Involvement of eicosanoids in the pathogenesis of pancreatic cancer: The roles of cyclooxygenase-2 and 5-lipoxygenase

Bovine serum albumin as a nanocarrier for efficient encapsulation of hydrophobic garcinol-A strategy for modifying the in vitro drug release kinetics

Garcinia indica, known as kokum, has been extensively researched for its therapeutic potential. Among the wide variety of phytoconstituents, garcinol is the most efficacious, holding anti-inflammatory, anti-cancer, and anti-diabetic properties. Hydrophobicity and a certain level of toxicity have constrained the drug's application and necessitated a modified dosage form design. The drug has been well explored in the form of extracts but bears very limited application in dosage forms. These prompted in implementation of protein polymers, due to non-toxicity, biocompatibility, and biodegradability. BSA encapsulates the drug, by the desolvation method. The unavailability of past exploration of garcinol with protein polymer accelerated the novelty of this study, to improve the solubility and bioavailability of the drug, modify the drug release kinetics, and ascertain the effectiveness of the NPs to combat inflammation in-vitro. NPs were characterized and satisfactory outcomes were retrieved in terms of all characterizations. The drug release studies depicted a sustained release of up to 85 % over 16 h, ensuring that garcinol can be modulated to give a desired scale of modified release. In vitro cellular uptake studies suggested a substantial uptake of NPs in cell lines and its effectiveness to mitigate inflammation was affirmed by in-vitro anti-inflammatory studies, using ELISA.

Arachidonic acid metabolism as a novel pathogenic factor in gastrointestinal cancers

Gastrointestinal (GI) cancers are a major global health burden, representing 20% of all cancer diagnoses and 22.5% of global cancer-related deaths. Their aggressive nature and resistance to treatment pose a significant challenge, with late-stage survival rates below 15% at five years. Therefore, there is an urgent need to delve deeper into the mechanisms of gastrointestinal cancer progression and optimize treatment strategies. Increasing evidence highlights the active involvement of abnormal arachidonic acid (AA) metabolism in various cancers. AA is a fatty acid mainly metabolized into diverse bioactive compounds by three enzymes: cyclooxygenase, lipoxygenase, and cytochrome P450 enzymes. Abnormal AA metabolism and altered levels of its metabolites may play a pivotal role in the development of GI cancers. However, the underlying mechanisms remain unclear. This review highlights a unique perspective by focusing on the abnormal metabolism of AA and its involvement in GI cancers. We summarize the latest advancements in understanding AA metabolism in GI cancers, outlining changes in AA levels and their potential role in liver, colorectal, pancreatic, esophageal, gastric, and gallbladder cancers. Moreover, we also explore the potential of targeting abnormal AA metabolism for future therapies, considering the current need to explore AA metabolism in GI cancers and outlining promising avenues for further research. Ultimately, such investigations aim to improve treatment options for patients with GI cancers and pave the way for better cancer management in this area.

Pathological and pharmacological functions of the metabolites of polyunsaturated fatty acids mediated by cyclooxygenases, lipoxygenases, and cytochrome P450s in cancers

Oxylipins have garnered increasing attention because they were consistently shown to play pathological and/or pharmacological roles in the development of multiple cancers. Oxylipins are the metabolites of polyunsaturated fatty acids via both enzymatic and nonenzymatic pathways. The enzymes mediating the metabolism of PUFAs include but not limited to lipoxygenases (LOXs), cyclooxygenases (COXs), and cytochrome P450s (CYPs) pathways, as well as the down-stream enzymes. Here, we systematically summarized the pleiotropic effects of oxylipins in different cancers through pathological and pharmacological aspects, with specific reference to the enzyme-mediated oxylipins. We discussed the specific roles of oxylipins on cancer onset, growth, invasion, and metastasis, as well as the expression changes in the associated metabolic enzymes and the associated underlying mechanisms. In addition, we also discussed the clinical application and potential of oxylipins and related metabolic enzymes as the targets for cancer prevention and treatment. We found the specific function of most oxylipins in cancers, especially the underlying mechanisms and clinic applications, deserves and needs further investigation. We believe that research on oxylipins will provide not only more therapeutic targets for various cancers but also dietary guidance for both cancer patients and healthy humans.

Proteomic detection of COX-2 pathway-related factors in patients with adenomyosis

Background

Investigating the relationship between cyclooxygenase-2 (COX-2) pathway-related factors and clinical features in patients with adenomyosis by proteomics could provide potential therapeutic targets.

Methods

This study recruited 40 patients undergoing surgical hysterectomy and pathological diagnosis of adenomyosis, collected ectopic endometrial specimens, and recorded clinical data. The expression levels of COX-2 in ectopic uterus lesions were detected using the immunohistochemical (IHC) SP method. The 40 samples were then divided into a COX-2 low or high expression group. Five samples with the most typical expression levels were selected from each of the two groups and the differential proteins between the two groups were identified using label-free quantitative proteomics. WW domain-binding protein 2 (WBP2), interferon induced transmembrane protein 3 (IFITM3), and secreted frizzled-related protein 4 (SFRP4) were selected for further verification, and their relationships with COX-2 and clinical characteristics were analyzed.

Results

There were statistically significant differences in the expression of WBP2, IFITM3, and SFRP4 between the COX-2 low and high expression groups (P < 0.01). The expressions of COX-2, IFITM3, and SFRP4 were significantly correlated with dysmenorrhea between the two groups (P < 0.05), but not with uterine size or menstrual volume (P > 0.05). However, there was no significant correlation between the expression of WBP2 and dysmenorrhea, uterine size, and menstruation volume in both the high expression and low expression groups (P > 0.05).

Conclusions

COX-2, IFITM3, SFRP4, and WBP2 may be involved in the pathogenesis of adenomyosis. COX-2, IFITM3, and SFRP4 may serve as potential molecular biomarkers or therapeutic targets in dysmenorrhea in patients with early adenomyosis.

Oxidative versus Reductive Stress in Breast Cancer Development and Cellular Mechanism of Alleviation: A Current Perspective with Anti-breast Cancer Drug Resistance

Redox homeostasis is essential for keeping our bodies healthy, but it also helps breast cancer cells grow, stay alive, and resist treatment. Changes in the redox balance and problems with redox signaling can make breast cancer cells grow and spread and make them resistant to chemotherapy and radiation therapy. Reactive oxygen species/reactive nitrogen species (ROS/RNS) generation and the oxidant defense system are out of equilibrium, which causes oxidative stress. Many studies have shown that oxidative stress can affect the start and spread of cancer by interfering with redox (reduction-oxidation) signaling and damaging molecules. The oxidation of invariant cysteine residues in FNIP1 is reversed by reductive stress, which is brought on by protracted antioxidant signaling or mitochondrial inactivity. This permits CUL2FEM1B to recognize its intended target. After the proteasome breaks down FNIP1, mitochondrial function is restored to keep redox balance and cell integrity. Reductive stress is caused by unchecked amplification of antioxidant signaling, and changes in metabolic pathways are a big part of breast tumors' growth. Also, redox reactions make pathways like PI3K, PKC, and protein kinases of the MAPK cascade work better. Kinases and phosphatases control the phosphorylation status of transcription factors like APE1/Ref-1, HIF-1, AP-1, Nrf2, NF-B, p53, FOXO, STAT, and - catenin. Also, how well anti-breast cancer drugs, especially those that cause cytotoxicity by making ROS, treat patients depends on how well the elements that support a cell's redox environment work together. Even though chemotherapy aims to kill cancer cells, which it does by making ROS, this can lead to drug resistance in the long run. The development of novel therapeutic approaches for treating breast cancer will be facilitated by a better understanding of the reductive stress and metabolic pathways in tumor microenvironments.

Membrane Lipid Derivatives: Roles of Arachidonic Acid and Its Metabolites in Pancreatic Physiology and Pathophysiology

One of the most important constituents of the cell membrane is arachidonic acid. Lipids forming part of the cellular membrane can be metabolized in a variety of cellular types of the body by a family of enzymes termed phospholipases: phospholipase A2, phospholipase C and phospholipase D. Phospholipase A2 is considered the most important enzyme type for the release of arachidonic acid. The latter is subsequently subjected to metabolization via different enzymes. Three enzymatic pathways, involving the enzymes cyclooxygenase, lipoxygenase and cytochrome P450, transform the lipid derivative into several bioactive compounds. Arachidonic acid itself plays a role as an intracellular signaling molecule. Additionally, its derivatives play critical roles in cell physiology and, moreover, are involved in the development of disease. Its metabolites comprise, predominantly, prostaglandins, thromboxanes, leukotrienes and hydroxyeicosatetraenoic acids. Their involvement in cellular responses leading to inflammation and/or cancer development is subject to intense study. This manuscript reviews the findings on the involvement of the membrane lipid derivative arachidonic acid and its metabolites in the development of pancreatitis, diabetes and/or pancreatic cancer.

Impact of Aspirin Intake on Postoperative Survival after Primary Pancreatic Resection of Pancreatic Ductal Adenocarcinoma-A Single-Center Evaluation

(1) Background: The intake of aspirin (ASS) has been demonstrated to have a relevant impact on the pathogenesis, incidence and outcome in different solid gastrointestinal tumors. However, data on the effect of ASS on the short-term outcome and the long-term survival in patients with pancreatic carcinoma are still limited. (2) Methods: A total of 213 patients who underwent primary resection of PDAC at the University Hospital of Erlangen from January 2000 to December 2018 were included in this retrospective single-center study in total. Patients were stratified according to the aspirin intake into three groups: continuous aspirin intake (cASS), perioperatively interrupted aspirin intake (iASS) and no aspirin intake (no ASS) at the timepoint of surgery. The postoperative outcome as well as long-term survival were compared between the groups. (3) Results: There were no differences regarding postoperative morbidity (iASS: 54% vs. cASS: 53% vs. no ASS: 64%, p = 0.448) and in-hospital mortality (iASS: 4% vs. cASS: 10% vs. no ASS: 3%, p = 0.198) between the groups. The overall survival (OS) and disease-free survival (DFS) did not differ in the groups when comparing the ASS-intake status (OS: iASS 17.8 months vs. cASS 19.6 months vs. no ASS 21.6 months, p = 0.489; DFS: iASS 14.0 months vs. cASS 18.3 months vs. no ASS 14.7 months, p = 0.957). Multivariate analysis revealed that age (hazard ratio (HR) 2.2, p < 0.001), lymph node-positive status (HR 2.0, p < 0.001), R status 1 or 2 (HR 2.8, p < 0.001) and differentiation with a grading of 3 (HR 1.7, p = 0.005) were significant independent prognostic factors regarding the OS. Moreover, age (HR 1.5, p = 0.040), lymph node-positive status (HR 1.8, p = 0.002) and high-grade (G3) carcinomas (HR 1.5, p = 0.037) could be identified as independent prognostic parameters for DFS. (4) Conclusions: In patients undergoing primary surgery for curative resection of pancreatic carcinoma, the perioperative intake of ASS had no significant impact on postoperative outcome, overall and disease-free survival.

Construction of a metabolism-related gene prognostic model to predict survival of pancreatic cancer patients

Pancreatic cancer (PC) is one of the most fatal malignant tumors, and is commonly diagnosed at an advanced stage with no effective therapy. Metabolism-related genes (MRGs) and immune-related genes (IRGs) play considerable roles in the tumor microenvironment. Therefore, an effective prediction model based on MRGs and IRGs could aid in the prognosis of PC. In this study, differential expression analysis was performed to gain 25 intersectional genes from 857 differentially expressed MRGs (DEMRGs), and 1353 differentially expressed IRGs, from The Cancer Genome Atlas database of PC. Cox and Lasso regression were applied and a five-DEMRGs prognostic model constructed. Survival analysis, ROC values, risk curve and validation analysis showed that the model could independently predict PC prognosis. In addition, the correlation analysis suggested that the five-DEMRGs prognostic model could reflect the status of the immune microenvironment, including Tregs, M1 macrophages and Mast cell resting. Therefore, our study provides new underlying predictive biomarkers and associated immunotherapy targets.

Exploring the metabolic landscape of pancreatic ductal adenocarcinoma cells using genome-scale metabolic modeling

Pancreatic ductal adenocarcinoma (PDAC) is a major research focus because of its poor therapy response and dismal prognosis. PDAC cells adapt their metabolism to the surrounding environment, often relying on diverse nutrient sources. Because traditional experimental techniques appear exhaustive to find a viable therapeutic strategy, a highly curated and omics-informed PDAC genome-scale metabolic model was reconstructed using patient-specific transcriptomics data. From the model-predictions, several new metabolic functions were explored as potential therapeutic targets in addition to the known metabolic hallmarks of PDAC. Significant downregulation in the peroxisomal beta oxidation pathway, flux modulation in the carnitine shuttle system, and upregulation in the reactive oxygen species detoxification pathway reactions were observed. These unique metabolic traits of PDAC were correlated with potential drug combinations targeting genes with poor prognosis in PDAC. Overall, this study provides a better understanding of the metabolic vulnerabilities in PDAC and will lead to novel effective therapeutic strategies.

MDACT: A New Principle of Adjunctive Cancer Treatment Using Combinations of Multiple Repurposed Drugs, with an Example Regimen

In part one of this two-part paper, we present eight principles that we believe must be considered for more effective treatment of the currently incurable cancers. These are addressed by multidrug adjunctive cancer treatment (MDACT), which uses multiple repurposed non-oncology drugs, not primarily to kill malignant cells, but rather to reduce the malignant cells' growth drives. Previous multidrug regimens have used MDACT principles, e.g., the CUSP9v3 glioblastoma treatment. MDACT is an amalgam of (1) the principle that to be effective in stopping a chain of events leading to an undesired outcome, one must break more than one link; (2) the principle of Palmer et al. of achieving fractional cancer cell killing via multiple drugs with independent mechanisms of action; (3) the principle of shaping versus decisive operations, both being required for successful cancer treatment; (4) an idea adapted from Chow et al., of using multiple cytotoxic medicines at low doses; (5) the idea behind CUSP9v3, using many non-oncology CNS-penetrant drugs from general medical practice, repurposed to block tumor survival paths; (6) the concept from chess that every move creates weaknesses and strengths; (7) the principle of mass-by adding force to a given effort, the chances of achieving the goal increase; and (8) the principle of blocking parallel signaling pathways. Part two gives an example MDACT regimen, gMDACT, which uses six repurposed drugs-celecoxib, dapsone, disulfiram, itraconazole, pyrimethamine, and telmisartan-to interfere with growth-driving elements common to cholangiocarcinoma, colon adenocarcinoma, glioblastoma, and non-small-cell lung cancer. gMDACT is another example of-not a replacement for-previous multidrug regimens already in clinical use, such as CUSP9v3. MDACT regimens are designed as adjuvants to be used with cytotoxic drugs.

Lipoxins and Resolvins in Patients With Pancreatic Cancer: A Preliminary Report

Eicosanoids are bioactive lipids derived from arachidonic acid, which have emerged as key regulators of a wide variety of pathophysiological processes in recent times and are implicated as mediators of gastrointestinal cancer. In this study, we investigated the systemic levels of lipoxygenase (LOX)-derived lipoxin A4 and B4, together with resolvin D1 and D2 in patients with pancreatic adenocarcinoma (n = 68), as well as in healthy individuals (n = 32). Systemic concentrations of the aforementioned immunoresolvents were measured using an enzyme-linked immunosorbent assay (ELISA). In this study, we observed that compared with concentrations in healthy individuals, the peripheral concentrations of the aforementioned eicosanoids were significantly elevated (2- to 10-fold) in patients with pancreatic cancer (in all cases p<0.00001). No significant association was observed between eicosanoid levels and the TNM clinical staging. Furthermore, we observed no significant differences in concentrations of the analyzed bioactive lipids between patients diagnosed with early-stage (TNM stage I-II) and more advanced disease (TNM stage III-IV). Receiver operating characteristic (ROC) curve analysis of each aforementioned immunoresolvent showed area under the curve values ranging between 0.79 and 1.00. Sensitivity, specificity, as well as positive and negative predictive values of the eicosanoids involved in the detection/differentiation of pancreatic adenocarcinoma ranged between 56.8% and 100%. In summary, our research is the first study that provides clinical evidence to support a systemic imbalance in LOX-derived lipoxins and resolvins as the mechanism underlying the pathogenesis of pancreatic adenocarcinoma. This phenomenon occurs regardless of the clinical TNM stage of the disease. Furthermore, our study is the first to preliminarily highlight the role of peripheral levels of immunoresolvents, particularly resolvin D1, as potential novel biomarkers of pancreatic cancer in humans.

Metabolomics Study Reveals Systematic Metabolic Dysregulation and Early Detection Markers Associated with Incident Pancreatic Cancer

Biomarkers for early detection of pancreatic cancer are in urgent need. To explore systematic circulating metabolites unbalance and identify potential biomarkers for pancreatic cancer in prospective Chinese cohorts, we conducted an untargeted metabolomics study in subjects with incident pancreatic cancer and matched controls (n=192) from the China Cardiometabolic Disease and Cancer Cohort (4C) Study. We characterized 998 metabolites in baseline serum and calculated 156 product-to-precursor ratios based on the KEGG database. The identified metabolic profiling revealed systematic metabolic network disorders before pancreatic cancer diagnosis. Forty-five metabolites or product-to-precursor ratios showed significant associations with pancreatic cancer (P < 0.05 and FDR < 0.1), revealing abnormal metabolism of amino acids (especially alanine, aspartate and glutamate), lipids (especially steroid hormone, vitamins, nucleotides and peptides. A novel metabolite panel containing aspartate/alanine (OR [95% CI]: 1.97 [1.31-2.94]), androstenediol monosulfate (0.69 [0.49-0.97]) and glycylvaline (1.68 [1.04-2.70]) was significantly associated with risk of pancreatic cancer. Area under the receiver operating characteristic curves (AUCs) was improved from 0.573 (reference model of CA 19-9) to 0.721. The novel metabolite panel was validated in an independent cohort with AUC improved from 0.529 to 0.661. These biomarkers may have a potential value in early detection of pancreatic cancer. This article is protected by copyright. All rights reserved.

Prognostic Value of COX-2, NF-κB, and Sp1 Tissue Expressions in Pancreatic Ductal Adenocarcinoma: A Systematic Review and Meta-analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is deadly cancer with a poor prognosis. Molecular prognostic markers are needed to predict the patient's survival. The cyclooxygenase-2 enzyme (COX-2) and its 2 major transcription factors--nuclear factorkappa B (NF-κB) and specificity protein 1 (Sp1)--are activated during inflammation caused by neoplasia. Several studies have investigated the association between the COX-2, NF-κB, and Sp1 tissue expressions with the patient's overall survival. Therefore, we conducted this systematic review and meta-analysis to evaluate those studies.

METHODS

We searched for relevant articles from the MEDLINE database through June 2020. Studies were eligible if they included dichotomized tissue protein expression status and the overall survival as the outcome. We used RevMan and ProMeta programs to perform the meta-analysis.

RESULTS

We identified 11 eligible studies. The meta-analysis showed that COX-2 tissue expression was associated with decreased overall survival (crude HR = 1.35; 95% CI, 1.05-1.74), although the result was not significant when controlling for other covariates. The NF-κB tissue expression was associated with decreased overall survival (crude HR = 2.18; 95% CI, 1.49-3.18), although it was not significant when controlling for other covariates. The Sp1 tissue expression showed significantly decreased overall survival even when adjusted with other covariates (aHR = 3.47; 95% CI, 1.52-7.94). The limitations included searching only for English publications and the substantial heterogeneity among the studies.

CONCLUSION

COX-2, NF-κB, and Sp1 tissue expressions have the potential to be used as prognostic markers in PDAC. Further studies are still needed to clarify the associations.

Mapping the Molecular Architecture Required for Lipid-Binding Pockets Using a Subset of Established and Orphan G-Protein Coupled Receptors

G-protein coupled receptors (GPCRs) sense a wide variety of stimuli, including lipids, and transduce signals to the intracellular environment to exert various physiological responses. However, the structural features of GPCRs responsible for detecting and triggering responses to distinct lipid ligands have only recently begun to be revealed. 14,15-epoxyeicosatrienoic acid (14,15-EET) is one such lipid mediator that plays an essential role in the vascular system, displaying both vasodilatory and anti-inflammatory properties. We recently reported multiple low-affinity 14,15-EET-binding GPCRs, but the mechanism by which these receptors sense 14,15-EET remains unclear. Here, we have taken a combined computational and experimental approach to identify and confirm critical residues and properties within the lipid-binding pocket. Furthermore, we generated mutants to engineer selected GPCR-predicted binding sites to either confer or abolish 14,15-EET-induced signaling. Our structure-function analyses indicate that hydrophobic and positively charged residues of the receptor-binding pocket are prerequisites for recognizing lipid ligands such as 14,15-EET and possibly other eicosanoids.

Fatty acids: facts vs. fiction

During the last 100 years official dietary guidelines have recommended an increased consumption of fats derived from seeds while decreasing the consumption of traditional fats, especially saturated fats. These recommendations are being challenged by recent studies. Furthermore, the increased use of refining processes in fat production had deleterious health effects. Today, the number of high-quality studies on fatty acids is large enough to make useful recommendations on clinical application and everyday practice. Saturated fats have many beneficial functions and palmitic acid appears to be problematic only when it is synthesized due to excess fructose consumption. Trans fatty acids were shown to be harmful when they are manmade but beneficial when of natural origin. Conjugated linoleic acid has many benefits but the isomer mix that is available in supplement form differs from its natural origin and may better be avoided. The ω3 fatty acid linolenic acid has rather limited use as an anti-inflammatory agent - a fact that is frequently overlooked. On the other hand, the targeted use of long chain ω3 fatty acids based on blood analysis has great potential to supplement or even be an alternative to various pharmacological therapies. At the same time ω6 fatty acids like linoleic acid and arachidonic acid have important physiological functions and should not be avoided but their consumption needs to be balanced with long chain ω3 fatty acids. The quality and quantity of these fats together with appropriate antioxidative protection are critical for their positive health effects.

Survival-Critical Genes Associated with Copy Number Alterations in Lung Adenocarcinoma

Chromosome Instability (CIN) in tumors affects carcinogenesis, drug resistance, and recurrence/prognosis. Thus, it has a high impact on outcomes in clinic. However, how CIN occurs in human tumors remains elusive. Although cells with CIN (i.e., pre/early cancer cells) are proposed to be removed by apoptosis and/or a surveillance mechanism, this surveillance mechanism is poorly understood. Here we employed a novel data-mining strategy (Gene Expression to Copy Number Alterations [CNA]; "GE-CNA") to comprehensively identify 1578 genes that associate with CIN, indicated by genomic CNA as its surrogate marker, in human lung adenocarcinoma. We found that (a) amplification/insertion CNA is facilitated by over-expressions of DNA replication stressor and suppressed by a broad range of immune cells (T-, B-, NK-cells, leukocytes), and (b) deletion CNA is facilitated by over-expressions of mitotic regulator genes and suppressed predominantly by leukocytes guided by leukocyte extravasation signaling. Among the 39 CNA- and survival-associated genes, the purine metabolism (PPAT, PAICS), immune-regulating CD4-LCK-MEC2C and CCL14-CCR1 axes, and ALOX5 emerged as survival-critical pathways. These findings revealed a broad role of the immune system in suppressing CIN/CNA and cancer development in lung, and identified components representing potential targets for future chemotherapy, chemoprevention, and immunomodulation approaches for lung adenocarcinoma.

Emerging role of cysteinyl LTs in cancer

Cysteinyl leukotrienes (CysLTs) are inflammatory lipid mediators that play a central role in the pathophysiology of several inflammatory diseases. Recently, there has been an increased interest in determining how these lipid mediators orchestrate tumour development and metastasis through promoting a pro-tumour micro-environment. Up-regulation of CysLTs receptors and CysLTs production is found in a number of cancers and has been associated with increased tumorigenesis. Understanding the molecular mechanisms underlying the role of CysLTs and their receptors in cancer progression will help investigate the potential of targeting CysLTs signalling for anti-cancer therapy. This review gives an overview of the biological effects of CysLTs and their receptors, along with current knowledge of their regulation and expression. It also provides a recent update on the molecular mechanisms that have been postulated to explain their role in tumorigenesis and on the potential of anti-CysLTs in the treatment of cancer.

The potential role of sesquiterpene lactones isolated from medicinal plants in the treatment of the metabolic syndrome - A review

Metabolic syndrome comprises a cluster of metabolic disorders related to the development of cardiovascular disease and type 2 diabetes mellitus. In latter years, plant secondary metabolites have become of special interest because of their potential role in preventing and managing metabolic syndrome. Sesquiterpene lactones constitute a large and diverse group of biologically active compounds widely distributed in several medicinal plants used for the treatment of metabolic disorders. The structural diversity and the broad spectrum of biological activities of these compounds drew significant interests in the pharmacological applications. This review describes selected sesquiterpene lactones that have been experimentally validated for their biological activities related to risk factors of metabolic syndrome, together with their mechanisms of action. The potential beneficial effects of sesquiterpene lactones discussed in this review demonstrate that these substances represent remarkable compounds with a diversity of molecular structure and high biological activity, providing new insights into the possible role in metabolic syndrome management.

Pleiotropic Functions of Cytochrome P450 Monooxygenase-Derived Eicosanoids in Cancer

Eicosanoids are a class of functionally bioactive lipid mediators derived from the metabolism of long-chain polyunsaturated fatty acids (PUFAs) mediated by multiple enzymes of three main branches, including cyclooxygenases (COXs), lipoxygenases (LOXs), and cytochrome P450s (CYPs). Recently, the role of eicosanoids derived by COXs and LOXs pathways in the control of physiological and pathological processes associated with cancer has been well documented. However, the role of CYPs-mediated eicosanoids, such as epoxyeicosatrienoic acids (EETs), epoxyoctadecenoic acids (EpOMEs), epoxyeicosatetraenoic acids (EpETEs), and epoxydocosapentaenoic acids (EDPs), as well as hydroxyeicosatetraenoic acids (HETEs), in tumorigenesis and cancer progression have not been fully elucidated yet. Here we summarized the association of polymorphisms of CYP monooxygenases with cancers and the pleiotropic functions of CYP monooxygenase-mediated eicosanoids (EETs, EpOMEs, EpETE, EDPs, and 20-HETE) in the tumorigenesis and metastasis of multiple cancers, including but not limited to colon, liver, kidney, breast and prostate cancers, which hopefully provides valuable insights into cancer therapeutics. We believe that manipulation of CYPs with or without supplement of ω-3 PUFAs to regulate eicosanoid profile is a promising strategy to prevent and/or treat cancers.

Anti-Inflammatory Drugs as Anticancer Agents

Inflammation is strictly associated with cancer and plays a key role in tumor development and progression. Several epidemiological studies have demonstrated that inflammation can predispose to tumors, therefore targeting inflammation and the molecules involved in the inflammatory process could represent a good strategy for cancer prevention and therapy. In the past, several clinical studies have demonstrated that many anti-inflammatory agents, including non-steroidal anti-inflammatory drugs (NSAIDs), are able to interfere with the tumor microenvironment by reducing cell migration and increasing apoptosis and chemo-sensitivity. This review focuses on the link between inflammation and cancer by describing the anti-inflammatory agents used in cancer therapy, and their mechanisms of action, emphasizing the use of novel anti-inflammatory agents with significant anticancer activity.

p110γ deficiency protects against pancreatic carcinogenesis yet predisposes to diet-induced hepatotoxicity

Pancreatic ductal adenocarcinoma (PDAC) is notorious for its poor survival and resistance to conventional therapies. PI3K signaling is implicated in both disease initiation and progression, and specific inhibitors of selected PI3K p110 isoforms for managing solid tumors are emerging. We demonstrate that increased activation of PI3K signals cooperates with oncogenic Kras to promote aggressive PDAC in vivo. The p110γ isoform is overexpressed in tumor tissue and promotes carcinogenesis via canonical AKT signaling. Its selective blockade sensitizes tumor cells to gemcitabine in vitro, and genetic ablation of p110γ protects against Kras-induced tumorigenesis. Diet/obesity was identified as a crucial means of p110 subunit up-regulation, and in the setting of a high-fat diet, p110γ ablation failed to protect against tumor development, showing increased activation of pAKT and hepatic damage. These observations suggest that a careful and judicious approach should be considered when targeting p110γ for therapy, particularly in obese patients.

Cyclooxygenase Inhibitors in Epithelial Ovarian Cancer Treatment

Epithelial ovarian cancer (EOC) is the fifth most common cause of cancer mortality among women. At present, EOC is treated with one or in a combination of treatments, commonly debulking surgery, combining a platinum-based and a taxane-based therapy; however, the patients have a risk of injury to the bowel, bladder, ureter, and vessels during surgery and many of them suffer from severe adverse effects caused by chemotherapy. Pharmaceutical inhibition of cyclooxygenase (COX) might be an important therapeutic tool in cancer treatment, as COX contributes to cancer progression by upregulating the levels of downstream metabolites. In this review article, we have discussed the role of COX in cancer progression and the therapeutic use of COX inhibitors in the treatment of EOC with subsequent clinical studies and future management. Usually, gonadotropins can promote prostaglandin E2 production in EOC cells via COX-1 and -2 upregulations through the PI3K/AKT signaling pathway. Several reports have shown that treatment of EOC cells with COX-1- and COX-2-specific inhibitors exhibits a therapeutic effect on EOC both in vitro and in vivo. However, more clinical investigations are needed to develop therapeutic COX inhibitors for the prevention and treatment of EOC without adverse effects.

Resveratrol Action on Lipid Metabolism in Cancer

Cancer diseases have the leading position in human mortality nowadays. The age of oncologic patients is still decreasing, and the entire scientific society is eager for new ways to fight against cancer. One of the most discussed issues is prevention by means of natural substances. Resveratrol is a naturally occurring plant polyphenol with proven antioxidant, anti-inflammatory, and anticancer effects. Tumor cells display specific changes in the metabolism of various lipids. Resveratrol alters lipid metabolism in cancer, thereby affecting storage of energy, cell signaling, proliferation, progression, and invasiveness of cancer cells. At the whole organism level, it contributes to the optimal metabolism extent with respect to the demands of the organism. Thus, resveratrol could be used as a preventive and anticancer agent. In this review, we focus on some of the plethora of lipid pathways and signal molecules which are affected by resveratrol during carcinogenesis.

Inhibition of secretory phospholipase A2 IIa attenuates prostaglandin E2-induced invasiveness in lung adenocarcinoma

Secretory phospholipase A2 IIa (sPLA2 IIa) catalyzes the production of multiple inflammatory mediators that influence the development of lung and other cancers. The most potent of these carcinogenic mediators is prostaglandin E2 (PGE2). We hypothesize that sPLA2 IIa inhibition modulates the production of PGE2, and sPLA2 IIa inhibition exerts its antineoplastic effects via downregulation of PGE2 production. We aim to evaluate these relationships via analysis of PGE2-mediated growth regulation pathways. A549 and H1650 lung adenocarcinoma cells were assayed for PGE2 production in the presence of sPLA2 IIa inhibitor. A549 and H1650 cells were treated with PGE2 and immune blotting was performed to assess ICAM-1 expression and STAT-3 activity. PGE2-induced ICAM-1 expression was measured via immunofluorescence. A549 and H1650 cells were treated with PGE2 in the presence of STAT3 inhibitor and assayed for ICAM-1 expression. A549 cells were treated with PGE2 in the presence ICAM-1 blocking antibody and assayed for invasion. PGE2 stimulation significantly increased the invasiveness and proliferation of lung adenocarcinoma (invasion p < 0.05, proliferation p < 0.05 A549 cells, p < 0.005 H1650 cells). sPLA2 IIa inhibition reduced PGE2 secretion (p < 0.05). PGE2 stimulation significantly upregulated the expression of cell adhesion molecule ICAM-1 and the phosphorylation of anti-apoptotic transcription factor STAT3 (p < 0.05). STAT3 inhibition attenuated ICAM-1 expression demonstrating the dependence of ICAM-1 on the STAT3 pathway (p < 0.05). ICAM-1 blockade attenuated the pro-invasive effects of PGE2 (p < 0.05). sPLA2 IIa inhibition attenuates the potent effects of PGE2-induced invasiveness. This is mediated by decreasing pro-inflammatory and invasion-promoting ICAM-1via the STAT-3 pathway. These data further describe how sPLA2 IIa inhibition mechanistically exerts its anticancer effects and support its use as an antineoplastic agent.

Antitumor mechanisms of cyclooxygenase and lipoxygenase

Eicosanoids, as the metabolic product of arachidonic acid, play an important role in tumor development and metastasis. Cyclooxygenase (COX)-2 and lipoxygenase (LOX) are two key enzymes that mediate the metabolism of arachidonic acid. So far, great progress has been made on the research of COX-2 and prostaglandins, and it has been demonstrated that they can induce the imbalance between cell growth and apoptosis as well as tumor angiogenesis. LOX and its metabolites, such as hydroxyeicosatetraenoic acid (HETE) and leukotriene (LT), have received more and more attention for their role in tumor development. Research has proved that LT-B4 and 5-HETE participate in the occurrence and development of multiple tumors. Therefore, COX and LOX dual inhibitors prove a new approach to anti-tumor therapy.

Tumor-promoting effects of pancreatic cancer cell exosomes on THP-1-derived macrophages

Pancreatic ductal adenocarcinoma (PDAC) tumor growth is enhanced by tumor-associated macrophages (TAMs), yet the mechanisms by which tumor cells and TAMs communicate are not fully understood. Here we show that exosomes secreted by PDAC cell lines differed in their surface proteins, lipid composition, and efficiency of fusing with THP-1-derived macrophages in vitro. Exosomes from AsPC-1, an ascites-derived human PDAC cell line, were enriched in ICAM-1, which mediated their docking to macrophages through interactions with surface-exposed CD11c on macrophages. AsPC-1 exosomes also contained much higher levels of arachidonic acid (AA), and they fused at a higher rate with THP-1-derived macrophages than did exosomes from other PDAC cell lines or from an immortalized normal pancreatic ductal epithelial cell line (HPDE) H6c7. Phospholipase A2 enzymatic cleavage of arachidonic acid from AsPC-1 exosomes reduced fusion efficiency. PGE2 secretion was elevated in macrophages treated with AsPC-1 exosomes but not in macrophages treated with exosomes from other cell lines, suggesting a functional role for the AsPC-1 exosome-delivered arachidonic acid in macrophages. Non-polarized (M0) macrophages treated with AsPC-1 exosomes had increased levels of surface markers indicative of polarization to an immunosuppressive M2-like phenotype (CD14hi CD163hi CD206hi). Furthermore, macrophages treated with AsPC-1 exosomes had significantly increased secretion of pro-tumoral, bioactive molecules including VEGF, MCP-1, IL-6, IL-1β, MMP-9, and TNFα. Together, these results demonstrate that compared to exosomes from other primary tumor-derived PDAC cell lines, AsPC-1 exosomes alter THP-1-derived macrophage phenotype and function. AsPC-1 exosomes mediate communication between tumor cells and TAMs that contributes to tumor progression.

Correlation of LOX‑5 and COX‑2 expression with inflammatory pathology and clinical features of adenomyosis

Adenomyosis is a common benign disease of women of childbearing age. The typical clinical features are prolonged menstruation, menorrhagia and ingravescent dysmenorrhea. In the present study, the severity of dysmenorrhea was assessed using the visual analogue scale system as follows: 0, No pain; 1‑3, minimal pain; 4‑6, moderate pain; and 7‑10, severe pain. Menstrual blood loss was evaluated using the pictorial blood loss assessment chart (PBAC). Menorrhagia was defined as excessive menstrual blood loss >80 ml (PBAC >100) per period. Specimens of eutopic endometrium (EU) and ectopic endometrium (EC) were collected from 20 patients with adenomyosis to evaluate the association between lipoxygenase‑5 (LOX‑5) and cyclooxygenase 2 (COX‑2) and inflammatory pathology and clinical features of adenomyosis. For that purpose, the expression levels of LOX‑5, COX‑2, interleukin (IL)‑6 and IL‑8 in the EU and EC of patients with adenomyosis were determined, and clinical data including dysmenorrhea and menstruation were analyzed. Differences in expression levels of LOX‑5 and COX‑2 were detected, and the correlations between LOX‑5, COX‑2, IL‑6 and IL‑8 in different groups were analyzed. In addition, the correlations between LOX‑5, COX‑2 and clinical features of adenomyosis were investigated. The present study demonstrated that LOX‑5 and COX‑2 are overexpressed in EU and EC, and they have positive correlations with IL‑6 and IL‑8, suggesting that adenomyosis lesions are present in inflammatory pathological conditions. The expression levels of LOX‑5 and COX‑2 exhibited a correlation with dysmenorrhea and menstruation.

Cyclooxygenase-1 (COX-1) and COX-1 Inhibitors in Cancer: A Review of Oncology and Medicinal Chemistry Literature

Prostaglandins and thromboxane are lipid signaling molecules deriving from arachidonic acid by the action of the cyclooxygenase isoenzymes COX-1 and COX-2. The role of cyclooxygenases (particularly COX-2) and prostaglandins (particularly PGE₂) in cancer-related inflammation has been extensively investigated. In contrast, COX-1 has received less attention, although its expression increases in several human cancers and a pathogenetic role emerges from experimental models. COX-1 and COX-2 isoforms seem to operate in a coordinate manner in cancer pathophysiology, especially in the tumorigenesis process. However, in some cases, exemplified by the serous ovarian carcinoma, COX-1 plays a pivotal role, suggesting that other histopathological and molecular subtypes of cancer disease could share this feature. Importantly, the analysis of functional implications of COX-1-signaling, as well as of pharmacological action of COX-1-selective inhibitors, should not be restricted to the COX pathway and to the effects of prostaglandins already known for their ability of affecting the tumor phenotype. A knowledge-based choice of the most appropriate tumor cell models, and a major effort in investigating the COX-1 issue in the more general context of arachidonic acid metabolic network by using the systems biology approaches, should be strongly encouraged.

ABC transporters as cancer drivers: Potential functions in cancer development

BACKGROUND

ABC transporters have attracted considerable attention for their function as drug transporters in a broad range of tumours and are therefore considered as major players in cancer chemoresistance. However, less attention has been focused on their potential role as active players in cancer development and progression.

SCOPE OF REVIEW

This review presents the evidence suggesting that ABC transporters might have a more active role in cancer other than the well known involvement in multidrug resistance and discusses the potential strategies to target each ABC transporter for a specific tumour setting.

MAJOR CONCLUSIONS

Emerging evidence suggests that ABC transporters are able to transport bioactive molecules capable of playing key roles in tumour development. Characterization of the effects of these transporters in specific cancer settings opens the possibility for the development of personalized treatments.

GENERAL SIGNIFICANCE

A more targeted approach of ABC transporters should be implemented that considers which specific transporter is playing a major role in a particular tumour setting in order to achieve a more successful outcome for ABC transporters inhibitors in cancer therapy.

Hydroxyeicosatetraenoic acids in patients with pancreatic cancer: a preliminary report

Previous experimental reports have demonstrated that lipoxygenase (LOX) derivatives of arachidonic acid (AA), such as hydroxyeicosatetraenoic acids (HETEs), may be of significance in the pathogenesis of pancreatic cancer. However, these observations have not been confirmed in clinical studies. In the current study, we comprehensively evaluated the systemic levels of selected LOX-derived HETEs such as 5-, 12- and 15-HETE in patients with pancreatic adenocarcinoma (n=36), chronic pancreatitis (n=39), and in healthy individuals (n=35). Compared to healthy individuals, patients with pancreatic adenocarcinoma showed 3-8-fold higher levels of 5-, 12- and 15-HETE (at least P<0.003). Similar results were observed in patients with chronic pancreatitis, who had elevated concentrations of all examined HETE acids compared to healthy volunteers (in all cases at least P<0.03). Interestingly, the levels of the examined HETEs were not significantly associated with the TNM stage of pancreatic cancer in our patients. Finally, analyses of receiver operating characteristic curves demonstrated that all HETEs examined had relatively low area under the curve values for discriminating pancreatic adenocarcinoma from non-cancerous conditions (0.49-0.61; P>0.05 in each case). Our study provides first preliminary clinical evidence for the significance of the examined HETEs in the clinical pathogenesis of pancreatic cancer and other pancreatic diseases in humans. Moreover, our data demonstrate that the HETEs examined here do not show sufficient clinical potential to be used as independent (bio)markers for differentiating pancreatic adenocarcinoma from other non-cancerous conditions in humans.

ATP-binding cassette transporters in progression and clinical outcome of pancreatic cancer: What is the way forward?

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive diseases and is characterized by high chemoresistance, leading to the lack of effective therapeutic approaches and grim prognosis. Despite increasing understanding of the mechanisms of chemoresistance in cancer and the role of ATP-binding cassette (ABC) transporters in this resistance, the therapeutic potential of their pharmacological inhibition has not been successfully exploited yet. In spite of the discovery of potent pharmacological modulators of ABC transporters, the results obtained in clinical trials have been so far disappointing, with high toxicity levels impairing their successful administration to the patients. Critically, although ABC transporters have been mostly studied for their involvement in development of multidrug resistance (MDR), in recent years the contribution of ABC transporters to cancer initiation and progression has emerged as an important area of research, the understanding of which could significantly influence the development of more specific and efficient therapies. In this review, we explore the role of ABC transporters in the development and progression of malignancies, with focus on PDAC. Their established involvement in development of MDR will be also presented. Moreover, an emerging role for ABC transporters as prognostic tools for patients' survival will be discussed, demonstrating the therapeutic potential of ABC transporters in cancer therapy.

Antiplatelet agents for cancer treatment: a real perspective or just an echo from the past?

The association between coagulation and cancer development has been observed for centuries. However, the connection between inflammation and malignancy is also well-recognized. The plethora of evidence indicates that among multiple hemostasis components, platelets play major roles in cancer progression by providing surface and granular contents for several interactions as well as behaving like immune cells. Therefore, the anticancer potential of anti-platelet therapy has been intensively investigated for many years. Anti-platelet agents may prevent cancer, decrease tumor growth, and metastatic potential, as well as improve survival of cancer patients. On the other hand, there are suggestions that antiplatelet treatment may promote solid tumor development in a phenomenon described as "cancers follow bleeding." The controversies around antiplatelet agents justify insight into the subject to establish what, if any, role platelet-directed therapy has in the continuum of anticancer management.

The arachidonic acid metabolism protein-protein interaction network and its expression pattern in esophageal diseases

Arachidonic acid (AA) and its metabolites are involved in the development and progression of inflammation and tumors in various tissues. We investigated the protein-protein interaction network (PPIN) of key enzymes in AA metabolism and their interacting proteins, as well as their expression patterns in different types of esophageal disease, involving esophagitis, Barrett's esophagus, adenocarcinoma and squamous cell carcinoma. PPINs were constructed to illustrate the key enzymes and their interacting proteins along the metabolic cascade. The network also showed key enzymes that could connect or cross-talk with at least one partner protein. The inflammation-related gene RELA (NF-kB) was found to interact with both PLA2G4A and ALOX5. Expression levels of the PPIN proteins, as well as their expression correlations, in different esophageal diseases were analyzed and integrated into the PPIN to illustrate a dynamic change. At least six significant pairs of expression relationships were identified across different esophageal diseases. The expression levels of eight enzymes (ALOX5, ALOX5AP, CYP2C8, CYP4F11, LTA4H, PLA2G4A, CYP2D6, PTGES2) correlated with the survival time of ESCC patients. In summary, we constructed an AA metabolic PPIN to explore AA metabolism-related gene expression patterns in esophageal diseases, showing their dynamic change and potential for therapeutic targeting from inflammation to cancer.

Characterising cis-regulatory variation in the transcriptome of histologically normal and tumour-derived pancreatic tissues

OBJECTIVE

To elucidate the genetic architecture of gene expression in pancreatic tissues.

DESIGN

We performed expression quantitative trait locus (eQTL) analysis in histologically normal pancreatic tissue samples (n=95) using RNA sequencing and the corresponding 1000 genomes imputed germline genotypes. Data from pancreatic tumour-derived tissue samples (n=115) from The Cancer Genome Atlas were included for comparison.

RESULTS

We identified 38 615 cis-eQTLs (in 484 genes) in histologically normal tissues and 39 713 cis-eQTL (in 237 genes) in tumour-derived tissues (false discovery rate <0.1), with the strongest effects seen near transcriptional start sites. Approximately 23% and 42% of genes with significant cis-eQTLs appeared to be specific for tumour-derived and normal-derived tissues, respectively. Significant enrichment of cis-eQTL variants was noted in non-coding regulatory regions, in particular for pancreatic tissues (1.53-fold to 3.12-fold, p≤0.0001), indicating tissue-specific functional relevance. A common pancreatic cancer risk locus on 9q34.2 (rs687289) was associated with ABO expression in histologically normal (p=5.8×10-8) and tumour-derived (p=8.3×10-5) tissues. The high linkage disequilibrium between this variant and the O blood group generating deletion variant in ABO (exon 6) suggested that nonsense-mediated decay (NMD) of the 'O' mRNA might explain this finding. However, knockdown of crucial NMD regulators did not influence decay of the ABO 'O' mRNA, indicating that a gene regulatory element influenced by pancreatic cancer risk alleles may underlie the eQTL.

CONCLUSIONS

We have identified cis-eQTLs representing potential functional regulatory variants in the pancreas and generated a rich data set for further studies on gene expression and its regulation in pancreatic tissues.

Identification of differentially expressed genes in the development of osteosarcoma using RNA-seq

Objective

Osteosarcoma (OS) is a malignant bone tumor with high morbidity in young adults and adolescents. This study aimed to discover potential early diagnosis biomarkers in OS.

Results

In total, 111 differentially expressed genes (DEGs) were identified in primary OS compared with normal controls and 235 DEGs were identified in metastatic OS compared with primary OS. AURKB and PPP2R2B were the significantly up-regulated and down-regulated hub proteins, respectively, in the PPI protein-protein network (PPI) network of primary OS. ISG15 and BTRC were the significantly up-regulated and down-regulated hub proteins, respectively, in the network of metastatic OS. The DEGs in metastatic OS compared with primary OS were significantly enriched in the arachidonic acid metabolism, malaria, and chemokine signaling pathways. Finally, we employed quantitative real-time polymerase chain reaction (qRT-PCR) to validate the expression levels of candidate DEGs and the results indicated that our bioinformatics approach was acceptable.

Materials and Methods

The mRNA expression profiling of 20 subjects was obtained through high-throughput RNA-sequencing. DEGs were identified between primary OS and normal Control, and between primary OS and metastatic OS, respectively. Functional annotation and PPI networks were used to obtain insights into the functions of DEGs. qRT-PCR was performed to detect the expression levels of dysregulated genes in OS.

Conclusions

Our work might provide groundwork for the further exploration of tumorigenesis and metastasis mechanisms of OS.

Reduction-oxidation pathways involved in cancer development: a systematic review of literature reviews

Oxidative stress results from an imbalance of the reactive oxygen species/reactive nitrogen species (ROS/RNS) production and the oxidants defense system. Extensive research during the last decades has revealed that oxidative stress can mediate cancer initiation and development by leading not only to molecular damage but also to a disruption of reduction-oxidation (redox) signaling. In order to provide a global overview of the redox signaling pathways, which play a role in cancer formation, we conducted a systematic literature search in PubMed and ISI Web of Science and identified 185 relevant reviews published in the last 10 years. The 20 most frequently described pathways were selected to be presented in this systematic review and could be categorized into 3 groups: Intracellular ROS/RNS generating organelles and enzymes, signal transduction cascades kinases/phosphatases and transcription factors. Intracellular ROS/RNS generation organelles are mitochondria, endoplasmic reticulum and peroxisomes. Enzymes, including NOX, COX, LOX and NOS, are the most prominent enzymes generating ROS/RNS. ROS/RNS act as redox messengers of transmembrane receptors and trigger the activation or inhibition of signal transduction kinases/phosphatases, such as the family members of protein tyrosine kinases and protein tyrosine phosphatases. Furthermore, these reactions activate downstream signaling pathways including protein kinase of the MAPK cascade, PI3K and PKC. The kinases and phosphatases regulate the phosphorylation status of transcription factors including APE1/Ref-1, HIF-1α, AP-1, Nrf2, NF-κB, p53, FOXO, STAT, and β-catenin. Finally, we briefly discuss cancer prevention and treatment opportunities, which address redox pathways and further research needs.

An overview of anticancer activity of Garcinia and Hypericum

Cancer is one of the leading causes of death worldwide (approximately 8.2 million cases/year) and, over the next two decades, a 70% increase in new cancer cases is expected. Through analysis of the available drugs between the years of 1930 and 2014, it was found that 48% were either natural products or their derivatives. This proportion increased to 66% when semi-synthetic products were included. The family Clusiaceae Juss. (Malpighiales) includes approximately 1000 species distributed throughout all tropical and temperate regions. The phytochemical profile of this family includes many chemicals with interesting pharmacological activities, including anticancer activities. This study includes an overview of the in vitro and in vivo anticancer activity of secondary metabolites from Garcinia and Hypericum and the mechanisms involved in this activity. Hypericum no longer belong to Clusiaceae family, but was considered in the past by taxonomists, due to similarities with this family. Research in the area has shown that several compounds belonging to different chemical classes exhibit activity in several tumor cell lines in different experimental models. This review shows the significant antineoplasic activity of these compounds, in particular of these two genera and validates the importance of natural products in the search for anticancer drugs.

Cross-Talk between Cancer Cells and the Tumour Microenvironment: The Role of the 5-Lipoxygenase Pathway

5-lipoxygenase is an enzyme responsible for the synthesis of a range of bioactive lipids signalling molecules known collectively as eicosanoids. 5-lipoxygenase metabolites such as 5-hydroxyeicosatetraenoic acid (5-HETE) and a number of leukotrienes are mostly derived from arachidonic acid and have been shown to be lipid mediators of inflammation in different pathological states including cancer. Upregulated 5-lipoxygenase expression and metabolite production is found in a number of cancer types and has been shown to be associated with increased tumorigenesis. 5-lipoxygenase activity is present in a number of diverse cell types of the immune system and connective tissue. In this review, we discuss potential routes through which cancer cells may utilise the 5-lipoxygenase pathway to interact with the tumour microenvironment during the development and progression of a tumour. Furthermore, immune-derived 5-lipoxygenase signalling can drive both pro- and anti-tumour effects depending on the immune cell subtype and an overview of evidence for these opposing effects is presented.

Inflammatory F2-isoprostane, prostaglandin F2α, pentraxin 3 levels and breast cancer risk: The Swedish Mammography Cohort

INTRODUCTION

Breast cancer is a common cancer among women. Identifying cellular participation of F₂-isoprostane, prostaglandin F_2α (PGF_2α) and pentraxin 3 (PTX3) in cancer we evaluated whether their prediagnostic systemic levels that originate from different inflammatory pathways were associated with breast cancer risk.

METHODS

Seventy-eight breast cancer cases diagnosed after blood collection and 797 controls from the Swedish Mammography Cohort were analysed for urinary F₂-isoprostane, PGF_2α and plasma PTX3 levels.

RESULTS

None of the biomarkers investigated were significantly associated with breast cancer risk. However, there was the suggestion of an inverse association with PTX3 with multivariable adjusted ORs (95% CI) of 0.56 (95% CI=0.29-1.06) and 0.67 (95% CI=0.35-1.28) for the second and third tertiles, respectively (p_trend=0.20). No associations were observed between F₂-isoprostane (OR=0.87; 95% CI=0.48-1.57; p_trend=0.67) and PGF_2α metabolite (OR=1.03; 95% CI=0.56-1.88; p_trend=0.91) comparing the top to bottom tertiles.

CONCLUSIONS

The systemic levels of F₂-isoprostane, PGF_2α and PTX3 witnessed in women who later developed breast cancer may not provide prognostic information regarding tumor development in spite of their known involvement in situ cellular context. These observations may indicate that other mechanisms exist in controlling cellular formation of F₂-isoprostane, PGF_2α and PTX3 and their systemic availability in breast cancer patients.

Resolvins and omega three polyunsaturated fatty acids: Clinical implications in inflammatory diseases and cancer

Inflammation is a central process in several disorders and contributes to cancer progression. Inflammation involves a complex cascade of pro-inflammatory and anti-inflammatory signaling events with protein and lipid mediators. Recent advances in lipid detection have revealed the importance of lipid mediators in inflammation. Omega three polyunsaturated fatty acids (ω-3 PUFA) are found naturally in fish oil and have been extensively studied in multiple inflammatory diseases with improved outcomes. Resolvins are thought to be the active metabolites of ω-3 PUFA, and are responsible for facilitating the resolving phase of acute inflammation. Clinically, resolvins have been associated with resolution of acute kidney injury and acute lung injury, micro and macro vascular response to injury, and inhibition of microglia-activated inflammation in neurodegenerative disorders. In addition to inflammatory diseases, ω-3 PUFA and resolvins appear to modulate cancer progression. ω-3 PUFA intake has been associated with reduced inflammation in colorectal cancer, and favorable phenotype in breast cancer. Resolvins offer promising therapeutic potential as they may modulate inflammation with minimal side-effects, in contrast to currently available anti-inflammatory medications. This review describes the roles of ω-3 PUFA and resolvins in the inflammatory cascade, various inflammatory diseases, and specific cancers. Additionally, it will discuss the clinical therapeutic potential of resolvins as targets in inflammatory diseases and cancers.

High Expression of PTGR1 Promotes NSCLC Cell Growth via Positive Regulation of Cyclin-Dependent Protein Kinase Complex

Lung cancer has been the most common cancer and the main cause of cancer-related deaths worldwide for several decades. PTGR1 (prostaglandin reductase 1), as a bifunctional enzyme, has been involved in the occurrence and progression of cancer. However, its impact on human lung cancer is rarely reported. In this study, we found that PTGR1 was overexpressed in lung cancer based on the analyses of Oncomine. Moreover, lentivirus-mediated shRNA knockdown of PTGR1 reduced cell viability in human lung carcinoma cells 95D and A549 by MTT and colony formation assay. PTGR1 depletion led to G2/M phase cell cycle arrest and increased the proportion of apoptotic cells in 95D cells by flow cytometry. Furthermore, silencing PTGR1 in 95D cells resulted in decreased levels of cyclin-dependent protein kinase complex (CDK1, CDK2, cyclin A2, and cyclin B1) by western blotting and then PTGR1 is positively correlated with cyclin-dependent protein by using the data mining of the Oncomine database. Therefore, our findings suggest that PTGR1 may play a role in lung carcinogenesis through regulating cell proliferation and is a potential new therapeutic strategy for lung cancer.

Evaluation of the anti-inflammatory action of curcumin analog (DM1): Effect on iNOS and COX-2 gene expression and autophagy pathways

This work describes the anti-inflammatory effect of the curcumin-analog compound, sodium 4-[5-(4-hydroxy-3-methoxyphenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate (DM1), and shows that DM1 modulates iNOS and COX-2 gene expression in cultured RAW 264.7 cells and induces autophagy on human melanoma cell line A375.

Phytomedicine polypharmacology: Cancer therapy through modulating the tumor microenvironment and oxylipin dynamics

Integrative approaches in cancer therapy have recently been extended beyond the induction of cytotoxicity to controlling the tumor microenvironment and modulating inflammatory cascades and pathways such as lipid mediator biosynthesis and their dynamics. Profiling of important lipid messengers, such as oxylipins, produced as part of the physiological response to pharmacological stimuli, provides a unique opportunity to explore drug pharmacology and the possibilities for molecular management of cancer physiopathology. Whereas single targeted chemotherapeutic drugs commonly lack efficacy and invoke drug resistance and/or adverse effects in cancer patients, traditional herbal medicines are seen as bright prospects for treating complex diseases, such as cancers, in a systematic and holistic manner. Understanding the molecular mechanisms of traditional medicine and its bioactive chemical constituents may aid the modernization of herbal remedies and the discovery of novel phytoagents for cancer management. In this review, systems-based polypharmacology and studies to develop multi-target drugs or leads from phytomedicines and their derived natural products that may overcome the problems of current anti-cancer drugs, are proposed and summarized.

Lipid metabolic reprogramming in cancer cells

Many human diseases, including metabolic, immune and central nervous system disorders, as well as cancer, are the consequence of an alteration in lipid metabolic enzymes and their pathways. This illustrates the fundamental role played by lipids in maintaining membrane homeostasis and normal function in healthy cells. We reviewed the major lipid dysfunctions occurring during tumor development, as determined using systems biology approaches. In it, we provide detailed insight into the essential roles exerted by specific lipids in mediating intracellular oncogenic signaling, endoplasmic reticulum stress and bidirectional crosstalk between cells of the tumor microenvironment and cancer cells. Finally, we summarize the advances in ongoing research aimed at exploiting the dependency of cancer cells on lipids to abolish tumor progression.

Co-expression of COX-2 and 5-LO in primary glioblastoma is associated with poor prognosis

Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LO) are important factors in tumorigenesis and malignant progression; however, studies of their roles in glioblastoma have produced conflicting results. To define the frequencies of COX-2 and 5-LO expression and their correlation with clinicopathological features and prognosis, tumor tissues from 76 cases of newly diagnosed primary ordinary glioblastoma were examined for COX-2 and 5-LO expression by immunohistochemistry. The expression levels of COX-2 and 5-LO and the relationships between the co-expression of COX-2/5-LO and patient age and gender, edema index (EI), Karnofsky Performance Scale and overall survival (OS) were analyzed. COX-2 and 5-LO were expressed in 73.7 % (56/76) and 92.1 % (70/76) of the samples, respectively. Among the clinicopathological characteristics, only age (>60 years) exhibited a significant association with the high expression of COX-2. No statistically significant correlations were found in the 5-LO cohort. A significant positive correlation was revealed between the COX-2 and 5-LO scores (r = 0.374; p = 0.001). The elevated co-expression of COX-2 and 5-LO was observed primarily in the patients over the age of 60 years. Patients with a high expression of COX-2 had a significantly shorter OS (p < 0.01), whereas the immunoexpression of 5-LO was not associated with the OS of patients with glioblastoma. Survival analysis indicated that simultaneous high levels of COX-2 and 5-LO expression were significantly correlated with poor OS and, conversely, that a low/low expression pattern of these two proteins was significantly associated with better OS (p < 0.05). Moreover, the Cox multivariable proportional hazard model showed that a high expression of COX-2, high co-expression of COX-2 and 5-LO, and a high Ki-67 index were significant predictors of shorter OS in primary glioblastoma, independent of age, gender, EI, 5-LO expression and p53 status. The hazard ratios for OS were 2.347 (95 % CI 1.30-4.25, p = 0.005), 1.900 (95 % CI 1.30-2.78, p = 0.001), and 2.210 (95 % CI 1.19-4.09, p = 0.011), respectively. These results suggest that COX-2 and 5-LO play roles in tumorigenesis and the progression of primary glioblastoma and that the co-expression pattern of COX-2/5-LO may be used as an independent prognostic factor in this disease.

Targeting pancreatitis blocks tumor-initiating stem cells and pancreatic cancer progression

Recent development of genetically engineered mouse models (GEMs) for pancreatic cancer (PC) that recapitulates human disease progression has helped to identify new strategies to delay/inhibit PC development. We first found that expression of the pancreatic tumor-initiating/cancer stem cells (CSC) marker DclK1 occurs in early stage PC and in both early and late pancreatic intraepithelial neoplasia (PanIN) and that it increases as disease progresses in GEM and also in human PC. Genome-wide next generation sequencing of pancreatic ductal adenocarcinoma (PDAC) from GEM mice revealed significantly increased DclK1 along with inflammatory genes. Genetic ablation of cyclo-oxygenase-2 (COX-2) decreased DclK1 in GEM. Induction of inflammation/pancreatitis with cerulein in GEM mice increased DclK1, and the novel dual COX/5-lipoxygenase (5-LOX) inhibitor licofelone reduced it. Dietary licofelone significantly inhibited the incidence of PDAC and carcinoma in situ with significant inhibition of pancreatic CSCs. Licofelone suppressed pancreatic tumor COX-2 and 5-LOX activities and modulated miRNAs characteristic of CSC and inflammation in correlation with PDAC inhibition. These results offer a preclinical proof of concept to target the inflammation initiation to inhibit cancer stem cells early for improving the treatment of pancreatic cancers, with immediate clinical implications for repositioning dual COX/5-LOX inhibitors in human trials for high risk patients.