Resveratrol (trans-3,5,4'-trihydroxystilbene) suppresses EL4 tumor growth by induction of apoptosis involving reciprocal regulation of SIRT1 and NF-κB

Potential anti-liver cancer targets and mechanisms of kaempferitrin based on network pharmacology, molecular docking and experimental verification

AIM

Kaempferitrin is an active component in Chenopodium ambrosioides, showing medicinal functions against liver cancer. This study aimed to identify the potential targets and pathways of kaempferitrin against liver cancer using network pharmacology and molecular docking, and verify the essential hub targets and pathway in mice model of SMMC-7721 cells xenografted tumors and SMMC-7721 cells.

METHODS

Kaempferitrin therapeutical targets were obtained by searching SwissTargetPrediction, PharmMapper, STITCH, DrugBank, and TTD databases. Liver cancer specific genes were obtained by searching GeneCards, DrugBank, TTD, OMIM, and DisGeNET databases. PPI network of "kaempferitrin-targets-liver cancer" was constructed to screen the hub targets. GO, KEGG pathway and MCODE clustering analyses were performed to identify possible enrichment of genes with specific biological subjects. Molecular docking and molecular dynamics simulation were employed to determine the docking pose, potential and stability of kaempferitrin with hub targets. The potential anti-liver cancer mechanisms of kaempferitrin, as predicted by network pharmacology analyses, were verified by in vitro and in vivo experiments.

RESULTS

228 kaempferitrin targets and 2186 liver cancer specific targets were identified, of which 50 targets were overlapped. 8 hub targets were identified through network topology analysis, and only SIRT1 and TP53 had a potent binding activity with kaempferitrin as indicated by molecular docking and molecular dynamics simulation. MCODE clustering analysis revealed the most significant functional module of PPI network including SIRT1 and TP53 was mainly related to cell apoptosis. GO and KEGG enrichment analyses suggested that kaempferitrin exerted therapeutic effects on liver cancer possibly by promoting apoptosis via p21/Bcl-2/Caspase 3 signaling pathway, which were confirmed by in vivo and in vitro experiments, such as HE staining of tumor tissues, CCK-8, qRT-PCR and Western blot.

CONCLUSION

This study provided not only insight into how kaempferitrin could act against liver cancer by identifying hub targets and their associated signaling pathways, but also experimental evidence for the clinical use of kaempferitrin in liver cancer treatment.

2,3,7,8-Tetrachlorodibenzo-p-dioxin induces multigenerational alterations in the expression of microRNA in the thymus through epigenetic modifications

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a potent AhR ligand, is an environmental contaminant that is known for mediating toxicity across generations. However, whether TCDD can induce multigenerational changes in the expression of microRNAs (miRs) has not been previously studied. In the current study, we investigated the effect of administration of TCDD in pregnant mice (F0) on gestational day 14, on the expression of miRs in the thymus of F0 and subsequent generations (F1 and F2). Of the 3200 miRs screened, 160 miRs were dysregulated similarly in F0, F1, and F2 generations, while 46 miRs were differentially altered in F0 to F2 generations. Pathway analysis revealed that the changes in miR signature profile mediated by TCDD affected the genes that regulate cell signaling, apoptosis, thymic atrophy, cancer, immunosuppression, and other physiological pathways. A significant number of miRs that showed altered expression exhibited dioxin response elements (DRE) on their promoters. Focusing on one such miR, namely miR-203 that expressed DREs and was induced across F0 to F2 by TCDD, promoter analysis showed that one of the DREs expressed by miR-203 was functional to TCDD-mediated upregulation. Also, the histone methylation status of H3K4me3 in the miR-203 promoter was significantly increased near the transcriptional start site in TCDD-treated thymocytes across F0 to F2 generations. Genome-wide chromatin immunoprecipitation sequencing study suggested that TCDD may cause alterations in histone methylation in certain genes across the three generations. Together, the current study demonstrates that gestational exposure to TCDD can alter the expression of miRs in F0 through direct activation of DREs as well as across F0, F1, and F2 generations through epigenetic pathways.

Molecular insights into a mechanism of resveratrol action using hybrid computational docking/CoMFA and machine learning approach

A phytoalexin, Resveratrol remains a legendary anticancer drug candidate in the archives of scientific literature. Although earlier wet-lab experiments rendering its multiple biological targets, for example, epidermal growth factors, Pro-apoptotic protein p53, sirtuins, and first apoptosis signal (Fas) receptor, Mouse double minute 2 (MDM2) ubiquitin-protein ligase, Estrogen receptor, Quinone reductase, etc. However, notwithstanding some notable successes, identification of an appropriate Resveratrol target(s) has remained a major challenge using physical methods, and hereby limiting its translation into an effective therapeutic(s). Thus, computational insights are much needed to establish proof-of-concept towards potential Resveratrol target(s) with minimum error rate, narrow down the search space, and to assess a more accurate Resveratrol signaling pathway/mechanism at the starting point. Herein, a brute-force technique combining computational receptor-, ligand-based virtual screening, and classification-based machine learning, reveals the precise mechanism of Resveratrol action. Overall, MDM2 ubiquitin-protein ligase (4OGN.pdb) and co-crystallized quinone reductases 2 (4QOH.pdb) were found two suitable drug targets in the case of Resveratrol derivatives. Indeed, carotenoid cleaving oxygenase together with later twos gave gigantic momentum in guiding the rational drug design of Resveratrol derivatives. These molecular modeling insights would be useful for Resveratrol lead optimization into a more precise science.Communicated by Ramaswamy H. Sarma.

Extracts of select endemic plants from the Republic of Mauritius exhibiting anti-cancer and immunomodulatory properties

Mauritius Island possesses unique plant biodiversity with a potential reservoir of biologically active compounds of pharmacological interest. In the current study, we investigated Mauritius endemic plant families Asteraceae, Ebenaceae, Sapotaceae, and Erythroxylaceae, for anti-cancer properties on T cell lymphoma and B16F10 Melanoma cells and immunomodulatory properties on primary T and B cells. The cytotoxicity of methanolic plant extracts at 1, 10, 25 µg/ml was determined. The most active plant species were evaluated for their apoptosis-inducing effects. The immunomodulatory properties of the plants were also studied, and preliminary phytochemical screening of selected plants was done by LC-MS analysis. Psiadia lithospermifolia (Lam.) Cordem (Asteraceae) at 25 µg/ml was the most cytotoxic on both EL4 and B16 cells and triggered apoptosis by the death receptor pathway, and at least in part, by the mitochondrial pathway. Most plant species from Asteraceae, Ebenaceae, Erythroxylaceae, and Sapotaceae inhibited the proliferation of activated T and B cells, although some promoted T cell proliferation. LC-MS profile of Asteraceae plants showed the presence of terpenes, terpenoids, fatty acids, and phenolic. Flavonoids and phenolic acid were also detected from Ebenaceae and Sapotaceae plants. Together, our study demonstrated that Mauritius endemic flora exhibit potential anti-cancer and anti-inflammatory properties worthy of further in-depth studies.

Resveratrol Suppresses Cross-Talk between Colorectal Cancer Cells and Stromal Cells in Multicellular Tumor Microenvironment: A Bridge between In Vitro and In Vivo Tumor Microenvironment Study

The interaction between tumor cells and the tumor microenvironment (TME) is an important process for the development of tumor malignancy. Modulation of paracrine cross-talk could be a promising strategy for tumor control within the TME. The exact mechanisms of multi-targeted compound resveratrol are not yet fully understood. Whether resveratrol can modulate paracrine signal transduction-induced malignancy in the multicellular-TME of colorectal cancer cells (CRC) was investigated. An in vitro model with 3D-alginate HCT116 cells in multicellular-TME cultures (fibroblast cells, T-lymphocytes) was used to elucidate the role of TNF-β, Sirt1-ASO and/or resveratrol in the proliferation, invasion and cancer stem cells (CSC) of CRC cells. We found that multicellular-TME, similar to TNF-β-TME, promoted proliferation, colony formation, invasion of CRC cells and enabled activation of CSCs. However, after co-treatment with resveratrol, the malignancy of multicellular-TME reversed to HCT116. In addition, resveratrol reduced the secretion of T-lymphocyte/fibroblast (TNF-β, TGF-β3) proteins, antagonized the T-lymphocyte/fibroblast-promoting NF-κB activation, NF-κB nuclear translocation and thus the expression of NF-κB-promoting biomarkers, associated with proliferation, invasion and survival of CSCs in 3D-alginate cultures of HCT116 cells induced by TNF-β- or multicellular-TME, but not by Sirt1-ASO, indicating the central role of this enzyme in the anti-tumor function of resveratrol. Our results suggest that in vitro multicellular-TME promotes crosstalk between CRC and stromal cells to increase survival, migration of HCT116 and the resveratrol/Sirt1 axis suppresses this loop by modulating paracrine agent secretion and NF-κB signaling. Fibroblasts and T-lymphocytes are promising targets for resveratrol in the prevention of CRC metastasis.

Review of Natural Compounds for the Management and Prevention of Lymphoma

Lymphoma is a type of blood cancer that can be categorized into two types-Hodgkin lymphoma (HL) and Non-Hodgkin lymphoma (NHL). A total of 509,590 and 79,990 cases of NHL and HL were newly diagnosed in 2018, respectively. Although conventional therapy has stridden forward over recent decades, its adverse effects are still a hurdle to be solved. Thus, to help researchers develop better lymphoma treatment, this study aims to review the systematic anticancer data for natural products and their compounds. A variety of natural products showed anticancerous effects on lymphoma by regulation of intracellular mechanisms including apoptosis as well as cell cycle arrest. As these results shed light on the potential to substitute conventional therapy with natural products, it may become a promising strategy for lymphoma treatment in the near future.

Resveratrol and insulin association reduced alveolar bone loss and produced an antioxidant effect in diabetic rats

BACKGROUND

The present investigation studied the effects of systemic administration of resveratrol (RSV) on the development of experimental periodontitis (EP) and on the release of markers of inflammation, bone metabolism, and oxidative stress in diabetic rats.

METHODS

Seventy-five male rats were divided into five groups: DM+PLAC: Diabetes Mellitus + placebo solution; DM+INS: DM + insulin therapy; DM+RSV: DM + RSV; DM+RSV+INS: DM + RSV and insulin; NDM: non-diabetic. Streptozotocin was used to induce DM and EP was induced by the placement of a ligature at the fist mandibular and the second maxillary molars. Euthanasia occurred 30 days after the initiation of the study and mandible specimens were subjected for morphometric analysis of bone level. Gingival tissues from mandibular molars were collected for quantification of inflammatory and oxidative stress markers by multiplex assay system and ELISA assay, respectively. Maxillary gingival tissues were processed for real-time polymerase chain reaction (real-time PCR) assessment of markers of bone metabolism and oxidative stress.

RESULTS

Morphometric analysis revealed greater bone loss in DM+PLAC and DM+INS in comparison to the other treatments (P < 0.05). RSV used in conjunction with INS reduced the levels of interleukin (IL)-1β, IL-6, IL-17, interferon-gamma (IFN-γ) and superoxide dismutase 1 (SOD) (P < 0.05). RSV alone reduced nicotinamide adenine dinucleotide phosphatase oxidase (NADPH oxidase) levels, in comparison to DM+INS and DM+RSV+INS (P < 0.05). All treatments upregulated mRNA levels for osteoprotegerin (OPG) in comparison to PLAC (P < 0.05). Sirtuin 1 (SIRT) mRNA levels were lower in PLAC when compared to DM+RSV, DM+RSV+INS and NDM (P < 0.05).

CONCLUSION

RSV reduced the progression of EP and the levels of NADPH oxidase. Co-treatment with RSV and insulin reduced the levels of pro-inflammatory factors (either proteins or mRNA) and increased the levels of SOD. The data also demonstrated that treatment with RSV and INS alone or in combination had beneficial effects on bone loss.

Alterations in the Gut Microbiome and Suppression of Histone Deacetylases by Resveratrol Are Associated with Attenuation of Colonic Inflammation and Protection Against Colorectal Cancer

Inflammatory bowel disease (IBD) is known to significantly increase the risk for development of colorectal cancer (CRC), suggesting inflammation and cancer development are closely intertwined. Thus, agents that suppress inflammation may prevent the onset of cancer. In the current study, we used resveratrol, an anti-inflammatory stilbenoid, to study the role of microbiota in preventing inflammation-driven CRC. Resveratrol treatment in the azoxymethane (AOM) and dextran sodium sulphate (DSS) CRC murine model caused an increase in anti-inflammatory CD4 + FOXP3 + (Tregs) and CD4 + IL10 + cells, a decrease in proinflammatory Th1 and Th17 cells, and attenuated CRC development. Gut microbial profile studies demonstrated that resveratrol altered the gut microbiome and short chain fatty acid (SCFA), with modest increases in n-butyric acid and a potential butyrate precursor isobutyric acid. Fecal transfer from resveratrol-treated CRC mice and butyrate supplementation resulted in attenuation of disease and suppression of the inflammatory T cell response. Data also revealed both resveratrol and sodium butyrate (BUT) were capable of inhibiting histone deacetylases (HDACs), correlating with Treg induction. Analysis of The Cancer Genome Atlas (TCGA) datasets revealed increased expression of Treg-specific transcription factor FoxP3 or anti-inflammatory IL-10 resulted in an increase in 5-year survival of patients with CRC. These data suggest that alterations in the gut microbiome lead to an anti-inflammatory T cell response, leading to attenuation of inflammation-driven CRC.

Resveratrol and Its Nanoformulation Attenuate Growth and the Angiogenesis of Xenograft and Orthotopic Colon Cancer Models

Cancer is a multifactorial disorder that induces mortality worldwide, and the colorectal type is the third most common cancer globally. Resveratrol (RSV) is a natural compound with an effective anticancer effect, especially against colorectal cancer, and therefore numerous studies recommended its use in colorectal cancer prevention and treatment. The current study investigated the effect of either RSV or its nanoformulation (NP-RSV) on the growth and vascularity of xenograft and orthotopic mice models in colon cancer (COLO205-luc). Both RSV and NP-RSV induced significant reductions in tumor growth and the hemoglobin percentages of the tumor mass, but NP-RSV showed greater bioavailability and efficacy than RSV. Generally, we recommend using NP-RSV as a therapeutic to control colon cancer.

Resveratrol Downregulates miR-31 to Promote T Regulatory Cells during Prevention of TNBS-Induced Colitis

SCOPE

Colitis, an inflammatory bowel disease, is associated with aberrant regulation of the colonic mucosal immune system. Resveratrol, a natural plant product, has been found to exert anti-inflammatory properties and attenuate the development of murine colitis. In the current study, the role of microRNA (miR) in the ability of resveratrol to suppress colonic inflammation is examined.

METHODS AND RESULTS

BALB/C mice with 2,4,6-Trinitrobenzenesulfonic acid solution (TNBS)-induced colitis, when treated with resveratrol, show improved clinical outcomes and reduce induction of inflammatory T cells (Th17 and Th1) while increasing CD4+Foxp3+ regulatory T cells (Tregs) and IL-10-producing CD4+ T cells. miR microarray analysis and polymerase chain reaction (PCR) validation from CD4+ T cells show treatment with resveratrol decreases the expression of several miRs (miR-31, Let7a, miR-132) that targets cytokines and transcription factors involved in anti-inflammatory T cell responses (Foxp3 and TGF-β). Transfection studies with miR-31 confirm that this miR directly regulates the expression of Foxp3. Lastly, analysis of public data from human patients with ulcerative colitis reveals that miR-31 expression is significantly increased when compared to controls.

CONCLUSION

Together, the current study demonstrates that resveratrol-mediated attenuation of colitis may be regulated by miR-31 through induction of Tregs and miR-31 may serve as a therapeutic target for human colitis.

Computational prediction and in vitro validation of VEGFR1 as a novel protein target for 2,3,7,8-tetrachlorodibenzo-p-dioxin

The toxic manifestations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an environmental contaminant, primarily depend on its ability to activate aryl hydrocarbon receptor (AhR), which is a ligand-dependent transcription factor belonging to the superfamily of basic-helix-loop-helix DNA-binding proteins. In the present study, we aimed to identify novel protein receptor targets for TCDD using computational and in vitro validation experiments. Interestingly, results from computational methods predicted that Vascular Endothelial Growth Factor Receptor 1 (VEGFR1) could be one of the potential targets for TCDD in both mouse and humans. Results from molecular docking studies showed that human VEGFR1 (hVEGFR1) has less affinity towards TCDD compared to the mouse VEGFR1 (mVEGFR1). In vitro validation results showed that TCDD can bind and phosphorylate hVEGFR1. Further, results from molecular dynamic simulation studies showed that hVEGFR1 interaction with TCDD is stable throughout the simulation time. Overall, the present study has identified VEGFR1 as a novel target for TCDD, which provides the basis for further elucidating the role of TCDD in angiogenesis.

Resveratrol (3, 5, 4'-Trihydroxy-trans-Stilbene) Attenuates a Mouse Model of Multiple Sclerosis by Altering the miR-124/Sphingosine Kinase 1 Axis in Encephalitogenic T Cells in the Brain

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) (RES) is a naturally-derived phytoestrogen found in the skins of red grapes and berries and has potential as a novel and effective therapeutic agent. In the current study, we investigated the role of microRNA (miRNA) in RES-mediated attenuation of experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis. Administration of RES effectively decreased disease severity, including inflammation and central nervous system immune cell infiltration. miRNA microarray analysis revealed an altered miRNA profile in encephalitogenic CD4+ T cells from EAE mice exposed to RES treatment. Additionally, bioinformatics and in silico pathway analysis suggested the involvement of RES-induced miRNA in pathways and processes that regulated cellular proliferation. Additional studies confirmed that RES affected cell cycle progression and apoptosis in activated T cells, specifically in the brain. RES treatment significantly upregulated miR-124 during EAE, while suppressing associated target gene, sphingosine kinase 1 (SK1), and this too was specific to mononuclear cells in the brains of treated mice, as peripheral immune cells remained unaltered upon RES treatment. Collectively, these studies demonstrate that RES treatment leads to amelioration of EAE development through mechanism(s) potentially involving suppression of neuroinflammation via alteration of the miR-124/SK1 axis, thereby halting cell-cycle progression and promoting apoptosis in activated encephalitogenic T cells. Graphical Abstract Resveratrol alters the miR-124/sphingosine kinase 1 (SK1) axis in encephalitogenic T cells, promotes cell-cycle arrest and apoptosis, and decreases neuroinflammation in experiemental autoimmune encephalomyelitis (EAE).

Leveraging the Cardio-Protective and Anticancer Properties of Resveratrol in Cardio-Oncology

Cardio-oncology is a clinical/scientific discipline which aims to prevent and/or treat cardiovascular diseases in cancer patients. Although a large number of cancer treatments are known to cause cardiovascular toxicity, they are still widely used because they are highly effective. Unfortunately, therapeutic interventions to prevent and/or treat cancer treatment-induced cardiovascular toxicity have not been established yet. A major challenge for such interventions is to protect the cardiovascular system without compromising the therapeutic benefit of anticancer medications. Intriguingly, the polyphenolic natural compound resveratrol and its analogs have been shown in preclinical studies to protect against cancer treatment-induced cardiovascular toxicity. They have also been shown to possess significant anticancer properties on their own, and to enhance the anticancer effect of other cancer treatments. Thus, they hold significant promise to protect the cardiovascular system and fight the cancer at the same time. In this review, we will discuss the current knowledge regarding the cardio-protective and the anticancer properties of resveratrol and its analogs. Thereafter, we will discuss the challenges that face the clinical application of these agents. To conclude, we will highlight important gaps of knowledge and future research directions to accelerate the translation of these exciting preclinical findings to cancer patient care.

Resveratrol-Mediated Attenuation of Staphylococcus aureus Enterotoxin B-Induced Acute Liver Injury Is Associated With Regulation of microRNA and Induction of Myeloid-Derived Suppressor Cells

Resveratrol (RES) is a polyphenolic compound found abundantly in plant products including red grapes, peanuts, and mulberries. Because of potent anti-inflammatory properties of RES, we investigated whether RES can protect from Staphylococcal enterotoxin B (SEB)-induced acute liver injury in mice. SEB is a potent super antigen that induces robust inflammation and releases inflammatory cytokines that can be fatal. We observed that SEB caused acute liver injury in mice with increases in enzyme aspartate transaminase (AST) levels, and massive infiltration of immune cells into the liver. Treatment with RES (100 mg/kg body weight) attenuated SEB-induced acute liver injury, as indicated by decreased AST levels and cellular infiltration in the liver. Interestingly, RES treatment increased the number of myeloid derived suppressor cells (MDSCs) in the liver. RES treatment led to alterations in the microRNA (miR) profile in liver mononuclear cells (MNCs) of mice exposed to SEB, and pathway analysis indicated these miRs targeted many inflammatory pathways. Of these, we identified miR-185, which was down-regulated by RES, to specifically target Colony Stimulating Factor (CSF1) using transfection studies. Moreover, the levels of CSF1 were significantly increased in RES-treated SEB mice. Because CSF1 is critical in MDSC induction, our studies suggest that RES may induce MDSCs by down-regulating miR-185 leading to increase the expression of CSF1. The data presented demonstrate for the first time that RES can effectively attenuates SEB-induced acute liver injury and that this may result from its action on miRs and induction of MDSCs.

Comparative analysis of interactions between aryl hydrocarbon receptor ligand binding domain with its ligands: a computational study

BACKGROUND

Aryl hydrocarbon receptor (AhR) ligands may act as potential carcinogens or anti-tumor agents. Understanding how some of the residues in AhR ligand binding domain (AhRLBD) modulate their interactions with ligands would be useful in assessing their divergent roles including toxic and beneficial effects. To this end, we have analysed the nature of AhRLBD interactions with 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD), 6-formylindolo[3,2-b]carbazole (FICZ), indole-3-carbinol (I3C) and its degradation product, 3,3'-diindolylmethane (DIM), Resveratrol (RES) and its analogue, Piceatannol (PTL) using molecular modeling approach followed by molecular dynamic simulations.

RESULTS

Results showed that each of the AhR ligands, TCDD, FICZ, I3C, DIM, RES and PTL affect the local and global conformations of AhRLBD.

CONCLUSION

The data presented in this study provide a structural understanding of AhR with its ligands and set the basis for its functions in several pathways and their related diseases.

Resveratrol attenuates oxidative stress during experimental periodontitis in rats exposed to cigarette smoke inhalation

OBJECTIVES

This study aimed at investigating the effect of the systemic administration of resveratrol (RESV) on oxidative stress during experimental periodontitis in rats subjected to cigarette smoke inhalation.

MATERIAL AND METHODS

Experimental periodontitis (EP) was induced in 26 male Wistar rats by the insertion of a ligature around one of the first mandibular and maxillary molars. The animals were assigned randomly to the following groups: cigarette smoke inhalation (CSI; 3 times/d, 8 minutes/d) + resveratrol (10 mg/Kg), that is, SMK + RESV (n = 13) and cigarette smoke inhalation + placebo, that is, SMK + PLAC (n = 13). The substances were administered daily for 30 days (19 days prior and 11 days following EP induction), and then, the animals were euthanized. The maxillary specimens were processed for morphometric analysis of bone loss, and the tissue surrounding the first maxillary molars was collected for mRNA quantification of Sirtuin 1 (SIRT1) by real-time PCR. The gingival tissues surrounding the mandibular first molars were collected for quantification of superoxide dismutase 1 (SOD1) and nicotinamide adenine dinucleotide phosphatase oxidase (NADPH) using an ELISA assay.

RESULTS

Reduced bone loss was demonstrated in animals in the SMK + RESV group as compared to those in the SMK + PLAC (P < 0.05) group on the basis of morphometric analysis. Resveratrol promoted higher levels of SIRT and SOD (P < 0.05) as well as reduced levels of NADPH oxidase (P < 0.05) were found in tissues derived from animals in the SMK + RESV group when compared to those in the SMK + PLAC group.

CONCLUSION

Resveratrol is an efficient therapeutic agent that reduces exacerbation of bone loss found in animals with EP that were also exposed to smoke. The results suggest that its effects could be mediated, at least in part, by its antioxidant and anti-inflammatory properties which attenuate the effects of oxidative stress on EP in the presence of cigarette smoke.

Establishment of malignantly transformed dendritic cell line SU3-ihDCTC induced by Glioma stem cells and study on its sensitivity to resveratrol

BACKGROUND

As a factor contributing to the tumor cell drug resistance, tumor microenvironment (TME) is being paid increasingly attention. However, the drug resistance of malignantly transformed cells in TME has rarely been revealed. This paper is designed to investigate the sensitivity of malignantly transformed cell line (ihDCTC) induced by glioma stem cells (GSCs) in TME to chemotherapeutic drugs.

METHODS

(1) Establishment of ihDCTC cell line,The bone marrow cells from enhanced green fluorescent protein (EGFP) transgenic nude mice were employed to culture the dendritic cells (DCs) in vitro, which were then co-cultured with red fluorescence protein (RFP) transgenic GSCs (SU3) to obtain ihDCTC (2) Res and Cis were used to intervene in the growth of abovemetioned cell lines in vitro and Res treated in bearing ihDCTC tumor mice, followed by evaluating their drug sensitivity and changes in key signaling proteins via half maximal inhibitory concentration (IC50), tumor mass and immunostaining method.

RESULTS

(1) ihDCTC could express CD11c and CD80 as well as possessed immortalized potential, heteroploid chromosomes and high tumorigenicity in nude mice in vivo. (2) At 24 h, 48 h and 72 h, the IC50 value of ihDCTC treated with Cis was 3.62, 3.25 and 2.10 times higher than that of SU3, while the IC50 value of ihDCTC treated with Res was 0.03, 0.47 and 1.19 times as much as that of SU3; (3) The xenograft mass (g) in vivo in the control, Res, Cis and Res + Cis groups were 1.44 ± 0.19, 0.45 ± 0.12, 0.94 ± 0.80 and 0.68 ± 0.35(x ± s) respectively. The expression levels of IL-6, p-STAT3 and NF-κB proteins in the xenograft tissue were significantly reduced only in the Res treatment group.

CONCLUSION

In vitro co-culture with GSC can induce the malignant transformation of bone marrow derived dendritic cells, on the one hand, ihDCTC shows higher drug resistance to the traditional chemotherapeutic drug Cis than GSCs, but, on the other hand, appears to be more sensitive to Res than GSCs. Therefore, our findings provide a broader vision not only for the further study on the correlation between TME and tumor drug resistance but also for the exploration of Res anti-cancer value.

Establishment of malignantly transformed dendritic cell line SU3-ihDCTC induced by Glioma stem cells and study on its sensitivity to resveratrol

BACKGROUND

As a factor contributing to the tumor cell drug resistance, tumor microenvironment (TME) is being paid increasingly attention. However, the drug resistance of malignantly transformed cells in TME has rarely been revealed. This paper is designed to investigate the sensitivity of malignantly transformed cell line (ihDCTC) induced by glioma stem cells (GSCs) in TME to chemotherapeutic drugs.

METHODS

(1) Establishment of ihDCTC cell line,The bone marrow cells from enhanced green fluorescent protein (EGFP) transgenic nude mice were employed to culture the dendritic cells (DCs) in vitro, which were then co-cultured with red fluorescence protein (RFP) transgenic GSCs (SU3) to obtain ihDCTC (2) Res and Cis were used to intervene in the growth of abovemetioned cell lines in vitro and Res treated in bearing ihDCTC tumor mice, followed by evaluating their drug sensitivity and changes in key signaling proteins via half maximal inhibitory concentration (IC₅₀), tumor mass and immunostaining method.

RESULTS

(1) ihDCTC could express CD11c and CD80 as well as possessed immortalized potential, heteroploid chromosomes and high tumorigenicity in nude mice in vivo. (2) At 24 h, 48 h and 72 h, the IC₅₀ value of ihDCTC treated with Cis was 3.62, 3.25 and 2.10 times higher than that of SU3, while the IC₅₀ value of ihDCTC treated with Res was 0.03, 0.47 and 1.19 times as much as that of SU3; (3) The xenograft mass (g) in vivo in the control, Res, Cis and Res + Cis groups were 1.44 ± 0.19, 0.45 ± 0.12, 0.94 ± 0.80 and 0.68 ± 0.35(x ± s) respectively. The expression levels of IL-6, p-STAT3 and NF-κB proteins in the xenograft tissue were significantly reduced only in the Res treatment group.

CONCLUSION

In vitro co-culture with GSC can induce the malignant transformation of bone marrow derived dendritic cells, on the one hand, ihDCTC shows higher drug resistance to the traditional chemotherapeutic drug Cis than GSCs, but, on the other hand, appears to be more sensitive to Res than GSCs. Therefore, our findings provide a broader vision not only for the further study on the correlation between TME and tumor drug resistance but also for the exploration of Res anti-cancer value.

Sirtuin 1 regulates matrix metalloproteinase-13 expression induced by Porphyromonas endodontalis lipopolysaccharide via targeting nuclear factor-κB in osteoblasts

Porphyromonas endodontalis lipopolysaccharide (P.e LPS) is an important initiating factor for periapical inflammation and bone destruction. Matrix metalloproteinase-13 (MMP-13) has been shown to participate in the formation and diffusion of periapical bone lesion in chronic apical periodontitis. Sirtuin 1 (SIRT1) is a key regulator of inflammation in mammalian cells which suppresses the release of inflammatory mediators. This study aimed to explore the role of SIRT1 in regulating MMP-13 expression induced by P.e LPS in osteoblasts. P.e LPS stimulated MMP-13 expression in MC3T3-E1 cells. Knockdown of SIRT1 reinforced the increase of MMP-13mRNA expression induced by P.e LPS. SIRT1 activator resveratrol significantly reduced the expression of MMP-13 and SIRT1 inhibitor EX-527 enhanced the expression of MMP-13. Moreover, SIRT1 activation with resveratrol inhibited acetylation of NF-κB p65 and NF-κB transcriptional activity, which were enhanced by P.e LPS. In addition, NF-κB p65 was involved in P.e LPS-induced MMP-13 expression via directly binding to the MMP-13 promoter. However, SIRT1 activation significantly interfered with this binding. These findings strongly suggest that P.e LPS induces MMP-13 expression in osteoblasts, and SIRT1 suppresses this expression of MMP-13 through targeting NF-κB p65. This provides new insights into understanding the actions of SIRT1 on anti-inflammatory and anti-bone resorption activity.

Inhibition of diethylnitrosamine-initiated alcohol-promoted hepatic inflammation and precancerous lesions by flavonoid luteolin is associated with increased sirtuin 1 activity in mice

BACKGROUND

Chronic and excessive alcohol consumption is an established risk for hepatic inflammation and carcinogenesis. Luteolin is one of the most common flavonoids present in plants and has potential beneficial effects against cancer. In this study, we examined the effect and potential mechanisms of luteolin supplementation in a carcinogen initiated alcohol-promoted pre-neoplastic liver lesion mouse model.

METHODS

C57BL/6 mice were injected with diethylnitrosamine (DEN) [i.p. 25 mg/kg of body weight (BW)] at 14 days of age. At 8 weeks of age mice were group pair-fed with Lieber-DeCarli liquid control diet or alcoholic diet [ethanol (EtOH) diet, 27% total energy from ethanol] and supplemented with a dose of 30 mg luteolin/kg BW per day for 21 days.

RESULTS

DEN-injected mice fed EtOH diet displayed a significant induction of pre-neoplastic lesions, a marker associated with presence of steatosis and inflammation. Dietary luteolin significantly reduced the severity and incidence of hepatic inflammatory foci and steatosis in DEN-injected mice fed EtOH diet, as well the presence of preneoplastic lesions. There was no difference on hepatic protein levels of sirtuin 1 (SIRT1) among all groups; however, luteolin supplementation significantly reversed alcohol-reduced SIRT1 activity assessed by the ratio of acetylated and total forkhead box protein O1 (FoXO1) and SIRT1 target proliferator-activated receptor gamma, coactivator 1 alpha (PGC1α).

CONCLUSIONS

Dietary intake of luteolin prevents alcohol promoted pre-neoplastic lesions, potentially mediated by SIRT1 signaling pathway.

Roles of SIRT1 in granulosa cell apoptosis during the process of follicular atresia in porcine ovary

Ovarian follicular atresia is characterized by granulosa cell apoptosis, however, the exact mechanism is still unclear. Sirtuin 1 (SIRT1) is a NAD(+)-dependent deacetylase, which is associated with apoptosis in several of cell types, but its exact role in ovarian granulosa cell apoptosis is not clearly defined. In present study, we identified the involvement of SIRT1 in the process of follicle degeneration, which is known as "follicular atresia", both from in vivo models and cell culture data. The results of immunohistochemistry showed that SIRT1 was widely detected in non-apoptotic granulosa cells of follicles, but significantly decreased during the process of granulosa cell apoptosis. Quantitative real-time PCR and Western blot analysis showed that the expression levels of SIRT1 mRNA and protein were increased (P<0.05) during follicular atresia. In order to provide more evidences elucidating the roles of SIRT1 during the process of follicular atresia, granulosa cells were cultured in vitro with resveratrol which acts as a potent activator of SIRT1. Results showed that resveratrol caused a dose-dependent increase in both SIRT1 mRNA and protein levels. Meanwhile, apoptotic rate of granulosa cell was increased (P<0.01) in a dose-dependent manner. Additionally, resveratrol significantly increased the expression levels of Caspase-3 (P<0.01) and Bax mRNA (P<0.01), while Bcl-2 mRNA level was significantly decreased (P<0.01). Thus, our results suggest that SIRT1 may play important roles in the regulation of granulosa cell apoptosis during follicular atresia in porcine ovary.

Identification of Hirsutine as an anti-metastatic phytochemical by targeting NF-κB activation

Nuclear factor-κB (NF-κB) activation has been implicated not only in carcinogenesis but also in cancer cell invasion and metastatic process; therefore, targeting the NF-κB pathway is an attractive strategy for controlling meta-stasis. Amongst 56 chemically defined compounds derived from natural products, we have identified a new phytochemical compound Hirsutine, which strongly suppresses NF-κB activity in murine 4T1 breast cancer cells. In accordance with the NF-κB inhibition, Hirsutine reduced the metastatic potential of 4T1 cells, as seen in the inhibition of the migration and invasion capacity of 4T1 cells. Hirsutine further inhibited the constitutive expression of MMP-2 and MMP-9 in 4T1 cells, and reduced the in vivo lung metastatic potential of 4T1 cells in the experimental model. Given that the migration of human breast cancer cells was also inhibited, our present study implies that Hirsutine is an attractive phytochemical compound for reducing metastasis potential of cancer cells by regulating tumor-promoting NF-κB activity.

The Anticancer Properties and Apoptosis-inducing Mechanisms of Cinnamaldehyde and the Herbal Prescription Huang-Lian-Jie-Du-Tang ( Huáng Lián Jiě Dú Tang) in Human Hepatoma Cells

Hepatocellular carcinoma (HCC) has long been one of the most important causes of cancer mortality in the world. Many natural products and traditional herbal medicines have been used to treat HCC in Asian countries such as Japan, Korea, Taiwan, and China. The present review aims to describe the anticancer properties and apoptotic mechanisms of cinnamaldehyde, the bioactive ingredient isolated from cinnamon trees, and the herbal prescription Huang-Lian-Jie-Du-Tang (黃連解毒湯 Huáng Lián Jiě Dú Tang; HLJDT) against human hepatoma cells in vitro and in vivo. Implication of their treatment for the development of targeted therapy against HCC is discussed.

Resveratrol attenuates NF-κB-binding activity but not cytokine production in mechanically ventilated mice

BACKGROUND

Mechanical ventilation (MV) can result in inflammation and subsequent lung injury. Toll-like receptor (TLR)4 and NF-κB are proposed to play a crucial role in the MV-induced inflammatory response. Resveratrol (RVT) exhibits anti-inflammatory effects in vitro and in vivo supposedly by interfering with TLR4 signaling and NF-κB. In the present study, we investigated the role of RVT in MV-induced inflammation in mice.

METHODS

RVT (10 mg/kg, 20 mg/kg and 40 mg/kg) or vehicle was intraperitoneally administered 1 h before start of MV (4 h, tidal volume 8 ml/kg, positive end-expiratory pressure 1,5 cmH2 O and FiO2 0.4). Blood and lungs were harvested for cytokine analysis. DNA binding activity of transcription factor NF-κB was measured in lung homogenates.

RESULTS

MV resulted in elevated pulmonary concentrations of IL-1β, IL-6, keratinocyte-derived chemokine (KC) and NF-κB DNA-binding activity. RVT at 10, 20 and 40 mg/kg reduced NF-κB's DNA-binding activity following MV compared with ventilated controls. However, no differences in cytokine release were found between RVT-treated and control ventilated mice. Similarly, in plasma, MV resulted in elevated concentrations of TNF-α, KC and IL-6, but RVT did not affect cytokine levels.

CONCLUSIONS

RVT abrogates the MV-induced increase in pulmonary NF-κB activity but does not attenuate cytokine levels. This implies a less prominent role for NF-κB in MV-induced inflammation than previously assumed.

The multiple mechanisms of cell death triggered by resveratrol in lymphoma and leukemia

Lymphoma and leukemia represent a serious threat to human health and life expectancy. Resveratrol is, among the natural-derived chemopreventive molecules, one of the most effective and better studied. In this paper the main mechanisms of cell death triggered by- or linked to- resveratrol are reviewed and discussed. The main focus is on lymphoma and leukemia experimental models where resveratrol has been tested and investigated at the cellular, molecular or physiological levels. The most relevant in vivo challenges involving resveratrol are also reported and analyzed in order to define the key features of this polyphenol and the potential for the treatment of hematologic tumors.

Sirtuin 6 protects cardiomyocytes from hypertrophy in vitro via inhibition of NF-κB-dependent transcriptional activity

BACKGROUND AND PURPOSE

Sirtuin 6 (SIRT6) is involved in regulation of glucose and fat metabolism. However, its possible contribution to cardiac dysfunction remains to be determined. In the present study, the effect of SIRT6 on cardiac hypertrophy induced by angiotensin II (AngII) and the underlying molecular mechanisms were investigated.

EXPERIMENTAL APPROACH

The expression and deacetylase activity of SIRT6 were measured in hypertrophic cardiomyocytes induced by AngII. After SIRT6 overexpression by transfection, or depletion by RNA interference in neonatal rat cardiomyocytes, cellular hypertrophy was monitored by measuring cell surface area and the mRNA levels of hypertrophic biomarkers. Further, the interaction between SIRT6 and the transcription factor NF-κB was investigated by co-immunoprecipitation, confocal immunofluorescence microscopy and luciferase reporter gene assay. The expression and deacetylase activity of SIRT6 were measured in vivo, using the abdominal aortic constriction (AAC) model of cardiac hypertrophy in rats.

KEY RESULTS

In AngII-induced hypertrophic cardiomyocytes and also in AAC-induced hypertrophic hearts, the expression of SIRT6 protein was upregulated, while its deacetylase activity was decreased. Overexpression of wild-type SIRT6 but not its catalytically inactive mutant, attenuated AngII-induced cardiomyocyte hypertrophy. We further demonstrated a physical interaction between SIRT6 and NF-κB catalytic subunit p65, whose transcriptional activity could be repressed by SIRT6 overexpression.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that SIRT6 suppressed cardiomyocyte hypertrophy in vitro via inhibition of NF-κB-dependent transcriptional activity and that this effect was dependent on its deacetylase activity.

Comparative Studies of Apoptosis in Xenopus laevis and Mouse Thymoma Cell Lines

With the use of in vitro methods and cell lines, functional aspects of apoptosis in the Xenopus laevis B3/B7 and mouse EL4 thymoma cell lines are revealed. Moreover, by using information gleaned from digital imaging and immunocytochemistry, changes in locations of key proteins implicated in apoptotic anti-cancer responses, e.g. p53 and Mdm2, are shown. Suggestions are offered as to what these results might mean with respect to the evolutionary conservation of the function and structure of these two molecules and to cancer resistance in amphibians. Finally, studies are described on resveratrol as an anti-cancer therapeutic reagent in the two thymoma cell lines and in normal X. laevis thymocytes.

SIRT1 activation enhances HDAC inhibition-mediated upregulation of GADD45G by repressing the binding of NF-κB/STAT3 complex to its promoter in malignant lymphoid cells

We explored the activity of SIRT1 activators (SRT501 and SRT2183) alone and in combination with panobinostat in a panel of malignant lymphoid cell lines in terms of biological and gene expression responses. SRT501 and SRT2183 induced growth arrest and apoptosis, concomitant with deacetylation of STAT3 and NF-κB, and reduction of c-Myc protein levels. PCR arrays revealed that SRT2183 leads to increased mRNA levels of pro-apoptosis and DNA-damage-response genes, accompanied by accumulation of phospho-H2A.X levels. Next, ChIP assays revealed that SRT2183 reduces the DNA-binding activity of both NF-κB and STAT3 to the promoter of GADD45G, which is one of the most upregulated genes following SRT2183 treatment. Combination of SRT2183 with panobinostat enhanced the anti-growth and anti-survival effects mediated by either compound alone. Quantitative-PCR confirmed that the panobinostat in combination with SRT2183, SRT501 or resveratrol leads to greater upregulation of GADD45G than any of the single agents. Panobinostat plus SRT2183 in combination showed greater inhibition of c-Myc protein levels and phosphorylation of H2A.X, and increased acetylation of p53. Furthermore, EMSA revealed that NF-κB binds directly to the GADD45G promoter, while STAT3 binds indirectly in complexes with NF-κB. In addition, the binding of NF-κB/STAT3 complexes to the GADD45G promoter is inhibited following panobinostat, SRT501 or resveratrol treatment. Moreover, the combination of panobinostat with SRT2183, SRT501 or resveratrol induces a greater binding repression than either agent alone. These data suggest that STAT3 is a corepressor with NF-κB of the GADD45G gene and provides in vitro proof-of-concept for the combination of HDACi with SIRT1 activators as a potential new therapeutic strategy in lymphoid malignancies.

Seven sirtuins for seven deadly diseases of aging

Sirtuins are a class of NAD(+)-dependent deacetylases having beneficial health effects. This extensive review describes the numerous intracellular actions of the seven mammalian sirtuins, their protein targets, intracellular localization, the pathways they modulate, and their role in common diseases of aging. Selective pharmacological targeting of sirtuins is of current interest in helping to alleviate global disease burden. Since all sirtuins are activated by NAD(+), strategies that boost NAD(+) in cells are of interest. While most is known about SIRT1, the functions of the six other sirtuins are now emerging. Best known is the involvement of sirtuins in helping cells adapt energy output to match energy requirements. SIRT1 and some of the other sirtuins enhance fat metabolism and modulate mitochondrial respiration to optimize energy harvesting. The AMP kinase/SIRT1-PGC-1α-PPAR axis and mitochondrial sirtuins appear pivotal to maintaining mitochondrial function. Downregulation with aging explains much of the pathophysiology that accumulates with aging. Posttranslational modifications of sirtuins and their substrates affect specificity. Although SIRT1 activation seems not to affect life span, activation of some of the other sirtuins might. Since sirtuins are crucial to pathways that counter the decline in health that accompanies aging, pharmacological agents that boost sirtuin activity have clinical potential in treatment of diabetes, cardiovascular disease, dementia, osteoporosis, arthritis, and other conditions. In cancer, however, SIRT1 inhibitors could have therapeutic value. Nutraceuticals such as resveratrol have a multiplicity of actions besides sirtuin activation. Their net health benefit and relative safety may have originated from the ability of animals to survive environmental changes by utilizing these stress resistance chemicals in the diet during evolution. Each sirtuin forms a key hub to the intracellular pathways affected.

Resveratrol prevents endothelial cells injury in high-dose interleukin-2 therapy against melanoma

Immunotherapy with high-dose interleukin-2 (HDIL-2) is an effective treatment for patients with metastatic melanoma and renal cell carcinoma. However, it is accompanied by severe toxicity involving endothelial cell injury and induction of vascular leak syndrome (VLS). In this study, we found that resveratrol, a plant polyphenol with anti-inflammatory and anti-cancer properties, was able to prevent the endothelial cell injury and inhibit the development of VLS while improving the efficacy of HDIL-2 therapy in the killing of metastasized melanoma. Specifically, C57BL/6 mice were injected with B16F10 cells followed by resveratrol by gavage the next day and continued treatment with resveratrol once a day. On day 9, mice received HDIL-2. On day 12, mice were evaluated for VLS and tumor metastasis. We found that resveratrol significantly inhibited the development of VLS in lung and liver by protecting endothelial cell integrity and preventing endothelial cells from undergoing apoptosis. The metastasis and growth of the tumor in lung were significantly inhibited by HDIL-2 and HDIL-2 + resveratrol treatment. Notably, HDIL-2 + resveratrol co-treatment was more effective in inhibiting tumor metastasis and growth than HDIL-2 treatment alone. We also analyzed the immune status of Gr-1(+)CD11b(+) myeloid-derived suppressor cells (MDSC) and FoxP3(+)CD4(+) regulatory T cells (Treg). We found that resveratrol induced expansion and suppressive function of MDSC which inhibited the development of VLS after adoptive transfer. However, resveratrol suppressed the HDIL-2-induced expansion of Treg cells. We also found that resveratrol enhanced the susceptibility of melanoma to the cytotoxicity of IL-2-activated killer cells, and induced the expression of the tumor suppressor gene FoxO1. Our results suggested the potential use of resveratrol in HDIL-2 treatment against melanoma. We also demonstrated, for the first time, that MDSC is the dominant suppressor cell than regulatory T cell in the development of VLS.

Nimbolide, a neem limonoid abrogates canonical NF-κB and Wnt signaling to induce caspase-dependent apoptosis in human hepatocarcinoma (HepG2) cells

Nuclear factor kappa B (NF-κB), an oncogenic signaling factor plays a critical role in the development and progression of various cancers. The objective of this study was to investigate the effect of nimbolide, a neem derived tetranortriterpenoid on NF-κB signaling and its downstream events - Wnt/β-catenin activation and apoptosis evasion in human hepatocarcinoma (HepG2) cells by evaluating NF-κB family members (NF-κB-p50, p65, IκB-α, p-IκB-α, and IKKβ), members of Wnt signaling (GSK-3β and β-catenin), and intrinsic apoptosis (Bcl-2, Bax, cytochrome c, Smac/DIABLO, caspase-3, and caspase-9). Our results demonstrate that nimbolide concurrently abrogates canonical NF-κB and Wnt signaling and induces intrinsic apoptosis in HepG2 cells. These data suggest that phytochemicals such as nimbolide that can target multiple steps along the NF-κB signaling circuit are promising candidates for future phytochemical-based mechanistic pathway targeted anticancer regimens.

Role of resveratrol-induced CD11b(+) Gr-1(+) myeloid derived suppressor cells (MDSCs) in the reduction of CXCR3(+) T cells and amelioration of chronic colitis in IL-10(-/-) mice

Resveratrol, a naturally occurring polyphenol has received significant attention as a potent anti-inflammatory agent. Inflammatory bowel disease (IBD) is a chronic intestinal inflammation caused by hyperactivated effector immune cells that produce proinflammatory cytokines. Myeloid derived suppressor cells (MDSCs) are a heterogeneous population characterized by the co-expression of CD11b(+) and Gr-1(+) and have long been known for their immunosuppressive function. We report that resveratrol effectively attenuated overall clinical scores as well as various pathological markers of colitis in IL-10(-/-) mice by down regulating Th1 responses. Resveratrol lessened the colitis-associated decrease in body weight and increased levels of serum amyloid A (SAA), CXCL10 and colon TNF-α, IL-6, RANTES, IL-12 and IL-1β concentrations. After resveratrol treatment, the percentage of CXCR3 expressing T cells was decreased in the spleen, mesenteric lymph nodes (MLN), and intestinal lamina propria (LP). However, the percentage and absolute numbers of CD11b(+) and Gr-1(+)cells in the lamina propria (LP) and spleen were increased after resveratrol treatment as compared with the vehicle treatment. Co-culture of resveratrol-induced CD11b(+) Gr-1(+) cells with T cells, attenuated T cell proliferation, and most importantly reduced IFN-γ and GM-CSF production by LP derived T cells from vehicle treated IL-10(-/-) mice with chronic colitis. The current study suggests that administration of resveratrol into IL-10(-/-) mice induces immunosuppressive CD11b(+) Gr-1(+) MDSCs in the colon, which correlates with reversal of established chronic colitis, and down regulation of mucosal and systemic CXCR3(+) expressing effector T cells as well as inflammatory cytokines in the colon. The induction of immunosuppressive CD11b(+) Gr-1(+) cells by resveratrol during colitis is unique, and suggests an as-yet-unidentified mode of anti-inflammatory action of this plant polyphenol.