Transcriptome Sequencing Reveals the Mechanism behind Chemically Induced Oral Mucositis in a 3D Cell Culture Model.

Oral mucositis is a common side effect of cancer treatment, and in particular of treatment with the mTORC1 inhibitor everolimus. Current treatment methods are not efficient enough and a better understanding of the causes and mechanisms behind oral mucositis is necessary to find potential therapeutic targets. Here, we treated an organotypic 3D oral mucosal tissue model consisting of human keratinocytes grown on top of human fibroblasts with a high or low dose of everolimus for 40 or 60 h and investigated (1) the effect of everolimus on microscopic sections of the 3D cell culture for evidence of morphologic changes and (2) changes in the transcriptome by high throughput RNA-Seq analysis. We show that the most affected pathways are cornification, cytokine expression, glycolysis, and cell proliferation and we provide further details. This study provides a good resource towards a better understanding of the development of oral mucositis. It gives a detailed overview of the different molecular pathways that are involved in mucositis. This in turn provides information about potential therapeutic targets, which is an important step towards preventing or managing this common side effect of cancer treatment.

The Niemann-Pick C1 gene interacts with a high-fat diet to promote weight gain through differential regulation of central energy metabolism pathways.

A genome-wide association study (GWAS) reported that common variation in the human Niemann-Pick C1 gene (NPC1) is associated with morbid adult obesity. This study was confirmed using our BALB/cJ Npc1 mouse model, whereby heterozygous mice (Npc1+/- ) with decreased gene dosage were susceptible to weight gain when fed a high-fat diet (HFD) compared with homozygous normal mice (Npc1+/+ ) fed the same diet. The objective for our current study was to validate this Npc1 gene-diet interaction using statistical modeling with fitted growth trajectories, conduct body weight analyses for different measures, and define the physiological basis responsible for weight gain. Metabolic phenotype analysis indicated no significant difference between Npc1+/+ and Npc1+/- mice fed a HFD for food and water intake, oxygen consumption, carbon dioxide production, locomotor activity, adaptive thermogenesis, and intestinal lipid absorption. However, the livers from Npc1+/- mice had significantly increased amounts of mature sterol regulatory element-binding protein-1 (SREBP-1) and increased expression of SREBP-1 target genes that regulate glycolysis and lipogenesis with an accumulation of triacylglycerol and cholesterol. Moreover, white adipose tissue from Npc1+/- mice had significantly decreased amounts of phosphorylated hormone-sensitive lipase with decreased triacylglycerol lipolysis. Consistent with these results, cellular energy metabolism studies indicated that Npc1+/- fibroblasts had significantly increased glycolysis and lipogenesis, in addition to significantly decreased substrate (glucose and endogenous fatty acid) oxidative metabolism with an accumulation of triacylglycerol and cholesterol. In conclusion, these studies demonstrate that the Npc1 gene interacts with a HFD to promote weight gain through differential regulation of central energy metabolism pathways.

The medicinal mushroom Ganoderma lucidum prevents lung tumorigenesis induced by tobacco smoke carcinogens.

Ganoderma lucidum (GL), commonly known as "Lingzhi", is a well-known medicinal mushroom with antioxidant and anti-cancer activity. This study examined the effects of a commercial GL product (GLSF) containing the spore and fruiting body in a 30:8 ratio on tobacco smoke carcinogen-induced lung toxicity and carcinogenesis. The potential chemopreventive effect of GLSF was evaluated in vitro and in vivo. The non-tumorous human bronchial epithelial cells (BEAS-2B cells) were treated with GLSF extract (0.025 and 0.05 mg/mL), which significantly blocked malignant transformation induced by benzo[a]pyrene diol epoxide (BPDE) in a dose-dependent manner. To confirm its anti-carcinogenic activity in vivo, the mice were pre-treated with GLSF (2.0 g/kg of body weight) or curcumin (100 mg/kg of body weight) by oral gavage daily for 7 days and then exposed to a single dose of benzo[a]pyrene (B[a]P) (125 mg/kg of body weight). The GLSF-treated mice showed a significant reduction in B[a]P-induced lung toxicity, as indicated by decreased lactate dehydrogenase activity, malondialdehyde levels, inflammatory cell infiltration, and improved lung histopathology. We next determined the chemopreventive activity of GLSF in mice which were exposed to two weekly doses of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK, 100 mg/kg, on the 1st and 8th days) and fed with control or a modified diet containing GLSF (2.0 g/kg) or metformin (250 mg/kg) for 33 weeks. The GLSF and metformin treatments blocked NNK-induced lung tumor development by decreasing the lung weight, tumor area, and tumor burden compared to the mice exposed to NNK only. GLSF treatment also attenuated the expression of inflammatory, angiogenic, and apoptotic markers in lung tumors. Therefore, GLSF may be used for ameliorating tobacco smoke carcinogens-induced lung toxicity and carcinogenesis.

Report of multiple high-grade gliomas in two patients with shared retained ATRX, wild-type IDH, losses of CDKN2A genes and alterations in the PTEN-PI3K axis.

Solitary gliomas have been well described in the literature. Multiple gliomas, however, have not received the same notoriety, and as such further studies may be helpful in elucidating their unique clinicopathologic features and molecular basis. We present two patients, each with multiple high-grade gliomas, and describe their clinicopathologic and molecular characteristics in comparison with those reported in the literature in an attempt to better understand their shared tumorigenic mechanisms. Extensive molecular, FISH and genomic profiling studies detected multiple unique abnormalities in our two cases with shared molecular features of retained ATRX, wild-type IDH, losses of CDKN2A genes and alterations in the PTEN-PI3K Axis.

The ß-Blocker Carvedilol Prevents Benzo(a)pyrene-Induced Lung Toxicity, Inflammation and Carcinogenesis.

The current study evaluated the effects of the ß-blocker carvedilol on benzo(a)pyrene (B(a)P) and its active metabolite benzo(a)pyrene diol epoxide (BPDE)-induced lung toxicity, inflammation and carcinogenesis and explored the potential mechanisms. Carvedilol blocked the BPDE-induced malignant transformation of human bronchial epithelial cells BEAS-2B. In BEAS-2B cells, B(a)P strongly activated ELK-1, a transcription factor regulating serum response element (SRE) signaling, which was attenuated by carvedilol. Carvedilol also inhibited the B(a)P-induced AhR/xenobiotic responsive element (XRE) and mRNA expression of CYP1A1 and attenuated B(a)P-induced NF-κB activation. In a B(a)P-induced acute lung toxicity model in CD-1/IGS mice, pretreatment with carvedilol for 7 days before B(a)P exposure effectively inhibited the B(a)P-induced plasma levels of lactate dehydrogenase and malondialdehyde, inflammatory cell infiltration and histopathologic abnormalities in the lung, and upregulated the expression of GADD45α, caspase-3 and COX-2 in the lung. In a B(a)P-induced lung carcinogenesis model in A/J mice, carvedilol treatment for 20 weeks did not affect body weight but significantly attenuated tumor multiplicity and volume. These data reveal a previously unexplored role of carvedilol in preventing B(a)P-induced lung inflammation and carcinogenesis by inhibiting the cross-talk of the oncogenic transcription factors ELK-1, AhR and NF-κB.

Transfersome Encapsulated with the R-carvedilol Enantiomer for Skin Cancer Chemoprevention.

The R-carvedilol enantiomer, present in the racemic mixture of the chiral drug carvedilol, does not bind to the ß-adrenergic receptors, but exhibits skin cancer preventive activity. For skin delivery, R-carvedilol-loaded transfersomes were prepared using various ratios of drug, lipids, and surfactants, and characterized for particle size, zeta potential, encapsulation efficiency, stability, and morphology. Transfersomes were compared for in vitro drug release and ex vivo skin penetration and retention. Skin irritation was evaluated by viability assay on murine epidermal cells and reconstructed human skin culture. Single-dose and repeated-dose dermal toxicity was determined in SKH-1 hairless mice. Efficacy was evaluated in SKH-1 mice exposed to single or multiple ultraviolet (UV) radiations. Transfersomes released the drug at a slower rate, but significantly increased skin drug permeation and retention compared with the free drug. The transfersome with a drug-lipid-surfactant ratio of 1:3:0.5 (T-RCAR-3) demonstrated the highest skin drug retention and was selected for further studies. T-RCAR-3 at 100 µM did not induce skin irritation in vitro and in vivo. Topical treatment with T-RCAR-3 at 10 µM effectively attenuated acute UV-induced skin inflammation and chronic UV-induced skin carcinogenesis. This study demonstrates feasibility of using R-carvedilol transfersome for preventing UV-induced skin inflammation and cancer.

The medicinal mushroom Ganoderma lucidum attenuates UV-induced skin carcinogenesis and immunosuppression.

The medicinal mushroom Ganoderma lucidum is traditionally used for treating multiple diseases, including cancer. This study examined skin cancer preventive activity of a commercial product containing spore and fruiting body in 30:8 ratio (GLSF). Extracts of GLSF and spore component (GLS) were prepared using artificial gastrointestinal juice and examined on JB6 cells. GLSF and GLS dose-dependently inhibited epidermal growth factor-induced JB6 transformation at non-toxic concentrations. SKH-1 mice which were fed with diets containing GLSF (1.25%), GLS (0.99%) or the fruiting body (GLF) (0.26%) were exposed to chronic low-dose ultraviolet (UV) radiation to assess their effects on skin carcinogenesis. GLSF, but not GLS or GLF, reduced skin tumor incidence and multiplicity. In non-tumor skin tissues of mice, GLSF attenuated UV-induced epidermal thickening, expression of Ki-67, COX-2 and NF-κB, while in tumor tissues, GLSF increased expression of CD8 and Granzyme B. To examine the effects of GLSF on UV-induced immunosuppression, mice which were fed with GLSF were evaluated for the contact hypersensitivity (CHS) response to dinitrofluorobenzene (DNFB). GLSF significantly reversed UV-mediated suppression of DNFB-induced CHS by increasing CD8+ and decreasing CD4+ and FoxP3+ T-cells in mouse ears. Therefore, GLSF prevents skin cancer probably via attenuating UV-induced immunosuppression.

Topical carvedilol delivery prevents UV-induced skin cancer with negligible systemic absorption.

The ß-blocker carvedilol prevents ultraviolet (UV)-induced skin cancer, but systemic drug administration may cause unwanted cadiovascular effects. To overcome this limitation, a topical delivery system based on transfersome (T-CAR) was characterized ex vivo and in vivo. T-CAR was visualized by Transmission Electron Microscopy as nanoparticles of spherical and unilamellar structure. T-CAR incorporated into carbopol gel and in suspension showed similar drug permeation and deposition profiles in Franz diffusion cells loaded with porcine ear skin. In mice exposed to a single dose UV, topical T-CAR gel (10 µM) significantly reduced UV-induced skin edema and cyclobutane pyrimidine dimer formation. In mice exposed to chronic UV radiation for 25 weeks, topical T-CAR gel (10 µM) significantly delayed the incidence of tumors, reduced tumor number and burden, and attenuated Ki-67 and COX-2 expression. The T-CAR gel was subsequently examined for skin deposition, systemic absorption and cardiovascular effects in mice. In mice treated with repeated doses of T-CAR gel (100 µM), the drug was undetectable in plasma, the heart rate was unaffected, but skin deposition was significantly higher than mice treated with oral carvedilol (32 mg/kg/day). These data indicate that the carbopol-based T-CAR gel holds great promise for skin cancer prevention with negligible systemic effects.

Identifying cell and molecular stress after radiation in a three-dimensional (3-D) model of oral mucositis.

Mucositis is a debilitating adverse effect of chemotherapy and radiation treatment. It is important to develop a simple and reliable in vitro model, which can routinely be used to screen new drugs for prevention and treatment of mucositis. Furthermore, identifying cell and molecular stresses especially in the initiation phase of mucositis in this model will help towards this end. We evaluated a three-dimensional (3-D) human oral cell culture that consisted of oral keratinocytes and fibroblasts as a model of oral mucositis. The 3-D cell culture model was irradiated with 12 or 2 Gy. Six hours after the irradiation we evaluated microscopic sections of the cell culture for evidence of morphologic changes including apoptosis. We used microarrays to compare the expression of several genes from the irradiated tissue with identical genes from tissue that was not irradiated. We found that irradiation with 12 Gy induced significant histopathologic effects including cellular apoptosis. Irradiation significantly affected the expression of several genes of the NF-kB pathway and several inflammatory cytokines, such as IL-1B, 1L-8, NF-kB1, and FOS compared to tissue that was not irradiated. We identified significant upregulation of several genes that belong to damage-associated molecular patterns (DAMPs) such as HMB1, S100A13, SA10014, and SA10016 in the 3-D tissues that received 12 Gy but not in tissues that received 2 Gy. In conclusion, this model quantifies radiation damage and this is an important first step towards the development 3-D tissue as a screening tool.

Prevention of Skin Carcinogenesis by the Non-ß-blocking R-carvedilol Enantiomer.

Skin cancer is the most common malignancy worldwide and is rapidly rising in incidence, representing a significant public health challenge. The ß-blocker, carvedilol, has shown promising effects in preventing skin cancer. However, as a potent ß-blocker, repurposing carvedilol to an anticancer agent is limited by cardiovascular effects. Carvedilol is a racemic mixture consisting of equimolar S- and R-carvedilol, whereas the R-carvedilol enantiomer does not possess ß-blocking activity. Because previous studies suggest that carvedilol's cancer preventive activity is independent of ß-blockade, we examined the skin cancer preventive activity of R-carvedilol compared with S-carvedilol and the racemic carvedilol. R- and S-carvedilol were equally effective in preventing EGF-induced neoplastic transformation of the mouse epidermal JB6 Cl 41-5a (JB6 P+) cells and displayed similar attenuation of EGF-induced ELK-1 activity. R-carvedilol appeared slightly better than S-carvedilol against UV-induced intracellular oxidative stress and release of prostaglandin E2 from the JB6 P+ cells. In an acute UV-induced skin damage and inflammation mouse model using a single irradiation of 300 mJ/cm2 UV, topical treatment with R-carvedilol dose dependently attenuated skin edema and reduced epidermal thickening, Ki-67 staining, COX-2 protein, and IL6 and IL1ß mRNA levels similar to carvedilol. In a chronic UV (50-150 mJ/cm2) induced skin carcinogenesis model in mice with pretreatment of test agents, topical treatment with R-carvedilol, but not racemic carvedilol, significantly delayed and reduced skin squamous cell carcinoma development. Therefore, as an enantiomer present in an FDA-approved agent, R-carvedilol may be a better option for developing a safer and more effective preventive agent for skin carcinogenesis. PREVENTION RELEVANCE: In this study, we demonstrated the skin cancer preventive activity of R-carvedilol, the non-ß-blocking enantiomer present in the racemic ß-blocker, carvedilol. As R-carvedilol does not have ß-blocking activity, such a preventive treatment would not lead to common cardiovascular side effects of ß-blockers.

Inhibitory activity of medicinal mushroom Ganoderma lucidum on colorectal cancer by attenuating inflammation.

The medicinal mushroom Ganoderma lucidum (GL, Reishi or Lingzhi) exhibits an inhibitory effect on cancers. However, the underlying mechanism of the antitumor activity of GL is not fully understood. In this study, we characterized the gene networks regulated by a commercial product of GL containing a mixture of spores and fruiting bodies namely "GLSF", in colorectal carcinoma. We found that in vitro co-administration of GLSF extract at non-toxic concentrations significantly potentiated growth inhibition and apoptosis induced by paclitaxel in CT26 and HCT-15 cells. GLSF inhibited NF-κB promoter activity in HEK-293 cells but did not affect the function of P-glycoprotein in K562/DOX cells. Furthermore, we found that when mice were fed a modified diet containing GLSF for 1 month prior to the CT26 tumor cell inoculation, GLSF alone or combined with Nab-paclitaxel markedly suppressed tumor growth and induced apoptosis. RNA-seq analysis of tumor tissues derived from GLSF-treated mice identified 53 differentially expressed genes compared to normal tissues. Many of the GLSF-down-regulated genes were involved in NF-κB-regulated inflammation pathways, such as IL-1ß, IL-11 and Cox-2. Pathway enrichment analysis suggested that several inflammatory pathways involving leukocyte migration and adhesion were most affected by the treatment. Upstream analysis predicted activation of multiple tumor suppressors such as α-catenin and TP53 and inhibition of critical inflammatory mediators. "Cancer" was the major significantly inhibited biological effect of GLSF treatment. These results demonstrate that GLSF can improve the therapeutic outcome for colorectal cancer through a mechanism involving suppression of NF-κB-regulated inflammation and carcinogenesis.

Paroxysmal Atrial Fibrillation of Vagal Mechanism with Episodes of Wide QRS Complex Tachycardia Due to Gouaux-Ashman's Phenomenon.

A 38-year-old male patient consulted for nocturnal palpitations described as fast chest pounding that woke him up from sleep. A physical examination yielded no remarkable findings. A 24-hour Holter ECG monitoring demonstrated nocturnal episodes of paroxysmal atrial fibrillation (PAF) with the coexistence of wide QRS complex tachycardia. To the best of our knowledge, this is the first reported case of nocturnal episodes of wide QRS complex tachycardia during vagally mediated PAF resulting from Gouaux-Ashman's phenomenon. It is paramount for general physicians to recognize this phenomenon because it should be differentiated from ventricular tachycardia, since prognosis and treatment of both entities are entirely different. General and emergency physicians should be aware in order to improve adequate diagnostic and therapeutic management of the arrhythmic episodes.

Highly aggressive undifferentiated small round blue cell tumor of foot with unique SMARCA1, KAT6A and NAV3 mutations.

Malignancies characterized histologically by high-grade monotonous small round blue cells (SRBCs) belong to a heterogeneous group of neoplasms often referred to as Ewing family of tumors. The most common molecular confirmation of these neoplasms is by fusions between EWSR1 gene on chromosome 22 and the ETS family of transcription factors, including FLI1 gene (11q24) and the ERG (21q22), that are implicated in the development of different tissues as well as cancer progression. In this article, we present a case of highly aggressive extraskeletal SRBC tumor involving the foot of a 24-year-old male with sole molecular findings of mutations in KAT6A, NAV3 and SMARCA1 genes with high expression of soft tissue markers (COL1A1, COL1A2, COL3A1) and MYC mRNA. To our knowledge, this unique mutational pattern has not previously been described in SRBCs.

Substituted trans-stilbenes can inhibit or enhance the TPA-induced up-regulation of activator protein-1.

BACKGROUND: The activator protein-1 (AP-1) family of transcription factors contributes to regulation of numerous genes involved in proliferation, apoptosis, and tumorigenesis. A wide array of stimuli can activate AP-1, including pro-inflammatory cytokines, growth factors, tumor promoters and stress. Numerous plant polyphenols have been shown to inhibit the activation of AP-1, which often is ascribed to the anti-oxidant properties of these natural products. METHODS: In the present study, a library of substituted trans-stilbenes, including polyphenols, was screened for activity against the TPA-induced activation of AP-1 using the Panomics AP-1 Reporter 293 Stable Cell Line, which is designed for screening potential inhibitors or activators. RESULTS: Several trans-stilbenes were identified that inhibit TPA-induced activation of AP-1, with IC50 values as low as 0.5 microM. Moreover, some other trans-stilbenes were able to enhance the effects of TPA 2 to 3-fold. Many of the trans-stilbenes identified as inhibitors or enhancers are devoid of anti-oxidant properties. CONCLUSION: The ability of trans-stilbenes to inhibit or enhance the effects of TPA does not depend upon their anti-oxidant properties.

Gene-nutrient interactions and susceptibility to human obesity.

A large number of genome-wide association studies, transferability studies, and candidate gene studies performed in diverse populations around the world have identified gene variants that are associated with common human obesity. The mounting evidence suggests that these obesity gene variants interact with multiple environmental factors and increase susceptibility to this complex metabolic disease. The objective of this review article is to provide concise and updated information on energy balance, heritability of body weight, origins of gene variants, and gene-nutrient interactions in relation to human obesity. It is proposed that knowledge of these related topics will provide valuable insight for future preventative lifestyle intervention using targeted nutritional and medicinal therapies.

A global evolutionary and metabolic analysis of human obesity gene risk variants.

It is generally accepted that the selection of gene variants during human evolution optimized energy metabolism that now interacts with our obesogenic environment to increase the prevalence of obesity. The purpose of this study was to perform a global evolutionary and metabolic analysis of human obesity gene risk variants (110 human obesity genes with 127 nearest gene risk variants) identified using genome-wide association studies (GWAS) to enhance our knowledge of early and late genotypes. As a result of determining the mean frequency of these obesity gene risk variants in 13 available populations from around the world our results provide evidence for the early selection of ancestral risk variants (defined as selection before migration from Africa) and late selection of derived risk variants (defined as selection after migration from Africa). Our results also provide novel information for association of these obesity genes or encoded proteins with diverse metabolic pathways and other human diseases. The overall results indicate a significant differential evolutionary pattern for the selection of obesity gene ancestral and derived risk variants proposed to optimize energy metabolism in varying global environments and complex association with metabolic pathways and other human diseases. These results are consistent with obesity genes that encode proteins possessing a fundamental role in maintaining energy metabolism and survival during the course of human evolution.

Inhibition of Neoplastic Transformation and Chemically-Induced Skin Hyperplasia in Mice by Traditional Chinese Medicinal Formula Si-Wu-Tang.

Exploring traditional medicines may lead to the development of low-cost and non-toxic cancer preventive agents. Si-Wu-Tang (SWT), comprising the combination of four herbs, Rehmanniae, Angelica, Chuanxiong, and Paeoniae, is one of the most popular traditional Chinese medicines for women's diseases. In our previous studies, the antioxidant Nrf2 pathways were strongly induced by SWT in vitro and in vivo. Since Nrf2 activation has been associated with anticarcinogenic effects, the purpose of this study is to evaluate SWT's activity of cancer prevention. In the Ames test, SWT demonstrated an antimutagenic activity against mutagenicity induced by the chemical carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). In JB6 P+ cells, a non-cancerous murine epidermal model for studying tumor promotion, SWT inhibited epidermal growth factor (EGF)-induced neoplastic transformation. The luciferase reporter gene assays demonstrated that SWT suppressed EGF-induced AP-1 and TNF-α-induced NF-κB activation, which are essential factors involved in skin carcinogenesis. In a DMBA-induced skin hyperplasia assay in 'Sensitivity to Carcinogenesis' (SENCAR) mice, both topical and oral SWT inhibited DMBA-induced epidermal hyperplasia, expression of the proliferation marker Proliferating cell nuclear antigen (PCNA), and H-ras mutations. These findings demonstrate, for the first time, that SWT prevents tumor promoter and chemical-induced carcinogenesis in vitro and in vivo, partly by inhibiting DNA damage and blocking the activation of AP-1 and NF-κB.

Topically Applied Carvedilol Attenuates Solar Ultraviolet Radiation Induced Skin Carcinogenesis.

In previous studies, the ß-blocker carvedilol inhibited EGF-induced epidermal cell transformation and chemical carcinogen-induced mouse skin hyperplasia. As exposure to ultraviolet (UV) radiation leads to skin cancer, the present study examined whether carvedilol can prevent UV-induced carcinogenesis. Carvedilol absorbs UV like a sunscreen; thus, to separate pharmacological from sunscreen effects, 4-hydroxycarbazole (4-OHC), which absorbs UV to the same degree as carvedilol, served as control. JB6 P+ cells, an established epidermal model for studying tumor promotion, were used for evaluating the effect of carvedilol on UV-induced neoplastic transformation. Both carvedilol and 4-OHC (1 µmol/L) blocked transformation induced by chronic UV (15 mJ/cm2) exposure for 8 weeks. However, EGF-mediated transformation was inhibited by only carvedilol but not by 4-OHC. Carvedilol (1 and 5 µmol/L), but not 4-OHC, attenuated UV-induced AP-1 and NF-κB luciferase reporter activity, suggesting a potential anti-inflammatory activity. In a single-dose UV (200 mJ/cm2)-induced skin inflammation mouse model, carvedilol (10 µmol/L), applied topically after UV exposure, reduced skin hyperplasia and the levels of cyclobutane pyrimidine dimers, IL1ß, IL6, and COX-2 in skin. In SKH-1 mice exposed to gradually increasing levels of UV (50-150 mJ/cm2) three times a week for 25 weeks, topical administration of carvedilol (10 µmol/L) after UV exposure increased tumor latency compared with control (week 18 vs. 15), decreased incidence and multiplicity of squamous cell carcinomas, while 4-OHC had no effect. These data suggest that carvedilol has a novel chemopreventive activity and topical carvedilol following UV exposure may be repurposed for preventing skin inflammation and cancer. Cancer Prev Res; 10(10); 598-606. ©2017 AACR.

Substituted trans-stilbenes, including analogues of the natural product resveratrol, inhibit the human tumor necrosis factor alpha-induced activation of transcription factor nuclear factor kappaB.

The transcription factor nuclear factor kappaB (NF-kappaB), which regulates expression of numerous antiinflammatory genes as well as genes that promote development of the prosurvival, antiapoptotic state is up-regulated in many cancer cells. The natural product resveratrol, a polyphenolic trans-stilbene, has numerous biological activities and is a known inhibitor of activation of NF-kappaB, which may account for some of its biological activities. Resveratrol exhibits activity against a wide variety of cancer cells and has demonstrated activity as a cancer chemopreventive against all stages, i.e., initiation, promotion, and progression. The biological activities of resveratrol are often ascribed to its antioxidant activity. Both antioxidant activity and biological activities of analogues of resveratrol depend upon the number and location of the hydroxy groups. In the present study, phenolic analogues of resveratrol and a series of substituted trans-stilbenes without hydroxy groups were compared with resveratrol for their abilities to inhibit the human tumor necrosis factor alpha-induced (TNF-alpha) activation of NF-kappaB, using the Panomics NF-kappaB stable reporter cell line 293/NF-kappaB-luc. A series of 75 compounds was screened to identify substituted trans-stilbenes that were more active than resveratrol. Dose-response studies of the most active compounds were carried out to obtain IC50 values. Numerous compounds were identified that were more active than resveratrol, including compounds that were devoid of hydroxy groups and were 100-fold more potent than resveratrol. The substituted trans-stilbenes that were potent inhibitors of the activation of NFkappaB generally did not exhibit antioxidant activity. The results from screening were confirmed using BV-2 microglial cells where resveratrol and analogues were shown to inhibit LPS-induced COX-2 expression.