Prostaglandin E2 Activates Mitogen-Activated Protein Kinase/Erk Pathway Signaling and Cell Proliferation in Non–Small Cell Lung Cancer Cells in an Epidermal Growth Factor Receptor–Independent Manner

Multi-Cohort Transcriptomic Profiling of Medical Gas Plasma-Treated Cancers Reveals the Role of Immunogenic Cell Death

The therapeutic potential of cold physical gas plasma operated at atmospheric pressure in oncology has been thoroughly demonstrated in numerous preclinical studies. The cytotoxic effect on malignant cells has been attributed mainly to biologically active plasma-generated compounds, namely, reactive oxygen and nitrogen species. The intracellular accumulation of reactive oxygen and nitrogen species interferes strongly with the antioxidant defense system of malignant cells, activating multiple signaling cascades and inevitably leading to oxidative stress-induced cell death. This study aims to determine whether plasma-induced cancer cell death operates through a universal molecular mechanism that is independent of the cancer cell type. Using whole transcriptome data, we sought to investigate the activation mechanism of plasma-treated samples in patient-derived prostate cell cultures, melanoma, breast, lymphoma, and lung cancer cells. The results from the standardized single-cohort gene expression analysis and parallel multi-cohort meta-analysis strongly indicate that plasma treatment globally induces cancer cell death through immune-mediated mechanisms, such as interleukin signaling, Toll-like receptor cascades, and MyD88 activation leading to pro-inflammatory cytokine release and tumor antigen presentation.

Unveiling Alterations of Epigenetic Modifications and Chromatin Architecture Leading to Lipid Metabolic Reprogramming during the Evolutionary Trastuzumab Adaptation of HER2-Positive Breast Cancer

Secondary trastuzumab resistance represents an evolutionary adaptation of HER2-positive breast cancer during anti-HER2 treatment. Most current studies have tended to prioritize HER2 and its associated signaling pathways, often overlooking broader but seemingly less relevant cellular processes, along with their associated genetic and epigenetic mechanisms. Here, transcriptome data is not only characterized but also examined epigenomic and 3D genome architecture information in both trastuzumab-sensitive and secondary-resistant breast cancer cells. The findings reveal that the global metabolic reprogramming associated with trastuzumab resistance may stem from genome-wide alterations in both histone modifications and chromatin structure. Specifically, the transcriptional activities of key genes involved in lipid metabolism appear to be regulated by variant promoter H3K27me3 and H3K4me3 modifications, as well as promoter-enhancer interactions. These discoveries offer valuable insights into how cancer cells adapt to anti-tumor drugs and have the potential to impact future diagnostic and treatment strategies.

Identification of PTPN12 Phosphatase as a Novel Negative Regulator of Hippo Pathway Effectors YAP/TAZ in Breast Cancer

The Hippo pathway plays crucial roles in governing various biological processes during tumorigenesis and metastasis. Within this pathway, upstream signaling stimuli activate a core kinase cascade, involving MST1/2 and LATS1/2, that subsequently phosphorylates and inhibits the transcriptional co-activators YAP and its paralog TAZ. This inhibition modulates the transcriptional regulation of downstream target genes, impacting cell proliferation, migration, and death. Despite the acknowledged significance of protein kinases in the Hippo pathway, the regulatory influence of protein phosphatases remains largely unexplored. In this study, we conducted the first gain-of-functional screen for protein tyrosine phosphatases (PTPs) regulating the Hippo pathway. Utilizing a LATS kinase biosensor (LATS-BS), a YAP/TAZ activity reporter (STBS-Luc), and a comprehensive PTP library, we identified numerous novel PTPs that play regulatory roles in the Hippo pathway. Subsequent experiments validated PTPN12, a master regulator of oncogenic receptor tyrosine kinases (RTKs), as a previously unrecognized negative regulator of the Hippo pathway effectors, oncogenic YAP/TAZ, influencing breast cancer cell proliferation and migration. In summary, our findings offer valuable insights into the roles of PTPs in the Hippo signaling pathway, significantly contributing to our understanding of breast cancer biology and potential therapeutic strategies.

Gene expression profile analysis unravelled the systems level association of renal cell carcinoma with diabetic nephropathy and Matrix-metalloproteinase-9 as a potential therapeutic target

Type 2 diabetes (T2D) and cancer share many common risk factors. However, the potential biological link that connects the two at the molecular level is still unclear. The experimental evidence suggests that several genes and their pathways may be involved in developing cancerous conditions associated with diabetes. In this study, we identified the protein-protein interaction (PPI) networks and the hub protein(s) that interlink T2D and cancer using genome-scale differential gene expression profiles. Further, the PPI network of AMP-activated protein kinase (AMPK) in cancer was analyzed to explore novel insights into the molecular association between the two conditions. The densely connected regions were analyzed by constructing the backbone and subnetworks with key nodes and shortest pathways, respectively. The PPI network studies identified Matrix-metalloproteinase-9 (MMP-9) as a hub protein playing a vital role in glomerulonephritis tubular diseases and some genetic kidney diseases. MMP-9 was also associated with different growth factors, like tumor necrosis factor (TNF-α), transforming growth factor 1 (TGF-1), and pathways like chemokine signaling, NOD-like receptor signaling, etc. Further, the molecular docking and molecular dynamic simulation studies supported the druggability of MMP-9, suggesting it as a potential therapeutic target in treating renal cell carcinoma linked with diabetic kidney disease.Communicated by Ramaswamy H. Sarma.

Inhibiting the Cytosolic Phospholipase A2-Arachidonic Acid Pathway With Arachidonyl Trifluoromethyl Ketone Attenuates Radiation-Induced Lung Fibrosis

PURPOSE

Radiation-induced lung fibrosis (RILF) is a serious late complication of thoracic radiation therapy. Inflammation is crucial in fibroblast activation and RILF, and arachidonic acid (AA) is an important inflammatory mediator released by cytosolic phospholipase A2 (cPLA2) and reduced by arachidonyl trifluoromethyl ketone (ATK)-targeting of cPLA2. Here, we aimed to investigate the roles of the cPLA2/AA pathway in RILF and assess the potential of targeting cPLA2 to prevent RILF.

METHODS AND MATERIALS

A computed tomography scan was used to obtain the mean lung density, and hematoxylin-eosin, Masson's trichrome, and Sirius Red staining were used to assess the histopathologic conditions in mouse models. AA levels in mouse serum and cell supernatants were tested by enzyme-linked immunosorbent assay. Fibroblast phenotype alterations were examined by a Cell Counting Kit-8, manual cell counting, and a Transwell system. The protein levels were evaluated via Western blotting, immunofluorescence, and immunohistochemistry.

RESULTS

AA protected fibroblasts against radiation-induced growth inhibition and promoted fibroblast activation, which was characterized by enhanced α-smooth muscle actin expression and migration capacity. Radiation could activate fibroblasts by upregulating cPLA2 expression and AA production, which could be reversed by ATK. Moreover, inhibiting cPLA2 with ATK significantly attenuated collagen deposition and radiation-induced pulmonary fibrosis in mouse models. We further identified extracellular-signal regulated protein kinase (ERK) as the downstream target of the radiation-AA regulatory axis. Radiation-induced AA increased phosphorylated-ERK levels, promoting cyclinD1, cyclin-dependent kinase 6, and α-smooth muscle actin expression and contributing to fibroblast activation. Inhibiting P-ERK impaired radiation- and AA-induced fibroblast activation. The related molecular mechanisms were verified using specimens from animal models.

CONCLUSIONS

Our findings uncover the role of the cPLA2/AA-ERK regulatory axis in response to radiation in pulmonary fibroblast activation and recognize cPLA2 as the key regulatory molecule during RILF for the first time. Targeting cPLA2 may be a promising protective strategy against RILF.

Prostaglandin E2 receptor EP1 expression in vulvar cancer

Purpose

In recent years, incidence of vulvar cancer has been on the rise, whereas therapeutic options are still restricted. Therefore, new prognosticators and therapeutic targets are essential. Chronic inflammation plays an important role in carcinogenesis and COX-2, and its product prostaglandin E2 and its receptors EP1–4 are known to be important mediators in cancer initiation and progression.

Methods

EP1 expression in vulvar cancer specimens (n = 129) was investigated via immunohistochemistry and evaluated using the well-established immunoreactive score (IRS). Subsequently, the values were correlated with clinicopathological parameters.

Results

Our analysis did not reveal EP1 expression as a negative prognostic factor in overall and disease-free survival. However, in the subgroup of patients with lymph-node metastasis, overall survival was significantly shorter in tumors with high EP1 expression. Moreover, EP1 expression correlated positively with good differentiation of the tumor, but not with p16 status or COX-2 expression.

Conclusions

This study shed first light on EP1 expression in vulvar carcinoma. EP1 expression correlated significantly with the grading of the tumor, suggesting that it influences cell differentiation. Further research on EP1 signaling may lead to a deeper understanding of the molecular mechanisms of carcinogenesis.

Metabolite activation of tumorigenic signaling pathways in the tumor microenvironment

The role of metabolites exchanged in the tumor microenvironment is largely thought of as fuels to drive the increased biosynthetic and bioenergetic demands of growing tumors. However, this view is shifting as metabolites are increasingly shown to function as signaling molecules that directly regulate oncogenic pathways. Combined with our growing understanding of the essential role of stromal cells, this shift has led to increased interest in how the collective and interconnected metabolome of the tumor microenvironment can drive malignant transformation, epithelial-to-mesenchymal transition, drug resistance, immune evasion, and metastasis. In this review, we discuss how metabolite exchange between tumors and various cell types in the tumor microenvironment—such as fibroblasts, adipocytes, and immune cells—can activate signaling pathways that drive cancer progression.

A novel prognostic index of stomach adenocarcinoma based on immunogenomic landscape analysis and immunotherapy options

Stomach adenocarcinoma (STAD) is one of the most common malignant tumors worldwide. In this study, we attempted to construct a valid immune-associated gene prognostic index risk model that can predict the survival of patients with STAD and the efficacy of immune checkpoint inhibitors (ICIs) treatment. Transcriptome, clinical, and gene mutational data were obtained from the TCGA database. Immune-related genes were downloaded from the ImmPort and InnateDB databases. A total of 493 immune-related genes were identified to be enriched in functions associated with immune response, as well as in immune and tumor-related pathways. Further, 36 candidate genes related to the overall survival (OS) of STAD were obtained by weighted gene co-expression network analysis (WGCNA). Next, based on a Cox regression analysis, we constructed an immune-associated gene prognostic index (IAGPI) risk model based on eight genes, which was verified using the GEO STAD cohort. The patients were divided into two subsets according to their risk score. Patients in the low-risk group had better OS than those in the high-risk group. In the low-risk group, there were more CD8, activated memory CD4, and follicular helper T cells, and M1 macrophages, whereas monocytes, M2 macrophages, eosinophils, and neutrophils were more abundant in the high-risk group. The patients in the low-risk group were more sensitive to ICIs therapy. The IAGPI risk model can precisely predict the prognosis, reflect the tumor immune microenvironment, and predict the efficacy of ICIs therapy in patients with STAD.

Signatures of Co-Deregulated Genes and Their Transcriptional Regulators in Lung Cancer

Despite the significant progress made towards comprehending the deregulated signatures in lung cancer, these vary from study to study. We reanalyzed 25 studies from the Gene Expression Omnibus (GEO) to detect and annotate co-deregulated signatures in lung cancer and in single-gene or single-drug perturbation experiments. We aimed to decipher the networks that these co-deregulated genes (co-DEGs) form along with their upstream regulators. Differential expression and upstream regulators were computed using Characteristic Direction and Systems Biology tools, including GEO2Enrichr and X2K. Co-deregulated gene expression profiles were further validated across different molecular and immune subtypes in lung adenocarcinoma (TCGA-LUAD) and lung adenocarcinoma (TCGA-LUSC) datasets, as well as using immunohistochemistry data from the Human Protein Atlas, before being subjected to subsequent GO and KEGG enrichment analysis. The functional alterations of the co-upregulated genes in lung cancer were mostly related to immune response regulating the cell surface signaling pathway, in contrast to the co-downregulated genes, which were related to S-nitrosylation. Networks of hub proteins across the co-DEGs consisted of overlapping TFs (SOX2, MYC, KAT2A) and kinases (MAPK14, CSNK2A1 and CDKs). Furthermore, using Connectivity Map we highlighted putative repurposing drugs, including valproic acid, betonicine and astemizole. Similarly, we analyzed the co-DEG signatures in single-gene and single-drug perturbation experiments in lung cancer cell lines. In summary, we identified critical co-DEGs in lung cancer providing an innovative framework for their potential use in developing personalized therapeutic strategies.

The Interaction of Human Papillomavirus Infection and Prostaglandin E2 Signaling in Carcinogenesis: A Focus on Cervical Cancer Therapeutics

Chronic infection by high-risk human papillomaviruses (HPV) and chronic inflammation are factors associated with the onset and progression of several neoplasias, including cervical cancer. Oncogenic proteins E5, E6, and E7 from HPV are the main drivers of cervical carcinogenesis. In the present article, we review the general mechanisms of HPV-driven cervical carcinogenesis, as well as the involvement of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and downstream effectors in this pathology. We also review the evidence on the crosstalk between chronic HPV infection and PGE2 signaling, leading to immune response weakening and cervical cancer development. Finally, the last section updates the current therapeutic and preventive options targeting PGE2-derived inflammation and HPV infection in cervical cancer. These treatments include nonsteroidal anti-inflammatory drugs, prophylactic and therapeutical vaccines, immunomodulators, antivirals, and nanotechnology. Inflammatory signaling pathways are closely related to the carcinogenic nature of the virus, highlighting inflammation as a co-factor for HPV-dependent carcinogenesis. Therefore, blocking inflammatory signaling pathways, modulating immune response against HPV, and targeting the virus represent excellent options for anti-tumoral therapies in cervical cancer.

Tumor-Suppressive Effect of Metformin via the Regulation of M2 Macrophages and Myeloid-Derived Suppressor Cells in the Tumor Microenvironment of Colorectal Cancer

Simple Summary

The tumor suppressing effect of metformin has been reported, and tumor microenvironment including immune cells contribute to tumor progression in colorectal cancer. However, the effects of metformin on tumor-promoting MDSCs and M2 macrophages and its mechanisms remain unclarified. Here, we demonstrated that metformin-induced activation of AMPK and subsequent mTOR inhibition decreased the MDSC and M2 macrophage fractions by downregulating the mevalonate pathway. Metformin may be a valuable drug for potential CRC prevention and treatment strategies by regulating the immune cells of the tumor microenvironment and tumor cells.

Abstract

Myeloid-derived suppressor cells (MDSCs) and M2 macrophages in the tumor microenvironment contribute to tumor progression by inducing immune tolerance to tumor antigens and cancer cells. Metformin, one of the most common diabetes drugs, has shown anti-inflammatory and anti-tumor effects. However, the effects of metformin on inflammatory cells of the tumor microenvironment and its underlying mechanisms remain unclarified. In this study, we investigated the effect of metformin on M2 macrophages and MDSCs using monocyte THP-1 cells and a dextran sodium sulfate (DSS)-treated Apc^Min/+ mouse model of colon cancer. Metformin decreased the fractions of MDSCs expressing CD33 and arginase, as well as M2 macrophages expressing CD206 and CD163. The inhibitory effect of metformin and rapamycin on MDSCs and M2 macrophages was reversed by the co-treatment of Compound C (an AMP-activated protein kinase (AMPK) inhibitor) or mevalonate. To examine the effect of protein prenylation and cholesterol synthesis (the final steps of the mevalonate pathway) on the MDSC and M2 macrophage populations, we used respective inhibitors (YM53601; SQLE inhibitor, FTI-277; farnesyl transferase inhibitor, GGTI-298; geranylgeranyl transferase inhibitor) and found that the MDSC and M2 populations were suppressed by the protein prenylation inhibitors. In the DSS-treated Apc^Min/+ mouse colon cancer model, metformin reduced the number and volume of colorectal tumors with decreased populations of MDSCs and M2 macrophages in the tumor microenvironment. In conclusion, the inhibitory effect of metformin on MDSCs and M2 macrophages in the tumor microenvironment of colon cancers is mediated by AMPK activation and subsequent mTOR inhibition, leading to the downregulation of the mevalonate pathway.

PACER lncRNA regulates COX-2 expression in lung cancer cells

Long noncoding RNAs (lncRNAs) are known to regulate gene expression; however, in many cases, the mechanism of this regulation is unknown. One novel lncRNA relevant to inflammation and arachidonic acid (AA) metabolism is the p50-associated COX-2 extragenic RNA (PACER). We focused our research on the regulation of PACER in lung cancer. While the function of PACER is not entirely understood, PACER is known to play a role in inflammation-associated conditions. Our data suggest that PACER is critically involved in COX-2 transcription and dysregulation in lung cancer cells. Our analysis of The Cancer Genome Atlas (TCGA) expression data revealed that PACER expression is significantly higher in lung adenocarcinomas than normal lung tissues. Additionally, we discovered that elevated PACER expression strongly correlates with COX-2 expression in lung adenocarcinoma patients. Specific siRNA-mediated knockdown of PACER decreases COX-2 expression indicating a direct relationship. Additionally, we show that PACER expression is induced upon treatment with proinflammatory cytokines to mimic inflammation. Treatment with prostaglandin E2 (PGE2) induces both PACER and COX-2 expression, suggesting a PGE2-mediated feedback loop. Inhibition of COX-2 with celecoxib decreased PACER expression, confirming this self-regulatory process. Significant overlap between the COX-2 promotor and the PACER promotor led us to investigate their transcriptional regulatory mechanisms. Treatment with pharmacologic inhibitors of NF-κB or AP-1 showed a modest effect on both PACER and COX-2 expression but did not eliminate expression. These data suggest that the regulation of expression of both PACER and COX-2 is complex and intricately linked.

How cancer cells remodel lipid metabolism: strategies targeting transcription factors

Reprogramming of lipid metabolism has received increasing recognition as a hallmark of cancer cells because lipid dysregulation and the alteration of related enzyme profiles are closely correlated with oncogenic signals and malignant phenotypes, such as metastasis and therapeutic resistance. In this review, we describe recent findings that support the importance of lipids, as well as the transcription factors involved in cancer lipid metabolism. With recent advances in transcription factor analysis, including computer-modeling techniques, transcription factors are emerging as central players in cancer biology. Considering the limited number and the crucial role of transcription factors associated with lipid rewiring in cancers, transcription factor targeting is a promising potential strategy for cancer therapy.

Photodynamic Priming Improves the Anti-Migratory Activity of Prostaglandin E Receptor 4 Antagonist in Cancer Cells In Vitro

The combination of photodynamic agents and biological inhibitors is rapidly gaining attention for its promise and approval in treating advanced cancer. The activity of photodynamic treatment is mainly governed by the formation of reactive oxygen species upon light activation of photosensitizers. Exposure to reactive oxygen species above a threshold dose can induce cellular damage and cancer cell death, while the surviving cancer cells are "photodynamically primed", or sensitized, to respond better to other drugs and biological treatments. Here, we report a new combination regimen of photodynamic priming (PDP) and prostaglandin E2 receptor 4 (EP4) inhibition that reduces the migration and invasion of two human ovarian cancer cell lines (OVCAR-5 and CAOV3) in vitro. PDP is achieved by red light activation of the FDA-approved photosensitizer, benzoporphyrin derivative (BPD), or a chemical conjugate composed of the BPD linked to cetuximab, an anti-epithelial growth factor receptor (EGFR) antibody. Immunoblotting data identify co-inhibition of EGFR, cAMP-response element binding protein (CREB), and extracellular signal-regulated kinase 1/2 (ERK1/2) as key in the signaling cascades modulated by the combination of EGFR-targeted PDP and EP4 inhibition. This study provides valuable insights into the development of a molecular-targeted photochemical strategy to improve the anti-metastatic effects of EP4 receptor antagonists.

Aptamer-based sensing of breast cancer biomarkers: a comprehensive review of analytical figures of merit

INTRODUCTION

Accurate determination of the aberrantly expressed biomarkers such as human epidermal growth factor receptor 2 (HER2), carcinoembryonic antigen (CEA), platelet-derived growth factor (PDGF), mucin 1 (MUC1), and vascular endothelial growth factor VEGF₁₆₅ have played an essential role in the clinical management of the breast cancer. Assessment of these cancer-specific biomarkers has conventionally relied on time-taking methods like the enzyme-linked immunosorbent assay and immunohistochemistry. However, recent development in the aptamer-based diagnostics has allowed developing tools that may substitute the conventional means of biomarker assessment in breast cancer. Adopting the aptamer-based diagnostic tools (aptasensors) to clinical practices will depend on their analytical performance on clinical samples.

AREAS COVERED

In this review, we provide an overview of the analytical merits of HER2, CEA, PDGF, MUC1, and VEGF₁₆₅ aptasensors. Scopus and Pubmed databases were searched for studies reporting aptasensor development for the listed breast cancer biomarkers in the past one decade. Linearity, detection limit, and response time are emphasized.

EXPERT OPINION

In our opinion, aptasensors have proven to be on a par with the antibody-based methods for detection of various breast cancer biomarkers. Though robust validation of the aptasensors on significant sample size is required, their ability to detect pathophysiological range of biomarkers suggest the possibility of future clinical adoption.

The Antipsychotic Drug Clozapine Suppresses the RGS4 Polyubiquitylation and Proteasomal Degradation Mediated by the Arg/N-Degron Pathway

Although diverse antipsychotic drugs have been developed for the treatment of schizophrenia, most of their mechanisms of action remain elusive. Regulator of G-protein signaling 4 (RGS4) has been reported to be linked, both genetically and functionally, with schizophrenia and is a physiological substrate of the arginylation branch of the N-degron pathway (Arg/N-degron pathway). Here, we show that the atypical antipsychotic drug clozapine significantly inhibits proteasomal degradation of RGS4 proteins without affecting their transcriptional expression. In addition, the levels of Arg- and Phe-GFP (artificial substrates of the Arg/N-degron pathway) were significantly elevated by clozapine treatment. In silico computational model suggested that clozapine may interact with active sites of N-recognin E3 ubiquitin ligases. Accordingly, treatment with clozapine resulted in reduced polyubiquitylation of RGS4 and Arg-GFP in the test tube and in cultured cells. Clozapine attenuated the activation of downstream effectors of G protein-coupled receptor signaling, such as MEK1 and ERK1, in HEK293 and SH-SY5Y cells. Furthermore, intraperitoneal injection of clozapine into rats significantly stabilized the endogenous RGS4 protein in the prefrontal cortex. Overall, these results reveal an additional therapeutic mechanism of action of clozapine: this drug posttranslationally inhibits the degradation of Arg/N-degron substrates, including RGS4. These findings imply that modulation of protein post-translational modifications, in particular the Arg/N-degron pathway, may be a novel molecular therapeutic strategy against schizophrenia.

Metabolism pathways of arachidonic acids: mechanisms and potential therapeutic targets

The arachidonic acid (AA) pathway plays a key role in cardiovascular biology, carcinogenesis, and many inflammatory diseases, such as asthma, arthritis, etc. Esterified AA on the inner surface of the cell membrane is hydrolyzed to its free form by phospholipase A2 (PLA2), which is in turn further metabolized by cyclooxygenases (COXs) and lipoxygenases (LOXs) and cytochrome P450 (CYP) enzymes to a spectrum of bioactive mediators that includes prostanoids, leukotrienes (LTs), epoxyeicosatrienoic acids (EETs), dihydroxyeicosatetraenoic acid (diHETEs), eicosatetraenoic acids (ETEs), and lipoxins (LXs). Many of the latter mediators are considered to be novel preventive and therapeutic targets for cardiovascular diseases (CVD), cancers, and inflammatory diseases. This review sets out to summarize the physiological and pathophysiological importance of the AA metabolizing pathways and outline the molecular mechanisms underlying the actions of AA related to its three main metabolic pathways in CVD and cancer progression will provide valuable insight for developing new therapeutic drugs for CVD and anti-cancer agents such as inhibitors of EETs or 2J2. Thus, we herein present a synopsis of AA metabolism in human health, cardiovascular and cancer biology, and the signaling pathways involved in these processes. To explore the role of the AA metabolism and potential therapies, we also introduce the current newly clinical studies targeting AA metabolisms in the different disease conditions.

Cyclooxygenase inhibition attenuates brain angiogenesis and independently decreases mouse survival under hypoxia

Although cyclooxygenase (COX) role in cancer angiogenesis has been studied, little is known about its role in brain angioplasticity. In the present study, we chronically infused mice with ketorolac, a non‐specific COX inhibitor that does not cross the blood–brain barrier (BBB), under normoxia or 50% isobaric hypoxia (10% O₂ by volume). Ketorolac increased mortality rate under hypoxia in a dose‐dependent manner. Using in vivo multiphoton microscopy, we demonstrated that chronic COX inhibition completely attenuated brain angiogenic response to hypoxia. Alterations in a number of angiogenic factors that were reported to be COX‐dependent in other models were assayed at 24‐hr and 10‐day hypoxia. Intriguingly, hypoxia‐inducible factor 1 was unaffected under COX inhibition, and vascular endothelial growth factor receptor type 2 (VEGFR2) and C‐X‐C chemokine receptor type 4 (CXCR4) were significantly but slightly decreased. However, a number of mitogen‐activated protein kinases (MAPKs) were significantly reduced upon COX inhibition. We conclude that additional, angiogenic factor‐independent mechanism might contribute to COX role in brain angioplasticity, probably including mitogenic COX effect on endothelium. Our data indicate that COX activity is critical for systemic adaptation to chronic hypoxia, and BBB COX is essential for hypoxia‐induced brain angioplasticity. These data also indicate a potential risk for using COX inhibitors under hypoxia conditions in clinics. Further studies are required to elucidate a complete mechanism for brain long‐term angiogenesis regulation through COX activity.

miR-708-5p enhances erlotinib/paclitaxel efficacy and overcomes chemoresistance in lung cancer cells

Lung cancer is a collection of aggressive tumors generally not diagnosed until late-stage, resulting in high mortality rates. The vast majority of non-small cell lung cancer (NSCLC) patients undergo combinatory chemotherapeutic treatment, which initially reduces tumor growth, but frequently becomes ineffective due to toxicity and resistance. Researchers have identified multiple signaling pathways involved in lung cancer chemoresistance, including cyclooxygenase-2 (COX-2)/microsomal prostaglandin E synthase-1 (mPGES-1) derived prostaglandin E2 (PGE₂). While COX-2 inhibitors have shown promise in the clinic, their use is limited due to severe side effects. One novel approach to effectively suppress COX-2 signaling is through microRNA (miRNA). MiRNAs are small-noncoding RNAs commonly misexpressed in cancer. One tumor suppressive miRNA, miR-708-5p, has been shown to repress pro-resistant signaling pathways, including COX-2 and mPGES-1. Here, we demonstrate that chemotherapies reduce COX-2 expression, possibly through induction of miR-708-5p. Moreover, combination treatment of erlotinib (ERL) or paclitaxel (PAC) with miR-708-5p enhances COX-2 and mPGES-1 protein suppression. We also show that combination chemotherapeutic and miR-708-5p treatment intensifies the anti-proliferative and pro-apoptotic effects of ERL and PAC. We also created ERL and PAC resistant lung cancer cell lines, which have increased COX-2 expression and diminished miR-708-5p levels compared to naïve lung cancer cells. While ERL and PAC treatments do not alter resistant cell phenotype alone, combination treatment with miR-708-5p partially restores the chemotherapies' anti-proliferative effects and fully restores their pro-apoptotic qualities. These data suggest miR-708-5p may have potential combinatory therapeutic value to more efficaciously treat lung tumors while overcoming chemoresistance.

Artepillin C: A comprehensive review of its chemistry, bioavailability, and pharmacological properties

Artepillin C (ARC), a prenylated derivative of p-coumaric acid, is one of the major phenolic compounds found in Brazilian green propolis (BGP) and its botanical source Baccharis dracunculifolia. Numerous studies on ARC show that its beneficial health effects correlate with the health effects of both BGP and B. dracunculifolia. Its wide range of pharmacological benefits include antioxidant, antimicrobial, anti-inflammatory, anti-diabetic, neuroprotective, gastroprotective, immunomodulatory, and anti-cancer effects. Most studies have focused on anti-oxidation, inflammation, diabetic, and cancers using both in vitro and in vivo approaches. Mechanisms underlying anti-cancer properties of ARC are apoptosis induction, cell cycle arrest, and the inhibition of p21-activated kinase 1 (PAK1), a protein characterized in many human diseases/disorders including COVID-19 infection. Therefore, further pre-clinical and clinical studies with ARC are necessary to explore its potential as intervention for a wide variety of diseases including the recent pandemic coronaviral infection. This review summarizes the comprehensive data on the pharmacological effects of ARC and could be a guideline for its future study and therapeutic usage.

Genome-Wide Comparison of the Target Genes of the Reactive Oxygen Species and Non-Reactive Oxygen Species Constituents of Cold Atmospheric Plasma in Cancer Cells

Simple Summary

Cold atmospheric plasma is being applied to treat cancer by virtue of its preferential anti-proliferative effect on cancer cells over normal cells. This study aimed to systemically determine the distribution of target genes regulated by the reactive oxygen species and non-reactive oxygen species constituents of the plasma. After analyzing genome-wide expression data for a leukemia and a melanoma cancer cell line from a public database followed by experimental approaches, PTGER3 and HSPA6 genes were found regulated by the non-reactive oxygen species and non-reactive nitrogen species constituents of the plasma in the cancer cells. This study could contribute to elucidate the molecular mechanism how each physicochemical constituent of the plasma induces the specific molecular changes in cancer cells.

Abstract

Cold atmospheric plasma (CAP) can induce cancer cell death. The majority of gene regulation studies have been biased towards reactive oxygen species (ROS) among the physicochemical components of CAP. The current study aimed to systemically determine the distribution of target genes regulated by the ROS and non-ROS constituents of CAP. Genome-wide expression data from a public database, which were obtained after treating U937 leukemia and SK-mel-147 melanoma cells with CAP or H₂O₂, were analyzed, and gene sets regulated by either or both of them were identified. The results showed 252 and 762 genes in H₂O₂-treated U937 and SK-mel-147 cells, respectively, and 112 and 843 genes in CAP-treated U937 and SK-mel-147 cells, respectively, with expression changes higher than two-fold. Notably, only four and two genes were regulated by H₂O₂ and CAP in common, respectively, indicating that non-ROS constituents were responsible for the regulation of the majority of CAP-regulated genes. Experiments using ROS and nitrogen oxide synthase (NOS) inhibitors demonstrated the ROS- and reactive nitrogen species (RNS)-independent regulation of PTGER3 and HSPA6 when U937 cancer cells were treated with CAP. Taken together, this study identified CAP-specific genes regulated by constituents other than ROS or RNS and could contribute to the annotation of the target genes of specific constituents in CAP.

Bioactive lipids, inflammation and chronic diseases

Endogenous bioactive lipids are part of a complex network that modulates a plethora of cellular and molecular processes involved in health and disease, of which inflammation represents one of the most prominent examples. Inflammation serves as a well-conserved defence mechanism, triggered in the event of chemical, mechanical or microbial damage, that is meant to eradicate the source of damage and restore tissue function. However, excessive inflammatory signals, or impairment of pro-resolving/anti-inflammatory pathways leads to chronic inflammation, which is a hallmark of chronic pathologies. All main classes of endogenous bioactive lipids - namely eicosanoids, specialized pro-resolving lipid mediators, lysoglycerophopsholipids and endocannabinoids - have been consistently involved in the chronic inflammation that characterises pathologies such as cancer, diabetes, atherosclerosis, asthma, as well as autoimmune and neurodegenerative disorders and inflammatory bowel diseases. This review gathers the current knowledge concerning the involvement of endogenous bioactive lipids in the pathogenic processes of chronic inflammatory pathologies.

miR-708-5p targets oncogenic prostaglandin E2 production to suppress a pro-tumorigenic phenotype in lung cancer cells

Many cancers maintain an inflammatory microenvironment to promote their growth. Lung cancer is of particular importance, as it is the deadliest cancer worldwide. One inflammatory pathway commonly dysregulated in cancer is the metabolism of arachidonic acid (AA) by Cyclooxygenase-2 (COX-2) and microsomal Prostaglandin E Synthase 1 (mPGES-1) into Prostaglandin E2 (PGE2). While researchers have identified PGE2's pro-tumorigenic functions, the mechanisms governing overexpression of COX-2 and mPGES-1 are incompletely understood. MicroRNAs (miRNAs) are important post-transcriptional regulators commonly dysregulated in cancer. Interestingly, miR-708-5p (miR-708) is predicted to target both COX-2 and mPGES-1. In this study, we show that high miR-708 expression is associated with survival rates in lung squamous cell carcinoma patients. miR-708 also represses PGE2 production by suppressing both COX-2 and mPGES-1 expression in lung cancer cells. miR-708 regulation of COX-2 and mPGES-1 is mediated through targeting of their 3' untranslated regions (UTRs). Moreover, miR-708 decreases proliferation, survival, and migration of lung cancer cells, which can be partially attributed to miR-708's inhibition of PGE2 signaling. Lastly, we identify novel miR-708 predicted targets and possible regulators of miR-708 expression in lung cancer. Collectively, these data demonstrate that dysregulated miR-708 expression contributes to exacerbated PGE2 production, leading to an enhanced pro-tumorigenic phenotype in lung cancer cells.

A curve free Bayesian decision-theoretic design for phase Ia/Ib trials considering both safety and efficacy outcomes

A curve-free, Bayesian decision-theoretic two-stage design is proposed to select biological efficacious doses (BEDs) for phase Ia/Ib trials in which both toxicity and efficacy signals are observed. No parametric models are assumed to govern the dose-toxicity, dose-efficacy, and toxicity-efficacy relationships. We assume that the dose-toxicity curve is monotonic non-decreasing and the dose-efficacy curve is unimodal. In the phase Ia stage, a Bayesian model on the toxicity rates is used to locate the maximum tolerated dose. In the phase Ib stage, we model the dose-efficacy curve using a step function while continuing to monitor the toxicity rates. Furthermore, a measure of the goodness of fit of a candidate step function is proposed, and the interval of BEDs associated with the best fitting step function is recommended. At the end of phase Ib, if some doses are recommended as BEDs, a cohort of confirmation is recruited and assigned at these doses to improve the precision of estimates at these doses. Extensive simulation studies show that the proposed design has desirable operating characteristics across different shapes of the underlying true toxicity and efficacy curves.

The proprotein convertase furin is a pro-oncogenic driver in KRAS and BRAF driven colorectal cancer

Mutations in KRAS and/or BRAF that activate the ERK kinase are frequently found in colorectal cancer (CRC) and drive resistance to targeted therapies. Therefore, the identification of therapeutic targets that affect multiple signaling pathways simultaneously is crucial for improving the treatment of patients with KRAS or BRAF mutations. The proprotein convertase furin activates several oncogenic protein precursors involved in the ERK-MAPK pathway by endoproteolytic cleavage. Here we show that genetic inactivation of furin suppresses tumorigenic growth, proliferation, and migration in KRAS or BRAF mutant CRC cell lines but not in wild-type KRAS and BRAF cells. In a mouse xenograft model, these KRAS or BRAF mutant cells lacking furin displayed reduced growth and angiogenesis, and increased apoptosis. Mechanistically, furin inactivation prevents the processing of various protein pecursors including proIGF1R, proIR, proc-MET, proTGF-β1 and NOTCH1 leading to potent and durable ERK-MAPK pathway suppression in KRAS or BRAF mutant cells. Furthermore, we identified genes involved in activating the ERK-MAPK pathway, such as PTGS2, which are downregulated in the KRAS or BRAF mutant cells after furin inactivation but upregulated in wild-type KRAS and BRAF cells. Analysis of human colorectal tumor samples reveals a positive correlation between enhanced furin expression and KRAS or BRAF expression. These results indicate that furin plays an important role in KRAS or BRAF-associated ERK-MAPK pathway activation and tumorigenesis, providing a potential target for personalized treatment.

Comparison of the benefits of celecoxib combined with anticancer therapy in advanced non-small cell lung cancer: A meta-analysis

Background: Studies have reported that advanced NSCLC benefits from celecoxib combined with systematic treatment. However, the optimal combination with different treatments remains unclear. A meta-analysis was conducted to explore treatment combinations.

Methods: We searched the relevant literature via PubMed, EMBASE, the Cochrane Library and PMC. The data for the overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and adverse effects were obtained. Subgroup analysis was performed according to the treatment pattern. Statistical analyses were carried out using Review Manager 5.3 software.

Results: A total of 18 eligible studies were included, with 1178 advanced NSCLC patients. Subgroup analysis revealed that celecoxib combined with chemotherapy or tyrosine kinase inhibitors (TKIs) significantly increased the ORR, with no significant difference between the two groups. Celecoxib combined with chemotherapy improved OS-6 (OR=0.65, 95% CI 0.59-0.71, P<0.001), while OS-6 was not changed with celecoxib combined with TKIs (OR=0.53, 95% CI 0.31-0.73, P=0.82). Differences were apparent between the chemotherapy and TKIs regarding OS-6 (P=0.0392). Celecoxib combined with chemotherapy significantly prolonged OS-12 (OR=0.39, 95% CI 0.33-0.45, P<0.001). In terms of OS-12, there was no significant improvement when celecoxib was combined with radiotherapy or TKIs. Celecoxib combined with chemotherapy or TKIs significantly improved PFS-6 and PFS-12, with no obvious difference in terms of PFS between the two groups. Additionally, celecoxib combined with chemotherapy or TKI treatment increased the incidence of adverse events, with no significant differences between the two groups.

Conclusions: Celecoxib combined with chemotherapy or TKIs improved the ORR, with no significant differences between the two groups. In terms of OS, celecoxib combined with chemotherapy was superior to TKIs or radiotherapy. Accordingly, celecoxib combined with chemotherapy increased hematological toxicity and cardiovascular events.

Chronic IL-1β-induced inflammation regulates epithelial-to-mesenchymal transition memory phenotypes via epigenetic modifications in non-small cell lung cancer

Chronic inflammation facilitates tumor progression. We discovered that a subset of non-small cell lung cancer cells underwent a gradually progressing epithelial-to-mesenchymal (EMT) phenotype following a 21-day exposure to IL-1β, an abundant proinflammatory cytokine in the at-risk for lung cancer pulmonary and the lung tumor microenvironments. Pathway analysis of the gene expression profile and in vitro functional studies revealed that the EMT and EMT-associated phenotypes, including enhanced cell invasion, PD-L1 upregulation, and chemoresistance, were sustained in the absence of continuous IL-1β exposure. We referred to this phenomenon as EMT memory. Utilizing a doxycycline-controlled SLUG expression system, we found that high expression of the transcription factor SLUG was indispensable for the establishment of EMT memory. High SLUG expression in tumors of lung cancer patients was associated with poor survival. Chemical or genetic inhibition of SLUG upregulation prevented EMT following the acute IL-1β exposure but did not reverse EMT memory. Chromatin immunoprecipitation and methylation-specific PCR further revealed a SLUG-mediated temporal regulation of epigenetic modifications, including accumulation of H3K27, H3K9, and DNA methylation, in the CDH1 (E-cadherin) promoter following the chronic IL-1β exposure. Chemical inhibition of DNA methylation not only restored E-cadherin expression in EMT memory, but also primed cells for chemotherapy-induced apoptosis.

Celecoxib combined with salirasib strongly inhibits pancreatic cancer cells in 2D and 3D cultures

Background/Aim: Pancreatic adenocarcinoma is a highly malignant tumor. Synergistic combinations of anticancer agents for the effective treatment of pancreatic cancer patients are urgently needed. Here, we investigated the combined effect of celecoxib (CEL) and salirasib (SAL) on pancreatic cancer cells. Methods: Cell viability and apoptosis were measured by the trypan blue assay, three-dimensional cultures, propidium iodide staining, and caspase-3 assay. NF-κB activation and the protein levels of Akt, pAkt, and Bcl-2 were determined by the luciferase reporter assay and western blot. Results: Co-treatment with CEL and SAL had stronger effects on decreasing cell viability and inducing apoptosis in Panc-1 cells as compared with each agent individually. This combination strongly inhibited NF-κB activity and reduced pAkt and Bcl-2 levels in Panc-1 cells. Conclusion: SAL in combination with CEL may represent a new approach for effective inhibition of pancreatic cancer.

Increased inflammatory lipid metabolism and anaplerotic mitochondrial activation follow acquired resistance to vemurafenib in BRAF-mutant melanoma cells

Background

BRAF inhibitors, such as vemurafenib, have shown efficacy in BRAF-mutant melanoma treatment but acquired-resistance invariably develops. Unveiling the potential vulnerabilities associated with vemurafenib resistance could provide rational strategies for combinatorial treatment.

Methods

This work investigates the metabolic characteristics and vulnerabilities of acquired resistance to vemurafenib in three generated BRAF-mutant human melanoma cell clones, analysing metabolic profiles, gene and protein expression in baseline and nutrient withdrawal conditions. Preclinical findings are correlated with gene expression analysis from publicly available clinical datasets.

Results

Two vemurafenib-resistant clones showed dependency on lipid metabolism and increased prostaglandin E2 synthesis and were more responsive to vemurafenib under EGFR inhibition, potentially implicating inflammatory lipid and EGFR signalling in ERK reactivation and vemurafenib resistance. The third resistant clone showed higher pyruvate-carboxylase (PC) activity indicating increased anaplerotic mitochondrial metabolism, concomitant with reduced GLUT-1, increased PC protein expression and survival advantage under nutrient-depleted conditions. Prostaglandin synthase (PTGES) expression was inversely correlated with melanoma patient survival. Increases in PC and PTGES gene expression were observed in some patients following progression on BRAF inhibitors.

Conclusions

Altogether, our data highlight heterogeneity in metabolic adaptations during acquired resistance to vemurafenib in BRAF-mutant melanoma, potentially uncovering key clinically-relevant mechanisms for combinatorial therapeutic targeting.

Photoacoustic imaging as a tool to probe the tumour microenvironment

The tumour microenvironment (TME) is a complex cellular ecosystem subjected to chemical and physical signals that play a role in shaping tumour heterogeneity, invasion and metastasis. Studying the roles of the TME in cancer progression would strongly benefit from non-invasive visualisation of the tumour as a whole organ in vivo, both preclinically in mouse models of the disease, as well as in patient tumours. Although imaging techniques exist that can probe different facets of the TME, they face several limitations, including limited spatial resolution, extended scan times and poor specificity from confounding signals. Photoacoustic imaging (PAI) is an emerging modality, currently in clinical trials, that has the potential to overcome these limitations. Here, we review the biological properties of the TME and potential of existing imaging methods that have been developed to analyse these properties non-invasively. We then introduce PAI and explore the preclinical and clinical evidence that support its use in probing multiple features of the TME simultaneously, including blood vessel architecture, blood oxygenation, acidity, extracellular matrix deposition, lipid concentration and immune cell infiltration. Finally, we highlight the future prospects and outstanding challenges in the application of PAI as a tool in cancer research and as part of a clinical oncologist's arsenal.

Summary: This Review details the potential of photoacoustic imaging to visualise features of the tumour microenvironment such as blood vessels, hypoxia, fibrosis and immune infiltrate to provide unprecedented insight into tumour biology.

Distinct Molecular Mechanisms Analysis of Three Lung Cancer Subtypes Based on Gene Expression Profiles

The purpose was to explore distinct molecular mechanisms of three lung cancer subtypes. GSE6044 microarray data downloaded from Gene Expression Omnibus (GEO) database were applied for identifying the differentially expressed genes (DEGs). Genetic global network was constructed to analyze the network annotation. The DEGs in the genetic global network related to small-cell lung carcinoma (SCLC), lung squamous cell carcinoma (SCC), and lung adenocarcinoma (AC) were screened. Protein-protein international networks of DEGs were constructed. Pathway enrichment analyses of DEGs in three subtypes were performed, followed by construction of interactional network among pathways. There were more DEGs screened in SCLC than in AC and SCC. The genetic global network with 341 genes and 1569 interaction edges was constructed. After annotating these DEGs into a protein interactional network, a total of 695 protein interactions related to these 36 DEGs were obtained. HSP90AA1 was the hub node with the highest degree of 81 in the annotation network. DEGs in SCLC and SCC were mainly enriched in some pathways, including cell cycle, DNA replication, and histidine metabolism; whereas DEGs in AC were enriched in complement and coagulation cascades, and extracellular matrix (ECM)-receptor interaction. Pathway interactional network was constructed with the hub node of a neuroactive ligand receptor interaction. The identified DEGs such as retinoid X receptor alpha (RXRA), cyclin-dependent kinase 2 (CDK2), histone deacetylase 2 (HDAC2), and KIT might be the target genes of lung cancer by participating in different pathways such as ECM-receptor interaction. Complement and coagulation cascades, and ECM-receptor interaction might be the specific pathways for AC; smoking might have a closer relationship with SCC.

mPGES-1 as a new target to overcome acquired resistance to gefitinib in non-small cell lung cancer cell lines

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) as gefitinib are standard treatment of non-small cell lung cancer (NSCLC), but resistance often occurs. This study demonstrates that NSCLC cells resistant to gefitinib (GR cells) displayed a significantly higher microsomal prostaglandin E synthase-1 (mPGES-1) expression and activity than parental cells. Overexpression of mPGES-1/prostaglandin E-2 (PGE-2) signaling in GR cells was associated with acquisition of mesenchymal and stem-like cell properties, nuclear EGFR translocation and tolerance to cisplatin. mPGES-1 inhibition reduced mesenchymal and stem-like properties, and nuclear EGFR translocation in GR cells. Consistently, inhibition of mPGES-1 activity enhanced sensitivity to cisplatin and responsiveness to gefitinib in GR cells. We propose the mPGES-1/PGE-2 signaling as a potential target for treating aggressive and resistant lung cancers.

Triumph and tumult of matrix metalloproteinases and their crosstalk with eicosanoids in cancer

Cancer development and metastasis are associated to perturbation in metabolic functions of tumor cells and surrounding inflammatory and stromal cell responses. Eicosanoids and lipid mediators, in this regard, attract potential attention during cancer development. Eicosanoids, which include prostaglandin, prostacyclin, thromboxane, and leukotriene, are synthesized from arachidonic acid when cells are stimulated by stress, cytokines, or other growth factors. However, the underlying mechanism of eicosanoids in cancer development, specially their interactions with proto-oncogene factors in tumor microenvironment, remain unexplored. On the other hand, matrix metalloproteinases (MMPs) are a group of zinc-dependent endopeptidases which are involved in degradation of different extracellular matrix (ECM) proteins. MMPs are associated with different physiological responses, including embryogenesis, vasculogenesis, and cellular remodeling, as well as different disease pathogenesis. Induced MMP responses are especially associated with cancer metastasis and secondary tumor development through proteolytic cleavage of several ECM and non-ECM proteins. Although both eicosanoids and MMPs are involved with cancer progression and metastasis, the interrelation between these two molecules are less explored. The present review discusses relevant studies that connect eicosanoids and MMPs and highlight the crosstalk between them offering novel therapeutic approach in cancer treatment.

The selective cyclooxygenase-2 inhibitor mavacoxib (Trocoxil) exerts anti-tumour effects in vitro independent of cyclooxygenase-2 expression levels

The inducible inflammatory enzyme cyclooxygenase-2 (COX-2) and its product prostaglandin E2 (PGE₂ ) are prominent tumour promoters, and expression of COX-2 is elevated in a number of tumours of both humans and canines. Targeting COX-2 in cancer is an attractive option because of readily available non-steroidal anti-inflammatory drugs (NSAIDs), and there is a clear epidemiological link between NSAID use and cancer risk. In this study, we aim to establish the anti-tumourigenic effects of the selective, long-acting COX-2 inhibitor mavacoxib. We show here that mavacoxib is cytotoxic to a panel of human and canine osteosarcoma, mammary and bladder carcinoma cancer cell lines; that it can induce apoptosis and inhibit the migration of these cells. Interestingly, we establish that mavacoxib can exert these effects independently of elevated COX-2 expression. This study highlights the potential novel use of mavacoxib as a cancer therapeutic, suggesting that mavacoxib may be an effective anti-cancer agent independent of tumour COX-2 expression.

Efficacy of erlotinib and celecoxib for patients with advanced non-small cell lung cancer: A retrospective study

This study evaluated the efficacy and toxicity of erlotinib and celecoxib (EC) for treating Chinese patients with advanced non-small cell lung cancer (ANSCLC) and epidermal growth factor receptor (EGFR) wild type.Totally, 75 subjects with ANSCLC and EGFR wild type were included. They all underwent EC treatment. The outcome measurements consisted of progression-free survival (PFS), overall survival (OS), complete response (CR), partial response (PR), stable disease (SD), progress disease (PD), and disease control rate (DCR). Additionally, adverse events were also documented.Two-year CR, PR, SD, PD, and DCR were 4.0%, 6.7%, 42.6%, 46.7%, and 53.3% respectively. The median PFS was 3.4 months, the median OS was 10.0 months. Additionally, acceptable toxicities were recorded in this study.The results showed that EC may be efficacious for patients with ANSCLC and EGFR wild type only, and acceptable toxicity among the Chinese Han population.

PYCR1 promotes the progression of non-small-cell lung cancer under the negative regulation of miR-488

PYCR1 is over-expressed in non-small-cell lung cancer (NSCLC) and its high expression accelerates the progression of NSCLC. However, the underlying mechanisms of PYCR1 in NSCLC progression remain poorly understood. Our study determined the mechanisms of PYCR1 in promotion of the occurrence and development of NSCLC in vitro and in vivo. Firstly, the expression patterns of PYCR1 in NSCLC tissues and cells were determined by RT-PCR, western blot and immunohistochemistry. Then, the effects of PYCR1 on cell proliferation and apoptosis were evaluated by CCK-8 and flow cytomery assays. Finally, we explored the up-regulatory microRNAs (miRs) of PYCR1 and determined if MAPK pathway involved in this process. PYCR1 expression was elevated in NSCLC tissue samples and cells, and the high expression of PYCR1 closely associated with patients' advanced clinical process and poor outcome. Up-regulation of PYCR1 significantly increased the expression of p38 and promoted its nuclear accumulation. Besides, PYCR1 expression was negatively regulated by miR-488, and up-regulation of miR-488 significantly inhibited cell proliferation and tumorigenesis and increased cell apoptosis, and decreased p38 expression and its nuclear accumulation, whereas up-regulation of PYCR1 rescued these results induced by miR-488 over-expression. Collectively, these data suggest the mechanism of PYCR1 in promotion of NSCLC progression. PYCR1 is negatively regulated by miR-488 and then promotes the occurrence and development of NSCLC and activates p38 MAPK pathway.

IKKα Promotes the Progression and Metastasis of Non-Small Cell Lung Cancer Independently of its Subcellular Localization

Lung cancer is the leading worldwide cause of cancer mortality, however, neither curative treatments nor substantial prolonged survival has been achieved, highlighting the need for investigating new proteins responsible for its development and progression. IKKα is an essential protein for cell survival and differentiation, which expression is enhanced in human non-small cell lung cancer (NSCLC) and correlates with poor patient survival, appearing as a relevant molecule in lung cancer progression. However, there are not conclusive results about its role in this type of cancer. We have recently found that IKKα performs different functions and activates different signaling pathways depending on its nuclear or cytoplasmic localization in tumor epidermal cells. In this work, we have studied the involvement of IKKα in lung cancer progression through the generation of lung cancer cell lines expressing exogenous IKKα either in the nucleus or in the cytoplasm. We demonstrate that IKKα signaling promotes increased cell malignancy of NSCLC cells as well as lung tumor progression and metastasis in either subcellular localization, through activation of common protumoral proteins, such as Erk, p38 and mTor. But, additionally, we found that depending on its subcellular localization, IKKα has non-overlapping roles in the activation of other different pathways known for their key implication in lung cancer progression: while cytoplasmic IKKα increases EGFR and NF-κB activities in lung tumor cells, nuclear IKKα causes lung tumor progression through c-Myc, Smad2/3 and Snail activation. These results suggest that IKKα may be a promising target for intervention in human NSCLC.

PTGER3 induces ovary tumorigenesis and confers resistance to cisplatin therapy through up-regulation Ras-MAPK/Erk-ETS1-ELK1/CFTR1 axis

Background

Inflammatory mediator prostaglandin E2–prostaglandin E2 receptor EP3 (PTGER3) signaling is critical for tumor-associated angiogenesis, tumor growth, and chemoresistance. However, the mechanism underlying these effects in ovarian cancer is not known.

Methods

An association between higher tumoral expression of PTGER3 and shorter patient survival in the ovarian cancer dataset of The Cancer Genome Atlas prompted investigation of the antitumor effects of PTGER3 downmodulation. PTGER3 mRNA and protein levels were higher in cisplatin-resistant ovarian cancer cells than in their cisplatin-sensitive counterparts.

Findings

Silencing of PTGER3 via siRNA in cancer cells was associated with decreased cell growth and less invasiveness, as well as cell-cycle arrest and increased apoptosis, mediated through the Ras-MAPK/Erk-ETS1-ELK1/CFTR1 axis. Furthermore, sustained PTGER3 silencing with multistage vector and liposomal 2’-F-phosphorodithioate-siRNA–mediated silencing of PTGER3 combined with cisplatin resulted in robust antitumor effects in cisplatin-resistant ovarian cancer models.

Interpretation

These findings identify PTGER3 as a potential therapeutic target in chemoresistant ovarian cancers expressing high levels of this oncogenic protein.

Fund

National Institutes of Health/National Cancer Institute, USA.

DUSP1 induces apatinib resistance by activating the MAPK pathway in gastric cancer

Dual-specificity phosphatase-1 (DUSP1) is an oncogene that is associated with cancer progression following drug resistance. In order to investigate the potential relationship between DUSP1 and apatinib resistance in gastric cancer cells, we preformed many assays to study this problem. DUSP1 gene was detected by RT-qPCR assay, proteins in MAPK pathway were quantified by western blot assay, and CCK-8 assay, flow cytometry and Hoechest 33342 stain were performed to detect the resistance of cells, cell cycles and apoptosis, respectively. Immunohistochemical staining was used to discover the expression of DUSP1 protein in patients' tumor or paratumor tissues. It was found that apatinib (Apa)-resistant gastric cancer (GC) cells showed increased expression of DUSP1, whereas the knockdown of DUSP1 in resistant cells resensitized these cells to Apa. The restored sensitivity to Apa was the result of inactivation of mitogen-activated protein kinase (MAPK) signaling and the induction of apoptosis. The in vitro use of Apa in combination with a DUSP1 inhibitor, triptolide, exerted significant effects on inhibiting the expression of DUSP1, growth inhibition, and apoptosis via the inactivation of MAPK signaling. In patients who did not undergo chemotherapy or targeted therapy, the expression of DUSP1 in adjacent tissues was higher when compared with that observed in tumor tissues. In addition, the expression of DUSP1 was higher in the early stages of GC than in the advanced stages. The expression of DUSP1 in tumor tissues was not associated with the survival rate of the patients. Therefore, increased expression of DUSP1 may be responsible for Apa resistance, and DUSP1 may serve as a biomarker for Apa efficacy. In conclusion, inducing the downregulation of DUSP1 may be a promising strategy to overcome Apa resistance.

Cyclooxygenase inhibitors combined with deuterium-enriched water augment cytotoxicity in A549 lung cancer cell line via activation of apoptosis and MAPK pathways

Objectives

Combination chemotherapy is a rational strategy to increase patient response and tolerability and to decrease adverse effects and drug resistance. Recently, the use of non-steroidal anti-inflammatory drugs (NSAIDs) has been reported to be associated with reduction in occurrence of a variety of cancers including lung cancer. On the other hand, growing evidences suggest that deuterium-enriched water (DEW, D2O) and deuterium-depleted water (DDW) play a role both in treatment and prevention of cancers. In the present study, we examined the effects of DEW and DDW in combination with two NSAIDs, celecoxib and indomethacin, on A549 human non-small lung cancer cell to identify novel treatment options.

Materials and Methods

The cytotoxicity of celecoxib or indomethacin, alone and in combination with DDW and DEW was determined. The COX-2, MAPK pathway proteins, the anti-apoptotic Bcl2 and pro-apoptotic Bax proteins and caspase-3 activity were studied for cytotoxic combinations.

Results

Co-administration of selective and non-selective COX-2 inhibitors with DEW led to a remarkable increase in cytotoxicity and apoptosis of A549 cells. These events were associated with activation of p38 and JNK MAPKs and decreasing pro-survival proteins Bcl-2, COX-2 and ERK1/2. Furthermore, the combination therapy activated caspase-3, and the apoptosis mediator, and disabled poly ADP-ribose polymerase (PARP), the key DNA repair enzyme, by cleaving it.

Conclusion

The combination of DEW with NSAIDs might be effective against lung cancer cells by influence on principal cell signalling pathways, and this has a potential to become a candidate for chemotherapy.

Celecoxib-erlotinib combination treatment enhances radiosensitivity in A549 human lung cancer cell

BACKGROUND

Radiosensitivity by blocking the epidermal growth factor receptor and cyclooxygenase-2 pathways with erlotinib and celecoxib in A549 human lung cancer cell was investigated.

METHODS

MTT assays were used to detect the antitumor effects of erlotinib and celecoxib in A549 cells. Colony formation assays were used to evaluate the antitumor effects. Flow cytometry analysis was used to assess the cell cycle and cell apoptosis, and western blotting analysis was performed to evaluate the expression of AKT and phosphorylated AKT.

RESULTS

Either erlotinib or celecoxib inhibited the A549 cell proliferation in a dose-dependent manner. Combining Erlotinib or celecoxib with radiation can suppress the cell colony formation and the Dq, D0, SF2 of the combining erlotinib or celecoxib with radiation was lower than in the combinations either erlotinib or celecoxib with radiation (t= 6.62, P< 0.05). The SER of radiation with celecoxib or erlotinib and celecoxib and erlotinib were 1.299, 1.503 and 2.217, respectively. The Flow cytometry analysis results showed that either celecoxib or erlotinib could induce G0/G1 arrest, and reduction of S phase cell proportion, especially when combinations erlotinib-celecoxib with radiation. Either celecoxib or erlotinib could enhance radiation-induced apoptosis, especially significant when combinations erlotinib-celecoxib with radiation. Moreover, radiation can promote the expression of pAKT, and the pAKT was remarkably lowest in the combinations erlotinib-celecoxib with radiation group (t= 4.89, P< 0.05).

CONCLUSIONS

Blocking both EGFR- and COX-2-related pathways could enhance the antitumor effect of radiation. The underlying mechanisms including the enhancement of apoptosis and radiation-induced G0/G1 arrest, possibly via inhibiting the PI3K/AKT signaling pathway.

Berberine inhibits the chemotherapy-induced repopulation by suppressing the arachidonic acid metabolic pathway and phosphorylation of FAK in ovarian cancer

OBJECTIVES

Cytotoxic chemotherapy is an effective and traditional treatment of ovarian cancer. However, chemotherapy-induced apoptosis may also trigger and ultimately accelerate the repopulation of the small number of adjacent surviving cells. This study mainly focused on the tumour cell repopulation caused by chemotherapy in ovarian cancer and the adjunctive/synergistic effect of Berberine on the prevention of tumour repopulation.

MATERIALS AND METHODS

The transwell system was used to mimic the co-culture of surviving ovarian cancer cells in the microenvironment of cytotoxic chemotherapy-treated dying cells. Tumour cell proliferation was observed by crystal violet staining. AA and PGE₂ levels were measured by ELISA, and changes of protein expression were analysed by Western blot.

RESULTS

Chemotherapy drug VP16 treatment triggered AA pathway, leading to the elevated PGE₂ level, and ultimately enhanced the repopulation of ovarian cancer cells. Berberine can block the caspase 3-iPLA₂ -AA-COX-2-PGE₂ pathway by inhibiting the expression of iPLA₂ and COX-2. Berberine can also reverse the increased phosphorylation of FAK caused by abnormal PGE₂ level and thus reverse the repopulation of ovarian cancer cells after VP16 treatment.

CONCLUSIONS

Our observation suggested that Berberine could inhibit the chemotherapy-induced repopulation of ovarian cancer cells by suppressing the AA pathway and phosphorylation of FAK. And these findings implicated a novel combined use of Berberine and chemotherapeutics, which might prevent ovarian cancer recurrence by abrogating early tumour repopulation.

DUSP1 inhibits cell proliferation, metastasis and invasion and angiogenesis in gallbladder cancer

DUSP1/MKP1 is a dual-specific phosphatase that regulates MAPK activity and is known to play a key role in tumor biology. Its function in gallbladder cancer (GBC) remains largely unknown, however. By exploring its activities in two GBC cell lines (SGC996 and GBC-SD), DUSP1 was found to inhibit GBC cell proliferation, migration and invasion. Moreover, DUSP1 inhibited GBC growth and metastasis in nude mice subcutaneously xenografted with SGC996 cells. The tumor suppression appeared to be mediated via the DUSP1-pERK/MAPK-MMP2 signal pathway. Angiogenesis was associated with the tumor metastasis in the mouse model and was impaired by DUSP1, which suppressed VEGF expression. These results suggest that DUSP1 suppresses GBC growth and metastasis by targeting the DUSP1-pERK-MMP2/VEGF axis. Identification of the DUSP1-pERK-MMP2/VEGF signals may provide new biomarkers and/or therapeutic targets to better suppress GBC metastasis in the future.

Expression of programmed cell death1 in T follicular helper cells is regulated by prostaglandin E2 secreted by HBV-infected HepG2.2.1.5 cells

The present study aimed to investigate the distribution of T follicular helper (Tfh)-cell subsets in patients with hepatitis B virus (HBV) and determine the underlying mechanism of HBV regulation of Tfh cells. The frequency of peripheral blood Tfh subsets was analyzed using flow cytometry. The expression level of programmed cell death‑1 (PD‑1) and prostaglandin E2 (PGE2) was quantified using reverse transcription‑quantitative polymerase chain reaction and western blotting. The PGE2 level in culture supernatant was detected using enzyme‑linked immunosorbent assay. A Transwell chamber was used to co‑culture Tfh cells with HepG2 and HepG2.2.1.5. The percentage of inducible T‑cell costimulator (ICOS)+ and total Tfh cells was high at the immune activation (IA) group; however, it was reduced in the immune tolerance (IT), responders with HBsAg seroconversion (RP) and healthy control (HC) groups. The percentage of PD‑1+ Tfh cells was significantly higher in IA and IT compared with RP and HC. The ratio of PD‑1+/total Tfh cells was positively correlated with the load of HBV DNA; therefore, this ratio may act as an indicator for HBV replication. The expression level of PD‑1 in Tfh cells was higher in the HepG2.2.1.5 co‑cultured group compared with the HepG2 group, this may be due to the high PGE2 expression level in HBV‑infected HepG2.2.1.5 cells. The findings of the present study revealed an imbalanced distribution of PD‑1+ Tfh cells in patients with HBV at different immune phases. Additionally, HBV may upregulate the expression of PD‑1 in Tfh cells by promoting HepG2.2.1.5 to secret PGE2. Identifying the effect of HBV on Tfh‑cell subsets is crucial for improving immuno-based therapy for HBV.

The Effects of Anti-inflammatory Drug Treatment in Gastric Cancer Prevention: an Update of a Meta-analysis

Gastric cancer has high incidence and fatality rates, making chemoprevention agents necessary. There is an ongoing debate about aspirin/nonsteroidal anti-inflammatory drugs (NSAIDs) use can significant reduce the risk of GC. We conducted a meta-analysis of existing studies evaluating the association of anti-inflammatory drug and GC. We performed a systematic literature search of PubMed, Web of Science, Embase, OVID, Cochrane Library and Clincialtrials.gov up to August 31, 2015. Either a fixed-effects or a random-effects model using was based on the result of homogeneity analysis. Subgroup, sensitivity, meta-regression, and publication bias analyses were evaluated. Forty-seven studies were finally included in this meta-analysis. The overall GC risk reduction benefit associated with anti-inflammatory drug use represented an RR of 0.78 (95% CI 0.71 to 0.85) and an adjusted RR of 0.74 (95% CI 0.71 to 0.77). Besides, the prevention benefit of aspirin/NSAIDs ingestion appeared to be confined to those patients with regiment of short or middle-term (≤5 years), high-frequency (>30 times per month) and low dose (<200 mg per day). Further, our data also suggest that COX-2 inhibitors use is a more effective approach in GC prevention (RR, 0.45; 95% CI, 0.29-0.70). In this meta-analysis, our finding support short or middle-term (≤5 years), high-frequency (>30 times per month) and low dose (<200 mg per day) aspirin/NSAIDs intake is a well method for GC prevention and also confirm the inverse association between aspirin/NSAIDs use and GC risk. Additionally, selective COX-2 inhibitors use probably a more effective approach to reduce GC risk.

Regulatory T cells and potential inmmunotherapeutic targets in lung cancer

Lung cancer and metastasis are two of the most lethal diseases globally and seldom have effective therapies. Immunotherapy is considered as one of the powerful alternatives. Regulatory T cells (Tregs) can suppress the activation of the immune system, maintain immune tolerance to self-antigens, and contribute to immunosuppression of antitumor immunity, which is critical for tumor immune evasion in epithelial malignancies, including lung cancer. The present review gives an overview of the biological functions and regulations of Tregs associated with the development of lung cancer and metastasis and explores the potentials of Treg-oriented therapeutic targets. Subsets and features of Tregs mainly include naturally occurring Tregs (nTregs) (CD4(+) nTregs and CD8(+) nTregs) and adaptive/induced Tregs (CD4(+) iTregs and CD8(+) iTregs). Tregs, especially in circulation or regional lymph nodes, play an important role in the progress and metastasis of lung cancer and are considered as therapeutic targets and biomarkers to predict the survival length and recurrence of lung cancer. Increasing understanding of Tregs' functional mechanisms will lead to a number of clinical trials on the discovery and development of Treg-oriented new therapies. Tregs play important roles in lung cancer and metastasis, and the understanding of Tregs becomes more critical for clinical applications and therapies. Thus, Tregs and associated factors can be potential therapeutic targets for lung cancer immunotherapy.

Deletion of cyclooxygenase-2 inhibits K-ras-induced lung carcinogenesis

The purpose of this study was to identify the role COX-2 plays in K-ras–induced lung carcinogenesis. We crossed COX-2–homozygous knockout mice with K-ras^LA1 (G12D) expressing mice to obtain COX-2–deficient mice with K-ras expression (K-ras/COX-2^−/− mice) and COX-2 wild type mice with K-ras expression (K-ras mice). At 3.5 months of age, the K-ras/COX-2^−/− mice had significantly fewer lung adenocarcinomas and substantially smaller tumors than K-ras mice. K-ras/COX-2^−/− mice also had significantly fewer bronchioalveolar hyperplasias than K-ras mice. Compared with lung tumors from K-Ras mice, the levels of prostaglandin E₂ (PGE₂) were significantly lower, whereas levels of the PGE₂ metabolite 13,14-dihydro-15-keto-PGE₂ were significantly higher, in lung tumors from K-ras/COX-2^−/− mice. In addition, K-ras/COX-2^−/− mice had strikingly lower rates of tumor cell proliferation and expressed less MEK and p-Erk1/2 protein than K-ras mice did. In line with this, knocking down COX-2 in mutant K-ras non-small cell lung cancer A549 cells reduced colony formation, PGE₂ synthesis and ERK phosphorylation compared to that of vector control cells. Taken together, these findings suggest that COX-2 deletion contributes to the repression of K-ras–induced lung tumorigenesis by reducing tumor cell proliferation, decreasing the production of PGE₂, and increasing the production of 13,14-dihydro-15-keto-PGE₂, possibly via the MAPK pathway. Thus, COX-2 is likely important in lung tumorigenesis, and COX-2 and its product, PGE₂, are potential targets for lung cancer prevention.