Tumor Hypoxia Regulates Forkhead Box C1 to Promote Lung Cancer Progression

CKLF1, transcriptionally activated by FOXC1, promotes hypoxia/reoxygenation‑induced oxidative stress and inflammation in H9c2 cells by NLRP3 inflammasome activation

Myocardial ischemia/reperfusion (I/R) injury is a clinical challenge in the treatment of ischemic heart disease. The present study aimed to establish a hypoxia/reoxygenation (H/R)-induced H9c2 cell model to explore the role and mechanism of chemokine-like factor 1 (CKLF1) in myocardial I/R injury. First, CKLF1 expression was measured in H/R-induced H9c2 cells by reverse transcription-quantitative PCR and western blotting. Subsequently, after CKLF1 silencing, cell viability and apoptosis were evaluated by Cell Counting Kit-8 assay and flow cytometry. In addition, 2,7-dichlorodihydrofluorescein diacetate staining was used to assess the levels of cellular reactive oxygen species. Additionally, the levels of superoxide dismutase, glutathione peroxidase and malondialdehyde, and the contents of inflammatory factors IL-6, IL-1β and TNF-α were detected using corresponding commercially available kits. Western blotting was used to examine the expression levels of proteins involved in the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome. The JASPAR database predicted that forkhead box protein C1 (FOXC1) would bind to the CKLF1 promoter region, and dual luciferase and chromatin immunoprecipitation assays were performed to verify it. Subsequently, FOXC1 overexpression and CKLF1 silencing were used to clarify the regulatory mechanism of FOXC1 on CKLF1 in H/R-induced H9c2 cells. The results revealed that CKLF1 expression was markedly enhanced in H/R-stimulated H9c2 cells. CKLF1 knockdown enhanced the viability and inhibited the apoptosis of H9c2 cells exposed to H/R. Moreover, the oxidative stress and inflammation induced by H/R were alleviated following CKLF1 silencing. CKLF1 knockdown also inhibited NLRP3 inflammasome activation. Furthermore, FOXC1 bound to the CKLF1 promoter region to upregulate CKLF1 expression, and FOXC1 overexpression alleviated the effects of CKLF1 knockdown on H9c2 cell damage induced by H/R via activation of the NLRP3 inflammasome. In conclusion, CKLF1 transcriptionally activated by FOXC1 may promote H/R-induced oxidative stress and inflammation in H9c2 cells via NLRP3 inflammasome activation.

Identification of genetic biomarkers, drug targets and agents for respiratory diseases utilising integrated bioinformatics approaches

Respiratory diseases (RD) are significant public health burdens and malignant diseases worldwide. However, the RD-related biological information and interconnection still need to be better understood. Thus, this study aims to detect common differential genes and potential hub genes (HubGs), emphasizing their actions, signaling pathways, regulatory biomarkers for diagnosing RD and candidate drugs for treating RD. In this paper we used integrated bioinformatics approaches (such as, gene ontology (GO) and KEGG pathway enrichment analysis, molecular docking, molecular dynamic simulation and network-based molecular interaction analysis). We discovered 73 common DEGs (CDEGs) and ten HubGs (ATAD2B, PPP1CB, FOXO1, AKT3, BCR, PDE4D, ITGB1, PCBP2, CD44 and SMARCA2). Several significant functions and signaling pathways were strongly related to RD. We recognized six transcription factor (TF) proteins (FOXC1, GATA2, FOXL1, YY1, POU2F2 and HINFP) and five microRNAs (hsa-mir-218-5p, hsa-mir-335-5p, hsa-mir-16-5p, hsa-mir-106b-5p and hsa-mir-15b-5p) as the important transcription and post-transcription regulators of RD. Ten HubGs and six major TF proteins were considered drug-specific receptors. Their binding energy analysis study was carried out with the 63 drug agents detected from network analysis. Finally, the five complexes (the PDE4D-benzo[a]pyrene, SMARCA2-benzo[a]pyrene, HINFP-benzo[a]pyrene, CD44-ketotifen and ATAD2B-ponatinib) were selected for RD based on their strong binding affinity scores and stable performance as the most probable repurposable protein-drug complexes. We believe our findings will give readers, wet-lab scientists, and pharmaceuticals a thorough grasp of the biology behind RD.

Glycine Decarboxylase (GLDC) Plays a Crucial Role in Regulating Energy Metabolism, Invasion, Metastasis and Immune Escape for Prostate Cancer

Glycine decarboxylase (GLDC) is one of the core enzymes for glycine metabolism, and its biological roles in prostate cancer (PCa) are unclear. First, we found that GLDC plays a central role in glycolysis in 540 TCGA PCa patients. Subsequently, a metabolomic microarray showed that GLDC enhanced aerobic glycolysis in PCa cells, and GLDC and its enzyme activity enhanced glucose uptake, lactate production and lactate dehydrogenase (LDH) activity in PCa cells. Next, we found that GLDC was highly expressed in PCa, was directly regulated by hypoxia-inducible factor (HIF1-α) and regulated downstream LDHA expression. In addition, GLDC and its enzyme activity showed a strong ability to promote the migration and invasion of PCa both in vivo and in vitro. Furthermore, we found that the GLDC-high group had a higher TP53 mutation frequency, lower CD8+ T-cell infiltration, higher immune checkpoint expression, and higher immune exclusion scores than the GLDC-low group. Finally, the GLDC-based prognostic risk model by applying LASSO Cox regression also showed good predictive power for the clinical characteristics and survival in PCa patients. This evidence indicates that GLDC plays crucial roles in glycolytic metabolism, invasion and metastasis, and immune escape in PCa, and it is a potential therapeutic target for prostate cancer.

Elevated galectin-3 levels detected in women with hyperglycemia during early and mid-pregnancy antagonizes high glucose - induced trophoblast cells apoptosis via galectin-3/foxc1 pathway

OBJECTIVE

This study was to evaluate plasma galectin-3 levels from early pregnancy to delivery and explore the effects of galectin-3 on the function of trophoblast cells under high glucose exposure.

METHODS

The plasma galectin-3 levels were quantified by enzyme-linked immunosorbent assay (ELISA) in the China National Birth Cohort (CNBC) at Peking University First Hospital, and the underlying signaling pathway was identified by protein-protein interaction (PPI) analysis, gene set enrichment analysis (GSEA), quantitative PCR (qPCR), western blotting, small interfering RNA (siRNA) transfections, and flow cytometry.

RESULTS

Significantly higher galectin-3 levels were found in patients with gestational diabetes mellitus (GDM group; n = 77) during the first and second trimesters than that in healthy pregnant women (HP group; n = 113) (P < 0.05). No significant differences in plasma galectin-3 levels were detected between GDM and HP groups in maternal third-trimester blood and cord blood. PPI analysis suggested potential interactions between galectin-3 and foxc1. The findings of GSEA showed that galectin-3 was involved in the cytochrome P450-related and complement-related pathways, and foxc1 was associated with type I diabetes mellitus. Additionally, high glucose (25 mM) significantly increased the expression levels of galectin-3 and foxc1 and induced apoptosis in HTR-8/SVneo cells. Further in vitro experiments showed that galectin-3/foxc1 pathway could protect HTR-8/SVneo cells against high glucose - induced apoptosis.

CONCLUSION

Future studies were required to validate whether plasma galectin-3 might become a potential biomarker for hyperglycemia during pregnancy. Elevated galectin-3 levels might be a vital protective mechanism among those exposed to hyperglycemia during pregnancy.

Pathogenesis of allergic diseases and implications for therapeutic interventions

Allergic diseases such as allergic rhinitis (AR), allergic asthma (AAS), atopic dermatitis (AD), food allergy (FA), and eczema are systemic diseases caused by an impaired immune system. Accompanied by high recurrence rates, the steadily rising incidence rates of these diseases are attracting increasing attention. The pathogenesis of allergic diseases is complex and involves many factors, including maternal-fetal environment, living environment, genetics, epigenetics, and the body's immune status. The pathogenesis of allergic diseases exhibits a marked heterogeneity, with phenotype and endotype defining visible features and associated molecular mechanisms, respectively. With the rapid development of immunology, molecular biology, and biotechnology, many new biological drugs have been designed for the treatment of allergic diseases, including anti-immunoglobulin E (IgE), anti-interleukin (IL)-5, and anti-thymic stromal lymphopoietin (TSLP)/IL-4, to control symptoms. For doctors and scientists, it is becoming more and more important to understand the influencing factors, pathogenesis, and treatment progress of allergic diseases. This review aimed to assess the epidemiology, pathogenesis, and therapeutic interventions of allergic diseases, including AR, AAS, AD, and FA. We hope to help doctors and scientists understand allergic diseases systematically.

METTL4-mediated nuclear N6-deoxyadenosine methylation promotes metastasis through activating multiple metastasis-inducing targets

BACKGROUND

DNA N6-methyldeoxyadenosine (6mA) is rarely present in mammalian cells and its nuclear role remains elusive.

RESULTS

Here we show that hypoxia induces nuclear 6mA modification through a DNA methyltransferase, METTL4, in hypoxia-induced epithelial-mesenchymal transition (EMT) and tumor metastasis. Co-expression of METTL4 and 6mA represents a prognosis marker for upper tract urothelial cancer patients. By RNA sequencing and 6mA chromatin immunoprecipitation-exonuclease digestion followed by sequencing, we identify lncRNA RP11-390F4.3 and one novel HIF-1α co-activator, ZMIZ1, that are co-regulated by hypoxia and METTL4. Other genes involved in hypoxia-mediated phenotypes are also regulated by 6mA modification. Quantitative chromatin isolation by RNA purification assay shows the occupancy of lncRNA RP11-390F4.3 on the promoters of multiple EMT regulators, indicating lncRNA-chromatin interaction. Knockdown of lncRNA RP11-390F4.3 abolishes METTL4-mediated tumor metastasis. We demonstrate that ZMIZ1 is an essential co-activator of HIF-1α.

CONCLUSIONS

We show that hypoxia results in enriched 6mA levels in mammalian tumor cells through METTL4. This METTL4-mediated nuclear 6mA deposition induces tumor metastasis through activating multiple metastasis-inducing genes. METTL4 is characterized as a potential therapeutic target in hypoxic tumors.

Systems biology models to identify the influence of SARS-CoV-2 infections to the progression of human autoimmune diseases

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been circulating since 2019, and its global dominance is rising. Evidences suggest the respiratory illness SARS-CoV-2 has a sensitive affect on causing organ damage and other complications to the patients with autoimmune diseases (AD), posing a significant risk factor. The genetic interrelationships and molecular appearances between SARS-CoV-2 and AD are yet unknown. We carried out the transcriptomic analytical framework to delve into the SARS-CoV-2 impacts on AD progression. We analyzed both gene expression microarray and RNA-Seq datasets from SARS-CoV-2 and AD affected tissues. With neighborhood-based benchmarks and multilevel network topology, we obtained dysfunctional signaling and ontological pathways, gene disease (diseasesome) association network and protein-protein interaction network (PPIN), uncovered essential shared infection recurrence connectivities with biological insights underlying between SARS-CoV-2 and AD. We found a total of 77, 21, 9, 54 common DEGs for SARS-CoV-2 and inflammatory bowel disorder (IBD), SARS-CoV-2 and rheumatoid arthritis (RA), SARS-CoV-2 and systemic lupus erythematosus (SLE) and SARS-CoV-2 and type 1 diabetes (T1D). The enclosure of these common DEGs with bimolecular networks revealed 10 hub proteins (FYN, VEGFA, CTNNB1, KDR, STAT1, B2M, CD3G, ITGAV, TGFB3). Drugs such as amlodipine besylate, vorinostat, methylprednisolone, and disulfiram have been identified as a common ground between SARS-CoV-2 and AD from drug repurposing investigation which will stimulate the optimal selection of medications in the battle against this ongoing pandemic triggered by COVID-19.

Long Non-Coding RNA ZEB2-AS1 Promotes Hepatocellular Carcinoma Progression by Regulating The miR-582-5p/FOXC1 Axis

OBJECTIVE

Long non-coding RNAs (lncRNAs) feature prominently in tumors. Reportedly, lncRNA zinc finger E-box-binding homeobox 2 antisense RNA 1 (ZEB2-AS1) is aberrantly expressed in a variety of tumors. The present study was aimed to explore ZEB2-AS1 functions and determine mechanism in hepatocellular carcinoma (HCC) progression.

MATERIALS AND METHODS

In this experimental study, expressions of ZEB2-AS1, microRNA (miR)-582-5p and forkhead box C1 (FOXC1) mRNA in HCC tissues and cell lines were detected via quantitative reveres transcription polymerase chain reaction (qRT-PCR). After establishing gain- and loss-of-functions models, cell counting kit-8, 5-bromo-2'-deoxyuridine (BrdU), Transwell assays and flow cytometry analysis were conducted to examine HCC cell multiplication, migration, invasion and apoptosis, respectively. The targeted relationship between miR-582- 5p and ZEB2-AS1 was verified via dual-luciferase reporter gene assay. Western blot was utilized for detecting FOXC1 expression in HCC cells after selectively regulating ZEB2-AS1 and miR-582-5p.

RESULTS

In HCC tissues and cells, ZEB2-AS1 expression was increased. High ZEB2-AS1 expression was related to relatively large tumor volume, increased tumor-node-metastasis (TNM) stage and positive lymph node metastasis of the patients. ZEB2-AS1 overexpression facilitated HCC cell multiplication, migration, invasion and suppressed apoptosis, while ZEB2-AS1 knock-down caused the opposite effects. It was also confirmed that ZEB2-AS1 could competitively bind with miR-582-5p to repress its expression, and indirectly up-regulate FOXC1 expression level in HCC cells.

CONCLUSION

The current study revealed that ZEB2-AS1 was over-expressed in HCC tissues and cells. It also upregulated (FOXC1), through sponging miR-582-5p, to promote HCC progression. This provides new perspectives for elucidating the pathogenesis of HCC.

HIF-1α Induces HECTD2 Up-Regulation and Aggravates the Malignant Progression of Renal Cell Cancer via Repressing miR-320a

Renal cell carcinoma (RCC) is a frequent malignancy of the urinary system. It has been found that hypoxia mediates the malignant evolvement of RCC. Here, we probe the impact and potential mechanism of HECT domain E3 ubiquitin-protein ligase 2 (HECTD2) and HIF-1α on regulating RCC evolvement. RCC tissues and adjacent normal tissues were collected, and the association between the expression profiles of HECTD2 and HIF-1α and the clinicopathological features was analyzed. Additionally, we constructed HECTD2/HIF-1α overexpression and knockdown models in RCC cell lines to ascertain the impacts of HECTD2 and HIF-1α on RCC cell proliferation, apoptosis, migration, and growth in vivo. We applied bioinformatics to predict the upstream miRNA targets of HECTD2. Meanwhile, RNA immunoprecipitation (RIP), and the dual-luciferase reporter assays were employed to clarify the targeting association between HECTD2 and miR-320a. The effect of miR-320a on HECTD2-mediated RCC progression was investigated. The results suggested that both HIF-1α and HECTD2 were up-regulated in RCC (compared with adjacent non-tumor tissues), and they had positive relationship. Moreover, higher level of HECTD2 and HIF-1α is associated with poorer overall survival of RCC patients. HECTD2 overexpression heightened RCC cell proliferation and migration, and weakened cell apoptosis. On the other hand, the malignant phenotypes of RCC cells were signally impeded by HECTD2 or HIF-1α knockdown. Moreover, miR-320a targeted the 3'-untranslated region of HECTD2 and suppressed HECTD2 expression. The rescue experiments showed that miR-320a restrained HECTD2-mediated malignant progression in RCC, while up-regulation of HIF-1α hampered miR-320a expression. Collectively, HIF-1α mediated HECTD2 up-regulation and aggravated RCC progression by attenuating miR-320a.

Therapeutically Targeting Cancers That Overexpress FOXC1: A Transcriptional Driver of Cell Plasticity, Partial EMT, and Cancer Metastasis

Metastasis accounts for more than 90% of cancer related mortality, thus the most pressing need in the field of oncology today is the ability to accurately predict future onset of metastatic disease, ideally at the time of initial diagnosis. As opposed to current practice, what would be desirable is that prognostic, biomarker-based detection of metastatic propensity and heightened risk of cancer recurrence be performed long before overt metastasis has set in. Without such timely information it will be impossible to formulate a rational therapeutic treatment plan to favorably alter the trajectory of disease progression. In order to help inform rational selection of targeted therapeutics, any recurrence/metastasis risk prediction strategy must occur with the paired identification of novel prognostic biomarkers and their underlying molecular regulatory mechanisms that help drive cancer recurrence/metastasis (i.e. recurrence biomarkers). Traditional clinical factors alone (such as TNM staging criteria) are no longer adequately prognostic for this purpose in the current molecular era. FOXC1 is a pivotal transcription factor that has been functionally implicated to drive cancer metastasis and has been demonstrated to be an independent predictor of heightened metastatic risk, at the time of initial diagnosis. In this review, we present our viewpoints on the master regulatory role that FOXC1 plays in mediating cancer stem cell traits that include cellular plasticity, partial EMT, treatment resistance, cancer invasion and cancer migration during cancer progression and metastasis. We also highlight potential therapeutic strategies to target cancers that are, or have evolved to become, “transcriptionally addicted” to FOXC1. The potential role of FOXC1 expression status in predicting the efficacy of these identified therapeutic approaches merits evaluation in clinical trials.

WITHDRAWN: FOXC1 modulates stem-like cell properties and chemoresistance through hedgehog and EMT signaling in gastric adenocarcinoma

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A hypoxia risk signature for the tumor immune microenvironment evaluation and prognosis prediction in acute myeloid leukemia

Acute myeloid leukemia (AML) is the most prevalent form of acute leukemia. Patients with AML often have poor clinical prognoses. Hypoxia can activate a series of immunosuppressive processes in tumors, resulting in diseases and poor clinical prognoses. However, how to evaluate the severity of hypoxia in tumor immune microenvironment remains unknown. In this study, we downloaded the profiles of RNA sequence and clinicopathological data of pediatric AML patients from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database, as well as those of AML patients from Gene Expression Omnibus (GEO). In order to explore the immune microenvironment in AML, we established a risk signature to predict clinical prognosis. Our data showed that patients with high hypoxia risk score had shorter overall survival, indicating that higher hypoxia risk scores was significantly linked to immunosuppressive microenvironment in AML. Further analysis showed that the hypoxia could be used to serve as an independent prognostic indicator for AML patients. Moreover, we found gene sets enriched in high-risk AML group participated in the carcinogenesis. In summary, the established hypoxia-related risk model could act as an independent predictor for the clinical prognosis of AML, and also reflect the response intensity of the immune microenvironment in AML.

The Hypoxia-Long Noncoding RNA Interaction in Solid Cancers

Hypoxia is one of the representative microenvironment features in cancer and is considered to be associated with the dismal prognosis of patients. Hypoxia-driven cellular pathways are largely regulated by hypoxia-inducible factors (HIFs) and notably exert influence on the hallmarks of cancer, such as stemness, angiogenesis, invasion, metastasis, and the resistance towards apoptotic cell death and therapeutic resistance; therefore, hypoxia has been considered as a potential hurdle for cancer therapy. Growing evidence has demonstrated that long noncoding RNAs (lncRNAs) are dysregulated in cancer and take part in gene regulatory networks owing to their various modes of action through interacting with proteins and microRNAs. In this review, we focus attention on the relationship between hypoxia/HIFs and lncRNAs, in company with the possibility of lncRNAs as candidate molecules for controlling cancer.

Defining super-enhancer landscape in triple-negative breast cancer by multiomic profiling

Breast cancer is a heterogeneous disease, affecting over 3.5 million women worldwide, yet the functional role of cis-regulatory elements including super-enhancers in different breast cancer subtypes remains poorly characterized. Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with a poor prognosis. Here we apply integrated epigenomic and transcriptomic profiling to uncover super-enhancer heterogeneity between breast cancer subtypes, and provide clinically relevant biological insights towards TNBC. Using CRISPR/Cas9-mediated gene editing, we identify genes that are specifically regulated by TNBC-specific super-enhancers, including FOXC1 and MET, thereby unveiling a mechanism for specific overexpression of the key oncogenes in TNBC. We also identify ANLN as a TNBC-specific gene regulated by super-enhancer. Our studies reveal a TNBC-specific epigenomic landscape, contributing to the dysregulated oncogene expression in breast tumorigenesis.

ELAVL1 is transcriptionally activated by FOXC1 and promotes ferroptosis in myocardial ischemia/reperfusion injury by regulating autophagy

Aims

Myocardial ischemia is the most common form of cardiovascular disease and the leading cause of morbidity and mortality. Understanding the mechanisms is very crucial for the development of effective therapy. Therefore, this study aimed to investigate the functional roles and mechanisms by which ELAVL1 regulates myocardial ischemia and reperfusion (I/R) injury.

Methods

Mouse myocardial I/R model and cultured myocardial cells exposed to hypoxia/reperfusion (H/R) were used in this study. Features of ferroptosis were evidenced by LDH activity, GPx4 activity, cellular iron, ROS, LPO, and GSH levels. The expression levels of autophagy markers (Beclin-1, p62, LC3), ELAVL1 and FOXC1 were measured by qRT-PCR, immunostaining and western blot. RIP assay, biotin-pull down, ChIP and dual luciferase activity assay were employed to examine the interactions of ELAVL1/Beclin-1 mRNA and FOXC1/ELAVL1 promoter. CCK-8 assay was used to examine viability of cells. TTC staining was performed to assess the myocardial I/R injury.

Results

Myocardial I/R surgery induced ferroptosis and up-regulated ELAVL1 level. Knockdown of ELAVL1 decreased ferroptosis and ameliorated I/R injury. Si-ELAVL1 repressed autophagy and inhibition of autophagy by inhibitor suppressed ferroptosis and I/R injury in myocardial cells. Increase of autophagy could reverse the effects of ELAVL1 knockdown on ferroptosis and I/R injury. ELAVL1 directly bound with and stabilized Beclin-1 mRNA. Furthermore, FOXC1 bound to ELAVL1 promoter region and activated its transcription upon H/R exposure.

Conclusion

FOXC1 transcriptionally activated ELAVL1 may promote ferroptosis during myocardial I/R by modulating autophagy, leading to myocardial injury. Inhibition of ELAVL1-mediated autophagic ferroptosis would be a new viewpoint in the treatment of myocardial I/R injury.

Co-expression of PD-L1 and HIF-1α predicts poor prognosis in Patients with Non-small Cell Lung Cancer after surgery

Purpose: PD-L1 is highly expressed in multiple cancers and suppresses anticancer immunity. HIF-1α, as a vital transcription factor, could regulate the proliferation, metastasis, and apoptosis of cancer cells. The aim of this study was to explore the correlation between PD-L1 and HIF-1α protein and further estimate its clinicopathological/prognostic impact on NSCLC patients. Methods: In this study, expression of PD-L1 and HIF-1α protein was detected by immunohistochemistry in tissue microarrays of NSCLC and non-cancerous tissues. Results: Expression of PD-L1 and HIF-1α protein was evidently elevated in NSCLC tissues compared with non-cancerous control lung tissues (both P<0.05). Also, PD-L1 was higher in male, lung SCC patients with lymph node metastasis (all P<0.05). There was a positive link between PD-L1 and HIF-1α in NSCLC (r=0.177, P=0.005). What's more, overall survival of lung ADC patients had to do with PD-L1 and clinical stage, while that of SCC patients was related to HIF-1α, pathological grade and LNM status (all P<0.05). Furthermore, multivariate analysis confirmed that PD-L1 and HIF-1α were considered to be independent prognostic factors for NSCLC patients (both P<0.05). Conclusion: PD-L1 and HIF-1α may serve as attractive independent worse prognostic biomarkers for NSCLC patients and the combined evaluation of PD-L1 and HIF-1α may also be valuable for prognosis judgment. Additionally, expression of PD-L1 was positively correlated with HIF-1α, which may provide evidences for a novel combinational therapy targeting PD-L1 and HIF-1α in NSCLC patients.

Carcinogenesis: Failure of resolution of inflammation?

Inflammation in the tumor microenvironment is a hallmark of cancer and is recognized as a key characteristic of carcinogens. However, the failure of resolution of inflammation in cancer is only recently being understood. Products of arachidonic acid and related fatty acid metabolism called eicosanoids, including prostaglandins, leukotrienes, lipoxins, and epoxyeicosanoids, critically regulate inflammation, as well as its resolution. The resolution of inflammation is now appreciated to be an active biochemical process regulated by endogenous specialized pro-resolving lipid autacoid mediators which combat infections and stimulate tissue repair/regeneration. Environmental and chemical human carcinogens, including aflatoxins, asbestos, nitrosamines, alcohol, and tobacco, induce tumor-promoting inflammation and can disrupt the resolution of inflammation contributing to a devastating global cancer burden. While mechanisms of carcinogenesis have focused on genotoxic activity to induce mutations, nongenotoxic mechanisms such as inflammation and oxidative stress promote genotoxicity, proliferation, and mutations. Moreover, carcinogens initiate oxidative stress to synergize with inflammation and DNA damage to fuel a vicious feedback loop of cell death, tissue damage, and carcinogenesis. In contrast, stimulation of resolution of inflammation may prevent carcinogenesis by clearance of cellular debris via macrophage phagocytosis and inhibition of an eicosanoid/cytokine storm of pro-inflammatory mediators. Controlling the host inflammatory response and its resolution in carcinogen-induced cancers will be critical to reducing carcinogen-induced morbidity and mortality. Here we review the recent evidence that stimulation of resolution of inflammation, including pro-resolution lipid mediators and soluble epoxide hydrolase inhibitors, may be a new chemopreventive approach to prevent carcinogen-induced cancer that should be evaluated in humans.

Oridonin inhibits hypoxia-induced epithelial-mesenchymal transition and cell migration by the hypoxia-inducible factor-1α/matrix metallopeptidase-9 signal pathway in gallbladder cancer

Hypoxia has crucial roles in cancer development and progression. Our previous study indicated that cell migration was increased in a hypoxic microenvironment in GBC-SD gallbladder cancer (GBC) cells. Oridonin, a bioactive diterpenoid compound that is isolated from the plant Rabdosia rubescens, has been identified as an anticancer agent in various types of cancer. However, its roles in cell proliferation, apoptosis, and migration in a hypoxic microenvironment and the associated regulatory mechanisms have not yet to be fully elucidated in GBC. The present study investigated the effect of oridonin on cell proliferation, apoptosis, the cell cycle and cell migration in GBC in vitro and in vivo. Furthermore, the role of oridonin in hypoxia-induced cell migration and its underlying mechanisms were explored in GBC. The results indicated that treatment with oridonin significantly suppressed cell proliferation and the metastatic ability of GBC-SD cells in a dose-dependent manner, increased the level of cell apoptosis and induced cell cycle arrest at the G0/G1 phase. Further experiments demonstrated that oridonin could inhibit hypoxia-induced epithelial-mesenchymal transition and cell migration by downregulating the expression levels of hypoxia-inducible factor (HIF)-1α/matrix metallopeptidase (MMP)-9. In addition, oridonin suppressed GBC cell growth and downregulated the expression levels of HIF-1α and MMP-9 in a GBC-SD cell xenograft model. Taken together, these results suggest that oridonin possesses anticancer properties in GBC. Notably, oridonin can suppress tumor epithelial-mesenchymal transition and cell migration by targeting the HIF-1α/MMP-9 signaling pathway.

A Regulatory Axis of circ_0008193/miR-1180-3p/TRIM62 Suppresses Proliferation, Migration, Invasion, and Warburg Effect in Lung Adenocarcinoma Cells Under Hypoxia

BACKGROUND Expression profiles of circular ribonucleic acids (circRNAs) have been recently reported in lung cancers including lung adenocarcinoma (LUAD). Hypoxia is a hallmark of lung cancers. However, the role of hsa_circ_0008193 (circ_0008193) in LUAD under hypoxia remains to be illuminated. MATERIAL AND METHODS Gene expression levels were detected using real-time quantitative polymerase chain reaction and western blotting. Cell proliferation, migration, invasion, and Warburg effect were detected using 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide assay, transwell assays, special kits, and xenograft experiments. The relationship among circ_0008193, micro (mi)RNA (miR)-1180-3p, and tripartite motif containing 62 (TRIM62) was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation. RESULTS Expression of circ_0008193 was downregulated in human LUAD tumor tissues and cell lines (A549 and H1975), accompanied by miR-1180-3p upregulation and TRIM62 downregulation. Moreover, circ_0008193 downregulation was correlated with tumor size and lymph node metastasis. Functionally, circ_0008193 overexpression inhibited cell viability, glucose uptake, lactate production, migration, and invasion, as well as expression of hexokinase II, lactate dehydrogenase A, matrix metalloproteinase 2 (MMP2), and MMP9 in hypoxic LUAD cells in vitro. Furthermore, tumor growth of A549 cells in vivo was also hindered by circ_0008193 overexpression. Mechanically, circ_0008193 regulated TRIM62 expression via sponging miR-1180-3p, and TRIM62 was targeted by miR-1180-3p. Both miR-1180-3p upregulation and TRIM62 downregulation could abolish the suppressive role of circ_0008193 in LUAD cells. CONCLUSIONS Upregulating circ_0008193 inhibited LUAD cell proliferation, migration, invasion, and Warburg effect under hypoxia in vitro and in vivo through regulation of the miR-1180-3p/TRIM62 axis.

Inhibition of lung cancer growth and metastasis by DHA and its metabolite, RvD1, through miR-138-5p/FOXC1 pathway

BACKGROUND

Non small cell lung cancer (NSCLC) is one of the most common cancers in the world. DHA is known to be capable of suppressing NSCLC cell proliferation and metastasis. However, the mechanisms by which DHA exhibits its antitumor effects are unknown. Here we aimed to identify the effects and mechanisms of DHA and its metabolites on lung cancer cell growth and invasion.

METHODS

As measures of cell proliferation and invasion ability, the cell viability and transwell assays were used in vitro. Transgenic mfat-1 mice, which convert ω-6 PUFAs to ω-3 PUFAs, were used to detect the effect of endogenous DHA on tumor transplantation. An LC - MS/MS analysis identified the elevation of several eicosanoid metabolites of DHA. By using qPCR miRNA microarray, online prediction software, luciferase reporter assays and Western blot analysis, we further elucidated the mechanisms.

RESULTS

Addition of exogenous DHA inhibited the growth and invasion in NSCLC cells in vitro. Endogenously produced DHA attenuated LLC-derived tumor growth and metastasis in the transgenic mfat-1 mice. Among the elevation of DHA metabolites, resolvin D1 (RvD1) significantly contributed to the inhibition in cell growth and invasion. MiRNA microarray revealed that the level of miR-138-5p was significantly increased after RvD1 treatment. MiR-138-5p mimics decreased cell viability and invasion; while miR-138-5p inhibitor abolished RvD1-mediated suppression of cell viability and invasion. The expression of FOXC1 was significantly reduced upon overexpression of miR-138-5p while luciferase reporter assay showed that FOXC1 was a direct target of miR-138-5p. In vivo, endogenous DHA by the mfat-1 transgene enhanced miR-138-5p expression and decreased FOXC1 expression. Furthermore, overexpression of FOXC1 reversed the inhibition in cell viability and invasion induced by RvD1 treatment.

CONCLUSIONS

These data identified the RvD1/miR-138-5p/FOXC1 pathway as a novel mechanism by DHA and its metabolite, RvD1, and the potential of targeting such pathway as a therapeutic strategy in treating NSCLC.

Forkhead box C1 promotes metastasis and invasion of non-small cell lung cancer by binding directly to the lysyl oxidase promoter

Increasing evidence indicates that human forkhead box C1 (FOXC1) plays important roles in tumor development and metastasis. However, the underlying molecular mechanism of FOXC1 in non–small cell lung cancer (NSCLC) metastasis remains unclear. Here, we identified FOXC1 as an independent prognostic factor in NSCLC and showed clear biological implications in invasion and metastasis. FOXC1 overexpression enhanced the proliferation, migration and invasion of NSCLC cells, whereas FOXC1 silencing impaired the effects both in vitro and in vivo. Importantly, we found a positive correlation between FOXC1 expression and lysyl oxidase (LOX) expression in NSCLC cells and patient samples. Downregulation of LOX or LOX activity inhibition in NSCLC cells inhibited the FOXC1‐driven effects on cellular migration and invasion. Xenograft models showed that inhibition of LOX activity by β‐aminopropionitrile monofumarate decreased the number of lung metastases. Mechanistically, we demonstrated a novel FOXC1‐LOX mechanism that was involved in the invasion and metastasis of NSCLC. Dual‐luciferase assay and ChIP identified that FOXC1 bound directly in the LOX promoter region and activated its transcription. Collectively, the present study offered new insight into FOXC1 in the mediation of NSCLC metastasis through interaction with the LOX promoter and further revealed that targeted inhibition of LOX protein activity could prevent lung metastasis in murine xenograft models. These data implicated FOXC1 as a potential therapeutic strategy for the treatment of NSCLC metastasis.

Targeting cell signaling in allergic asthma

Asthma is chronic inflammation of the airways characterized by airway hyper-responsiveness, wheezing, cough, and dyspnea. Asthma affects >350 million people worldwide. The Th2 immune response is a major contributor to the pathophysiology of asthma. Targeted therapy modulating cell signaling pathways can be a powerful strategy to design new drugs to treat asthma. The potential molecular pathways that can be targeted include IL-4-IL-13-JAK-STAT-MAP kinases, adiponectin-iNOS-NF-κB, PGD2-CRTH2, IFNs-RIG, Wnt/β-catenin-FAM13A, FOXC1-miR-PI3K/AKT, JNK-Gal-7, Nrf2-ROS, Foxp3-RORγt, CysLTR, AMP, Fas-FasL, PTHrP/PPARγ, PAI-1, FcɛRI-LAT-SLP-76, Tim-3-Gal-9, TLRs-MyD88, PAR2, and Keap1/Nrf2/ARE. Therapeutic drugs can be designed to target one or more of these pathways to treat asthma.

FOXC1 up-regulates the expression of toll-like receptors in myocardial ischaemia

Myocardial ischaemia (MI) remains a major cause of death and disability worldwide. Accumulating evidence suggests a significant role for innate immunity, in which the family of toll‐like receptors (TLRs) acts as an essential player. We previously reported and reviewed the changes of Tlr expression in models of MI. However, the underlying mechanisms regulating Tlr expression in MI remain unclear. The present study first screened transcription factors (TFs) that potentially regulate Tlr gene transcription based on in silico analyses followed by experimental verification, using both in vivo and in vitro models. Forkhead box C1 (FOXC1) was identified as a putative TF, which was highly responsive to MI. Next, by focusing on two representative TLR subtypes, an intracellular subtype TLR3 and a cell‐surface subtype TLR4, the regulation of FOXC1 on Tlr expression was investigated. The overexpression or knockdown of FoxC1 was observed to up‐ or down‐regulate Tlr3/4 mRNA and protein levels, respectively. A dual‐luciferase assay showed that FOXC1 trans‐activated Tlr3/4 promoter, and a ChIP assay showed direct binding of FOXC1 to Tlr3/4 promoter. Last, a functional study of FOXC1 was performed, which revealed the pro‐inflammatory effects of FOXC1 and its destructive effects on infarct size and heart function in a mouse model of MI. The present study for the first time identified FOXC1 as a novel regulator of Tlr expression and described its function in MI.

The Diverse Consequences of FOXC1 Deregulation in Cancer

Forkhead box C1 (FOXC1) is a transcription factor with essential roles in mesenchymal lineage specification and organ development during normal embryogenesis. In keeping with these developmental properties, mutations that impair the activity of FOXC1 result in the heritable Axenfeld-Rieger Syndrome and other congenital disorders. Crucially, gain of FOXC1 function is emerging as a recurrent feature of malignancy; FOXC1 overexpression is now documented in more than 16 cancer types, often in association with an unfavorable prognosis. This review explores current evidence for FOXC1 deregulation in cancer and the putative mechanisms by which FOXC1 confers its oncogenic effects.

Retracted Article: FOXC1 silencing promotes A549 cell apoptosis through inhibiting the PI3K/AKT/hedgehog/Gli2 signaling pathway

Lung cancer begins in the lung and is a leading cause of premature death. Forkhead box C1 (FOXC1) has been reported to play an important role in different types of cancer, and evidence suggests that FOXC1 is highly expressed in non-small cell lung cancer (NSCLC) patients. However, the function and molecular mechanism of FOXC1 in the NSCLC cell line A549 is still unclear. In the present study, we indicate that FOXC1 is expressed in the NSCLC cell lines A549, H460, and SK-MES-1 at a high level compared with control human bronchial epithelial (HBE) cells. FOXC1 silencing promotes A549 cell apoptosis, whereas it inhibits cell survival. The levels of anti-apoptosis protein Bcl-2 decreased and the expression of pro-apoptosis protein Bax increased in FOXC1 silenced cells. Further studies show that FOXC1 knockdown inhibits the PI3K/AKT/hedgehog/Gli2 pathway. Overexpressed AKT or Gli2 reversed the effects of FOXC1 silencing on A549 cell survival and apoptosis. Taken together, our results conclude that FOXC1 silencing reduced the survival of cancer cells and promoted their apoptosis, and that the PI3K/AKT/hedgehog/Gli2 pathway plays an important role in the functioning of FOXC1 silencing.

RGS4 deficit in prefrontal cortex contributes to the behaviors related to schizophrenia via system xc--mediated glutamatergic dysfunction in mice

Rationale: Although molecular investigations of regulator of G-protein signaling 4 (RGS4) alterations in schizophrenia patients yielded partially inconsistent findings, the previous studies suggested that RGS4 is both a positional and functional candidate gene for schizophrenia and is significantly decreased in the prefrontal cortex. However, the exact role of RGS4 in the pathophysiology of schizophrenia is unclear. Moreover, a whole genome transcription profile study showed the possibility of RGS4-regulated expression of SLC7A11(xCT), a component of cysteine/glutamate transporter or system x_c^-. We hypothesized that system x_c^- is a therapeutic target of RGS4 deficit-mediated schizophrenia. Methods: Pharmacological and genetic manipulation of RGS4 in organotypic brain slice cultures were used as an ex vivo model to investigate its role in system x_c^- and glutamatergic function. Lentiviral-based mouse models with RGS4 deficit in the prefrontal cortex and treatment with system x_c^- activator, N-acetyl cysteine (NAC), were utilized to observe their impacts on glutamatergic function and schizophrenic behaviors. Results: Genetic and pharmacological inhibition of RGS4 resulted in a significant decrease in SLC7A11 (xCT) expression and hypofunction of system x_c^- and reduced glutamatergic function in organotypic brain slice cultures. However, NAC restored the dysregulation of RGS4-mediated functional deficits of glutamate. Moreover, knockdown of RGS4 specifically in the prefrontal cortex caused mice to exhibit behaviors related to schizophrenia such as increased stereotypy, impaired prepulse inhibition, deficits in social interactions, working memory, and nesting behavior, while enhancing sensitivity to the locomotor stimulatory effect of MK-801. These mice displayed glutamatergic dysfunction in the prefrontal cortex, which may have contributed to the behavioral deficits. RGS4 knockdown mice that received NAC treatment had improved glutamatergic dysfunction and schizophrenia behaviors. Conclusion: Our results suggest that RGS4 deficit induces dysregulation and dysfunction of system x_c^-, which further results in functional deficits of the glutamatergic system and subsequently to schizophrenia-related behavioral phenotypes. Activation of system x_c^- offers a promising strategy to treat RGS4 deficit-mediated schizophrenia.

FOXC1 induces cancer stem cell-like properties through upregulation of beta-catenin in NSCLC

Background

Accumulating evidence suggests that cancer stem cells (CSCs) play a critical role in tumor initiation, progression and therapy, and recent studies have indicated that Forkhead box C1 (FOXC1) is strongly associated with CSCs. This study investigates the regulatory effects of FOXC1 on CSC-like properties in non-small cell lung cancer (NSCLC).

Methods

We analyzed FOXC1 expression in NSCLC using the Cancer Genome Atlas (TCGA) database on UALCANC and performed survival analyses of NSCLC patients on Human Protein Atlas. CSC-like properties were analyzed based on CSC marker-positive cell population, self-renewal ability, stemness-related gene expression, tumorigenicity and drug resistance. The percentage of CD133⁺ cells was analyzed by flow cytometric analysis. Self-renewal ability was detected by sphere-formation analysis. Real-time PCR, western blotting and immunohistochemical staining were employed to detect mRNA and protein levels. Tumorigenicity was determined based on a xenograft formation assay, and effects of FOXC1 on drug resistance were assessed by cell viability and apoptosis assays. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays were used to investigate the binding of FOXC1 to beta-catenin promoter.

Results

FOXC1 expression was found to be elevated in NSCLC tissues and negatively correlated with patient survival. FOXC1 knockdown reduced CD133⁺ cell percentage, suppressed self-renewal ability, decreased expression of stemness-related genes (Oct4, NANOG, SOX2 and ABCG2) and inhibited NSCLC cell tumorigenicity in vivo. Moreover, FOXC1 knockdown increased cisplatin and docetaxel sensitivity and reduced gefitinib resistance, whereas FOXC1 overexpression enhanced CSC-like properties. Luciferase reporter and ChIP assays showed beta-catenin to be a direct transcriptional target of FOXC1. Furthermore, overexpression of beta-catenin reversed the CSC-like property inhibition induced by FOXC1 knockdown, and knockdown of beta-catenin attenuated the CSC-like properties induced by FOXC1 overexpression.

Conclusions

This study demonstrates that FOXC1 induces CSC-like properties in NSCLC by promoting beta-catenin expression. The findings indicate that FOXC1 is a potential molecular target for anti-CSC-based therapies in NSCLC.

Silencing FOXC1 inhibits growth and migration of human oral squamous cell carcinoma cells

Forkhead box C1 (FOXC1) is a transcription factor that serves an important role in regulating tumorigenesis and cancer progression. However, the expression and functional role of FOXC1 in oral squamous cell carcinoma (OSCC) remains unclear. FOXC1 protein expression was determined using immunohistochemical staining of OSCC tissues and normal tissues. Cell Counting Kit-8, colony formation, migration and 5-ethynyl-2′-deoxyuridine assays were performed to investigate the role and underlying mechanism of action of FOXC1 in OSCC. A consistent increase in the immunoreactive intensity of FOXC1 in OSCC tissues as compared with that in adjacent normal tissues was demonstrated. Knockdown of FOXC1 impaired cell growth and colony formation by inhibiting cell proliferation and reducing cyclin B1 and cyclin D1 levels in OSCC cells. FOXC1-silenced OSCC cells exhibited decreased migration compared with that demonstrated by the control cells, accompanied by a downregulation of matrix metalloproteinase (MMP)-2 and MMP-9. Collectively, the results of the present study demonstrated that FOXC1 functions as an oncogene in OSCC and may be an important therapeutic target and predictive biomarker for OSCC.

Wild-type IDH2 promotes the Warburg effect and tumor growth through HIF1α in lung cancer

Hotspot mutations of isocitrate dehydrogenase 1 and 2 (IDH1/2) have been studied in several cancers. However, the function of wild-type IDH2 in lung cancer and the mechanism of its contribution to growth of cancer cells remain unknown. Here, we explored the role and mechanism of wild-type IDH2 in promoting growth of lung cancer.

Methods: Information regarding genomic and clinical application focusing on IDH2 in cancer was examined in several databases of more than 1,000 tumor samples. IDH2 expression was assessed by immunohistochemistry in tissues from lung cancer patients. The biological functions of IDH2 were evaluated by using cell-based assays and in vivo xenograft mouse models.

Results: Here we reported that wild-type IDH2 is up-regulated and is an indicator of poor survival in lung cancer and several other cancers. Targeting IDH2 with shRNA resulted in decreased HIF1α expression, leading to the attenuation of lung cancer cell proliferation and tumor growth. Treatment of lung cancer cells with AGI-6780 (a small molecule inhibitor of IDH2), PX-478 (an inhibitor of HIF1α) or incubation with octyl-α-KG inhibited lung cancer cell proliferation.

Conclusion: IDH2 promotes the Warburg effect and lung cancer cell growth, which is mediated through HIF1α activation followed by decreased α-KG. Therefore, IDH2 could possibly serve as a novel therapeutic target for lung cancer.

Hypoxia-Induced Activation of JAK/STAT3 Signaling Pathway Promotes Trophoblast Cell Viability and Angiogenesis in Preeclampsia

Background

To explore the effect of hypoxic preconditioning on the JAK/STAT3 signaling pathway and its effect on trophoblast cell viability and angiogenesis in preeclampsia (PE).

Material/Methods

Placental tissues from normal pregnant women and PE patients were collected to detect the expression levels of JAK and STAT3. Trophoblast cells separated from the PE patients were assigned to 4 groups. The expression levels of phosphorylated p-JAK and p-STAT3 were measured by Western blot. Cell viability, colony-forming ability, and cell apoptosis were assessed. The levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and hepatocyte growth factor (HGF) were determined by enzyme-linked immunosorbent assay (ELISA).

Results

The expression levels of JAK and STAT3 were higher in the placental tissues of PE patients than in those of normal pregnant women. Compared with the blank group, in the hypoxia group the expression levels of p-JAK and p-STAT3 were increased, cell viability was promoted, the number of colonies was increased, cell apoptosis was inhibited, and the levels of VEGF, bFGF, and HGF were all elevated. However, in comparison with the hypoxia group, the expression levels of p-JAK and p-STAT3 were reduced, the cell viability was inhibited, the colonies were decreased, the levels of VEGF, bFGF, and HGF were all decreased, and cell apoptosis was promoted in the hypoxia + si-JAK group.

Conclusions

These findings indicate that hypoxic preconditioning may contribute to activation of the JAK/STAT3 signaling pathway, thus promoting trophoblast cell viability and angiogenesis in PE.

EGLN1/c-Myc Induced Lymphoid-Specific Helicase Inhibits Ferroptosis through Lipid Metabolic Gene Expression Changes

Ferroptosis is a newly discovered form of non-apoptotic cell death in multiple human diseases. However, the epigenetic mechanisms underlying ferroptosis remain poorly defined. First, we demonstrated that lymphoid-specific helicase (LSH), which is a DNA methylation modifier, interacted with WDR76 to inhibit ferroptosis by activating lipid metabolism-associated genes, including GLUT1, and ferroptosis related genes SCD1 and FADS2, in turn, involved in the Warburg effect. WDR76 targeted these genes expression in dependent manner of LSH and chromatin modification in DNA methylation and histone modification. These effects were dependent on iron and lipid reactive oxygen species. We further demonstrated that EGLN1 and c-Myc directly activated the expression of LSH by inhibiting HIF-1α. Finally, we demonstrated that LSH functioned as an oncogene in lung cancer in vitro and in vivo. Therefore, our study elucidates the molecular basis of the c-Myc/EGLN1-mediated induction of LSH expression that inhibits ferroptosis, which can be exploited for the development of therapeutic strategies targeting ferroptosis for the treatment of cancer.