Potential Role of ANGPTL4 in the Cross Talk between Metabolism and Cancer through PPAR Signaling Pathway

PPAR beta/delta regulates the immune response mechanisms in the porcine endometrium during LPS-induced inflammation - An in vitro study

Inflammation in the reproductive tract has become a serious threat to animal fertility. Recently, the role of peroxisome proliferator-activated receptor gamma (PPARγ) in the context of reproduction and the inflammatory response has been highlighted, but the role of PPARβ/δ has not been fully elucidated. The aim of the present study was to investigate the in vitro effect of PPARβ/δ ligands (agonist: L-165,041 and antagonist: GSK 3787) on the transcriptome profile of porcine endometrium during LPS-induced inflammation in the mid-luteal and follicular phases of the oestrous cycle (days 10-12 and 18-20, respectively) using the RNA-Seq method. During the mid-luteal phase of the oestrous cycle, the current study identified 145 and 143 differentially expressed genes (DEGs) after treatment with an agonist or antagonist, respectively. During the follicular phase of the oestrous cycle, 55 and 207 DEGs were detected after treatment with an agonist or antagonist, respectively. The detected DEGs are engaged in the regulation of various processes, such as the complement and coagulation cascade, NF-κB signalling pathway, or the pathway of 15-eicosatetraenoic acid derivatives synthesis. The results of the current study indicate that PPARβ/δ ligands are involved in the control of the endometrial inflammatory response.

Identification and validation of an immune-derived multiple programmed cell death index for predicting clinical outcomes, molecular subtyping, and drug sensitivity in lung adenocarcinoma

OBJECTIVES

Comprehensive cross-interaction of multiple programmed cell death (PCD) patterns in the patients with lung adenocarcinoma (LUAD) have not yet been thoroughly investigated.

METHODS

Here, we collected 19 different PCD patterns, including 1911 PCD-related genes, and developed an immune-derived multiple programmed cell death index (MPCDI) based on machine learning methods.

RESULTS

Using the median MPCDI scores, we categorized the LUAD patients into two groups: low-MPCDI and high-MPCDI. Our analysis of the TCGA-LUAD training cohort and three external GEO cohorts (GSE37745, GSE30219, and GSE68465) revealed that patients with high-MPCDI experienced a more unfavorable prognosis, whereas those with low-MPCDI had a better prognosis. Furthermore, the results of both univariate and multivariate Cox regression analyses further confirmed that MPCDI serves as a novel independent risk factor. By combining clinical characteristics with the MPCDI, we constructed a nomogram that provides an accurate and reliable quantitative tool for personalized clinical management of LUAD patients. The findings obtained from the analysis of C-index and the decision curve revealed that the nomogram outperformed various clinical variables in terms of net clinical benefit. Encouragingly, the low-MPCDI patients are more sensitive to commonly used chemotherapy drugs, which suggests that MPCDI scores have a guiding role in chemotherapy for LUAD patients.

CONCLUSION

Therefore, MPCDI can be used as a novel clinical diagnostic classifier, providing valuable insights into the clinical management and clinical decision-making for LUAD patients.

9-HODE and 9-HOTrE alter mitochondrial metabolism, increase triglycerides, and perturb fatty acid uptake and synthesis associated gene expression in HepG2 cells

Non-Alcoholic Fatty Liver Disease (NAFLD) prevalence is rising and can lead to detrimental health outcomes such as Non-Alcoholic Steatohepatitis (NASH), cirrhosis, and cancer. Recent studies have indicated that Cytochrome P450 2B6 (CYP2B6) is an anti-obesity CYP in humans and mice. Cyp2b-null mice are diet-induced obese, and human CYP2B6-transgenic (hCYP2B6-Tg) mice reverse the obesity or diabetes progression, but with increased liver triglyceride accumulation in association with an increase of several oxylipins. Notably, 9-hydroxyoctadecadienoic acid (9-HODE) produced from linoleic acid (LA, 18:2, ω-6) is the most prominent of these and 9-hydroxyoctadecatrienoic acid (9-HOTrE) from alpha-linolenic acid (ALA, 18:3, ω-3) is the most preferentially produced when controlling for substrate concentrations in vitro. Transactivation assays indicate that 9-HODE and 9-HOTrE activate PPARα and PPARγ. In Seahorse assays performed in HepG2 cells, 9-HOTrE increased spare respiratory capacity, slightly decreased palmitate metabolism, and increased non-glycolytic acidification in a manner consistent with slightly increased glutamine utilization; however, 9-HODE exhibited no effect on metabolism. Both compounds increased triglyceride and pyruvate concentrations, most strongly by 9-HOTrE, consistent with increased spare respiratory capacity. qPCR analysis revealed several perturbations in fatty acid uptake and metabolism gene expression. 9-HODE increased expression of CD36, FASN, PPARγ, and FoxA2 that are involved in lipid uptake and production. 9-HOTrE decreased ANGPTL4 expression and increased FASN expression consistent with increased fatty acid uptake, fatty acid production, and AMPK activation. Our findings support the hypothesis that 9-HODE and 9-HOTrE promote steatosis, but through different mechanisms as 9-HODE is directly involved in fatty acid uptake and synthesis; 9-HOTrE weakly inhibits mitochondrial fatty acid metabolism while increasing glutamine use.

Hepatokines: unveiling the molecular and cellular mechanisms connecting hepatic tissue to insulin resistance and inflammation

Insulin resistance arising from Non-Alcoholic Fatty Liver Disease (NAFLD) stands as a prevalent global ailment, a manifestation within societies stemming from individuals' suboptimal dietary habits and lifestyles. This form of insulin resistance emerges as a pivotal factor in the development of type 2 diabetes mellitus (T2DM). Emerging evidence underscores the significant role of hepatokines, as hepatic-secreted hormone-like entities, in the genesis of insulin resistance and eventual onset of type 2 diabetes. Hepatokines exert influence over extrahepatic metabolism regulation. Their principal functions encompass impacting adipocytes, pancreatic cells, muscles, and the brain, thereby playing a crucial role in shaping body metabolism through signaling to target tissues. This review explores the most important hepatokines, each with distinct influences. Our review shows that Fetuin-A promotes lipid-induced insulin resistance by acting as an endogenous ligand for Toll-like receptor 4 (TLR-4). FGF21 reduces inflammation in diabetes by blocking the nuclear translocation of nuclear factor-κB (NF-κB) in adipocytes and adipose tissue, while also improving glucose metabolism. ANGPTL6 enhances AMPK and insulin signaling in muscle, and suppresses gluconeogenesis. Follistatin can influence insulin resistance and inflammation by interacting with members of the TGF-β family. Adropin show a positive correlation with phosphoenolpyruvate carboxykinase 1 (PCK1), a key regulator of gluconeogenesis. This article delves into hepatokines' impact on NAFLD, inflammation, and T2DM, with a specific focus on insulin resistance. The aim is to comprehend the influence of these recently identified hormones on disease development and their underlying physiological and pathological mechanisms.

PPARβ/δ as a promising molecular drug target for liver diseases: A focused review

Various liver diseases pose great threats to humans. Although the etiologies of these liver diseases are quite diverse, they share similar pathologic phenotypes and molecular mechanisms such as oxidative stress, lipid and glucose metabolism disturbance, hepatic Kupffer cell (KC) proinflammatory polarization and inflammation, insulin resistance, and hepatic stellate cell (HSC) activation and proliferation. Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) is expressed in various types of liver cells with relatively higher expression in KCs and HSCs. Accumulating evidence has revealed the versatile functions of PPARβ/δ such as controlling lipid homeostasis, inhibiting inflammation, regulating glucose metabolism, and restoring insulin sensitivity, suggesting that PPARβ/δ may serve as a potential molecular drug target for various liver diseases. This article aims to provide a concise review of the structure, expression pattern and biological functions of PPARβ/δ in the liver and its roles in various liver diseases, and to discuss potential future research perspectives.

Construction of an Anoikis-Related Gene Prognostic Signature and Identification of ANGPTL4 as a Key Oncogene in Lung Adenocarcinoma

Anoikis plays an important role in cancer invasion and metastasis. However, the role of anoikis-related genes, AnRGs, in lung adenocarcinoma (LUAD) is not clear. First, anoikis-related genes (AnRGs) were obtained from the Genecard database. Second, the prognostic risk model of AnRGs was established by univariate Cox analysis, the Least Absolute Shrinkage and Selection Operator (LASSO) analysis, and multivariate Cox analysis. Finally, in vitro cell experiments were carried out to determine the expression and function of the key gene AnRGs. Three AnRGs (angiopoietin-like 4, ANGPTL4; Cyclin-Dependent Kinase Inhibitor 3, CDKN3; Solute Carrier Organic Anion Transporter Family Member 1B3, SLCO1B3) were screened for the construction of risk prediction model. Additionally, ANGPTL4 was significantly highly expressed in tumor cells, and the knockdown of ANGPTL4 expression on tumor cells could inhibit tumor cell migration and apoptosis. Constructing a risk model based on anoikis-related genes can effectively differentiate the prognosis of LUAD. ANGPTL4 can be used as a potential new target for LUAD treatment.

PPARβ/δ-ANGPTL4 axis mediates the promotion of mono-2-ethylhexyl phthalic acid on MYCN-amplified neuroblastoma development

Di-2-ethylhexyl phthalic acid (DEHP) is one of the most widely used plasticizers in the industry, which can improve the flexibility and durability of plastics. It is prone to migrate from various daily plastic products through wear and leaching into the surrounding environment and decompose into the more toxic metabolite mono-2-ethylhexyl phthalic acid (MEHP) after entering the human body. However, the impacts and mechanisms of MEHP on neuroblastoma are unclear. We exposed MYCN-amplified neuroblastoma SK-N-BE(2)C cells to an environmentally related concentration of MEHP and found that MEHP increased the proliferation and migration ability of tumor cells. The peroxisome proliferator-activated receptor (PPAR) β/δ pathway was identified as a pivotal signaling pathway in neuroblastoma, mediating the effects of MEHP through transcriptional sequencing analysis. Because MEHP can bind to the PPARβ/δ protein and initiate the expression of the downstream gene angiopoietin-like 4 (ANGPTL4), the PPARβ/δ-specific agonist GW501516 and antagonist GSK3787, the recombinant human ANGPTL4 protein, and the knockdown of gene expression confirmed the regulation of the PPARβ/δ-ANGPTL4 axis on the malignant phenotype of neuroblastoma. Based on the critical role of PPARβ/δ and ANGPTL4 in the metabolic process, a non-targeted metabolomics analysis revealed that MEHP altered multiple metabolic pathways, particularly lipid metabolites involving fatty acyls, glycerophospholipids, and sterol lipids, which may also be potential factors promoting tumor progression. We have demonstrated for the first time that MEHP can target binding to PPARβ/δ and affect the progression of neuroblastoma by activating the PPARβ/δ-ANGPTL4 axis. This mechanism confirms the health risks of plasticizers as tumor promoters and provides new data support for targeted prevention and treatment of neuroblastoma.

Therapy-Induced Senescence Contributes to the Efficacy of Abemaciclib in Patients with Dedifferentiated Liposarcoma

PURPOSE

We conducted research on CDK4/6 inhibitors (CDK4/6i) simultaneously in the preclinical and clinical spaces to gain a deeper understanding of how senescence influences tumor growth in humans.

PATIENTS AND METHODS

We coordinated a first-in-kind phase II clinical trial of the CDK4/6i abemaciclib for patients with progressive dedifferentiated liposarcoma (DDLS) with cellular studies interrogating the molecular basis of geroconversion.

RESULTS

Thirty patients with progressing DDLS enrolled and were treated with 200 mg of abemaciclib twice daily. The median progression-free survival was 33 weeks at the time of the data lock, with 23 of 30 progression-free at 12 weeks (76.7%, two-sided 95% CI, 57.7%-90.1%). No new safety signals were identified. Concurrent preclinical work in liposarcoma cell lines identified ANGPTL4 as a necessary late regulator of geroconversion, the pathway from reversible cell-cycle exit to a stably arrested inflammation-provoking senescent cell. Using this insight, we were able to identify patients in which abemaciclib induced tumor cell senescence. Senescence correlated with increased leukocyte infiltration, primarily CD4-positive cells, within a month of therapy. However, those individuals with both senescence and increased TILs were also more likely to acquire resistance later in therapy. These suggest that combining senolytics with abemaciclib in a subset of patients may improve the duration of response.

CONCLUSIONS

Abemaciclib was well tolerated and showed promising activity in DDLS. The discovery of ANGPTL4 as a late regulator of geroconversion helped to define how CDK4/6i-induced cellular senescence modulates the immune tumor microenvironment and contributes to both positive and negative clinical outcomes. See related commentary by Weiss et al., p. 649.

Endothelial cells in tumor microenvironment: insights and perspectives

The tumor microenvironment is a highly complex and dynamic mixture of cell types, including tumor, immune and endothelial cells (ECs), soluble factors (cytokines, chemokines, and growth factors), blood vessels and extracellular matrix. Within this complex network, ECs are not only relevant for controlling blood fluidity and permeability, and orchestrating tumor angiogenesis but also for regulating the antitumor immune response. Lining the luminal side of vessels, ECs check the passage of molecules into the tumor compartment, regulate cellular transmigration, and interact with both circulating pathogens and innate and adaptive immune cells. Thus, they represent a first-line defense system that participates in immune responses. Tumor-associated ECs are involved in T cell priming, activation, and proliferation by acting as semi-professional antigen presenting cells. Thus, targeting ECs may assist in improving antitumor immune cell functions. Moreover, tumor-associated ECs contribute to the development at the tumor site of tertiary lymphoid structures, which have recently been associated with enhanced response to immune checkpoint inhibitors (ICI). When compared to normal ECs, tumor-associated ECs are abnormal in terms of phenotype, genetic expression profile, and functions. They are characterized by high proliferative potential and the ability to activate immunosuppressive mechanisms that support tumor progression and metastatic dissemination. A complete phenotypic and functional characterization of tumor-associated ECs could be helpful to clarify their complex role within the tumor microenvironment and to identify EC specific drug targets to improve cancer therapy. The emerging therapeutic strategies based on the combination of anti-angiogenic treatments with immunotherapy strategies, including ICI, CAR T cells and bispecific antibodies aim to impact both ECs and immune cells to block angiogenesis and at the same time to increase recruitment and activation of effector cells within the tumor.

ANGPTL4, a direct target of hsa-miR-133a-3p, accelerates lung adenocarcinoma lipid metabolism, proliferation and invasion

BACKGROUND

Globally, lung adenocarcinoma (LUAD) is the most common type of lung cancer. The secreted protein angiopoietin-like 4 (ANGPTL4) has been implicated in a number of physiological and pathological processes, including angiogenesis and lipid metabolism. But the role of ANGPTL4 in LUAD remains unknown.

METHODS

The expression of ANGPTL4 and miR-133a-3p was confirmed by public database analysis. Xenograft model, MTT, Clone formation and EdU analysis were used to confirm the effects of miR-133a-3p/ANGPTL4 on LUAD cell proliferation and growth. Wound healing and Transwell analysis were used to elucidate the role of miR-133a-3p/ANGPTL4 in LUAD cell migration and invasion. Oil red O staining was used to confirm ANGPTL4 in LUAD lipids production. Dual-luciferase reporter gene analysis was used to demonstrate miR-133a-3p could directly bind ANGPTL4 3'-UTR. WB and PCR were used to confirm the protein expression of ANGPTL4.

RESULTS

ANGPTL4 was significantly increased in LUAD samples, which could promote LUAD cell proliferation, migration, invasion, growth and lipid production. miR-133a-3p could directly bind to ANGPTL4 mRNA, and repress the expression ANGPTL4, resulting in suppressing LUAD proliferation and metastasis.

CONCLUSION

In conclusion, miR-133a-3p/ANGPTL4 axis might be a potential biomarker and therapeutic target for LUAD patients.

Angiopoietin-Like Proteins: Cardiovascular Biology and Therapeutic Targeting for the Prevention of Cardiovascular Diseases

Despite the best pharmacologic tools available, cardiovascular diseases (CVDs) remain a major cause of morbidity and mortality in developed countries. After 2 decades of research, new therapeutic targets, such as angiopoietin-like proteins (ANGPTLs), are emerging. ANGPTLs belong to a family of 8 members, from ANGPTL1 to ANGPTL8; they have structural homology with angiopoietins and are secreted in the circulation. ANGPTLs display a multitude of physiological and pathologic functions; they contribute to inflammation, angiogenesis, cell death, senescence, hematopoiesis, and play a role in repair, maintenance, and tissue homeostasis. ANGPTLs-particularly the triad ANGPTL3, 4, and 8-have an established role in lipid metabolism through the regulation of triacylglycerol trafficking according to the nutritional status. Some ANGPTLs also contribute to glucose metabolism. Therefore, dysregulation in ANGPTL expression associated with abnormal circulating levels are linked to a plethora of CVD and metabolic disorders including atherosclerosis, heart diseases, diabetes, but also obesity and cancers. Because ANGPTLs bind to different receptors according to the cell type, antagonists are therapeutically inadequate. Recently, direct inhibitors of ANGPTLs, mainly ANGPTL3, have been developed, and specific monoclonal antibodies and antisense oligonucleotides are currently being tested in clinical trials. The aim of the current review is to provide an up-to-date preclinical and clinical overview on the function of the 8 members of the ANGPTL family in the cardiovascular system, their contribution to CVD, and the therapeutic potential of manipulating some of them.

Epithelial cell invasion by salmonella typhimurium induces modulation of genes controlled by aryl hydrocarbon receptor signaling and involved in extracellular matrix biogenesis

Salmonella is the only bacterium able to enter a host cell by the two known mechanisms: trigger and zipper. The trigger mechanism relies on the injection of bacterial effectors into the host cell through the Salmonella type III secretion system 1. In the zipper mechanism, mediated by the invasins Rck and PagN, the bacterium takes advantage of a cellular receptor for invasion. This study describes the transcriptomic reprogramming of the IEC-6 intestinal epithelial cell line to Salmonella Typhimurium strains that invaded cells by a trigger, a zipper, or both mechanisms. Using S. Typhimurium strains invalidated for one or other entry mechanism, we have shown that IEC-6 cells could support both entries. Comparison of the gene expression profiles of exposed cells showed that irrespective of the mechanism used for entry, the transcriptomic reprogramming of the cell was nearly the same. On the other hand, when gene expression was compared between cells unexposed or exposed to the bacterium, the transcriptomic reprogramming of exposed cells was significantly different. It is particularly interesting to note the modulation of expression of numerous target genes of the aryl hydrocarbon receptor showing that this transcription factor was activated by S. Typhimurium infection. Numerous genes associated with the extracellular matrix were also modified. This was confirmed at the protein level by western-blotting showing a dramatic modification in some extracellular matrix proteins. Analysis of a selected set of modulated genes showed that the expression of the majority of these genes was modulated during the intracellular life of S. Typhimurium.

Deficiency of angiopoietin-like 4 enhances CD8+ T cell bioactivity via metabolic reprogramming for impairing tumour progression

Angiopoietin-like 4 (ANGPTL4) is a secreted metabolism-modulating glycoprotein involved in the progression of tumours, cardiovascular diseases, metabolic syndrome and infectious diseases. In this study, more CD8+ T cells were activated to be effector T cells in ANGPTL4-/- mice. Impaired growth of tumours implanted in 3LL, B16BL6 or MC38 cells and reduced metastasis by B16F10 cells were observed in ANGPTL4-/- mice. Bone marrow (BM) transplantation experiments displayed that deficiency of ANGPTL4 in either host or BM cells promoted CD8+ T cell activation. However, ANGPTL4 deficiency in CD8+ T cells themselves showed more efficient anti-tumour activities. Recombinant ANGPTL4 protein promoted tumour growth in vivo with the less CD8+ T cell infiltration and it directly downregulated CD8+ T cell activation ex vivo. Transcriptome sequencing and metabolism analysis identified that ANGPTL4-/- CD8+ T cells increased glycolysis and decreased oxidative phosphorylation, which was dependent on the PKCζ-LKB1-AMPK-mTOR signalling axis. Reverse correlation of elevated ANGPTL4 levels in sera and tumour tissues with activated CD8+ T cells in the peripheral blood was displayed in patients with colorectal cancer. These results demonstrated that ANGPTL4 decreased immune surveillance in tumour progression by playing an immune-modulatory role on CD8+ T cells via metabolic reprogramming. Efficient blockade of ANGPTL4 expression in tumour patients would generate an effective anti-tumour effect mediated by CD8+ T cells.

Transcriptomic and functional analysis of ANGPTL4 overexpression in pancreatic cancer nominates targets that reverse chemoresistance

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers based on five-year survival rates. Genes contributing to chemoresistance represent novel therapeutic targets that can improve treatment response. Increased expression of ANGPTL4 in tumors correlates with poor outcomes in pancreatic cancer.

METHODS

We used statistical analysis of publicly available gene expression data (TCGA-PAAD) to test whether expression of ANGPTL4 and its downstream targets, ITGB4 and APOL1, were correlated with patient survival. We measured the impact of ANGPTL4 overexpression in a common pancreatic cancer cell line, MIA PaCa-2 cells, using CRISPRa for overexpression and DsiRNA for knockdown. We characterized global gene expression changes associated with high levels of ANGPTL4 and response to gemcitabine treatment using RNA-sequencing. Gemcitabine dose response curves were calculated on modified cell lines by measuring cell viability with CellTiter-Glo (Promega). Impacts on cell migration were measured using a time course scratch assay.

RESULTS

We show that ANGPTL4 overexpression leads to in vitro resistance to gemcitabine and reduced survival times in patients. Overexpression of ANGPTL4 induces transcriptional signatures of tumor invasion and metastasis, proliferation and differentiation, and inhibition of apoptosis. Analyses revealed an overlapping signature of genes associated with both ANGPTL4 activation and gemcitabine response. Increased expression of the genes in this signature in patient PDAC tissues was significantly associated with shorter patient survival. We identified 42 genes that were both co-regulated with ANGPTL4 and were responsive to gemcitabine treatment. ITGB4 and APOL1 were among these genes. Knockdown of either of these genes in cell lines overexpressing ANGPTL4 reversed the observed gemcitabine resistance and inhibited cellular migration associated with epithelial to mesenchymal transition (EMT) and ANGPTL4 overexpression.

CONCLUSIONS

These data suggest that ANGPTL4 promotes EMT and regulates the genes APOL1 and ITGB4. Importantly, we show that inhibition of both targets reverses chemoresistance and decreases migratory potential. Our findings have revealed a novel pathway regulating tumor response to treatment and suggest relevant therapeutic targets in pancreatic cancer.

Determination of in vitro hepatotoxic potencies of a series of perfluoroalkyl substances (PFASs) based on gene expression changes in HepaRG liver cells

Per- and polyfluoroalkyl substances (PFASs) are omnipresent and have been shown to induce a wide range of adverse health effects, including hepatotoxicity, developmental toxicity, and immunotoxicity. The aim of the present work was to assess whether human HepaRG liver cells can be used to obtain insight into differences in hepatotoxic potencies of a series of PFASs. Therefore, the effects of 18 PFASs on cellular triglyceride accumulation (AdipoRed assay) and gene expression (DNA microarray for PFOS and RT-qPCR for all 18 PFASs) were studied in HepaRG cells. BMDExpress analysis of the PFOS microarray data indicated that various cellular processes were affected at the gene expression level. From these data, ten genes were selected to assess the concentration-effect relationship of all 18 PFASs using RT-qPCR analysis. The AdipoRed data and the RT-qPCR data were used for the derivation of in vitro relative potencies using PROAST analysis. In vitro relative potency factors (RPFs) could be obtained for 8 PFASs (including index chemical PFOA) based on the AdipoRed data, whereas for the selected genes, in vitro RPFs could be obtained for 11-18 PFASs (including index chemical PFOA). For the readout OAT5 expression, in vitro RPFs were obtained for all PFASs. In vitro RPFs were found to correlate in general well with each other (Spearman correlation) except for the PPAR target genes ANGPTL4 and PDK4. Comparison of in vitro RPFs with RPFs obtained from in vivo studies in rats indicate that best correlations (Spearman correlation) were obtained for in vitro RPFs based on OAT5 and CXCL10 expression changes and external in vivo RPFs. HFPO-TA was found to be the most potent PFAS tested, being around tenfold more potent than PFOA. Altogether, it may be concluded that the HepaRG model may provide relevant data to provide insight into which PFASs are relevant regarding their hepatotoxic effects and that it can be applied as a screening tool to prioritize other PFASs for further hazard and risk assessment.

Cyanotoxin exposure and hepatocellular carcinoma

Cyanobacteria are ubiquitous in aquatic and terrestrial environments worldwide and include a number of species producing tumor-promoting hepatotoxins. Human exposure to cyanobacteria and cyanotoxins primarily occurs though ingestion of contaminated drinking water and food sources. In a Northeast U.S. population, we recently reported an independent association of oral cyanobacteria with risk of hepatocellular carcinoma (HCC). In a cross-sectional study of 55 HCC patients in Hawaii, U.S.A., serum microcystin/nodularin (MC/NOD), cylindrospermopsin (CYN), and anabaenopeptin (AB) were measured by ELISA. In a subset of 16 patients, cyanotoxin levels were compared by tumor expression of over 700 genes analyzed via the Nanostring nCounter Fibrosis panel. MC/NOD, CYN, and AB were detected in all HCC patients. MC/NOD and CYN levels significantly varied by etiology with the highest levels in cases attributed to metabolic risk factors, specifically, hyperlipidemia, type 2 diabetes, and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. Cyanotoxin levels were significantly positively correlated with tumor expression of genes functioning in PPAR signaling and lipid metabolism. Our study provides novel albeit limited evidence that cyanotoxins may a role in the pathogenesis of HCC through the dysregulation of lipid metabolism and progression of hepatic steatosis.

Comprehensive in-silico analysis of deleterious SNPs in APOC2 and APOA5 and their differential expression in cancer and cardiovascular diseases conditions

Genetic variations in APOC2 and APOA5 genes involve activating lipoprotein lipase (LPL), responsible for the hydrolysis of triglycerides (TG) in blood and whose impaired functions affect the TG metabolism and are associated with metabolic diseases. In this study, we investigate the biological significance of genetic variations at the DNA sequence and structural level using various computational tools. Subsequently, 8 (APOC2) and 17 (APOA5) non-synonymous SNPs (nsSNPs) were identified as high-confidence deleterious SNPs based on the effects of the mutations on protein conservation, stability, and solvent accessibility. Furthermore, based on our docking results, the interaction of native and mutant forms of the corresponding proteins with LPL depicts differences in root mean square deviation (RMSD), and binding affinities suggest that these mutations may affect their function. Furthermore, in vivo, and in vitro studies have shown that differential expression of these genes in disease conditions due to the influence of nsSNPs abundance may be associated with promoting the development of cancer and cardiovascular diseases. Preliminary screening using computational methods can be a helpful start in understanding the effects of mutations in APOC2 and APOA5 on lipid metabolism; however, further wet-lab experiments would further strengthen the conclusions drawn from the computational study.

New approach methodologies: A quantitative in vitro to in vivo extrapolation case study with PFASs

PER: and polyfluoroalkyl substances (PFASs) have been associated with increased blood lipids in humans. Perfluorooctanoic acid (PFOA) has been also linked with elevated alanine transferase (ALT) serum levels in humans, and in rodents the liver is a main target organ for many PFASs. With the focus on New Approach Methodologies, the chronic oral equivalent effect doses were calculated for PFOA, PFNA (perfluorononanoic acid), PFHxS (perfluorohexanesulfonic acid) and PFOS (perfluorooctane sulfonic acid) based on in vitro effects measured in the HepaRG cell line. Selected in vitro readouts were considered biomarkers for lipid disturbances and hepatotoxicity. Concentration-response data obtained from HepaRG cells on triglyceride (TG) accumulation and expression changes of 12 selected genes (some involved in cholesterol homeostasis) were converted into corresponding human dose-response data, using physiologically based kinetic (PBK) model-facilitated reverse dosimetry. Next to this, the biokinetics of the chemicals were studied in the cell system. The current European dietary PFASs exposure overlaps with the calculated oral equivalent effect doses, indicating that the latter may lead to interference with hepatic gene expression and lipid metabolism. These findings illustrate an in vitro-in silico methodology, which can be applied for more PFASs, to select those that should be prioritized for further hazard characterization.

Increased expression of angiopoietin-like protein 4 regulates matrix metalloproteinase-13 expression in Porphyromonas gingivalis lipopolysaccharides-stimulated gingival fibroblasts and ligature-induced experimental periodontitis

BACKGROUND

Angiopoietin-like protein 4 (ANGPTL4) is produced in chronic or acute inflammation. Although ANGPTL4 increases in the periodontal ligament fibroblasts during hypoxia, the involvement and role of ANGPTL4 in periodontitis have not been elucidated.

OBJECTIVE

In this study, we investigated whether ligature-induced experimental periodontitis and/or Porphyromonas gingivalis lipopolysaccharides (Pg-LPS) would upregulate ANGPTL4 expression and whether ANGPTL4 would somehow involve in the expression of matrix metalloproteinases (MMPs) which are key molecules in the process of periodontal tissue destruction.

METHODS

Experimental periodontitis was induced in 6-week-old male Sprague-Dawley rats by placing a nylon suture around the neck of the maxillary second molar. Two weeks after the induction of periodontitis, the periodontal tissue was excised and analyzed by histological/immunohistochemical staining and gene expression analyses. Human gingival fibroblasts (hGFs) were stimulated with Pg-LPS. The gene expression of ANGPTLs and receptors involved in ANGPTL4 recognition were observed. We also confirmed the changes in gene expression of MMPs upon stimulation with human ANGPTL4. Furthermore, we downregulated ANGPTL4 expression by short interfering RNA in hGFs and investigated the effect of Pg-LPS on MMP production.

RESULTS

Induction of periodontitis significantly increased the expression of ANGPTL4 in the gingiva. Pg-LPS significantly increased the gene and protein expression of ANGPTL4 in hGFs but not the gene expression of other ANGPTLs or ANGPTL receptors. Recombinant human ANGPTL4 significantly increased MMP13 gene expression in hGFs. We also confirmed that MMP13 expression was increased in the gingiva during experimental periodontitis. Pg-LPS induced MMP13 gene expression in hGFs. These results suggest the pivotal role of ANGPTL4 in periodontitis.

CONCLUSION

Periodontitis increases ANGPTL4 expression in the gingiva, further suggesting that increased ANGPTL4 may be a factor involved in enhancing MMP13 expression.

Establishment of a Lymph Node Metastasis-Associated Prognostic Signature for Lung Adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is the most common histological subtype of non-small cell lung cancer (NSCLC) with a low 5-year survival rate, which may be associated with the presence of metastatic tumors at the time of diagnosis, especially lymph node metastasis (LNM). This study aimed to construct a LNM-related gene signature for predicting the prognosis of patients with LUAD.

Methods

RNA sequencing data and clinical information of LUAD patients were extracted from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Samples were divided into metastasis (M) and nonmetastasis (NM) groups based on LNM status. Differentially expressed genes (DEGs) between M and NM groups were screened, and then WGCNA was applied to identify key genes. Furthermore, univariate Cox and LASSO regression analyses were conducted to construct a risk score model, and the predictive performance of model was validated by GSE68465, GSE42127, and GSE50081. The protein and mRNA expression level of LNM-associated genes were detected by human protein atlas (HPA) and GSE68465.

Results

A prognostic model based on eight LNM-related genes (ANGPTL4, BARX2, GPR98, KRT6A, PTPRH, RGS20, TCN1, and TNS4) was developed. Patients in the high-risk group had poorer overall survival than those in the low-risk group, and validation analysis showed that this model had potential predictive value for patients with LUAD. HPA analysis supported the upregulation of ANGPTL4, KRT6A, BARX2, RGS20 and the downregulation of GPR98 in LUAD compared with normal tissues.

Conclusion

Our results indicated that the eight LNM-related genes signature had potential value in the prognosis of patients with LUAD, which may have important practical implications.

Transcriptomic and functional analysis of ANGPTL4 overexpression in pancreatic cancer nominates targets that reverse chemoresistance

Background Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers based on five-year survival rates. Genes contributing to chemoresistance represent novel therapeutic targets that can improve treatment response. Increased expression of ANGPTL4 in tumors correlates with poor outcomes in pancreatic cancer. Methods We used statistical analysis of publicly available gene expression data (TCGA-PAAD) to test whether expression of ANGPTL4 and its downstream targets, ITGB 4 and APOL1 , were correlated with patient survival. We measured the impact of ANGPTL4 overexpression in a common pancreatic cancer cell line, MIA PaCa-2 cells, using CRISPRa for overexpression and DsiRNA for knockdown. We characterized global gene expression changes associated with high levels of ANGPTL4 and response to gemcitabine treatment using RNA-sequencing. Gemcitabine dose response curves were calculated on modified cell lines by measuring cell viability with CellTiter-Glo (Promega). Impacts on cell migration were measured using a time course scratch assay. Results We show that ANGPTL4 overexpression leads to in vitro resistance to gemcitabine and reduced survival times in patients. Overexpression of ANGPTL4 induces transcriptional signatures of tumor invasion and metastasis, proliferation and differentiation, and inhibition of apoptosis. Analyses revealed an overlapping signature of genes associated with both ANGPTL4 activation and gemcitabine response. Increased expression of the genes in this signature in patient PDAC tissues was significantly associated with shorter patient survival. We identified 42 genes that were both co-regulated with ANGPTL4 and were responsive to gemcitabine treatment. ITGB4 and APOL1 were among these genes. Knockdown of either of these genes in cell lines overexpressing ANGPTL4 reversed the observed gemcitabine resistance and inhibited cellular migration associated with epithelial to mesenchymal transition (EMT) and ANGPTL4 overexpression. Conclusions These data suggest that ANGPTL4 promotes EMT and regulates the genes APOL1 and ITGB4 . Importantly, we show that inhibition of both targets reverses chemoresistance and decreases migratory potential. Our findings have revealed a novel pathway regulating tumor response to treatment and suggest relevant therapeutic targets in pancreatic cancer.

Primary tumor-derived systemic nANGPTL4 inhibits metastasis

Primary tumors and distant site metastases form a bidirectionally communicating system. Yet, the molecular mechanisms of this crosstalk are poorly understood. Here, we identified the proteolytically cleaved fragments of angiopoietin-like 4 (ANGPTL4) as contextually active protumorigenic and antitumorigenic contributors in this communication ecosystem. Preclinical studies in multiple tumor models revealed that the C-terminal fragment (cANGPTL4) promoted tumor growth and metastasis. In contrast, the N-terminal fragment of ANGPTL4 (nANGPTL4) inhibited metastasis and enhanced overall survival in a postsurgical metastasis model by inhibiting WNT signaling and reducing vascularity at the metastatic site. Tracing ANGPTL4 and its fragments in tumor patients detected full-length ANGPTL4 primarily in tumor tissues, whereas nANGPTL4 predominated in systemic circulation and correlated inversely with disease progression. The study highlights the spatial context of the proteolytic cleavage-dependent pro- and antitumorigenic functions of ANGPTL4 and identifies and validates nANGPTL4 as a novel biomarker of tumor progression and antimetastatic therapeutic agent.

PPARβ/δ-Interfering Peptide Enhanced Mesenchymal Stromal Cell Immunoregulatory Properties

Background

Mesenchymal stem/stromal cells (MSCs) have been widely used for their therapeutic properties in many clinical applications including osteoarthritis. Despite promising preclinical results showing the ability of MSC to reduce the clinical severity of osteoarthritis (OA) in experimental animal models, the benefits of intra-articular injection of MSC in OA patients are limited to the short term. In this regard, it is anticipated that improving the properties of MSC may collectively enhance their long-term beneficial effects on OA.

Methods and Results

Recently, we have shown that PPARβ/δ inhibition using a commercially available antagonist in murine MSC increases their immunoregulatory potential in vitro as well as their therapeutic potential in an experimental murine arthritis model. Here, we relied on an innovative strategy to inhibit PPARβ/δ:NF-κB TF65 subunit interaction in human MSC by designing and synthesizing an interfering peptide, referred to PP11. Through RT-qPCR experiments, we evidenced that the newly synthesized PP11 peptide reduced the expression level of PDK4, a PPARβ/δ target gene, but did not modify the expression levels of ACOX1 and CPT1A, PPARα target genes, and FABP4, a PPARγ target gene compared with untreated human MSC. Moreover, we showed that human MSCs pretreated with PP11 exhibit a significantly higher capacity to inhibit the proliferation of activated PBMC and to decrease the frequency of M1-like macrophages.

Conclusions

We designed and synthesized an interfering peptide that potently and specifically blocks PPARβ/δ activity with concomitant enhancement of MSC immunoregulatory properties.

Proteomics analysis uncovers plasminogen activator PLAU as a target of the STING pathway for suppression of cancer cell migration and invasion

The stimulator of interferon genes (STING) pathway is vital for immune defense against pathogen invasion and cancer. Although ample evidence substantiates that the STING signaling pathway plays an essential role in various cancers via cytokines, no comprehensive investigation of secretory proteins regulated by the STING pathway has been conducted hitherto. Herein, we identify 24 secretory proteins significantly regulated by the STING signaling pathway through quantitative proteomics. Mechanistic analyses reveal that STING activation inhibits the translation of urokinase-type plasminogen activator (PLAU) via the STING-PERK-eIF2α signaling axis. PLAU is highly expressed in a variety of cancers and promotes the migration and invasion of cancer cells. Notably, the activation of STING inhibits cancer cell migration and invasion by suppressing PLAU. Collectively, these results provide novel insights into the anticancer mechanism of the STING pathway, offering a theoretical basis for precision therapy for this patient population.

Molecular Characterization of the Dual Effect of the GPER Agonist G-1 in Glioblastoma

Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite conventional treatment, consisting of a chirurgical resection followed by concomitant radio-chemotherapy, the 5-year survival rate is less than 5%. Few risk factors are clearly identified, but women are 1.4-fold less affected than men, suggesting that hormone and particularly estrogen signaling could have protective properties. Indeed, a high GPER1 (G-protein-coupled estrogen receptor) expression is associated with better survival, especially in women who produce a greater amount of estrogen. Therefore, we addressed the anti-tumor effect of the GPER agonist G-1 in vivo and characterized its molecular mechanism of action in vitro. First, the antiproliferative effect of G-1 was confirmed in a model of xenografted nude mice. A transcriptome analysis of GBM cells exposed to G-1 was performed, followed by functional analysis of the differentially expressed genes. Lipid and steroid synthesis pathways as well as cell division processes were both affected by G-1, depending on the dose and duration of the treatment. ANGPTL4, the first marker of G-1 exposure in GBM, was identified and validated in primary GBM cells and patient samples. These data strongly support the potential of G-1 as a promising chemotherapeutic compound for the treatment of GBM.

Integrated analysis of transcriptomics, proteomics and metabolomics data reveals the role of SLC39A1 in renal cell carcinoma

Purpose: Accumulating evidence suggests that solute carrier family 39 member 1 (SLC39A1) conceivably function as a tumor suppressor, but the underlying mechanism in renal cell carcinoma (RCC) is poorly understood. Methods: OSRC-2 renal cancer cells were first transfected with SLC39A1 overexpressed vectors and empty vectors and then used in transcriptomics, proteomics, and metabolomics integrated analyses. Results: SLC39A1 significantly altered several metabolisms at transcriptional, protein and metabolic levels, including purine and pyrimidine metabolism, amino acids and derivatives metabolism, lactose metabolism, and free fatty acid metabolism. Additionally, SLC39A1 could promote ferroptosis, and triggered significant crosstalk in PI3K-AKT signal pathway, cAMP signal pathway, and peroxisome proliferators-activated receptor (PPAR) signal pathway. Conclusion: We found SLC39A1 transfection impaired tumor metabolism and perturbed tumor metabolism-related pathways, which was a likely cause of the alteration in cell proliferation, migration, and cell cycle progression in RCC cells. These multi-omics analyses results provided both a macroscopic picture of molecular perturbation by SLC39A1 and novel insights into RCC tumorigenesis and development.

Prognostic Significance of ANGPTL4 in Lung Adenocarcinoma: A Meta-Analysis Based on Integrated TCGA and GEO Databases

Lung adenocarcinoma (LUAD) is a common malignant tumor with a poor prognosis. Recent studies have found that angiopoietin-like 4 (ANGPTL4) is abnormally expressed in many tumors, so it can serve as a potential prognostic marker and therapeutic target. However, its prognostic value in LUAD remains unclear. We downloaded RNA sequence data for LUAD from The Cancer Genome Atlas (TCGA) database, methylation data from the University of California Santa Cruz genome database, and clinical information. R software (version 4.1.1) was applied to analyze the ANGPTL4 expression in LUAD and nontumor samples, and the correlation with clinical characteristics to assess its prognostic and diagnostic value. In addition, we analyzed the relationship between the ANGPTL4 expression and methylation levels. Tumor IMmune Estimation Resource (TIMER) tool was taken for immune infiltration analysis, and two Gene Expression Omnibus (GEO) datasets were combined for meta-analysis. Finally, differentially expressed genes (DEGs) related to ANGPTL4 were analyzed to clarify its function. As shown in our results, ANGPTL4 was upregulated in LUAD and was an independent risk factor for the diagnosis and prognosis of LUAD. The general methylation level and eight ANGPTL4 methylation sites were significantly negatively correlated with the ANGPTL4 expression. Furthermore, we found that B cell infiltration was negatively correlated with ANGPTL4 expression and was an independent risk factor. Meta-analysis showed that the high expression of ANGPTL4 was closely associated with a poor prognosis. 153 DEGs, including the matrix metalloproteinase family, the chemokines subfamily, and the collagen family, were correlated with ANGPTL4. In this study, we found that ANGPTL4 was significantly elevated in LUAD and was closely associated with the development and poor prognosis of LUAD, suggesting that ANGPTL4 may be a prognostic biomarker and a potential therapeutic target for LUAD.

TAZ Regulates the Cisplatin Resistance of Epithelial Ovarian Cancer Cells via the ANGPTL4/SOX2 Axis

Objective

Epithelial ovarian cancer (EOC) is a fatal gynecological malignancy. This study explored the mechanism of TAZ in regulating drug sensitivity of cisplatin (DDP-)-resistant EOC cells through the ANGPTL4/SOX2 axis.

Methods

The A2780/DDP cells were prepared by stepwise progressive concentration method. The drug resistance and TAZ expression in EOC cells were determined. Drug sensitivity was measured after TAZ overexpression in A2780 cells and TAZ downregulation in A2780/DDP cells, respectively. The effects of TAZ knockdown on apoptosis rate, stemness, and cancer stem cell (CSC) marker (CD44, OCT4, and ALDH1A) levels in A2780/DDP and DDP-treated A2780/DDP cells were assessed. The binding of TAZ and ANGPTL4 was verified using ChIP-qPCR, and ANGPTL4 and SOX2 levels were determined. The effects of different combined treatments of TAZ, ANGPTL4, and SOX2 on drug sensitivity of A2780/DDP cells and DDP-treated A2780/DDP cells were evaluated.

Results

TAZ was upregulated in drug-resistant EOC cells. TAZ knockdown significantly increased the drug sensitivity of A2780/DDP cells, while TAZ overexpression markedly decreased the drug sensitivity of A2780 cells. TAZ silencing promoted apoptosis of drug-resistant EOC cells and inhibited cell stemness. TAZ targeted ANGPTL4 and TAZ silencing enhanced drug sensitivity of A2780/DDP cells by inhibiting ANGPTL4. ANGPTL4 overexpression elevated SOX2 expression, and SOX2 downregulation reduced the drug resistance and promoted the apoptosis of A2780/DDP cells.

Conclusion

TAZ regulates DDP sensitivity of drug-resistant EOC cells via the ANGPTL4/SOX2 axis.

Bioinformatics prediction and experimental verification of key biomarkers for diabetic kidney disease based on transcriptome sequencing in mice

Background

Diabetic kidney disease (DKD) is the leading cause of death in people with type 2 diabetes mellitus (T2DM). The main objective of this study is to find the potential biomarkers for DKD.

Materials and Methods

Two datasets (GSE86300 and GSE184836) retrieved from Gene Expression Omnibus (GEO) database were used, combined with our RNA sequencing (RNA-seq) results of DKD mice (C57 BLKS-32w db/db) and non-diabetic (db/m) mice for further analysis. After processing the expression matrix of the three sets of data using R software "Limma", differential expression analysis was performed. The significantly differentially expressed genes (DEGs) (-logFC- > 1, p-value < 0.05) were visualized by heatmaps and volcano plots respectively. Next, the co-expression genes expressed in the three groups of DEGs were obtained by constructing a Venn diagram. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were further analyzed the related functions and enrichment pathways of these co-expression genes. Then, qRT-PCR was used to verify the expression levels of co-expression genes in the kidney of DKD and control mice. Finally, protein-protein interaction network (PPI), GO, KEGG analysis and Pearson correlation test were performed on the experimentally validated genes, in order to clarify the possible mechanism of them in DKD.

Results

Our RNA-seq results identified a total of 125 DEGs, including 59 up-regulated and 66 down-regulated DEGs. At the same time, 183 up-regulated and 153 down-regulated DEGs were obtained in GEO database GSE86300, and 76 up-regulated and 117 down-regulated DEGs were obtained in GSE184836. Venn diagram showed that 13 co-expression DEGs among the three groups of DEGs. GO analysis showed that biological processes (BP) were mainly enriched inresponse to stilbenoid, response to fatty acid, response to nutrient, positive regulation of macrophage derived foam cell differentiation, triglyceride metabolic process. KEGG pathway analysis showed that the three major enriched pathways were cholesterol metabolism, drug metabolism-cytochrome P450, PPAR signaling pathway. After qRT-PCR validation, we obtained 11 genes that were significant differentially expressed in the kidney tissues of DKD mice compared with control mice. (The mRNA expression levels of Aacs, Cpe, Cd36, Slc22a7, Slc1a4, Lpl, Cyp7b1, Akr1c14 and Apoh were declined, whereas Abcc4 and Gsta2 were elevated).

Conclusion

Our study, based on RNA-seq results, GEO databases and qRT-PCR, identified 11 significant dysregulated DEGs, which play an important role in lipid metabolism and the PPAR signaling pathway, which provide novel targets for diagnosis and treatment of DKD.

A Review of free fatty acid-induced cell signaling, angiopoietin-like protein 4, and skeletal muscle differentiation

Postnatal skeletal muscle differentiation from quiescent satellite cells is a highly regulated process, although our understanding of the contribution of nutritional factors in myogenesis is limited. Free fatty acids (FFAs) are known to cause detrimental effects to differentiated skeletal muscle cells by increasing oxidative stress which leads to muscle wasting and insulin resistance in skeletal muscle. In addition, FFAs are thought to act as inhibitors of skeletal muscle differentiation. However, the precise molecular mechanisms underlying the effects of FFAs on skeletal muscle differentiation remains to be elucidated. There is a clear relationship between dietary FFAs and their ability to suppress myogenesis and we propose the hypothesis that the FFA-mediated increase in angiopoietin-like protein 4 (ANGPTL4) may play a role in the inhibition of differentiation. This review discusses the role of FFAs in skeletal muscle differentiation to-date and proposes potential mechanisms of FFA-induced ANGPTL4 mediated inhibition of skeletal muscle differentiation.

Interleukin-1β in tendon injury enhances reparative gene and protein expression in mesenchymal stem cells

Tendon injury in the horse carries a high morbidity and monetary burden. Despite appropriate therapy, reinjury is estimated to occur in 50–65% of cases. Although intralesional mesenchymal stem cell (MSC) therapy has improved tissue architecture and reinjury rates, the mechanisms by which they promote repair are still being investigated. Additionally, reevaluating our application of MSCs in tendon injury is necessary given recent evidence that suggests MSCs exposed to inflammation (deemed MSC licensing) have an enhanced reparative effect. However, applying MSC therapy in this context is limited by the inadequate quantification of the temporal cytokine profile in tendon injury, which hinders our ability to administer MSCs into an environment that could potentiate their effect. Therefore, the objectives of this study were to define the temporal cytokine microenvironment in a surgically induced model of equine tendon injury using ultrafiltration probes and subsequently evaluate changes in MSC gene and protein expression following in vitro inflammatory licensing with cytokines of similar concentration as identified in vivo. In our in vivo surgically induced tendon injury model, IL-1β and IL-6 were the predominant pro-inflammatory cytokines present in tendon ultrafiltrate where a discrete peak in cytokine concentration occurred within 48 h following injury. Thereafter, MSCs were licensed in vitro with IL-1β and IL-6 at a concentration identified from the in vivo study; however, only IL-1β induced upregulation of multiple genes beneficial to tendon healing as identified by RNA-sequencing. Specifically, vascular development, ECM synthesis and remodeling, chemokine and growth factor function alteration, and immunomodulation and tissue reparative genes were significantly upregulated. A significant increase in the protein expression of IL-6, VEGF, and PGE2 was confirmed in IL-1β-licensed MSCs compared to naïve MSCs. This study improves our knowledge of the temporal tendon cytokine microenvironment following injury, which could be beneficial for the development and determining optimal timing of administration of regenerative therapies. Furthermore, these data support the need to further study the benefit of MSCs administered within the inflamed tendon microenvironment or exogenously licensed with IL-1β in vitro prior to treatment as licensed MSCs could enhance their therapeutic benefit in the healing tendon.

ANGPTL4 Regulates Psoriasis via Modulating Hyperproliferation and Inflammation of Keratinocytes

Background: Psoriasis is characterized by keratinocyte proliferation and massive inflammatory leukocytes infiltration, affecting 0.14%–1.99% of the world’s population. Our aim was to identify novel potential therapeutic strategies for psoriasis.

Methods: Weighted gene co-expression network analysis (WGCNA) was performed to identify gene modules that were closely related to psoriasis based on the GSE30999 dataset, which contained expression data from 85 patients with moderate-to-severe psoriasis. Then, angiopoietin-like 4 (ANGPTL4), one of the most related hub genes, was selected for in vitro and in vivo functional assays. In our experiments, imiquimod (IMQ)-induced psoriasiform dermatitis in mice and human keratinocytes (HaCaT) cells were used to study the potential roles and mechanisms of ANGPTL4 in psoriasis.

Results: WGCNA analysis revealed the turquoise module was most correlated with psoriasis, and ANGPTL4 is one of the most related hub genes that significantly upregulated in psoriasis lesions compared with non-lesional skin. Consistent with the bioinformatic analysis, the expression of ANGPTL4 was significantly upregulated in IMQ-induced psoriasiform skin of mice. Exogenous recombinant ANGPLT4 protein treatment could promote the proliferation and induce the expression of inflammatory cytokines in HaCaTs, whereas silencing of ANGPTL4 effectively inhibited these effects. Then we demonstrated that recombinant ANGPTL4 protein exacerbated psoriasiform inflammation and epidermal hyperproliferation in vivo. Mechanismly, extracellular signal-regulated kinase 1/2 (ERK1/2) and signal transducer and activator of transcription 3 (STAT3) pathways were involved in ANGPTL4-mediated regulation of proliferation and inflammation.

Conclusion: We found ANGPTL4 was significantly increased in IMQ-induced psoriasiform skin of mice. ANGPTL4 could promote keratinocyte proliferation and inflammatory response via ERK1/2 and STAT3 dependent signaling pathways in psoriasis.

A Study on the Molecular Mechanism of High Altitude Heart Disease in Children

Objective

High altitude heart disease (HAHD) is a common pediatric disease in high altitude areas. It usually occurs in people who have lived for a long time or have lived for more than 2500m above sea level. Its common inducement is respiratory tract infection. The clinical differential diagnosis is difficult because the symptoms of HAHD are similar to those of congenital heart disease; Due to the limitation of medical conditions, many patients are in the state of losing follow-up or not seeking medical treatment, resulting in poor prognosis of HAHD and becoming a high-altitude disease with high mortality. Clarifying the molecular mechanism of HAHD, developing early molecular screening technology and accurate treatment methods of HAHD are the key to improve the ability of prevention and treatment of HAHD.

Methods

First, the literature in the PubMed and CNKI databases were screened based on keywords and abstracts. Then, the literature for the study was identified based on the fitness between the content of the literature, the research objectives, and the timeliness of the literature. Finally, a systematic molecular mechanism of HAHD was established by investigating the literature and sorting out the genetic adaptations of Tibetan populations compared with low-altitude populations that migrated to the plateau.

Results

With the investigation of the 48 papers screened, it was found that genes capable of enhancing the hypoxic ventilatory response and resistance to pulmonary hypertension were all correlated with the hypoxia-inducible factor (HIF) pathway, consisting mainly of three pathways, HIF-1α, HIF-2α, and NO.

Conclusion

The low prevalence of HAHD in Tibetan aboriginal children was mainly due to the genetic adaptation of the Tibetan population to the high altitude environment, which coordinated the cellular response to hypoxia by regulating the downstream hypoxia control genes in the HIF pathway.

2,2',4,4'-Tetrabromodiphenyl Ether (PBDE 47) Selectively Stimulates Proatherogenic PPARγ Signatures in Human THP-1 Macrophages to Contribute to Foam Cell Formation

2,2',4,4'-Tetrabromodiphenyl ether (PBDE 47) is one of the most prominent PBDE congeners detected in the human body, suggesting that the potential health risks of PBDE 47 should be thoroughly considered. However, the cardiovascular toxicity of PBDE 47 remains poorly understood. Here, toxic outcomes of PBDE 47 in human THP-1 macrophages concerning foam cell formation, which play crucial roles in the occurrence and development of atherosclerosis, were elucidated. First, our results indicated that PBDE 47 affected the PPARγ pathway most efficiently in THP-1 macrophages by transcriptomic analysis. Second, the PPARγ target genes CD36 and FABP4, responsible for lipid uptake and accumulation in macrophages, were consistently upregulated both at transcriptional and translational levels in THP-1 macrophages upon PBDE 47. Unexpectedly, PBDE 47 failed to activate the PPARγ target gene LXRα and PPARγ-LXRα-ABCA1/G1 cascade, which is activated by the PPARγ full agonist rosiglitazone and enables cholesterol efflux in macrophages. Thus, coincident with the selective upregulation of the PPARγ target genes CD36 and FABP4, PBDE 47, distinct from rosiglitazone, functionally resulted in more lipid accumulation and oxLDL uptake in THP-1 macrophages through high-content analysis (HCA). Moreover, these effects were markedly abrogated by the addition of the PPARγ antagonist T0070907. Mechanistically, the structural basis of selective activation of PPARγ by PBDE 47 was explored by molecular docking and dynamics simulation, which indicated that PBDE 47 interacted with the PPARγ ligand binding domain (PPARγ-LBD) distinctively from that of rosiglitazone. PBDE 47 was revealed to interact with helix 3 and helix 5 but not helix 12 in the PPARγ-LBD. Collectively, these results unraveled the potential cardiovascular toxicity of PBDE 47 by selective activation of PPARγ to facilitate foam cell formation for the first time.

ANGPTL4 negatively regulates the progression of osteosarcoma by remodeling branched-chain amino acid metabolism

Angiopoietin-like-4 (ANGPTL4), a secreted glycoprotein that is mainly known as a regulator in lipid metabolism, now, is also indicated to be involved in the regulation of cancer progression and metastasis. However, little is known about not only biological functions, but also underlying mechanism of ANGPTL4 in the progression of osteosarcoma (OS). Here, we discovered that ANGPTL4 is downregulated in OS, and is associated with branched-chain amino acid (BCAA) metabolism. The BCAAs (valine, leucine, and isoleucine) are essential amino acids that play an important role in metabolic regulation. Aberrant BCAA metabolism is also found in various cancers and is associated with tumor progression, including proliferation, invasion, and metastasis. In this study, we indicated that the negative relation between the expression of ANGPTL4 and BCAA catabolism in OS samples and cell lines. The knockdown of ANGPTL4 in OS cells resulted in the accumulation of BCAAs, which in turn activated the mTOR signaling pathway, enhancing OS cell proliferation. Thus, reduced expression of ANGPTL4 is associated with the progression of OS. Taken together, our results demonstrated that the ANGPTL4/BCAA/mTOR axis is an important pathway in OS progression and may be a potential therapeutic target to slow OS progression.

Using a Machine Learning Approach to Identify Key Biomarkers for Renal Clear Cell Carcinoma

Background

The most common and deadly subtype of renal carcinoma is kidney renal clear cell carcinoma (KIRC), which accounts for approximately 75% of renal carcinoma. However, the main cause of death in KIRC patients is tumor metastasis. There are no obvious clinical features in the early stage of kidney cancer, and 25–30% of patients have already metastasized when they are first diagnosed. Moreover, KIRC patients whose local tumors have been removed by nephrectomy are still at high risk of metastasis and recurrence and are not sensitive to chemotherapy and radiotherapy, leading to poor prognosis. Therefore, early diagnosis and treatment of this disease are very important.

Methods

KIRC-related patient datasets were downloaded from the GEO database and TCGA database. DEG screening and GO, KEGG and GSEA enrichment analysis was firstly conducted and then the LASSO and support vector machine (SVM) RFE algorithms were adopted to identify KIRC-associated key genes in training sets and validate them in the test set. The clinical prognostic analysis including the association between the expression of key genes and the overall survival, stage, grade across KIRC, the immune infiltration difference between normal samples and cancer samples, the correlation between the key genes and immune cells, immunomodulator, immune subtypes of KIRC were investigated in this research.

Results

We finally screened out 4 key genes, including ACPP, ANGPTL4, SCNN1G, SLC22A7. The expression of key genes show difference among normal samples and tumor samples, SCNN1G and SLC22A7 could be predictor of prognosis of patients. The expression of key genes was related with the abundance of tumor infiltration immune cells and the gene expression of immune checkpoint.

Conclusion

This study screened the 4 key genes, which contributed to early diagnosis, prognosis assessment and immune target treatment of patients with KIRC.

Small Extracellular Vesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells Enhanced Proangiogenic Potential of Cardiac Fibroblasts via Angiopoietin-Like 4

Background and Objectives. After myocardial hypoxic injury, it is important to enhance vascular formation and restore blood supply for injury repair. Previous studies have suggested that cardiac fibroblasts (CFs) play a crucial role in angiogenesis after myocardial injury. Small extracellular vesicles (sEVs) derived from human umbilical cord mesenchymal stem cells (hucMSCs) promote fibroblast-to-myofibroblast differentiation in inflammatory environment and have cardioprotective effects. It remains unknown whether sEVs regulate cardiac fibroblasts to promote angiogenesis after myocardial injury. Methods and Results. We isolated primary CFs from Sprague-Dawley rats (1–3 days old) and treated them with lipopolysaccharide (LPS) and LPS+sEVs. RNA sequencing analysis revealed that angiopoietin-like 4 (Angptl4) was increased in the LPS+sEVs group more than in the LPS group. After inhibition of Angptl4 expression in sEVs and CFs, cell proliferation, Transwell migration, and tube formation assays were used to detect the angiogenic activity of human umbilical vein endothelial cells. β-Catenin expression in CFs was detected by western blotting. The β-catenin inhibitor ICG001 was used to examine whether β-catenin was involved in the proangiogenic potential of CFs promoted by sEVs. sEVs enhanced the proangiogenic potential of CFs under inflammatory conditions, which was associated with β-catenin signaling. The proangiogenic potential of CFs was decreased when Angptl4 was knocked down in CFs and in hucMSCs. Conclusions. The sEVs regulated CFs to promote angiogenesis via Angptl4 in an inflammatory environment. This may provide a research basis for treating myocardial injury with sEVs.

PPARα and PPARγ activation is associated with pleural mesothelioma invasion but therapeutic inhibition is ineffective

Mesothelioma is a cancer that typically originates in the pleura of the lungs. It rapidly invades the surrounding tissues, causing pain and shortness of breath. We compared cell lines injected either subcutaneously or intrapleurally and found that only the latter resulted in invasive and rapid growth. Pleural tumors displayed a transcriptional signature consistent with increased activity of nuclear receptors PPARα and PPARγ and with an increased abundance of endogenous PPAR-activating ligands. We found that chemical probe GW6471 is a potent, dual PPARα/γ antagonist with anti-invasive and anti-proliferative activity in vitro. However, administration of GW6471 at doses that provided sustained plasma exposure levels sufficient for inhibition of PPARα/γ transcriptional activity did not result in significant anti-mesothelioma activity in mice. Lastly, we demonstrate that the in vitro anti-tumor effect of GW6471 is off-target. We conclude that dual PPARα/γ antagonism alone is not a viable treatment modality for mesothelioma.

Analysis of Gene Expression Profiles in the Liver of Rats With Intrauterine Growth Retardation

BACKGROUND

Intrauterine growth restriction (IUGR) is highly associated with fetal as well as neonatal morbidity, mortality, and an increased risk metabolic disease development later in life. The mechanism involved in the increased risk has not been established. We compared differentially expressed genes between the liver of appropriate for gestational age (AGA) and IUGR rat models and identified their effects on molecular pathways involved in the metabolic syndrome.

METHODS

We extracted RNA from the liver of IUGR and AGA rats and profiled gene expression by microarray analysis. GO function and KEGG pathway enrichment analyses were conducted using the Search Tool for the Retrieval of Interacting Genes database. Then, the Cytoscape software was used to visualize regulatory interaction networks of IUGR-related genes. The results were further verified via quantitative reverse transcriptase PCR analysis.

RESULTS

In this study, 815 genes were found to be markedly differentially expressed (fold-change >1.5, p < 0.05) between IUGR and AGA, with 347 genes elevated and 468 suppressed in IUGR, relative to AGA. Enrichment and protein-protein interaction network analyses of target genes revealed that core genes including Ppargc1a, Prkaa2, Slc2a1, Rxrg, and Gcgr, and pathways, including the PPAR signaling pathway and FoxO signaling pathway, had a potential association with metabolic syndrome development in IUGR. We also confirmed that at the mRNA level, five genes involved in glycometabolism were differentially expressed between IUGR and AGA.

CONCLUSION

Our findings elucidate on differential gene expression profiles in IUGR and AGA. Moreover, they elucidate on the pathogenesis of IUGR-associated metabolic syndromes. The suggested candidates are potential biomarkers and eventually intended to treat them appropriately.

Lipid metabolism-related gene prognostic index (LMRGPI) reveals distinct prognosis and treatment patterns for patients with early-stage pulmonary adenocarcinoma

Background: Lipid metabolism plays a pivotal role in cancer progression and metastasis. This study aimed to investigate the prognostic value of lipid metabolism-related genes (LMRGs) in early-stage lung adenocarcinoma (LUAD) and develop a lipid metabolism-related gene prognostic index (LMRGPI) to predict their overall survival (OS) and treatment response. Methods: A total of 774 early-stage LUAD patients were identified from The Cancer Genome Atlas (TCGA, 403 patients) database and Gene Expression Omnibus (GEO, 371 patients) database. The non-negative Matrix Factorization (NMF) algorithm was used to identify different population subtypes based on LMRGs. The Least Absolute Shrinkage and Selection Operator (LASSO) and multivariate Cox regression analyses were used to develop the LMRGPI, with receiver operating characteristic (ROC) curves and concordance index being used to evaluate its performance. The characteristics of mutation landscape, enriched pathways, tumor microenvironment (TME), and treatment response between different LMRGPI groups were also investigated. Results: We identified two population subtypes based on LMRGs in the TCGA-LUAD cohort, with distinct prognosis, TME, and immune status being observed. LMRGPI was developed based on the expression levels of six LMRGs, including ANGPTL4, NPAS2, SLCO1B3, ACOXL, ALOX15, and B3GALNT1. Higher LMRGPI was correlated with poor OS both in TCGA and GSE68465 cohorts. Two nomograms were established to predict the survival probability of early-stage LUAD, with higher consistencies being observed between the predicted and actual OS. Higher LMRGPI was significantly correlated with more frequent TP53 mutation, higher tumor mutation burden (TMB), and up-regulation of CD274. Besides, patients with higher LMRGPI presented unremarkable responses for gefitinib, erlotinib, cisplatin, and vinorelbine, while they tend to have a favorable response for immune checkpoint inhibitors (ICIs). The opposite results were observed in the low-LMRGPI group. Conclusions: We comprehensively investigated the prognostic value of LMRGs in early-stage LUAD. Given its good prognostic ability, LMRGPI could serve as a promising biomarker to predict the OS and treatment response of these patients.

PPARγ Regulates Triclosan Induced Placental Dysfunction

Exposure to the antibacterial agent triclosan (TCS) is associated with abnormal placenta growth and fetal development during pregnancy. Peroxisome proliferator-activated receptor γ (PPARγ) is crucial in placenta development. However, the mechanism of PPARγ in placenta injury induced by TCS remains unknown. Herein, we demonstrated that PPARγ worked as a protector against TCS-induced toxicity. TCS inhibited cell viability, migration, and angiogenesis dose-dependently in HTR-8/SVneo and JEG-3 cells. Furthermore, TCS downregulated expression of PPARγ and its downstream viability, migration, angiogenesis-related genes HMOX1, ANGPTL4, VEGFA, MMP-2, MMP-9, and upregulated inflammatory genes p65, IL-6, IL-1β, and TNF-α in vitro and in vivo. Further investigation showed that overexpression or activation (rosiglitazone) alleviated cell viability, migration, angiogenesis inhibition, and inflammatory response caused by TCS, while knockdown or inhibition (GW9662) of PPARγ had the opposite effect. Moreover, TCS caused placenta dysfunction characterized by the significant decrease in weight and size of the placenta and fetus, while PPARγ agonist rosiglitazone alleviated this damage in mice. Taken together, our results illustrated that TCS-induced placenta dysfunction, which was mediated by the PPARγ pathway. Our findings reveal that activation of PPARγ might be a promising strategy against the adverse effects of TCS exposure on the placenta and fetus.

Metabogenomic analysis to functionally annotate the regulatory role of long non-coding RNAs in the liver of cows with different nutrient partitioning phenotype

Long non-coding RNAs (lncRNAs) hold gene regulatory potential, but require substantial further functional annotation in livestock. Applying two metabogenomic approaches by combining transcriptomic and metabolomic analyses, we aimed to identify lncRNAs with potential regulatory function for divergent nutrient partitioning of lactating crossbred cows and to establish metabogenomic interaction networks comprising metabolites, genes and lncRNAs. Through correlation analysis of lncRNA expression with transcriptomic and metabolomic data, we unraveled lncRNAs that have a putative regulatory role in energy and lipid metabolism, the urea and tricarboxylic acid cycles, and gluconeogenesis. Especially FGF21, which correlated with a plentitude of differentially expressed genes, differentially abundant metabolites, as well as lncRNAs, suggested itself as a key metabolic regulator. Notably, lncRNAs in close physical proximity to coding-genes as well as lncRNAs with natural antisense transcripts appear to perform a fine-tuning function in gene expression involved in metabolic pathways associated with different nutrient partitioning phenotypes.

Astrocytic lipid metabolism determines susceptibility to diet-induced obesity

Hypothalamic astrocytes play pivotal roles in both nutrient sensing and the modulation of synaptic plasticity of hypothalamic neuronal circuits in control of feeding and systemic glucose and energy metabolism. Here, we show the relevance of astrocytic fatty acid (FA) homeostasis under the opposing control of angiopoietin-like 4 (ANGPTL-4) and peroxisome proliferator–activated receptor gamma (PPARγ) in the cellular adaptations of hypothalamic astrocytes and neurons to the changing metabolic milieu. We observed that increased availability of FA in astrocytes induced by cell- and time-selective knockdown of Angptl4 protected against diet-induced obesity, while cell- and time-selective knockdown of Angptl4-regulated Pparγ lead to elevated susceptibility to obesity. Overall, our results unravel a previously unidentified role for astrocytic FA metabolism in central control of body weight and glucose homeostasis.

Expression of ANGPTL4 in Nucleus Pulposus Tissues Is Associated with Intervertebral Disc Degeneration

Objective

Angiopoietin-like protein 4 (ANGPTL4), encoding a glycosylated secreted protein, has been reported to be closely related to many kinds of diseases, including diabetes, tumor, and some musculoskeletal pathologies, such as rheumatoid arthritis, osteoarthritis, and osteoporosis. The aim of the current study is to investigate the role of ANGPTL4 in intervertebral disc degeneration and analyze the association of ANGPTL4 expression with Pfirrmann grades.

Methods

A total of 162 nucleus pulposus tissues were collected from lumbar intervertebral disc herniation patients undergoing interforaminal endoscopic surgery. Real-time quantitative PCR and western blot were performed to determine the mRNA and protein expression of ANGPTL4 in nucleus pulposus samples. Statistical analysis was performed to analyze the association of ANGPTL4 expression with Pfirrmann grades.

Results

Based on the clinical data of 162 patients, results showed that Pfirrmann grades were significantly associated with patients' age (r = 0.162, P = 0.047) and were not significantly associated with patients' gender (P > 0.05). RT-qPCR and western blot results showed that the mRNA (r = 0.287, P < 0.05) and protein (r = 0.356, P < 0.05) expressions of ANGPTL4 were both closely associated with Pfirrmann grades. The expression of ANGPTL4 was remarkably increased in the groups of high IVDD Pfirrmann grades.

Conclusion

The results demonstrated that ANGPTL4 expression was positively associated with the Pfirrmann grades and the severity of intervertebral disc degeneration. ANGPTL4 may be served as a candidate biomarker for intervertebral disc degeneration.

Transcription profiles in BEAS-2B cells exposed to organic extracts from particulate emissions produced by a port-fuel injection vehicle, fueled with conventional fossil gasoline and gasoline-ethanol blend

Emissions from road traffic are among the major contributors to air pollution worldwide and represent a serious environmental health risk. Although traffic-related pollution has been most commonly associated with diesel engines, increasing evidence suggests that gasoline engines also produce a considerable amount of potentially hazardous particulate matter (PM). The primary objective of this study was to compare the intrinsic toxic properties of the organic components of PM, generated by a conventional gasoline engine fueled with neat gasoline (E0), or gasoline-ethanol blend (15 % ethanol, v/v, E15). Our results showed that while E15 has produced, compared to gasoline and per kg of fuel, comparable particle mass (μg PM/kg fuel) and slightly more particles by number, the organic extract from the particulate matter produced by E15 contained a larger amount of harmful polycyclic aromatic hydrocarbons (PAHs), as determined by the chemical analysis. To examine the toxicity, we monitored genome-wide gene expression changes in human lung BEAS-2B cells, exposed for 4 h and 24 h to a subtoxic dose of each PM extract. After 4 h exposure, numerous dysregulated genes and processes such as oxidative stress, lipid and steroid metabolism, PPARα signaling and immune response, were found to be common for both extract treatments. On the other hand, 24 h exposure resulted in more distinctive gene expression patterns. Although we identified several common modulated processes indicating the metabolism of PAHs and activation of aryl hydrocarbon receptor (AhR), E15 specifically dysregulated a variety of other genes and pathways related to cancer promotion and progression. Overall, our findings suggest that the ethanol addition to gasoline changed the intrinsic properties of PM emissions and increased the PAH content in PM organic extract, thus contributing to a more extensive toxic response particularly after 24 h exposure in BEAS-2B cells.

Synthesis and antitumour evaluation of indole-2-carboxamides against paediatric brain cancer cells

Paediatric glioblastomas are rapidly growing, devastating brain neoplasms with an invasive phenotype. Radiotherapy and chemotherapy, which are the current therapeutic adjuvant to surgical resection, are still associated with various toxicity profiles and only marginally improve the course of the disease and life expectancy. A considerable body of evidence supports the antitumour and apoptotic effects of certain cannabinoids, such as WIN55,212-2, against a wide spectrum of cancer cells, including gliomas. In fact, we previously highlighted the potent cytotoxic activity of the cannabinoid ligand 5 against glioblastoma KNS42 cells. Taken together, in this study, we designed, synthesised, and evaluated several indoles and indole bioisosteres for their antitumour activities. Compounds 8a, 8c, 8f, 12c, and 24d demonstrated significant inhibitory activities against the viability (IC50 = 2.34-9.06 μM) and proliferation (IC50 = 2.88-9.85 μM) of paediatric glioblastoma KNS42 cells. All five compounds further retained their antitumour activities against two atypical teratoid/rhabdoid tumour (AT/RT) cell lines. When tested against a medulloblastoma DAOY cell line, only 8c, 8f, 12c, and 24d maintained their viability inhibitory activities. The viability assay against non-neoplastic human fibroblast HFF1 cells suggested that compounds 8a, 8c, 8f, and 12c act selectively towards the panel of paediatric brain tumour cells. In contrast, compound 24d and WIN55,212-2 were highly toxic toward HFF1 cells. Due to their structural resemblance to known cannabimimetics, the most potent compounds were tested in cannabinoid 1 and 2 receptor (CB1R and CB2R) functional assays. Compounds 8a, 8c, and 12c failed to activate or antagonise both CB1R and CB2R, whereas compounds 8f and 24d antagonised CB1R and CB2R, respectively. We also performed a transcriptional analysis on KNS42 cells treated with our prototype compound 8a and highlighted a set of seven genes that were significantly downregulated. The expression levels of these genes were previously shown to be positively correlated with tumour growth and progression, indicating their implication in the antitumour activity of 8a. Overall, the drug-like and selective antitumour profiles of indole-2-carboxamides 8a, 8c, 8f, and 12c substantiate the versatility of the indole scaffold in cancer drug discovery.

Nickel chloride regulates ANGPTL4 via the HIF-1α-mediated TET1 expression in lung cells

Angiopoietin-like protein 4 (ANGPTL4) is a hypoxia-induced gene, and its high expression is associated with poor prognosis and promotion of tumour progression in several cancers. Some studies reported that ANGPTL4 is affected by epigenetic regulation. Our previous results demonstrated that ANGPTL4 is highly expressed in most lung cancer cell lines than in normal cell lines and is upregulated by HIF-1α accumulation under NiCl₂ exposure. The accurate role of ANGPTL4 and its methylation status caused by nickel in the lung carcinogenesis is not fully explored yet. In this study, we found that ANGPTL4 and HIF-1α in lung adenocarcinoma (LUAD) tissues were significantly upregulated compared with those in normal tissues in The Cancer Genome Atlas (TCGA) cohort (p < 0.001). The ANGPTL4 expression was statistically correlated to advanced stage (p = 0.019) and N value (p = 0.002). The Kaplan-Meier analysis revealed that ANGPTL4 and HIF-1α expression levels were independently associated with the 5-year survival of patients with LUAD in TCGA database and immunohistochemistry staining. In vitro experiments indicated that ANGPTL4 was upregulated by the demethylation agent. The methylation-specific PCR and bisulfite sequencing assessed the methylation status of the ANGPTL4 promoter, and results showed that NiCl₂-treated cells had low ANGPTL4 methylation status. We further demonstrated that the DNA demethylase, TET1, was significantly increased under NiCl₂ exposure. The knockdown of TET1 expression repressed the NiCl₂-induced ANGPTL4. We also showed that nickel-induced TET1 was stimulated by HIF-1α. Our work established ANGPTL4 as a potential oncogene that contributes to lung cancer progression and nickel-elicited carcinogenesis.

A New Light on Potential Therapeutic Targets for Colorectal Cancer Treatment

The development and progression of colorectal cancer (CRC) involve changes in genetic and epigenetic levels of oncogenes and/or tumor suppressors. In spite of advances in understanding of the molecular mechanisms involved in CRC, the overall survival rate of CRC still remains relatively low. Thus, more research is needed to discover and investigate effective biomarkers and targets for diagnosing and treating CRC. The roles of long non-coding RNAs (lncRNAs) participating in various aspects of cell biology have been investigated and potentially contribute to tumor development. Our recent study also showed that CRNDE was among the top 20 upregulated genes in CRC clinical tissues compared to normal colorectal tissues by analyzing a Gene Expression Omnibus (GEO) dataset (GSE21815). Although CRNDE is widely reported to be associated with different types of cancer, most studies of CRNDE were limited to examining regulation of its transcription levels, and in-depth mechanistic research is lacking. In the present study, CRNDE was found to be significantly upregulated in CRC patients at an advanced TNM stage, and its high expression was correlated with poor outcomes of CRC patients. In addition, we found that knocking down CRNDE could reduce lipid accumulation through the miR-29b-3p/ANGPTL4 axis and consequently induce autophagy of CRC cells.