both protein ubiquitination and degradation, as well as cellular immune responses.
Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/immunology , Disease Progression , Lung Neoplasms/genetics , Lung Neoplasms/immunology , RNA, Circular/metabolism , RNA-Binding Proteins/metabolism , Animals , Carcinoma, Non-Small-Cell Lung/pathology , Cell Proliferation , DEAD Box Protein 58/metabolism , Down-Regulation/genetics , Female , Gene Expression Regulation, Neoplastic , Humans , Lung Neoplasms/pathology , Mice, Inbred BALB C , Mice, Nude , Models, Biological , Neoplasm Metastasis , Proteasome Endopeptidase Complex/metabolism , Protein Binding , Protein Stability , Proteolysis , RNA, Circular/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Immunologic , Transcription Factors/metabolism , Tripartite Motif Proteins/metabolism , Ubiquitin/metabolism , Ubiquitin-Protein Ligases/metabolism , UbiquitinationABSTRACT
BACKGROUND: Biological role and clinical significance of circular RNAs (circRNAs) remain largely unknown. Herein, we aimed to investigate biological function, molecular mechanism, and clinical significance of a circular RNA FOXM1 (circFOXM1) in non-small cell lung cancer (NSCLC). METHODS: Expression of circFOXM1 was measured in 48 paired samples of NSCLC by qRT-PCR. Functional roles of circFOXM1 on tumor cells were explored by in vitro and in vivo assays. Transcriptome sequencing was employed to screen the molecules involved in circFOXM1 regulatory network. RNA immunoprecipitation, luciferase analysis, RNA pull-down, and rescue assay were used to investigate potential mechanisms of circFOXM1. RESULTS: We found that circFOXM1 was significantly upregulated in NSCLC tissues, and its upregulation was positively correlated with advanced clinical stage and poor prognosis of NSCLC patients. Gain or loss-of-function assay showed that circFOXM1 promoted cell proliferation and cell cycle progression. In vivo assays showed that silencing circFOXM1 inhibited xenograft tumor growth. Mechanically, transcriptome sequencing data indicated that silencing circFOXM1 led to the downregulation of cell cycle-related mRNAs. RNA pull-down and dual-luciferase reporter assay suggested that circFOXM1 could bind to miR-614, and FAM83D was an essential gene involved in the circFOXM1/miR-614 regulatory network. CONCLUSIONS: circFOXM1promotes NSCLC progression by interacting with miR-614 and thus inactivating the function of miR-614, which will further release the suppression of FAM83D. circFOXM1/miR-614/FAM83D regulatory network may serve as a potential therapeutic target for NSCLC patients.
Subject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Cell Cycle Proteins/metabolism , Forkhead Box Protein M1/genetics , Lung Neoplasms/metabolism , Microtubule-Associated Proteins/metabolism , RNA, Circular/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Cell Cycle Proteins/genetics , Cell Line, Tumor , Cell Proliferation/physiology , Female , Forkhead Box Protein M1/metabolism , Humans , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Male , Microtubule-Associated Proteins/genetics , Middle Aged , RNA, Circular/genetics , Up-RegulationABSTRACT
Alterations in cellular metabolism are one of the characteristics in cancer. They are not only the result of tumor progression but also the cause of cancer initiation. Pyruvate dehydrogenase kinase 4 (PDK4) is a key metabolic enzyme, which regulates cell metabolism by inhibiting pyruvate dehydrogenase (PDH). However, the function and regulating mechanism of PDK4 in HCC remain unclear. Here, we found that the expression of PDK4 was significantly decreased in HCC tissues, and its downregulation could predict poor prognosis of HCC patients. Silencing PDK4 significantly facilitated proliferation and migration of HCC cells. Knockdown of PDK4 didn't influence the oxidative phosphorylation and glycolysis capacity of HCC cells in vitro. However, knockdown of PDK4 increased expression of key lipogenic enzymes, fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD), which finally induced lipogenesis. These data suggest that PDK4 inhibits proliferation and migration of HCC cells probably via suppressing lipogenesis.
ABSTRACT
Circular RNAs (circRNAs) are identified as vital regulators in a variety of cancers. However, the role of circRNA in lung squamous cell carcinoma (LUSC) remains largely unknown. Herein, we explore the expression profiles of circRNA and mRNA in 5 paired samples of LUSC. By analyzing the co-expression network of differentially expressed circRNAs and dysregulated mRNAs, we identify that a cell cycle-related circRNA, circTP63, is upregulated in LUSC tissues and its upregulation is correlated with larger tumor size and higher TNM stage in LUSC patients. Elevated circTP63 promotes cell proliferation both in vitro and in vivo. Mechanistically, circTP63 shares miRNA response elements with FOXM1. circTP63 competitively binds to miR-873-3p and prevents miR-873-3p to decrease the level of FOXM1, which upregulates CENPA and CENPB, and finally facilitates cell cycle progression.
Subject(s)
Carcinoma, Squamous Cell/metabolism , Disease Progression , Forkhead Box Protein M1/metabolism , Gene Expression Regulation, Neoplastic , RNA, Circular/metabolism , Transcription Factors/metabolism , Tumor Suppressor Proteins/metabolism , Up-Regulation , Animals , Carcinoma, Squamous Cell/genetics , Cell Cycle/physiology , Cell Line, Tumor , Cell Proliferation , Centromere Protein A/metabolism , Centromere Protein B/metabolism , Female , Gene Expression Profiling , Gene Regulatory Networks , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Male , Mice, Inbred BALB C , MicroRNAs , Middle Aged , Neoplasms, Experimental , RNA, Circular/genetics , RNA, Messenger/metabolism , Transcription Factors/genetics , Transcriptome , Tumor Suppressor Proteins/geneticsABSTRACT
Long noncoding RNAs (lncRNAs) are implicated as novel drivers in hepatocellular carcinoma (HCC), but the underlying mechanisms of this relationship with hepatocarcinogenesis are unknown. We report a novel, liver-specific lncRNA LINC01093 that shows significant downregulation in HCC tissues. LINC01093 expression is inversely correlated with cancer embolus and HCC TNM stage and as a prognostic predictor for HCC patients. LINC01093 overexpression significantly suppresses HCC cell proliferation and metastasis in vitro and in vivo. Conversely, its knockdown promotes HCC progression. Mechanistic analyses indicate that LINC01093 directly binds insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), interfering with interaction between IGF2BP1 and glioma-associated oncogene homolog 1 (GLI1) mRNA. The result is degradation of GLI1 mRNA, further affecting expression of GLI1 downstream molecules involved in HCC progression. The liver-enriched lncRNA LINC01093 is a promising prognostic indicator for HCC patients, and the newly identified LINC01093-IGF2BP1-GLI1 axis shows potential for therapeutic targets in HCC.
Subject(s)
Carcinoma, Hepatocellular/genetics , Liver Neoplasms/genetics , RNA, Long Noncoding/metabolism , RNA-Binding Proteins/metabolism , Zinc Finger Protein GLI1/genetics , Animals , Carcinogenesis , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Down-Regulation , Genes, Tumor Suppressor , Heterografts , Humans , Liver Neoplasms/metabolism , Mice , Neoplasm Metastasis , RNA, Long Noncoding/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA-Binding Proteins/genetics , Zinc Finger Protein GLI1/metabolismABSTRACT
In lung cancer and other malignancies, the so-called "liquid biopsy" is quickly moving into clinical practice. Its full potential has not yet been fully identified, but the "liquid biopsy" is no longer a promise but has become a reality that allows for better treatment selection and monitoring of lung cancer. This emerging field has significant potential to make up for the limitations of the traditional tissue-derived biomaterials. Exosomes are spherical nano-sized vesicles with a diameter of 40-100â¯nm and a density of 1.13-1.19â¯g/ml. In both physiological and pathological conditions, exosomes can be released by different cell types, including immune cells, stem cells and tumor cells. These small molecules may serve as promising biomarkers in lung cancer "liquid biopsy" as they can be easily obtained from most body fluids. In addition, the lipid bilayer of exosomes allows for stable cargoes which are relatively hard to degrade. Furthermore, the composition of exosomes reflects that of their parental cells, suggesting that exosomes are potential surrogates of the original cells and, therefore, are useful for understanding cell biology. Previous studies have demonstrated that exosomes play important roles in cell-to-cell communication. Moreover, tumor-derived exosomes are evolved in tumor-specific biological process, including tumor proliferation and progression. Recently, a growing number of studies has focused on exosomal cargo and their use in lung cancer genesis and progression. In addition, their utility as lung cancer diagnostic, prognostic and predictive biomarkers have also been studied. The current review primarily summaries lung cancer-related exosomal biomarkers that have recently been identified and discusses their potential in clinical practice.
Subject(s)
Exosomes/pathology , Liquid Biopsy/methods , Lung Neoplasms/pathology , HumansABSTRACT
Hypertension is one of the most frequent complications of solid organ transplantation, and cyclosporin A (CsA) plays a predominant role in the pathophysiology of post-transplant hypertension. However, the exact molecular mechanisms of CsA-induced hypertension remain obscure. We previously showed that CsA increased the mRNA expression and contractile function of endothelin B (ETB) receptor in vascular smooth muscle cells. The present study was designed to investigate the underlying mechanisms of CsA-induced upregulation of ETB receptor in vasculature. Rat mesenteric arteries were incubated with CsA in an organ culture system, and results showed that CsA enhanced ETB receptor mRNA in the time- and dose-dependent manner, and increased protein expression levels of ETB receptor after treatment with CsA 10(-5)M for 6h. Furthermore, CsA induced phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2), p38, and translocation of nuclear factor-kappaB (NF-κB) p65 in vasculature. Blocking ERK1/2, p38, or NF-κB activation with their specific inhibitors markedly attenuated CsA-induced upregulation of ETB receptor mRNA expression and protein levels, and ETB receptor-mediated contraction. In summary, this study showed that mitogen-activating protein kinases (ERK1/2 and p38) and the downstream transcriptional factor NF-κB pathways were involved in CsA-induced upregulation of ETB receptor in arterial smooth muscle cells.