Inhibition Of Cyclooxygenase-2 Expression Research Articles

Crosstalk Between nNOS/NO and COX-2 Enhances Interferon-Gamma-Stimulated Melanoma Progression

Background/Objectives: Interferon gamma (IFN-γ) in the melanoma tumor microenvironment plays opposing roles, orchestrating both pro-tumorigenic activity and anticancer immune responses. Our previous studies demonstrated the role of neuronal nitric oxide synthase (nNOS) in IFN-γ-stimulated melanoma progression. However, the underlying mechanism has not been well defined. This study determined whether the nNOS/NO and COX-2/PGE2 signaling pathways crosstalk and augment the pro-tumorigenic effects of IFN-γ in melanoma. Methods: Bioinformatic analysis of patient and cellular proteomic data was conducted to identify proteins of interest associated with IFN-γ treatment in melanoma. Changes in protein expression were determined using various analytical techniques including western blot, flow cytometry, and confocal microscopy. The levels of PGE2 and nitric oxide (NO) were analyzed by HPLC chromatography and flow cytometry. In vivo antitumor efficacy was determined utilizing a human melanoma xenograft mouse model. Results: Our omics analyses revealed that the induction of COX-2 was significantly predictive of IFN-γ treatment in melanoma cells. In the presence of IFN-γ, PGE2 further enhanced PD-L1 expression and amplified the induction of nNOS, which increased intracellular NO levels. Cotreatment with celecoxib effectively diminished these changes induced by PGE2. In addition, nNOS blockade using a selective small molecule inhibitor (HH044), efficiently inhibited IFN-γ-induced PGE2 and COX-2 expression levels in melanoma cells. STAT3 inhibitor napabucasin also inhibited COX-2 expression both in the presence and absence of IFN-γ. Furthermore, celecoxib was shown to enhance HH044 cytotoxicity in vitro and effectively inhibit human melanoma tumor growth in vivo. HH044 treatment also significantly reduced tumor PGE2 levels in vivo. Conclusions: Our study demonstrates the positive feedback loop linking nNOS-mediated NO signaling to the COX-2/PGE2 signaling axis in melanoma, which further potentiates the pro-tumorigenic activity of IFN-γ.

Chloroform Extract from Fermented Viola mandshurica Regulates LPS-Induced Inflammation Response in RAW 264.7 Cells by Inhibiting iNOS and COX-2.

Inflammatory is a crucial part of the immune system of body protect it from harmful invaders, such as bacteria, viruses, and other foreign substances. In this study, the effects of chloroform extract of fermented Viola mandshurica (CEFV) on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 macrophages were investigated. The CEFV significantly inhibited NO production and reduced the expression of inducible nitric oxide synthase (iNOS) at both protein and mRNA levels in a dose-dependent manner. Also, CEFV decreased PGE2 production, suppressed COX-2 expression, and inhibited the activation of the ERK and JNK pathways but not the p38 pathway. Taken together, CEFV suppressed NF-κB activation, which is a key regulator in the inflammatory response. The main phenolic compounds identified in CEFV were tectoridin, luteolin, resveratrol, and hesperetin. Therefore, in this study, CEFC exhibits potent anti-inflammatory effects by downregulating the production of pro-inflammatory mediators and inhibiting key inflammatory pathway in RAW264.7 cells.

P2Y12 receptor-mediated cyclooxygenase 2 (COX-2) expression enhances tumor cell progression in a mouse model of lymphoma.

The pro-inflammatory enzyme cyclooxygenase 2 (COX-2) has been known to impart metastatic property to cancer cells. However, blocking of COX-2 with nonsteroidal anti-inflammatory drugs or COX-2-specific inhibitors has failed in clinical trials due to adverse effects associated with their prolonged use. We have previously shown that extracellular ATP (eATP), a major component of the tumor microenvironment, enhances COX-2 expression several-fold, both in macrophages and in various cancer cells, by acting on purinergic (P2) receptors. In this study, we show that blocking of P2 receptors significantly reduced tumor growth in a mouse model of lymphoma. Tumors were induced in mice through subcutaneous injection of syngeneic EL4 lymphoma cells. Various P2 receptor antagonists were injected within the tumors after they were palpable. The broad-spectrum P2 receptor antagonist, suramin, P2X7 receptor-specific antagonist, oATP, P2Y6 receptor-specific antagonist, MRS 2578, and P2Y12 receptor-specific antagonist, AR-C 69931, all showed significant arrest in tumor growth. Both suramin and AR-C 69931-treated tumors showed strong reduction in COX-2 expression and modulation of various metastatic markers. Disaggregated cells from AR-C 69931-treated tumors, when injected intravenously in naïve mice, did not exhibit metastasis in various tissues which was observed in mice injected with cells from saline-treated tumors. Our results show that blocking of P2 receptors is a therapeutic alternative to inhibit COX-2 expression, and thereby, arrest tumor progression and metastasis.

Inhibition of Colon Cancer Xenograft Growth by Celecoxib Analog OSU-03013 Through Wnt/β-Catenin Pathway Modulation

OSU-03013 is a Celecoxib analog that dose not inhibit COX-2 expression. OSU-03013 effectively mimics the anti-tumor effects of Celecoxib, however, its exact mechanism in colon cancer (CC) is unknown. SW480 cells were injected subcutaneously into the axilla of nude mice until the volume of the transplanted tumor reached 80 mm3. SW480 cells were inoculated into the tail vein of nude mice to establish a liver metastasis model of CC. OSU-03013 was administered by gavage. The pathology of the tumor tissues was assessed using HE staining and cell apoptosis was measured using TUNEL staining. EMT markers in the tumors were determined using Western Blot, and IL-1β and TNF-α were determined using ELISA. VEGF-A and VEGFR-2 in tumor tissues were measured to assess angiogenesis using immunofluorescence. HE staining was conducted to detect the effect of OSU-03013 on liver metastasis. Western Blot assay was performed to determine the expression of Wnt2, β-catenin and GSK-3β. OSU-03013 reduced inflammatory cell infiltration and inhibited IL-1β and TNF-α production by modulating the Wnt/β-catenin pathway. OSU-03013 induced apoptosis of cancer cells in tumor tissues and possessed anti-angiogenic activity. OSU-03013 treatment reduced the number and size of metastatic nodules of cancer cells in liver tissues. OSU-03013 may inhibit tumor growth and angiogenesis through the Wnt3a/β-catenin pathway in CC nude mice.

Potential skin anti-aging effects of main phenolic compounds, tremulacin and tremuloidin from Salix chaenomeloides leaves on TNF-α-stimulated human dermal fibroblasts

The genus Salix spp. has long been recognized as a healing herb for its use in treating fever, inflammation, and pain relief, as well as a food source for its nutritional value. In this study, we aimed to explore the potential bioactive natural products in the leaves of Salix chaenomeloides, commonly known as Korean pussy willow, for their protective effects against skin damage, including aging. Utilizing LC/MS-guided chemical analysis of the ethanol extract of S. chaenomeloides leaves, with a focus on major compounds, we successfully isolated two main phenolic compounds, tremulacin (1) and tremuloidin (2). Subsequently, we investigated the protective effects of tremulacin (1) and tremuloidin (2) in TNF-α-stimulated human dermal fibroblasts (HDFs). The results revealed that both tremulacin (1) and tremuloidin (2) inhibited TNF-α-stimulation-induced ROS, suppressed matrix metalloproteinase-1 (MMP-1) expression, and enhanced collagen secretion. This implies that both tremulacin (1) and tremuloidin (2) hold promise as preventive agents against photoaging-induced skin aging. Furthermore, we assessed the activity of mitogen-activated protein kinases (MAPKs), cyclooxygenase-2 (COX-2), and heme oxygenase 1 (HO-1) to elucidate the mechanism of photoaging inhibition by tremuloidin (2), which exhibited superior efficacy. We found that tremuloidin (2) inhibited ERK and p38 phosphorylation and notably suppressed COX-2 expression while significantly upregulating HO-1 expression. These findings suggest potent anti-inflammatory and antioxidant properties of tremuloidin (2), positioning it as a potential candidate for combating photoaging-induced skin aging.

Nrf1 Reduces COX-2 Expression and Maintains Cellular Homeostasis After Cerebral Ischemia/Reperfusion By Targeting IL-6/TNF-α Protein Production.

Neuroinflammation has been considered involved in the process of cerebral ischemia-reperfusion injury (CIRI). Transcription factors play a crucial role in regulating gene transcription and the expressions of specific proteins during the progression of various neurological diseases. Evidence showed that transcription factor nuclear factor erythroid 2-related factor 1 (NFE2L1, also known as Nrf1) possessed strong biological activities including antioxidant, anti-inflammatory and neuroprotective properties. However, its role and potential molecular mechanisms in CIRI remain unclear. In our study, we observed a significant elevation of Nrf1 in the cerebral cortex following cerebral ischemia-reperfusion in rats. The Nrf1 downregulation markedly raised COX-2, TNF-α, IL-1β, and IL-6 protein levels during middle cerebral artery occlusion/reperfusion in rats, which led to worsened neurological deficits, higher cerebral infarct volume, and intensified cortical histopathological damage. In subsequent in vitro studies, the expression of Nrf1 protein increased following oxygen-glucose deprivation/reperfusion treatment on neurons. Subsequently, Nrf1 knockdown resulted in a significant upregulation of inflammatory factors, leading to a substantial increase in the cell death rate. Through analyzing the alterations in the expression of inflammatory factors under diverse interventions, it is indicated that Nrf1 possesses the capacity to discern variations in inflammatory factors via specific structural domains. Our findings demonstrate the translocation of the Nrf1 protein from the cytoplasm to the nucleus, thereby modulating the protein expression of IL-6/TNF-α and subsequently reducing the expression of multiple inflammatory factors. This study signifies, for the first time, that during cerebral ischemia-reperfusion, Nrf1 translocases to the nucleus to regulate the protein expression of IL-6/TNF-α, consequently suppressing COX-2 expression and governing cellular inflammation, ultimately upholding cellular homeostasis.

Garlic peel extract as an antioxidant inhibits triple-negative breast tumor growth and angiogenesis by inhibiting cyclooxygenase-2 expression.

Garlic peels are frequently disposed of as agro-waste; their bioactivity and physiological activity for health benefits and disease protection are neglected. This study aims to examine the potential inhibitory effects of garlic peel extract as an antioxidant on 4 T1 triple-negative breast cancer (TNBC) tumors in mice. The bioactive constituents of garlic peel were identified through HPLC-MS/MS analysis, while the antioxidant properties of garlic peel extract were assessed using peroxyl radical scavenging capacity (PSC) and cellular antioxidant activity (CAA) assays. Subsequently, the inhibitory effects of garlic peel extract on 4T1 tumor growth were evaluated using a 4T1 model. The results showed that 433 polyphenol compounds were found in garlic peel extract; among them, flavonoids and phenolic acid are the primary polyphenols with natural antioxidant activity, and both high and low concentrations of the extract exhibited tumor-suppressive effects. Immunohistochemistry was employed to assess the expression levels of COX-2, CD31, VEGFA, MMP2, and MMP9 in tumor tissues in order to investigate the antioxidant properties of garlic peel extract, specifically its ability to suppress COX-2 expression. The findings of this study offer a foundation for the advancement of garlic peel-based functional products and contribute to the identification of potential anti-cancer agents and therapeutic targets.

Novel anti-cancer effect of 2-arachidonoylglycerol via processing body formation in HCA-7 human colon cancer cells

The endocannabinoid 2-arachidonoylglycerol (2-AG) has been reported to exhibit anticancer effects, including against colorectal cancer (CRC); however, the detailed mechanisms have not been clarified. Herein, we demonstrated that 2-AG suppressed cyclooxygenase-2 (COX-2) expression induced by prostaglandin E2 in human colon cancer HCA-7 cells. The suppression of COX-2 expression by 2-AG was through the acceleration of processing body (P-body) formation followed by COX-2 mRNA degradation. These effects were restored by TAK-715, a specific inhibitor of p38 MAPK. Therefore, the effect of 2-AG on COX-2 may be distinct from conventional non-steroidal anti-inflammatory drugs (NSAIDs). NSAIDs inhibit the function of COX-2, whereas 2-AG suppresses the protein expression of COX-2. Recently, the cardiovascular risks of NSAIDs were reported by the Food and Drug Administration in the United States. Therefore, elucidation of the effect of 2-AG is expected to contribute to the development of an alternative and novel therapeutic option that would have no or fewer risks regarding cardiovascular events.

A Breast Cancer Stem Active Cobalt(III)-Cyclam Complex Containing Flufenamic Acid with Immunogenic Potential.

The cytotoxic and immunogenic-activating properties of a cobalt(III)-cyclam complex bearing the non-steroidal anti-inflammatory drug, flufenamic acid is reported within the context of anti-cancer stem cell (CSC) drug discovery. The cobalt(III)-cyclam complex 1 displays sub-micromolar potency towards breast CSCs grown in monolayers, 24-fold and 31-fold greater than salinomycin (an established anti-breast CSC agent) and cisplatin (an anticancer metallopharmaceutical), respectively. Strikingly, the cobalt(III)-cyclam complex 1 is 69-fold and 50-fold more potent than salinomycin and cisplatin towards three-dimensionally cultured breast CSC mammospheres. Mechanistic studies reveal that 1 induces DNA damage, inhibits cyclooxygenase-2 expression, and prompts caspase-dependent apoptosis. Breast CSCs treated with 1 exhibit damage-associated molecular patterns characteristic of immunogenic cell death and are phagocytosed by macrophages. As far as we are aware, 1 is the first cobalt complex of any oxidation state or geometry to display both cytotoxic and immunogenic-activating effects on breast CSCs.

Anti-cancer activity and cellular uptake of 7,3′,4′- and 7,8,4′-trihydroxyisoflavone in HepG2 cells under hypoxic conditions

Transarterial chemoembolisation (TACE) is used for unresectable hepatocellular carcinoma (HCC) treatment, but TACE-induced hypoxia leads to poor prognosis. The anti-cancer effects of soybean isoflavones daidzein derivatives 7,3′,4′-trihydroxyisoflavone (734THIF) and 7,8,4′-trihydroxyisoflavone (784THIF) were evaluated under hypoxic microenvironments. Molecular docking of these isomers with cyclooxygenase-2 (COX-2) and vascular endothelial growth factor receptor 2 (VEGFR2) was assessed. About 40 μM of 734THIF and 784THIF have the best effect on inhibiting the proliferation of HepG2 cells under hypoxic conditions. At a concentration of 40 μM, 784THIF significantly inhibits COX-2 expression in pre-hypoxia conditions compared to 734THIF, with an inhibition rate of 67.73%. Additionally, 40 μM 784THIF downregulates the expression of hypoxic, inflammatory, and metastatic-related proteins, regulates oxidative stress, and inhibits the expression of anti-apoptotic proteins. The uptake by HepG2 confirmed higher 784THIF level and slower degradation characteristics under post- or pre-hypoxic conditions. In conclusion, our results showed that 784THIF had better anti-cancer effects and cellular uptake than 734THIF.

NMDAR activation attenuates the protective effect of BM-MSCs on bleomycin-induced ALI via the COX-2/PGE2 pathway

N-methyl-d-aspartate (NMDA) receptor (NMDAR) activation mediates glutamate (Glu) toxicity and involves bleomycin (BLM)-induced acute lung injury (ALI). We have reported that bone marrow-derived mesenchymal stem cells (BM-MSCs) are NMDAR-regulated target cells, and NMDAR activation inhibits the protective effect of BM-MSCs on BLM-induced pulmonary fibrosis, but its effect on ALI remains unknown. Here, we found that Glu release was significantly elevated in plasma of mice at d 7 after intratracheally injected with BLM. BM-MSCs were pretreated with NMDA (the selective agonist of NMDAR) and transplanted into the recipient mice after the BLM challenge. BM-MSCs administration significantly alleviated the pathological changes, inflammatory response, myeloperoxidase activity, and malondialdehyde content in the damaged lungs, but NMDA-pretreated BM-MSCs did not ameliorate BLM-induced lung injury in vivo. Moreover, NMDA down-regulated prostaglandin E2 (PGE2) secretion and cyclooxygenase (COX)-2 expression instead of COX-1 expression in BM-MSCs in vitro. We also found that NMDAR1 expression was increased and COX-2 expression was decreased, but COX-1 expression was not changed in primary BM-MSCs of BLM-induced ALI mice. Further, the cultured supernatants of lipopolysaccharide (LPS)-pretreated RAW264.7 macrophages were collected to detect inflammatory factors after co-culture with NMDA-pretreated BM-MSCs. The co-culture experiments showed that NMDA precondition inhibited the anti-inflammatory effect of BM-MSCs on LPS-induced macrophage inflammation, and PGE2 could partially alleviate this inhibition. Our findings suggest that NMDAR activation attenuated the protective effect of BM-MSCs on BLM-induced ALI in vivo. NMDAR activation inhibited COX-2 expression and PGE2 secretion in BM-MSCs and weakened the anti-inflammatory effect of BM-MSCs on LPS-induced macrophage inflammation in vitro. In conclusion, NMDAR activation attenuates the protective effect of BM-MSCs on BLM-induced ALI via the COX-2/PGE2 pathway. Keywords: Acute Lung Injury, BM-MSCs, NMDA receptor, COX-1/2, PGE2.

Glucocorticoids alleviate particulate matter-induced COX-2 expression and mitochondrial dysfunction through the Bcl-2/GR complex in A549 cells

Exposure to particulate matter (PM) causes mitochondrial dysfunction and lung inflammation. The cyclooxygenase-2 (COX-2) pathway is important for inflammation and mitochondrial function. However, the mechanisms by which glucocorticoid receptors (GRs) suppress COX-2 expression during PM exposure have not been elucidated yet. Hence, we examined the mechanisms underlying the dexamethasone-mediated suppression of the PM-induced COX-2/prostaglandin E2 (PGE2) pathway in A549 cells. The PM-induced increase in COX-2 protein, mRNA, and promoter activity was suppressed by glucocorticoids; this effect of glucocorticoids was antagonized by the GR antagonist RU486. COX-2 induction was correlated with the ability of PM to increase reactive oxygen species (ROS) levels. Consistent with this, antioxidant treatment significantly abolished COX-2 induction, suggesting that ROS is involved in PM-mediated COX-2 induction. We also observed a low mitochondrial membrane potential in PM-treated A549 cells, which was reversed by dexamethasone. Moreover, glucocorticoids significantly enhanced Bcl-2/GR complex formation in PM-treated A549 cells. Glucocorticoids regulate the PM-exposed induction of COX-2 expression and mitochondrial dysfunction and increase the interaction between GR and Bcl-2. These findings suggest that the COX-2/PGE2 pathway and the interaction between GR and Bcl-2 are potential key therapeutic targets for the suppression of inflammation under PM exposure.

Supramolecular nanofiber of indomethacin derivative confers highly cyclooxygenase-2 (COX-2) selectivity and boosts anti-inflammatory efficacy

Herein, we report a facile method for converting carboxylate-containing indomethacin (Idm) into a cyclooxygenase-2 (COX-2) selective inhibitor via the amidation of an unnatural peptide sequence (Nal-Nal-Asp). The resulting indomethacin amides (i.e., Idm-Nal-Nal-Asp) have high selectivity for COX-2, and can self-assemble into a one-component supramolecular hydrogel that acts as a ‘self-delivery’ system for boosting anti-inflammatory efficacy. Self-assembled Idm-Nal-Nal-Asp hydrogel robustly inhibits COX-2 expression in lipopolysaccharide (LPS)-activated Raw 264.7 macrophages while also exhibits superior anti-inflammatory and antioxidant activities via reactive oxygen species (ROS)-related NF-κB and Nrf2/HO-1 pathways. Moreover, a rabbit model of endotoxin-induced uveitis (EIU) reveals that the Idm-Nal-Nal-Asp hydrogel outperforms clinically used 0.1 wt% diclofenac sodium eye drops in terms of in vivo anti-inflammatory efficacy via topical instillation route. As a rational approach to designing and applying COX-2 selective inhibitors, this work presents a simple method for converting non-selective nonsteriodal anti-inflammatory drugs (NSAIDs) into highly selective COX-2 inhibitors that can self-assemble into supramolecular hydrogel for anti-inflammation applications.

The Potency of Polyphenols Extract of Robusta Coffee Bean (Coffea robusta) on COX-2 Inhibition in Neutrophil Cells

Inflammation is a physiological response to various stimuli including infection and tissue injury. One cause of inflammation is gram-negative bacteria that release various toxins, e.g. lipopolysaccharide endotoxin (LPS). The first body defense response is neutrophils. Body defense response is expressed by the cyclooxygenase (COX) enzyme that functions to transform arachidonic acid into prostaglandin. Polyphenols extract from Robusta coffee bean is known to play an anti-inflammatory role, but the mechanism for inhibiting COX-2 remains unknown. This study aimed to determine the potential of polyphenols extracted from Robusta coffee beans on COX-2 inhibition in neutrophils exposed to E. coli LPS. The research design was experimental in vitro with a post-test-only control group design. The sample consisted of 6 treatment groups, neutrophil isolates was incubated in concentrations of Robusta coffee polyphenols extract of 3.13%, 6.25%, 12.5%, and 25% and exposed to E. coli LPS. Measurement of COX-2 expression was conducted using immunohistochemical methods. ANOVA and LSD test results showed COX-2 expression in the treatment groups, namely neutrophils which were incubated with Robusta coffee polyphenols extract and exposed to E. coli LPS, was lower than the neutrophil group exposed only to E. coli LPS. The conclusion of this study is that the polyphenols extract of the Robusta coffee bean can inhibit COX-2 expression on neutrophils exposed to E. coli LPS.

The underlying regulatory mechanisms of colorectal carcinoma by combining Vitexin and Aspirin: based on systems biology, molecular docking, molecular dynamics simulation, and in vitro study.

Colorectal cancer (CRC) is a highly prevalent digestive system malignancy. Aspirin is currently one of the most promising chemopreventive agents for CRC, and the combination of aspirin and natural compounds helps to enhance the anticancer activity of aspirin. Natural flavonoids like vitexin have an anticancer activity focusing on colorectal carcinoma. This study investigated the potential mechanism of action of the novel combination of vitexin and aspirin against colorectal cancer through network pharmacology, molecular docking, molecular dynamics simulation, and in vitro experiments. The results of network pharmacology suggested that vitexin and aspirin regulate multiple signaling pathways through various target proteins such as NFKB1, PTGS2 (COX-2), MAPK1, MAPK3, and TP53. Cellular experiments revealed that the combined effect of vitexin and aspirin significantly inhibited HT-29 cell growth. Vitexin dose-dependently inhibited COX-2 expression in cells and enhanced the down-regulation of COX-2 and NF-κB expression in colorectal cancer cells by aspirin. This study provides a pharmacodynamic material and theoretical basis for applying agents against colorectal cancer to delay the development of drug resistance and improve the prognosis of cancer patients.

Effect of Cocoa Pod Husk Proanthocyanidins Extract on Cyclooxigenase-2 (COX-2) Expression in Gingival Crevicular Fluid of Periodontitis Rats

Inflammation of periodontal tissue due to Porphyromonas gingivalis which invades the gingival tissue due to the activity of virulence factors. This causes the host immune system changes and increases COX-2 production in periodontal tissue so resulting excessive tissue destruction. The aim of this study was to analyze the potency of proanthocyanidins extract of cacao pod husk to inhibit COX-2 expression in rat gingival sulcus fluid. 3 groups in this study, namely negative control, positive control, and treatment. In all groups, on the 0 day, gingival sulcus fluid was taken, then the rats were induced by Porphyromonas gingivalis once every 3 days for 2 weeks; then in the negative control group a placebo gel was applied and the treatment group was applied proanthocyanidins extract gel of cacao pod husk extract every day for 7, 14, and 28 days and serial gingival crevicular fluid collection was carried out on days 7, 14, and 28. The expression of COX-2 in the gingival crevicular fluid was observed using the ELISA method. The statistical test used was Anova. There were a significant difference in COX-2 expressions (p <0.05). There was a decrease in the expression of COX-2 in rat gingival sulcus fluid induced by Porphyromonas gingivalis and given 10% cacao pod husk extract. Bioactive compounds in cocoa pod husk extract potential to reduce COX-2 expression in periodontitis rats. Article Details

EISA in Tandem with ICD to form in Situ Nanofiber Vaccine for Enhanced Tumor Radioimmunotherapy.

Radiotherapy (RT) can produce a vaccine effect and remodel a tumor microenvironment (TME) by inducing immunogenic cell death (ICD) and inflammation in tumors. However, RT alone is insufficient to elicit a systemic antitumor immune response owing to limited antigen presentation, immunosuppressive microenvironment, and chronic inflammation within the tumor. Here, we report a novel strategy for the generation of in situ peptide-based nanovaccines via enzyme-induced self-assembly (EISA) in tandem with ICD. As ICD progresses, the peptide Fbp-pY, dephosphorylated by alkaline phosphatase (ALP), forms a fibrous nanostructure around the tumor cells, resulting in the capture and encapsulation of the autologous antigens produced by radiation. Utilizing the adjuvant and controlled-release advantages of self-assembling peptides, this nanofiber vaccine effectively increased antigen accumulation in the lymph nodes and cross-presentation by antigen-presenting cells. In addition, the inhibition of COX-2 expression by the nanofibers promoted the repolarization of M2-macrophages into M1 and reduced the number of Tregs and MDSCs required for TME remodeling. As a result, the combination of nanovaccines and RT significantly enhanced the therapeutic effect on 4T1 tumors compared with RT alone, suggesting a promising treatment strategy for tumor radioimmunotherapy. This article is protected by copyright. All rights reserved.

Potential of siRNA-Bearing Subtilosomes in the Treatment of Diethylnitrosamine-Induced Hepatocellular Carcinoma

Therapeutics, based on small interfering RNA (siRNA), have demonstrated tremendous potential for treating cancer. However, issues such as non-specific targeting, premature degradation, and the intrinsic toxicity of the siRNA, have to be solved before they are ready for use in translational medicines. To address these challenges, nanotechnology-based tools might help to shield siRNA and ensure its specific delivery to the target site. Besides playing a crucial role in prostaglandin synthesis, the cyclo-oxygenase-2 (COX-2) enzyme has been reported to mediate carcinogenesis in various types of cancer, including hepatocellular carcinoma (HCC). We encapsulated COX-2-specific siRNA in Bacillus subtilis membrane lipid-based liposomes (subtilosomes) and evaluated their potential in the treatment of diethylnitrosamine (DEN)-induced hepatocellular carcinoma. Our findings suggested that the subtilosome-based formulation was stable, releasing COX-2 siRNA in a sustained manner, and has the potential to abruptly release encapsulated material at acidic pH. The fusogenic property of subtilosomes was revealed by FRET, fluorescence dequenching, content-mixing assay, etc. The subtilosome-based siRNA formulation was successful in inhibiting TNF-α expression in the experimental animals. The apoptosis study indicated that the subtilosomized siRNA inhibits DEN-induced carcinogenesis more effectively than free siRNA. The as-developed formulation also suppressed COX-2 expression, which in turn up-regulated the expression of wild-type p53 and Bax on one hand and down-regulated Bcl-2 expression on the other. The survival data established the increased efficacy of subtilosome-encapsulated COX-2 siRNA against hepatocellular carcinoma.

Effects of Lactobacillus plantarum IS-10506 on gastric protective mucosal factors: an ibuprofen-induced gastric mucosal injury

Background: Gastric mucosal protective factor plays an important roles in gastric homeostasis between mucosal injury and mucosal repair. Previous study implicated probiotics in the repair of the intestinal mucosa, while probiotic role in gastric mucosa remains poorly understood. This study aims to determine the role of probiotic L. plantarum IS-10506 in gastric protective mucosal factors by examining the expression of cyclooxygenase-1 (COX-1), COX-2, prostaglandin E2 (PGE2), and gastric mucus production (Mucin 5AC/ MUC5AC) by surface mucous cells as gastric mucosal protective factors. Methods: Twenty-seven male Wistar rats (Rattus norwegicus) were divided into 3 groups, ie. control, curative and preventive group. Ibuprofen 300mg/kgBW were given to all groups to induce gastric injury, while Lactobacillus plantarum IS-10506 1x109 CFU/day were given into the curative (5 days) and preventive (12 days) groups. Antrum tissue with primary monoclonal antibodies againts COX-1, COX-2, PGE2, and MUC5AC were examined in the day -1, -3, and -5 after necropsy. Results: Number of cells expressed COX-1, COX-2, PGE2 and MUC5AC in curative and preventive groups were significantly higher than control group. L. plantarum IS-10506 showed its efficacy in gastric mucosal repair on third day in the curative group and on first day in the preventive group. L. plantarum IS-10506 probiotic plays a role in gastric protective mucosal factors by promoting cell expression of COX-1, PGE2, and MUC5AC. In addition, it has been determined that L. plantarum IS-10506 inhibits COX-2 expression, that may lead to minimalize the inflammatory conditions and a deterioration of the gastric mucosal environment. Conclusion: Lactobacillus plantarum IS-10506 can prevent ibuprofen-induced antral mucosal damage through gastric protective mucosal factors.

New Anti-Inflammatory β-Resorcylic Acid Lactones Derived from an Endophytic Fungus, Colletotrichum sp.

The endophytic fungus Colletotrichum gloeosprioides JS0419, isolated from the leaves of the halophyte Suaeda japonica, produced four new β-resorcylic acid derivatives, colletogloeopyrones A and B (1 and 2) and colletogloeolactones A and B (3 and 4), and seven known β-resorcylic acid lactones (RALs). The structures of these compounds were elucidated via analysis of the high-resolution mass spectrometry and nuclear magnetic resonance data. Compounds 1 and 2 showed a dihydrobenzopyranone ring with a linear C9 side chain, which is rarely observed in RALs. All isolated compounds were evaluated for their anti-inflammatory activities. Colletogloeopyrone A (1), monocillin II (5), and monocillin II glycoside (6) were effective in reducing nitric oxide production without cytotoxicity. They also inhibited the secretion of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), as demonstrated by the expression of mRNA corresponding to IL-6 and TNF-α. Mechanistically, compounds 5 and 6 significantly inhibited the protein expression of nuclear factor-κB, IκBα, IKKα/β, inducible nitric oxide synthase, and cyclooxygenase (COX)-2, whereas compound 1 only inhibited COX-2 expression. This study indicated that RAL-type compounds 1, 5, and 6 demonstrated potential anti-inflammatory activity by inhibiting the synthesis of pro-inflammatory cytokines.