Cyclo-oxygenase 2: a pharmacological target for the prevention of cancer

Phospholipase A2 expression in prostate cancer as a biomarker of good prognosis: A comprehensive study in patients with long follow-up

BACKGROUND

Phospholipase A2 (PLA2) is a large family of enzymes involved in the inflammatory process that catalyzes the hydrolysis of membrane phospholipids, leading to the production of free fatty acids and lysophospholipids, starting the arachidonic acid cascade. Their expression has been related to the behavior of several cancers. Our objective is to search for PLA2 expression in prostate cancer (PCa) tissue that correlates with prognosis and survival.

METHODS

Using qRT-PCR, we analyzed the expression levels of PLA2G1B, PLA2G2A, PLA2G2D, PLA2G4A, PLA2G4B, PLA2G4C, PLA2G4D, PLA2G4E, PLA2G4F, PLA2G6, PLA2G7, PLA2G16, PNPLA1, and PNPLA2 in PCa tissue from 108 patients submitted to radical prostatectomy, followed by a mean time of 163 months.

RESULTS

All PLA2 was overexpressed in PCa compared to normal tissue. Interestingly, higher expression of some PLA2 was related to favorable prognostic factors: lower levels of PSA (PLA2G2A, PLA2G4D), lower rates of lymph node metastasis (PLA2G16 and PLA2G1B), and organ-confined disease (PLA2G4A). Most importantly, PLAG4B was independently related to longer disease-free survival.

CONCLUSION

This is the first study exploring comprehensively the expression levels of PLA2 in PCa, showing that the higher expression of some PLA2 should be used as biomarkers of good prognosis and longer disease-free survival.

Synthesis, molecular docking evaluation for LOX and COX-2 inhibition and determination of in-vivo analgesic potentials of aurone derivatives

In the current study, seven (7) aurone derivatives (ADs) were synthesized and employed to in-vitro LOX and COX-2 assays, in-vivo models of acetic acid-induced mice writhing, formalin-induced mice paw licking and tail immersion test to evaluate their analgesic potential at the doses of 10 mg and 20 mg/kg body weight. Molecular docking was performed to know the active binding site at both LOX and COX-2 as compared to standard drugs. Among the ADs, 2-(3,4-dimethoxybenzylidene)benzofuran-3(2H)-one (WE-4)possessed optimal LOX and COX-2 inhibitory strength (IC50=0.30 μM and 0.22 μM) as compared to standard (ZileutonIC50 = 0.08 μM, CelecoxibIC50 = 0.05 μM). Similarly in various pain models compound WE-4 showed significantly (p < 0.05) highest percent analgesic potency as compared to control at a dose of 20 mg/kg i.e. 77.60 % analgesic effect in acetic acid model, 49.97 % (in Phase-1) and 70.93 % (inPhase-2) analgesic effect in formalin pain model and 74.71 % analgesic response in tail immersion model. By the administration of Naloxone, the tail flicking latencies were reversed (antagonized) in all treatments. The WE-4 (at 10 mg/kg and 20 mg/kg) was antagonized after 90 min from 11.23 ± 0.93 and 13.41 ± 1.21 to 5.30 ± 0.48 and 4.80 ± 0.61 respectively as compared to standard Tramadol (from 17.74 ± 1.33 to 3.70 ± 0.48), showing the opiodergic receptor involvement. The molecular docking study of ADs revealed that WE-4 had a higher affinity for LOX and COX-2 with docking scores of -4.324 and -5.843 respectively. As a whole, among the tested ADs, compound WE-4 demonstrated excellent analgesic effects that may have been caused by inhibiting the LOX and COX-2 pathways.

Gingerol and/or sorafenib attenuates the DAB-induced HCC and hepatic portal vein dilatation via ATG4/CASP3 and COIIV/COX-2/NF-κB expression

Ginger (Gin) has numerous therapeutic properties. One of Gin's most potent components is 6-gingerol, a naturally occurring phenol. This study aimed to investigate the therapeutic impact of gingerol and/or sorafenib on the ATG4/CASP3 and COIIV/COX-2/NF-B Expression as a potential therapy for DAB-induced HCC. Gin was administered to HCC mice induced by p-Dimethylaminoazobenzene (DAB) alone or combined with sorafenib (Sor). Superoxide dismutase (SOD), catalase (CAT), and oxidative stress malondialdehyde (MDA), as well as biochemical markers including AST, ALT, ALP, Albumin, and Bilirubin, were examined. The expression of oncogenes (COIIV, COX-2, NF-κB, and survivin) and tumor suppressor genes (ATG4 and CASP3) was evaluated using qPCR. According to the results, the levels of MDA have been markedly decreased, while SOD and CAT have been increased. Further, the expression levels of tumor suppressor genes were upregulated, whereas the expression levels of oncogene genes were downregulated. Furthermore, in a dose-dependent manner, gingerol has shown the potential to alleviate hepatic portal vein (PV) dilatation and could offer a reliable therapy for HCC. This suggests combining the two compounds may be more effective than alone and that Gin could be a promising therapeutic option for HCC. The binding of Gin and Sor to the active sites of the target genes prevents them from functioning normally, which in turn stops the pathways from carrying out their oncogenic functions. Additionally, COX-2 inhibition reduces the production of certain pro-inflammatory compounds, which further averts oncogenesis. Conclusively, this study indicated that Gin has cytoprotective properties and anti-cancer activity that may be related to controlling oxidative stress. This effect may be achieved by suppressing the COIIV/COX-2/NF-κB pathway and upregulating the ATG4 /CASP3 pathways.

Nimesulide, a COX-2 inhibitor, sensitizes pancreatic cancer cells to TRAIL-induced apoptosis by promoting DR5 clustering †

Nimesulide is a nonsteroidal anti-inflammatory drug and a COX-2 inhibitor with antitumor and antiproliferative activities that induces apoptosis in oral, esophagus, breast, and pancreatic cancer cells. Despite being removed from the market due to hepatotoxicity, nimesulide is still an important research tool being used to develop new anticancer drugs. Multiple studies have been done to modify the nimesulide skeleton to develop more potent anticancer agents and related compounds are promising scaffolds for future development. As such, establishing a mechanism of action for nimesulide remains an important part of realizing its potential. Here, we show that nimesulide enhances TRAIL-induced apoptosis in resistant pancreatic cancer cells by promoting clustering of DR5 in the plasma membrane. In this way, nimesulide acts like a related compound, DuP-697, which sensitizes TRAIL-resistant colon cancer cells in a similar manner. Our approach applies a time-resolved FRET-based biosensor that monitors DR5 clustering and conformational states in the plasma membrane. We show that this tool can be used for future high-throughput screens to identify novel, nontoxic small molecule scaffolds to overcome TRAIL resistance in cancer cells.

All That Glitters Is Not Gold: Assessment of Bee Pollen Supplementation Effects on Gastric Mucosa

The aim of this study was to assess the influence of bee pollen supplementation on the levels of enzymes important for gastric mucosal homeostasis, namely cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and a biomarker-asymmetric dimethylarginine (ADMA)-in the gastric mucosa of Wistar rats. The experimental phase divided the rats into four groups: two control groups, sedentary and active, both not supplemented, and two experimental groups, sedentary and active, supplemented with bee pollen. The results indicated that bee pollen supplementation reduced the levels of COX-1 and elevated iNOS levels, while showing no significant impact on COX-2 levels. These findings do not conclusively support the gastroprotective and anti-inflammatory effects of bee pollen on gastric mucosa. However, the supplementation could have resulted in reduced ADMA levels in the physically active supplemented group. Our study does not unequivocally demonstrate the positive effects of bee pollen supplementation on the gastric mucosa, which may be attributed to the specific metabolism and bioavailability of substances within unprocessed, dried bee pollen. Further research should explore the topic of potential therapeutic applications of bee pollen in gastrointestinal health and its interactions with ADMA signaling pathways.

Amino Acids as Chelating Ligands for Platinum: Enhanced Stability in an Aqueous Environment Promoted by Biocompatible Molecules

Platinum-based chemotherapeutics are a cornerstone in the treatment of many malignancies. However, their dose-limiting side effects have rooted efforts to develop new drug candidates with higher selectivity for tumor tissues and less problematic side effects. Here, we developed a cytotoxic platinum(II) complex based on Zeise's salt, containing the nonsteroidal anti-inflammatory drug acetylsalicylic acid and alanine as ligands (4). The previously developed complex (5) displayed high reactivity against sulfur-containing biomolecules; therefore, we put the focus on the optimization of the structure regarding its stability. Different amino acids were used as biocompatible chelating ligands to achieve this aim. Differences in the coordination sphere caused pronounced changes in the stability of Zeise-type precursors 1-3. Coordination with l-Ala through N in the trans position to ethylene showed the most promising results and was employed to stabilize 5. As a result, complex 4 showed improved stability and cytotoxicity, outperforming both 5 and 1.

Inactivation of TRPM7 Kinase Targets AKT Signaling and Cyclooxygenase-2 Expression in Human CML Cells

Cyclooxygenase-2 (COX-2) is a key regulator of inflammation. High constitutive COX-2 expression enhances survival and proliferation of cancer cells, and adversely impacts antitumor immunity. The expression of COX-2 is modulated by various signaling pathways. Recently, we identified the melastatin-like transient-receptor-potential-7 (TRPM7) channel-kinase as modulator of immune homeostasis. TRPM7 protein is essential for leukocyte proliferation and differentiation, and upregulated in several cancers. It comprises of a cation channel and an atypical α-kinase, linked to inflammatory cell signals and associated with hallmarks of tumor progression. A role in leukemia has not been established, and signaling pathways are yet to be deciphered. We show that inhibiting TRPM7 channel-kinase in chronic myeloid leukemia (CML) cells results in reduced constitutive COX-2 expression. By utilizing a CML-derived cell line, HAP1, harboring CRISPR/Cas9-mediated TRPM7 knockout, or a point mutation inactivating TRPM7 kinase, we could link this to reduced activation of AKT serine/threonine kinase and mothers against decapentaplegic homolog 2 (SMAD2). We identified AKT as a direct in vitro substrate of TRPM7 kinase. Pharmacologic blockade of TRPM7 in wildtype HAP1 cells confirmed the effect on COX-2 via altered AKT signaling. Addition of an AKT activator on TRPM7 kinase-dead cells reconstituted the wildtype phenotype. Inhibition of TRPM7 resulted in reduced phosphorylation of AKT and diminished COX-2 expression in peripheral blood mononuclear cells derived from CML patients, and reduced proliferation in patient-derived CD34+ cells. These results highlight a role of TRPM7 kinase in AKT-driven COX-2 expression and suggest a beneficial potential of TRPM7 blockade in COX-2-related inflammation and malignancy.

Selective COX-2 inhibitors do not increase gastrointestinal reactions after colorectal cancer surgery: a systematic review and meta-analysis

BACKGROUND

The effectiveness of selective COX-2 inhibitors in preventing colorectal cancer recurrence has been demonstrated, however it is unknown how safe and successful they will be over the long term. As a result, we looked at the efficacy, safety, and consequences of adding COX-2 inhibitors to the treatment plan afterward.

METHODS

In patients with advanced colorectal cancer, we compared the efficacy of celecoxib at two different doses (200 mg twice day and 400 mg twice daily) with placebo. To evaluate the impacts of post-treatment, several datasets from inception to June 2022 were searched. Response rate, illness control rate, and 3-year survival were the main results. And evaluated several safety outcomes, particularly those that were susceptible to adverse events.

RESULTS

The study comprised a total of 9 randomized controlled trials (3206 participants). Celecoxib and rofecoxib doidn't significantly improved the 1-3 year remission rate (OR, 1.57 [95% CI: 0.95-2.57]) and disease control rate (OR, 1.08 [95% CI: 0.99-1.17]). Subgroup analysis of different doses showed that 400 mg of celecoxib significantly improved the response rate (OR, 2.82 [95%CI: 1.20-6.61]). 200 mg celecoxib was not significant (OR, 1.28 [95% CI: 0.66-2.49]). Rofecoxib also did not fully improve disease response rates. Celecoxib at any dose improved 3-year survival (OR, 1.21 [95% CI: 1.02-1.45]). It is important to note that COX-2 inhibitors did not significantly enhance the likelihood of adverse events including gastrointestinal or cardiovascular side effects at any dose.

CONCLUSIONS

For patients with advanced colorectal cancer, a reasonable chemoprevention regimen can include celecoxib 400 mg twice daily.

Unraveling the Complex Interconnection between Specific Inflammatory Signaling Pathways and Mechanisms Involved in HIV-Associated Colorectal Oncogenesis

The advancement of HIV treatment has led to increased life expectancy. However, people living with HIV (PLWH) are at a higher risk of developing colorectal cancers. Chronic inflammation has a key role in oncogenesis, affecting the initiation, promotion, transformation, and advancement of the disease. PLWH are prone to opportunistic infections that trigger inflammation. It has been documented that 15-20% of cancers are triggered by infections, and this percentage is expected to be increased in HIV co-infections. The incidence of parasitic infections such as helminths, with Ascariasis being the most common, is higher in HIV-infected individuals. Cancer cells and opportunistic infections drive a cascade of inflammatory responses which assist in evading immune surveillance, making them survive longer in the affected individuals. Their survival leads to a chronic inflammatory state which further increases the probability of oncogenesis. This review discusses the key inflammatory signaling pathways involved in disease pathogenesis in HIV-positive patients with colorectal cancers. The possibility of the involvement of co-infections in the advancement of the disease, along with highlights on signaling mechanisms that can potentially be utilized as therapeutic strategies to prevent oncogenesis or halt cancer progression, are addressed.

Emerging roles of polyunsaturated fatty acid synthesis pathway in colorectal cancer

The development of colorectal cancer typically involves the accumulated influences of genetic alterations, medical issues, lifestyle, and diet. Dietary fatty acids appear to affect the tumorigenesis and progression of colorectal cancer. Despite conflicting results, the current consensus on the effects of very long-chain polyunsaturated fatty acids on colorectal cancer is that low levels of eicosapentaenoic acid and docosahexaenoic acid, and high levels of arachidonic acid are associated with an increased risk of colorectal cancer. Altered levels of arachidonic acid in membrane phospholipids can change the levels of prostaglandin E₂, which affect the biological activities of cancer cells in multiple stages. Arachidonic acid and other very long-chain polyunsaturated fatty acids can affect tumorigenesis in prostaglandin E₂-independent manners as well, including stabilization of β-catenine, ferroptosis, ROS generation, regulation of transcription factors, and de novo lipogenesis. Recent studies have revealed an association between the activities of enzymes synthesizing very long-chain polyunsaturated fatty acids and tumorigenesis and cancer progression, although the mechanisms are still unknown. In this study, PUFA effects on tumorigenesis, the endogenous very long-chain polyunsaturated fatty acid synthesis pathway, metabolites of arachidonic acid and their effects on tumorigenesis and progression of CRC, and current knowledge that supports the association of the enzymes involved in the polyunsaturated fatty acid synthesis pathway with colorectal cancer tumorigenesis and progression are reviewed.

Novel bioactive hybrid Celecoxib-HDAC Inhibitor, induces apoptosis in human acute lymphoblastic leukemia cells

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children. Here, we exploited the synergy between histone deacetylase inhibitors (HDACi) and cyclooxygenase 2 (COX-2) inhibitors by generating and testing a series of hybrid Celecoxib-HDAC inhibitors (selenium-containing analogues of Celecoxib) on ALL cells, of which compound 11 exhibited significant inducement to kill NALM6 cells with an average IC50 of 9.95 ± 0.44 μM compared with control Celecoxib at 28.58 ± 1.44 μM and inhibited NALM6 cells growth via the inhibition of the cell cycle in G2 phase. Furthermore, compound 11 induced apoptosis by activating PARP cleavage. Taken together, compound 11 possessed the potential to be developed further as a chemotherapeutic agent for ALL.

Functional high-throughput screen identifies microRNAs that promote butyrate-induced death in colorectal cancer cells

The gut fermentation product butyrate displays anti-cancer properties in the human proximal colon, including the ability to inhibit proliferation and induce apoptosis in colorectal cancer (CRC) cells. A natural histone deacetylase inhibitor (HDACi), butyrate can alter histone acetylation patterns in CRC cells, and thereby regulate global gene expression, including the non-coding transcriptome and microRNAs (miRNAs). Dysregulated miRNA expression affects CRC development and progression; however, the interplay between miRNA activity and butyrate response remains to be elucidated. A high-throughput functional screen was employed to identify miRNAs that can act as enhancers of the anti-cancer properties of butyrate. Validation studies confirmed that several miRNAs, including miR-125b, miR-181a, miR-593, and miR-1227, enhanced apoptosis, decreased proliferation, and promoted cell-cycle arrest in the presence of butyrate. Pathway analyses of predicted miRNA target genes highlighted their likely involvement in critical cancer-related growth pathways, including WNT and PI3K signaling. Several cancer-associated miRNA targets, including TRIM29, COX2, PIK3R3, CCND1, MET, EEF2K, DVL3, and NUP62 were synergistically regulated by the combination of cognate miRNAs and butyrate. Overall, this study has exposed the potential of miRNAs to act as enhancers of the anti-cancer effects of HDAC inhibition and identifies specific miRNAs that might be exploited for therapeutic benefit.

Design and synthesis of multifunctional microtubule targeting agents endowed with dual pro-apoptotic and anti-autophagic efficacy

Autophagy is a lysosome dependent cell survival mechanism and is central to the maintenance of organismal homeostasis in both physiological and pathological situations. Targeting autophagy in cancer therapy attracted considerable attention in the past as stress-induced autophagy has been demonstrated to contribute to both drug resistance and malignant progression and recently interest in this area has re-emerged. Unlocking the therapeutic potential of autophagy modulation could be a valuable strategy for designing innovative tools for cancer treatment. Microtubule-targeting agents (MTAs) are some of the most successful anti-cancer drugs used in the clinic to date. Scaling up our efforts to develop new anti-cancer agents, we rationally designed multifunctional agents 5a-l with improved potency and safety that combine tubulin depolymerising efficacy with autophagic flux inhibitory activity. Through a combination of computational, biological, biochemical, pharmacokinetic-safety, metabolic studies and SAR analyses we identified the hits 5i,k. These MTAs were characterised as potent pro-apoptotic agents and also demonstrated autophagy inhibition efficacy. To measure their efficacy at inhibiting autophagy, we investigated their effects on basal and starvation-mediated autophagic flux by quantifying the expression of LC3II/LC3I and p62 proteins in oral squamous cell carcinoma and human leukaemia through western blotting and by immunofluorescence study of LC3 and LAMP1 in a cervical carcinoma cell line. Analogues 5i and 5k, endowed with pro-apoptotic activity on a range of hematological cancer cells (including ex-vivo chronic lymphocytic leukaemia (CLL) cells) and several solid tumor cell lines, also behaved as late-stage autophagy inhibitors by impairing autophagosome-lysosome fusion.

Investigation of Cyclooxygenase-2 Gene Polymorphism in Patients with Gastric Cancer and Healthy Individuals in Northern Iran

Background: Gastric cancer is one of the most common types of cancer in the world. Cyclooxygenase-2 (COX-2) is a pro-inflammatory enzyme and an important mediator of tumor cell proliferation and angiogenesis. Objectives: The aim of this study was to investigate the relationship between COX-2 gene polymorphism and the risk of developing gastric cancer. Methods: This case-control study was carried out on 150 patients with gastric cancer and 150 healthy individuals. Genomic DNA was extracted using a modified method of protein precipitation at high salt concentrations. Polymorphisms of the COX-2 gene were investigated by polymerase chain reaction-restriction fragment length polymorphism analysis. Results: In this study, the frequency of GG genotype and CC genotype was significantly higher in patients with gastric cancer and healthy individuals, respectively (P < 0.05). However, the frequency of CC genotype did not significantly differ between the 2 study groups. Conclusions: We demonstrated that the homozygous GG genotype of COX-2 is significantly more frequent in patients with gastric cancer compared to healthy individuals. This could indicate the possible role of COX-2 in the development or progression of gastric cancer.

Immune Regulation of Mammary Fibroblasts and the Impact of Mammographic Density

Mammographic density is associated with a 4–6-fold increase in breast cancer risk independent of age and BMI. High mammographic density is characterized by breast tissue with high proportions of stroma comprised of fibroblasts, collagen, and immune cells. This study sought to investigate whether stromal fibroblasts from high mammographic density breast tissue contributes to increased extracellular matrix deposition and pro-tumorigenic signaling. Mammary fibroblasts were isolated from women with high and low mammographic density and exposed to immune factors myeloperoxidase (MPO), eosinophil peroxidase (EPO), transforming growth factor beta 1 (TGFB1) and tumour necrosis factor alpha (TNFA) for 72 h and profiled for expression of cancer-associated fibroblast and extracellular matrix regulation markers. No differences in gene expression profiles or collagen production were observed between fibroblasts with high or low mammographic density, and they did not have a differential response to immune mediators. MPO and EPO significantly increased the production of collagen 1. TGFB and TNFA induced variable changes in gene expression. Fibroblasts cultured in vitro from women with high mammographic density do not appear to be inherently different to those from women with low mammographic density. The function of fibroblasts in mammographic density-associated breast cancer risk is likely to be regulated by immune signals from surrounding cells in the microenvironment.

Pros and Cons of Pharmacological Manipulation of cGMP-PDEs in the Prevention and Treatment of Breast Cancer

The cyclic nucleotides, cAMP and cGMP, are ubiquitous second messengers responsible for translating extracellular signals to intracellular biological responses in both normal and tumor cells. When these signals are aberrant or missing, cells may undergo neoplastic transformation or become resistant to chemotherapy. cGMP-hydrolyzing phosphodiesterases (PDEs) are attracting tremendous interest as drug targets for many diseases, including cancer, where they regulate cell growth, apoptosis and sensitization to radio- and chemotherapy. In breast cancer, PDE5 inhibition is associated with increased intracellular cGMP levels, which is responsible for the phosphorylation of PKG and other downstream molecules involved in cell proliferation or apoptosis. In this review, we provide an overview of the most relevant studies regarding the controversial role of PDE inhibitors as off-label adjuvants in cancer therapy.

Mollusc-Derived Brominated Indoles for the Selective Inhibition of Cyclooxygenase: A Computational Expedition

Inflammation plays an important role in different chronic diseases. Brominated indoles derived from the Australian marine mollusk Dicathais orbita (D. orbita) are of interest for their anti-inflammatory properties. This study evaluates the binding mechanism and potentiality of several brominated indoles (tyrindoxyl sulfate, tyrindoleninone, 6-bromoisatin, and 6,6′-dibromoindirubin) against inflammatory mediators cyclooxygenases-1/2 (COX-1/2) using molecular docking, followed by molecular dynamics simulation, along with physicochemical, drug-likeness, pharmacokinetic (pk), and toxicokinetic (tk) properties. Molecular docking identified that these indole compounds are anchored, with the main amino acid residues, positioned in the binding pocket of the COX-1/2, required for selective inhibition. Moreover, the molecular dynamics simulation based on root mean square deviation (RMSD), radius of gyration (Rg), solvent accessible surface area (SASA), and root mean square fluctuation (RMSF) analyses showed that these natural brominated molecules transit rapidly to a progressive constant configuration during binding with COX-1/2 and seem to accomplish a consistent dynamic behavior by maintaining conformational stability and compactness. The results were comparable to the Food and Drug Administration (FDA)-approved selective COX inhibitor, aspirin. Furthermore, the free energy of binding for the compounds assessed by molecular mechanics–Poisson–Boltzmann surface area (MM–PBSA) confirmed the binding capacity of indoles towards COX-1/2, with suitable binding energy values except for the polar precursor tyrindoxyl sulfate (with COX-1). The physicochemical and drug-likeness analysis showed zero violations of Lipinski’s rule, and the compounds are predicted to have excellent pharmacokinetic profiles. These indoles are projected to be non-mutagenic and free from hepatotoxicity, with no inhibition of human ether-a-go–go gene (hERG) I inhibitors, and the oral acute toxicity LD₅₀ in rats is predicted to be similar or lower than aspirin. Overall, this work has identified a plausible mechanism for selective COX inhibition by natural marine indoles as potential therapeutic candidates for the mitigation of inflammation.

Metformin acts to suppress β-hydroxybutyric acid-mediated inflammatory responses through activation of AMPK signaling in bovine hepatocytes

The occurrence of bovine ketosis involves the accumulation of β-hydroxybutyric acid (BHBA), which contributes to the initiation and acceleration of hepatic metabolic stress and inflammation. Metformin has other beneficial effects apart from its medical intervention for diabetes, such as prevention of laminitis and hyper-triglyceridemic. AMPK maintains energy homeostasis and is the intracellular target of metformin action. This study aims to uncover the role of metformin in modulating BHBA-induced inflammatory responses through the activation of AMPK signaling. The hepatocytes were isolated from the liver tissue of mid-lactation multiparous Holstein cows (~160 d postpartum). Treatments were conducted as follows: treated with PBS for 18 h (control); pretreated with PBS for 12 h followed by treatment of 1.2 mM BHBA for 6 h (BHBA); pretreated with 1.5 mM or 3 mM metformin for 12 h followed by the BHBA treatment (1.2 mM) for 6 h (M(1.5)+B; M(3)+B). The inhibitor of AMPK, Compound C, at a concentration of 10 μM, was applied to substantiate the AMPK-dependent responses. RT-qPCR were applied for the mRNA expression while Western-blots and immunofluorescence were conducted for the target proteins expression. Among dose-dependent assays for BHBA, the concentration of BHBA at 1.2 mM activated NF-κB signaling by upregulating the expression of phosphorylated NF-κB and pro-inflammatory cytokines compared with the control cells (P < 0.05). Along with the upregulation of phosphorylated AMPKα and ACCα, metformin at 1.5 and 3 mM inactivated NF-κB signaling components (p65 and IκBα) and the inflammatory genes (TNFA, IL6, IL1B and COX-2) which were activated by BHBA. Additionally, BHBA inhibited cells staining intensity in EdU assay were increased by pretreatment with metformin. The activation of AMPK resulted in the increased gene and protein expression of SIRT1, along with the deacetylation of H3K9 and H3K14. However, the AMPK inhibitor compound C blocked this effect. Compared with BHBA treated cells, the protein expression of COX-2 and IL-1β were decreased by the pretreatment with metformin, and the inhibitory effect of metformin was released by compound C. The bound of NF-κB onto IL1B promoter displayed higher in BHBA group and this was suppressed by pretreatment with metformin (P < 0.05). Altogether, metformin attenuates the BHBA-induced inflammation through the inactivation of NF-κB as a target for AMPK/SIRT1 signaling in bovine hepatocytes.

Identification of plant metabolite classes from Waltheria Indica L. extracts regulating inflammatory immune responses via COX-2 inhibition

ETHNOPHARMACOLOGICAL RELEVANCE

Waltheria Indica L. is traditionally used in Africa, South America and Hawaii to treat pain, anemia, diarrhea, epilepsy and inflammatory related diseases.

AIM OF THE STUDY

This study aimed to identify extraction parameters to maximize tiliroside yield and to quantitative secondary metabolite composition of Waltheria Indica under various extraction conditions. The extracts were tested for COX-2 inhibition and their activity correlated with the type and quantity of the secondary metabolites. Insight was gained about how extraction parameters influence the extract composition and thus the COX-2 enzymatic inhibitory activity.

MATERIALS AND METHODS

Powdered leaves of Waltheria Indica were extracted using water, methanol, ethyl acetate and ethanol at different temperatures. Tiliroside was identified by HPLC-HRMS n and quantified using a tiliroside standard. The compound groups of the secondary metabolites were quantified by spectrometric methods. Inhibitory potential of different Waltheria extracts against the COX-2 enzyme was determined using a fluorometric COX-2 inhibition assay.

RESULTS

The molecule, tiliroside, exhibited a COX-2 inhibition of 10.4% starting at a concentration of 15 μM and increased in a dose dependent manner up to 51.2% at 150 μM. The ethanolic extract at 30 °C and the ethyl acetate extract at 90 °C inhibited COX-2 with 37.7% and 38.9%, while the methanolic and aqueous extract showed a lower inhibition of 21.9% and 9.2% respectively. The results concerning phenol, alkaloid and tiliroside concentration in the extracts showed no dependence on COX-2 inhibition. The extracts demonstrated a direct correlation of COX-2 inhibitory activity with their triterpenoid-/steroidal-saponin concentration. COX-2 inhibition increased linearly with the concentration of the saponins.

CONCLUSION

The data suggest that Waltheria Indica extracts inhibit the key inflammatory enzyme, COX-2, as a function of triterpenoid- and steroidal-saponin concentration and support the known efficacy of extracted Waltheria Indica leaves as a traditional treatment against inflammation related diseases.

The Protective Role of Urtica dioica Seed Extract Against Azoxymethane-Induced Colon Carcinogenesis in Rats

The aim of this study was to investigate the protective role of Urtica dioica seed (UDS) extract against azoxymethane (AOM)-induced colon carcinogenesis in rats. Thirty-two male Wistar albino rats were divided into four groups: Control, AOM, AOM + UDS, and UDS. The AOM and AOM + UDS groups were induced by AOM (15 mg/kg body weight) subcutaneously once a week for 10 weeks. AOM + UDS and UDS groups additionally received fed with pellets included 30 ml/kg UDS extract. At the end of the trial, blood and colon tissue samples were taken from the rats following necropsy. The gross and histopathological findings revealed that the administration of UDS extract significantly decreased lesions including aberrant cript foci, adenoma, and adenocarcinoma formation both numerically and dimensionally. Immunohistochemically, slight CEA and COX-2, strong Caspase-3 immune-expressions were detected in the group AOM + UDS compared to AOM group. Biochemical examinations indicated that a markedly increase in the malondialdehyde and fluctuated antioxidant defense system constituents levels such as reduced glutathione, glutathione s-transferase, glutathione peroxidase, superoxide dismutase were restored in AOM + UDS group. These results reveal that the UDS may act as a chemopreventive dietary agent, inducing apoptosis, resulting in a significant reduction of colon carcinogenesis.

Non-Steroidal Anti-Inflammatory Drugs in Colorectal Cancer Chemoprevention

Simple Summary

There is growing evidence from epidemiologic, preclinical and clinical studies suggesting that non-steroidal anti-inflammatory drugs (NSAIDs) play a beneficial role in colorectal cancer chemoprevention. They reduce the risk of colorectal polyps, mostly by cyclooxygenase-2 inhibition. The aim of our work was to describe the current state of scientific knowledge on the potential added value of the use of NSAIDs (such as aspirin, sulindac, and celecoxib) as chemopreventive agents in patients at risk of colorectal cancer. The study confirmed that there is a link between the long-term use of the NSAIDs and a decrease in the risk of colorectal cancer.

Abstract

Since colorectal cancer is one of the world’s most common cancers, studies on its prevention and early diagnosis are an emerging area of clinical oncology these days. For this study, a review of randomized controlled, double-blind clinical trials of selected NSAIDs (aspirin, sulindac and celecoxib) in chemoprevention of colorectal cancer was conducted. The main molecular anticancer activity of NSAIDs is thought to be a suppression of prostaglandin E₂ synthesis via cyclooxygenase-2 inhibition, which causes a decrease in tumor cell proliferation, angiogenesis, and increases apoptosis. The lower incidence of colorectal cancer in the NSAID patients suggests the long-lasting chemopreventive effect of drugs studied. This new approach to therapy of colorectal cancer may transform the disease from a terminal to a chronic one that can be taken under control.

Application of chloroquine as an endosomal escape enhancing agent: new frontiers for an old drug

INTRODUCTION

Adequate transfection efficiency is indispensable to safe and effective delivery of therapeutically active agents, particularly in cancer. Endosomal escape is regarded as a critical and determining step devoted a significant number of studies of the drug/gene delivery field.

AREAS COVERED

This paper critically reviews the fundamental properties of chloroquine (CQ), its pharmacokinetics, pharmacodynamics, and clinical applications and the present knowledge of CQ application as an endosomal escape enhancing agent. Different approaches to enhance the endosomal escape process of nanoparticles have been introduced including use of endosomal escape enhancing agents. Application of CQ as either a pre-treatment modality in which cells or animals are exposed to CQ prior to the main treatment or a component of co-delivery systems where CQ and other anti-cancer agents are simultaneously entered the cancer cells, is discussed with recent studies.

EXPERT OPINION

CQ is founded to intervene with the natural process of endosomal maturation. Moreover, CQ seems to increase the effectiveness of gene delivery by its electrostatic interaction with negatively charged components of the transferred genetic molecules. Endosomal escape might be regarded as the bottleneck of efficient gene delivery and CQ as an effective and available endosomal escape enhancing agent deserves more sophisticated studies.

Synthesis and biological evaluation as well as in silico studies of arylpiperazine-1,2-benzothiazine derivatives as novel anti-inflammatory agents

Novel arylpiperazine-1,2-benzothiazine derivatives have been designed and synthesized as potential anti-inflammatory agents. Their structure and properties have been studied using spectroscopic techniques (¹H NMR, ¹³C NMR, FT-IR), MS, elemental analyses, and single-crystal X-ray diffraction (SCXRD, for compound 7b). This study aimed to evaluate the inhibitory activity of new derivatives against both cyclooxygenase isoforms COX-1 and COX-2 due to the similarity of new compounds to oxicams drugs from the NSAIDs group. All new compounds were divided into two series - A and B - with a different linker between thiazine and piperazines nitrogens. Series A included the three-carbon aliphatic linker and series B - two-carbon with a carbonyl group. According to in vitro and molecular docking studies all new compounds exhibited cyclooxygenase inhibitory activity. The series of A compounds included COX-1 inhibitors only. In contrast, the B series showed inhibition of both COX-1 and COX-2, which suggested the importance of the acetoxy linker for COX-2 inhibition. Moreover, the most selective compound 7b, towards COX-2, was non-toxic for the normal human cell line (in concentration of 10 µM) comparable to reference drug meloxicam. Additionally, investigation of influence on model membranes confirmed the ability of the compound 7b to penetrate lipid bilayers which seemed to be important to the influence with membrane protein-cyclooxygenase.

Novel Molecular Mechanism of Aspirin and Celecoxib Targeting Mammalian Neuraminidase-1 Impedes Epidermal Growth Factor Receptor Signaling Axis and Induces Apoptosis in Pancreatic Cancer Cells

Background

Aspirin (acetylsalicylic acid) and celecoxib have been used as potential anti-cancer therapies. Aspirin exerts its therapeutic effect in both cyclooxygenase (COX)-dependent and -independent pathways to reduce tumor growth and disable tumorigenesis. Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, reduces factors that cause inflammation and pain. The question is whether aspirin and celecoxib have other molecular targets of equal or more therapeutic efficacy with significant anti-cancer preventive benefits.

Aim

Here, we propose that aspirin and celecoxib exert their anti-cancer effects by targeting and inhibiting mammalian neuraminidase-1 (Neu-1). Neu-1 has been reported to regulate the activation of several receptor tyrosine kinases (RTKs) and TOLL-like receptors and their downstream signaling pathways. Neu-1 in complex with matrix metalloproteinase-9 (MMP-9) and G protein-coupled receptors (GPCRs) has been reported to be tethered to RTKs at the ectodomain.

Materials and Methods

The WST-1 cell viability assay, Caspase 3/7 assay, and Annexin V assay were used to evaluate the cell viability and detect apoptotic and necrotic cells following treatment in MiaPaCa-2, PANC-1 and the gemcitabine-resistant PANC-1 variant (PANC-1 GemR) cells. Microscopic imaging, lectin cytochemistry, and flow cytometry were used to detect levels of α-2,3 sialic acid. Epidermal growth factor (EGF)-stimulated live cell sialidase assays and neuraminidase assays were used to detect Neu-1 activity. Immunocytochemistry was used to detect levels of EGFR and phosphorylated EGFR (pEGFR) following treatment.

Results

For the first time, aspirin and celecoxib were shown to significantly inhibit Neu-1 sialidase activity in a dose- and time-dependent manner following stimulation with EGF. Aspirin blocked Neu-1 desialylation of α-2,3-sialic acid expression following 30 min stimulation with EGF. Aspirin and celecoxib significantly and dose-dependently inhibited isolated neuraminidase (Clostridium perfringens) activity on fluorogenic substrate 2ʹ-(4-methylumbelliferyl)-α-D-N-acetylneuraminic acid (4-MUNANA). Aspirin inhibited phosphorylation of the EGFR in EGF-stimulated cells. Aspirin dose- and time-dependently induced CellEvent caspase-3/7⁺ cells as well as apoptosis and necrosis on PANC-1 cells.

Conclusion

These findings signify a novel multimodality mechanism(s) of action for aspirin and celecoxib, specifically targeting and inhibiting Neu-1 activity, regulating EGF-induced growth receptor activation and inducing apoptosis and necrosis in a dose- and time-dependent manner. Repurposing aspirin and celecoxib as anti-cancer agents may also upend other critical targets involved in multistage tumorigenesis regulated by mammalian neuraminidase-1.

Significance

These findings may be the missing link connecting the anti-cancer efficacy of NSAIDs to the role of glycosylation in inflammation and tumorigenesis.

Phycocyanin of marine Oscillatoria sp. inhibits lipoxygenase by protein-protein interaction-induced change of active site entry apace: A model for non-specific biofunctions of phycocyanins

An overview of the biological properties of phycocyanin (PC) amply illustrates that it may not have any specific functional feature towards any system at which it may elicit a specific function, but for the molecular interactions. Nevertheless, based on existing evidences, it is hypothesized that PC has more than one functional target with the interacting systems; therefore, it has diversity of effects. The mechanism of PC action remains elusive of a comprehensive idea. The present investigation focuses on the pro inflammatory enzyme, lipoxygenase (LOX) inhibiting property of PC purified from Oscillatoria sp. Enzyme kinetics studies show that the molecular composite of PC is required for its inhibition shown on LOX. Isothermal titration calorimetric study proves that one molecule of PC interacts with two molecules of LOX. Molecular dynamics simulation study pertaining to PC-LOX interactions shows it to be appropriate as a model to give molecular mechanistic insight into the varied biological properties of PC, demonstrated elsewhere in experimental studies including animal model studies. It explains that the PC-LOX interaction is of a function-freezing, protein-protein interaction in nature. The wide spectrum of properties of PC might be due to its function as a powerful protein hub showing non-specific protein-protein interactions.

Epidermal growth factor-induced COX-2 regulates metastasis of head and neck squamous cell carcinoma through upregulation of angiopoietin-like 4

Epidermal growth factor receptor (EGFR) expression and activation are the major causes of metastasis in cancers such as head and neck squamous cell carcinoma (HNSCC). However, the reciprocal effect of EGF‐induced COX‐2 and angiopoietin‐like 4 (ANGPTL4) on HNSCC metastasis remains unclear. In this study, we revealed that the expression of ANGPTL4 is essential for COX‐2‐derived prostaglandin E₂ (PGE₂)‐induced tumor cell metastasis. We showed that EGF‐induced ANGPTL4 expression was dramatically inhibited with the depletion and inactivation of COX‐2 by knockdown of COX‐2 and celecoxib treatment, respectively. Prostaglandin E₂ induced ANGPTL4 expression in a time‐ and dose‐dependent manners in various HNSCC cell lines through the ERK pathway. In addition, the depletion of ANGPTL4 and MMP1 significantly impeded the PGE₂‐induced transendothelial invasion ability of HNSCC cells and the binding of tumor cells to endothelial cells. The induction of molecules involved in the regulation of epithelial‐mesenchymal transition was also dependent on ANGPTL4 expression in PGE₂‐treated cells. The depletion of ANGPTL4 further blocked PGE₂‐primed tumor cell metastatic seeding of lungs. These results indicate that the EGF‐activated PGE₂/ANGPTL4 axis enhanced HNSCC metastasis. The concurrent expression of COX‐2 and ANGPTL4 in HNSCC tumor specimens provides insight into potential therapeutic targets for the treatment of EGFR‐associated HNSCC metastasis.

COX-2 promotes metastasis and predicts prognosis in gastric cancer via regulating mTOR

Aim: Gastric cancer (GC) is one of the most common malignant tumors in the world. It is important to find accurate and reliable biomarkers in order to decrease whole morbidity and mortality. Results: We examined the expression of COX-2 and mTOR on GC tissue microarrays by immunohistochemistry. Multivariate COX regression analysis showed that the expression of COX-2 or mTOR was an independent factor in the prognosis of GC patients. In addition, COX-2 and mTOR have a potentially synergistic effect on predicting the prognosis of GC. Conclusion: The combined expression of COX-2 and mTOR could serve as efficient prognostic indicators and COX-2 could suppress GC metastasis via regulating mTOR.

Over-expression of cyclo-oxygenase-2 predicts poor survival of patients with nasopharyngeal carcinoma: a meta-analysis

OBJECTIVES

The conclusive prognostic significance of cyclo-oxygenase-2 has been determined in various cancers but not in nasopharyngeal carcinoma. Therefore, this study aimed to evaluate the relationship of cyclo-oxygenase-2 expression with the survival outcome and treatment response of nasopharyngeal carcinoma patients via a systematic meta-analysis approach.

METHODS

A meta-analysis was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses ('PRISMA') checklist. The primary clinical characteristics of patients, and hazard ratios with 95 per cent confidence intervals of overall survival data, were tabulated from eligible studies. The relationship of cyclo-oxygenase-2 expression with survival outcome (expressed as hazard ratio) and treatment response (expressed as odds ratio) in nasopharyngeal carcinoma patients was analysed, and explained with the aid of forest plot charts.

RESULTS AND CONCLUSION

The pooled hazard ratio for overall survival was 2.02 (95 per cent confidence interval = 1.65-2.47). This indicates that the over-expression of cyclo-oxygenase-2 is significantly associated with the poor survival of nasopharyngeal carcinoma patients. The pooled odds ratio of 0.98 (95 per cent confidence interval = 0.27-3.49) reveals that over-expression of cyclo-oxygenase-2 was not significantly related to the treatment outcome.

Aloperine suppresses LPS-induced macrophage activation through inhibiting the TLR4/NF-κB pathway

OBJECTIVE

The currently available anti-inflammatory drugs often cause diverse side effects with long-term use. Exploring anti-inflammatory drugs with better efficacy and lower toxicity presents an ongoing challenge. Aloperine is an alkaloid extracted from the leaves and seeds of Sophora alopecuroides L. However, the anti-inflammatory effects of Aloperine have not been fully elucidated. This study aimed to investigate whether Aloperine suppresses lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 macrophages.

METHODS

RAW264.7 macrophages were stimulated with LPS (1 μg/mL) in the presence or absence of Aloperine (50 and 100 μM). mRNA expression was measured by real-time PCR, and protein expression was assessed by western blot analysis. The secretion of pro-inflammatory cytokines was measured by ELISA. The levels of nitric oxide (NO) and reactive oxygen species (ROS) were measured by staining. The transcriptional activity of NF-κB was assayed by a luciferase activity assay.

RESULTS

The results proved that Aloperine inhibited the expression of LPS-induced pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-17A (IL-17A)] in macrophages. Treatment with Aloperine inhibited NO production through suppressing inducible nitric oxide synthase (iNOS) expression and the secretion of prostaglandin E₂ (PGE₂) by inhibiting cyclooxygenase 2 (COX-2) expression. Aloperine prevented LPS-induced oxidative stress by reducing the generation of ROS. Furthermore, aloperine significantly reduced Toll-like receptor 4 (TLR4) and myeloid differentiation factor (Myd-88) levels and prevented the nuclear translocation of nuclear factor-κB (NF-κB) in LPS-treated macrophages.

CONCLUSION

Taken together, our findings show that Aloperine could suppress LPS-induced macrophage activation by inhibiting the TLR4/Myd-88/NF-κB pathway.

Medulloblastoma cancer stem cells: molecular signatures and therapeutic targets

Medulloblastoma (MB) is the most common malignant primary intracranial neoplasm diagnosed in childhood. Although numerous efforts have been made during the past few years to exploit novel targeted therapies for this aggressive neoplasm, there still exist substantial hitches hindering successful management of MB. Lately, progress in cancer biology has shown evidence that a subpopulation of cells within the tumour, namely cancer stem cells (CSCs), are thought to be responsible for the resistance to most chemotherapeutic agents and radiation therapy, accounting for cancer recurrence. Hence, it is crucial to identify the molecular signatures and genetic aberrations that characterise those CSCs and develop therapies that specifically target them. In this review, we aim to give an overview of the main genetic and molecular cues that depict MB-CSCs and provide a synopsis of the novel therapeutic approaches that specifically target this population of cells to attain enhanced antitumorous effects and therefore overcome resistance to therapy.

Anticancer activities of fatty acids and their heterocyclic derivatives

Traditional chemotherapy relies on the premise that rapidly proliferating cancer cells are more likely to be killed by a cytotoxic agent, but in reality, the long-standing problem of chemotherapy is the lack of tumor-specific treatments. Apart from the impact on tumor cells, the drugs' major limitation is their severe adverse side effects on normal cells and tissues. Nutritional and epidemiological studies have indicated that cancer progression is correlated with the consumption of fatty acids, but the exact mechanisms still remain unknown. In the first part of our review, we discussed the beneficial effects of free fatty acids (saturated and unsaturated) on the progress of carcinogenesis in different tumor cell lines. We presented various mechanisms proposed in the literature, which explain the possible impact on the cells metabolism. The second part describes modifications of different fatty acids with existing anticancer drugs and heterocyclic moieties by condensation reactions. Such conjugations increased the tissue selectivity and made chemotherapy potentially more effective and less toxic in in vivo and in vitro studies. This fatty acid modifications, which change the activity of compounds, their uptake selectivity and alter drug delivery methods, may be the key to unlocking true medical potential of fatty acids.

Cardio-renal safety of non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used therapeutic class in clinical medicine. These are sub-divided based on their selectivity for inhibition of cyclooxygenase (COX) isoforms (COX-1 and COX-2) into: (1) non-selective (ns-NSAIDs), and (2) selective NSAIDs (s-NSAIDs) with preferential inhibition of COX-2 isozyme. The safety and pathophysiology of NSAIDs on the renal and cardiovascular systems have continued to evolve over the years following short- and long-term treatment in both preclinical models and humans. This review summarizes major learnings on cardiac and renal complications associated with pharmaceutical inhibition of COX-1 and COX-2 with focus on preclinical to clinical translatability of cardio-renal data.

Synbiotics suppress colitis-induced tumorigenesis in a colon-specific cancer mouse model

Although synbiotics may be effective in maintaining remission of inflammatory bowel disease, their anticarcinogenic effects are still debated. To address this issue, we evaluated the effects of synbiotics, probiotics, and prebiotics on tumorigenesis using a CDX2P-Cre; Apc^+/flox mouse model harboring a colon-specific Apc knock out, which develops adenoma and adenocarcinoma of the colon. Dextran sodium sulfate (DSS)-administration promoted colonic tumor development in CDX2P-Cre; Apc^+/flox mice, and these tumors were associated with loss of Apc heterozygosity, as confirmed by observation of well-differentiated adenocarcinomas with β-catenin accumulation in tumor cell cytoplasm. Synbiotics-treatment suppressed dextran sodium sulfate-induced colitis in CDX2P-Cre; Apc^+/flox mice, thereby reducing mortality, and inhibited tumorigenesis accelerated by DSS-administration. Conversely, neither probiotics nor prebiotics had any effect on inflammation and tumorigenesis. Lactobacillus casei and Bifidobacterium breve were detected in the fecal microbiota of probiotics-treated mice. Synbiotics-treatment suppressed DSS-induced expression of IL-6, STAT-3, COX-2, and TNF-α gene transcripts in normal colonic epithelium, indicating the possibility of suppressing tumor development. Importantly, these genes may be potential therapeutic targets in inflammation-associated colon cancer.

Ethanol extracts of Allium sp. regulate cyclooxygenase-2 and E-cadherin expression in gastric cancer MKN74 cell line and enhance doxorubicin toxicity

Background

Gastric cancer (GC) remains one of the leading causes of cancer-related death. Its aetiology is multifactorial, but the major risk factor is a high in salt diet. During gastric carcinogenesis, cadherin-1 (CDH1) down-expression and cyclooxygenase 2 (COX2) overexpression may be observed. The intensity of these alterations contributes to the GC invasion, its metastases and poor prognosis. As the diet plays a significant role in the aetiology of GC, it is reasonable to include the nutritional chemoprevention agents. One of the plant genus demonstrating chemoprotective properties is Allium genus, which includes garlic. The relationship between CDH1 and COX2 in GC cells treated with Allium species extract has never been evaluated.

Methods

In this study, the MKN28 and MKN74 GC cell lines were treated with ethanol extracts of Allium angulosum L., Allium lusitanicum Lam., Allium sativum L. (from Malaysia and Poland), Allium tibeticum Rendle and Allium ursinum L. The cytotoxicity of the extracts and their influence on COX2 and CDH1 mRNA and protein expression were evaluated as well as their influence on doxorubicin's (DOX) efficacy - a drug that has been used in GC treatment.

Results

Among the tested species, ethanol extracts of A. sativum L. (Poland and Malaysia), A. tibeticum Rendle and A. ursinum L. influenced the levels of CDH1 and COX2, but only in the MKN74 cell line. Thus, it is possible that tumours with increased COX2 expression will be more susceptible to garlic treatment. Observed phenomenon was independent of Allium extract's toxicity. In comparison to DOX, tested extracts were more toxic. Moreover, A. sativum revealed synergistic effect with the drug.

Conclusion

In conclusion, the results indicate the potential application of Allium genus to GC chemoprevention and treatment support through CDH restoration and COX2 downregulation. This issue needs further investigations as it might be used in clinics.

Oroxylin A Suppresses the Cell Proliferation, Migration, and EMT via NF-κB Signaling Pathway in Human Breast Cancer Cells

Oroxylin A is a natural extract and has been reported to have a remarkable anticancer function. However, the mechanism of its anticancer activity remains not quite clear. In this study, we examined the inhibiting effects of Oroxylin A on breast cancer cell proliferation, migration, and epithelial-mesenchymal transition (EMT) and its possible molecular mechanism. The cytoactive and inflammatory factors were analyzed via Cell Counting Kit-8 assay and ELISA assay, respectively. Flow cytometry and western blotting were used to assess the cell proliferation. In addition, a wound healing assay and transwell assay were used to detect cell invasion and migration. qRT-PCR and western blot were employed to determine the effect of Oroxylin A on the EMT formation. Moreover, expression level of protein related to NF-κB signaling pathway was determined by western blot. The results revealed that Oroxylin A attenuated the cytoactivity of MDA-MB-231 cells in a dose- and a time-dependent manner. Moreover, cell proliferation, invasion, and migration of breast cancer cells were inhibited by Oroxylin A compared to the control. The mRNA and protein expression levels of E-cadherin were remarkably increased while N-cadherin and Vimentin remarkably decreased. Besides, Oroxylin A suppressed the expression of inflammatory factors and NF-κB activation. Furthermore, we also found that supplement of TNF-α reversed the effects of Oroxylin A on the cell proliferation, invasion, migration, and EMT in breast cancer cells. Taken together, our results suggested that Oroxylin A inhibited the cell proliferation, invasion, migration, and EMT through inactivating NF-κB signaling pathway in human breast cancer cells. These findings strongly suggest that Oroxylin A could be a therapeutic potential candidate for the treatment of breast cancer.

Mechanism of Apoptosis Induced by Curcumin in Colorectal Cancer

Colorectal cancer (CRC) is among the top three cancer with higher incident and mortality rate worldwide. It is estimated that about over than 1.1 million of death and 2.2 million new cases by the year 2030. The current treatment modalities with the usage of chemo drugs such as FOLFOX and FOLFIRI, surgery and radiotherapy, which are usually accompanied with major side effects, are rarely cured along with poor survival rate and at higher recurrence outcome. This trigger the needs of exploring new natural compounds with anti-cancer properties which possess fewer side effects. Curcumin, a common spice used in ancient medicine was found to induce apoptosis by targeting various molecules and signaling pathways involved in CRC. Disruption of the homeostatic balance between cell proliferation and apoptosis could be one of the promoting factors in colorectal cancer progression. In this review, we describe the current knowledge of apoptosis regulation by curcumin in CRC with regard to molecular targets and associated signaling pathways.

Impact of Silver Nanoparticles on the Ultraviolet Radiation Direct and Bystander Effects on TK6 Cell Line

PURPOSE/AIM

Ultraviolet C (UVC) radiation is harmful to cells and living organisms that cause direct and indirect DNA damage. UVC can also increase the inflammatory genes expression such as COX-2 that results in elevated oxidative stress that plays a role in radiation-induced bystander effect (BSE). Silver nanoparticles (AgNPs) have used widely in commercial and medical products and the toxicological risks of AgNPs must be determined. The aim of this study was to investigate the direct and BSEs of UVC radiation and AgNPs on TK6 cell line.

MATERIALS AND METHODS

TK6 cells were exposed to AgNPs (10 μg/ml, 1 h). Then, they were exposed to UVC and to determine the BSEs of radiation, the irradiated cells media were transferred to nonirradiated cells. Expression level of H2AX and COX-2 mRNAs were examined by quantitative real-time PCR and 8-OHdG formation was examined by ELISA. The cell viability examined by MTT assay.

RESULTS

P < 0.05 was considered as the level of significance. The results showed that the mean expression level of H2AX mRNA in the AgNPs + UVC group increased significantly in comparison with UVC group. 8-OHdG increased significantly in the BSE of UV group in comparison with sham control of BSE. COX-2 mRNA increased significantly in the BSE of AgNPs + UVC with sham control in BSE.

CONCLUSIONS

Our findings showed the induced DNA damage in TK6 cell by AgNPs and UVC radiation and also were seen BSE.

Efficacy of targeted liposomes and nanocochleates containing imatinib plus dexketoprofen against fibrosarcoma

The main challenges in treating cancer using chemotherapeutics are insufficient dose at the target site and the development of drug resistance, while higher doses can induce side effects by damaging nontarget tissues. Combinatorial drug therapy may overcome these limitations by permitting lower doses and more specific targeting, thereby mitigating drug resistance and nontarget side effects. Recent reports indicate that nonsteroidal anti-inflammatory drugs (NSAIDs) have anticancer potential and can be used together with conventional chemotherapeutics to improve efficacy and safety. In the present study, imatinib mesylate and dexketoprofen trometamol were selected as model drugs to develop targeted surface-modified liposome and nanocochleate formulations for fibrosarcoma treatment. The physicochemical properties and in vitro efficacy of various formulations were evaluated by measurement of particle size distribution, polydispersity index, zeta potential, encapsulation efficiency, diffusion through Caco-2 cells, and toxicity in culture. Selected formulations were then evaluated in fibrosarcoma-bearing model mice by histopathological observations and tyrosine kinase receptor inhibition assays. The most effective formulation on the fibrosarcoma model was a PEGylated nanocochleate formulation. These findings provide a foundation for developing more effective formulations and chemotherapeutic strategies for the treatment of fibrosarcoma and other types of cancer.

Significance of immunohistochemical overexpression of cyclooxygenase-2 in overall and disease-free survival of oral squamous cell carcinoma patients

OBJECTIVE

In Pakistan, oral cancer ranks as the most common malignancy in males and the second most common malignancy in females. Cyclooxygenase-2 has been explored as an agent of carcinogenesis in oral and other neoplasms. This study aimed to observe the expression of cyclooxygenase-2 in oral squamous cell carcinoma, and to correlate the expression with patients' clinical features and overall and disease-free survival.

METHODS

Immunohistochemistry for cyclooxygenase-2 was performed on a total of 100 oral squamous cell carcinoma formalin-fixed, paraffin-embedded blocks. Expression was correlated with patients' clinicopathological variables and overall and disease-free survival.

RESULTS

Cyclooxygenase-2 was overexpressed in 55 per cent of oral squamous cell carcinoma patients. Overexpression was correlated with overall survival (p = 0.013) and disease-free survival (p = 0.001) on univariate analysis. However, on multivariate analysis, cyclooxygenase-2 was associated with only disease-free survival (p = 0.044) and not overall survival (p = 0.208).

CONCLUSION

Expression of cyclooxygenase-2 is associated with poorer overall survival and higher rates of recurrence in oral squamous cell carcinoma patients.

Inflammation and pancreatic cancer: An updated review

Pancreatic cancer is a devastating disease with poor prognosis in the modern era. Inflammatory processes have emerged as key mediators of pancreatic cancer development and progression. Recently, studies have been carried out to investigate the underlying mechanisms that contribute to tumorigenesis induced by inflammation. In this review, the role of inflammation in the initiation and progression of pancreatic cancer is discussed.

Thiazolidinedione Derivative Suppresses LPS-induced COX-2 Expression and NO Production in RAW 264.7 Macrophages

The present study was designed to investigate the inhibitory effect of 2,4 bis-[(4-ethoxyphenyl)azo] 5-(3-hydroxybenzylidene) thiazolidine-2,4-dione (TZD-OCH2CH3) on the cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in RAW 264.7 cells. The effects of TZD-OCH2CH3 on COX-2 and iNOS mRNA expression in LPS-activated RAW 264.7 cells were detected by real time PCR. Also, to understand structure and substrate specificity, we have utilized molecular docking simulations (AutoDock Vina) and the active residues in the binding pocket were determined from COX-2 and iNOS. The treatment of RAW 264.7 cells with TZD-OCH2CH3 significantly inhibited LPS-induced COX-2 mRNA expression, corresponding to 46.1% and 61.06% at 30 and 60 μg/mL, respectively. The present study revealed that the TZD-OCH2CH3 had a little effect on iNOS mRNA expression. Meanwhile, the TZD-OCH2CH3 also could inhibit the production of NO compared to single LPS-stimulated cell. According to the results obtained, TZD-OCH2CH3 dramatically suppressed lipopolysaccharide (LPS) induced nitric oxide (NO) production after 24 h, in a concentration-dependent manner with an IC50 of 65 μg/mL. Our data suggest that TZD-OCH2CH3, as a functionally novel agent, inhibits the inflammatory pathway via suppression of COX-2 mRNA expression and also by the inhibition of the iNOS activity. Therefore, this compound could be suggested as a novel therapeutic strategy for inflammation-associated disorders.

NF-κB p65 and p105 implicate in interleukin 1β-mediated COX-2 expression in melanoma cells

Inflammatory and microenvironmental factors produced by cancer cells are thought to directly or indirectly promote cancer cell growth. Prostaglandins, including prostaglandin E2, have key roles as a microenvironment factor in influencing the development of tumors, and are produced by the rate limiting enzyme cyclooxygenase 2 (COX-2). In this study, we used canine melanoma cells treated with the proinflammatory cytokine interleukin 1β (IL-1β) and investigated the transcriptional factor nuclear factor-κB (NF-κB) signaling in IL-1β-induced COX-2 expression. IL-1β induced prostaglandin E2 release and COX-2 mRNA expression in a time- and dose-dependent manner. In the cells treated with the NF-κB inhibitors BAY11-7082 and TPC-1, IL-1β-mediated prostaglandin E2 release and COX-2 mRNA expression were inhibited. IL-1β also provoked phosphorylation of p65/RelA and p105/NF-κB1, which are members of the NF-κB families. The IL-1β-induced phosphorylation of p65 and p105 was attenuated in the presence of both NF-κB inhibitors. In melanoma cells transfected with siRNA of p65 or p105, IL-1β-mediated COX-2 mRNA expression was inhibited. These findings suggest that canonical activation of NF-κB signaling plays a crucial role for inflammatory states in melanoma cells.

Expression and Molecular Regulation of the Cox2 Gene in Gastroenteropancreatic Neuroendocrine Tumors and Antiproliferation of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Background

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has had a significant increase over the past 4 decades. The pathophysiological role of the cyclooxygenase-2 (cox-2) gene and factors responsible for the expression in GEP-NETs is of clinical value. Current study determined the expression of cox-2 gene in human GEP-NET tissues and corresponding cell lines, investigated the molecular mechanisms underlying the regulation of cox-2 gene expression and assessed the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on both anchorage-dependent and independent growth of GEP-NET cells.

Material/Methods

GEP-NET tissues and QGP-1, BON, and LCC-18 GEP-NET cell lines were used. The expression of cox-2 gene was analyzed by immunohistochemistry, western blot, RT-PCR, and enzyme immunoassay. Transient transfection and luciferase assays along with electrophoretic mobility shift assays were conducted to explore the regulation of cox-2 gene expression. The effect of COX-inhibitors on GEP-NET cell growth was determined by proliferation assays and colony growth assessment.

Results

We found 87.8% of GEP-NET tissues stained positive for COX-2. QGP-1 and LCC-18 cells expressed cox-2 gene. PGE2 (prostaglandin E2) amounts quantified in the supernatants of NET cells matched to cox-2 expression level. The CRE-E-box element (−56 to −48 bp) and binding of USF1, USF2, and CREB transcription factors to this proximal promoter element were essential for cox-2 promoter activity in GEP-NET cells. COX-2-specific inhibitor NS-398 potently and dose-dependently inhibited PGE2 release from QGP-1 cells. Interestingly, both NS-398 and acetylic salicylic acid effectively suppressed proliferation of QGP-1 and BON cells in a dose-dependent manner.

Conclusions

The majority of GEP-NETs over express cox-2 gene. The binding of CREB and USF-1/-2 transcription factors to a proximal, overlapping CRE-Ebox element is the underlying mechanism for cox-2 gene expression. NSAIDs potently suppressed the proliferations and may offer a novel approach for chemoprevention and therapy of GEP-NETs.

Thrombospondin-1 interactions regulate eicosanoid metabolism and signaling in cancer-related inflammation

The metabolism of arachidonic acid and other polyunsaturated fatty acids produces eicosanoids, a family of biologically active lipids that are implicated in homeostasis and in several pathologies that involve inflammation. Inflammatory processes mediated by eicosanoids promote carcinogenesis by exerting direct effects on cancer cells and by affecting the tumor microenvironment. Therefore, understanding how eicosanoids mediate cancer progression may lead to better approaches and chemopreventive strategies for the treatment of cancer. The matricellular protein thrombospondin-1 is involved in processes that profoundly regulate inflammatory pathways that contribute to carcinogenesis and metastatic spread. This review focuses on interactions of thrombospondin-1 and eicosanoids in the microenvironment that promote carcinogenesis and how the microenvironment can be targeted for cancer prevention to increase curative responses of cancer patients.